Inovio Pharmaceuticals (INO) 10-K 1 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-14888
Entity Registrant Name	INOVIO PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0969592
Entity Address, Address Line One	660 W. Germantown Pike
Entity Address, Address Line Two	Suite 110
Entity Address, City or Town	Plymouth Meeting
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19462
City Area Code	267
Local Phone Number	440-4200
Title of 12(b) Security	COMMON STOCK, $0.001 PAR VALUE
Trading Symbol	INO
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 4.2
Entity Common Stock, Shares Outstanding		207,632,584
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive proxy statement to be filed with the Commission pursuant to Regulation 14A in connection with the registrant’s 2021 Annual Meeting of Stockholders (the “Proxy Statement’) are incorporated by reference into Part III of this Report. Such Proxy Statement will be filed with the Commission not later than 120 days after the conclusion of the registrant’s fiscal year ended December 31, 2020.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001055726

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 250,728,118	$ 22,196,097
Short-term investments	160,914,935	67,338,017
Accounts receivable	18,559,967	700,073
Accounts receivable from affiliated entities	503,782	1,332,044
Prepaid expenses and other current assets	40,357,456	1,584,598
Prepaid expenses and other current assets from affiliated entities	106,432	1,050,140
Total current assets	471,170,690	94,200,969
Fixed assets, net	11,348,144	12,773,017
Investments in affiliated entities	4,460,366	6,315,356
Investment in Geneos	434,387	0
Intangible assets, net	3,146,770	3,693,851
Goodwill	10,513,371	10,513,371
Operating lease right-of-use assets	12,741,296	13,783,009
Other assets	25,957,448	2,672,024
Total assets	539,772,472	143,951,597
Current liabilities:
Accounts payable and accrued expenses	21,203,808	18,237,258
Accounts payable and accrued expenses due to affiliated entities	642,969	729,729
Accrued clinical trial expenses	9,950,345	4,049,727
Deferred revenue	46,628	92,353
Deferred revenue from affiliated entities	0	31,775
Operating lease liability	2,329,394	2,074,842
Grant funding liability	7,474,310	6,065,212
Grant funding liability from affiliated entities	58,500	708,425
Total current liabilities	41,705,954	31,989,321
Deferred revenue, net of current portion	79,214	101,567
Derivative liability	0	8,819,023
Operating lease liability, net of current portion	18,063,515	20,409,922
Deferred tax liabilities	32,046	32,046
Grant funding liability from affiliated entity, net of current portion	37,500	135,000
Other liabilities	57,663	36,943
Total liabilities	78,631,714	138,546,739
Commitments and contingencies
Inovio Pharmaceuticals, Inc. stockholders’ equity:
Preferred stock—par value $0.001; Authorized shares: 10,000,000, issued and outstanding shares: 9 at December 31, 2020 and 23 at December 31, 2019	0	0
Common stock—par value $0.001; Authorized shares: 600,000,000 at December 31, 2020 and December 31, 2019, issued and outstanding: 186,851,493 at December 31, 2020 and 101,361,034 at December 31, 2019	186,851	101,361
Additional paid-in capital	1,367,406,869	742,646,785
Accumulated deficit	(906,196,812)	(739,785,655)
Accumulated other comprehensive income (loss)	(256,150)	472,608
Total Inovio Pharmaceuticals, Inc. stockholders’ equity	461,140,758	3,435,099
Non-controlling interest	0	1,969,759
Total stockholders’ equity	461,140,758	5,404,858
Total liabilities and stockholders’ equity	539,772,472	143,951,597
6.50% Convertible Senior Notes Due 2024
Current liabilities:
Convertible debt	14,139,988	64,180,325
Convertible Bonds
Current liabilities:
Convertible debt	$ 4,515,834	$ 12,842,592

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	9	23
Preferred stock, shares outstanding (in shares)	9	23
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	600,000,000	600,000,000
Common stock, shares issued (in shares)	186,851,493	101,361,034
Common stock, shares outstanding (in shares)	186,851,493	101,361,034

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Total revenues	$ 7,411,220	$ 4,111,930	$ 30,481,897
Operating expenses:
Research and development	94,245,436	88,017,319	95,257,876
General and administrative	37,247,828	27,203,156	29,315,159
Total operating expenses	131,493,264	115,220,475	124,573,035
Loss from operations	(124,082,044)	(111,108,545)	(94,091,138)
Other income (expense):
Interest income	3,311,846	2,605,981	2,264,747
Interest expense	(8,702,450)	(7,948,539)	0
Change in fair value of common stock warrants	0	0	360,795
Change in fair value of derivative liability	(75,670,977)	(1,763,652)	0
Gain (loss) on investment in affiliated entities	36,556,658	(3,090,557)	(1,988,567)
Net unrealized gain on available-for-sale equity securities	1,695,497	0	0
Other income (expense), net	(704,896)	496,200	(1,343,856)
Gain on deconsolidation of Geneos	4,121,075	0	0
Net loss before income tax benefit/(provision for income tax)	(162,890,304)	(120,809,112)	(94,798,019)
Income tax benefit (provision for income taxes)	0	257,335	(2,169,811)
Share in net loss of Geneos	(4,584,610)	0	0
Net loss	(167,474,914)	(120,551,777)	(96,967,830)
Net loss attributable to non-controlling interest	1,063,757	1,192,558	0
Net loss attributable to Inovio Pharmaceuticals, Inc.	$ (166,411,157)	$ (119,359,219)	$ (96,967,830)
Net loss per share attributable to Inovio Pharmaceuticals, Inc. stockholders
Basic and diluted (in USD per share)	$ (1.07)	$ (1.21)	$ (1.05)
Weighted average number of common shares outstanding
Basic and diluted (in shares)	155,126,857	98,717,999	92,539,997
Convertible Bonds
Other income (expense):
Gain (loss) on extinguishment of debt	$ (8,177,043)	$ 0	$ 0
6.50% Convertible Senior Notes Due 2024
Other income (expense):
Gain (loss) on extinguishment of debt	8,762,030	0	0
Revenue under collaborative research and development arrangements
Revenues:
Total revenues	5,170,586	3,636,945	29,860,785
Revenue under collaborative research and development arrangements from affiliated entities
Revenues:
Total revenues	1,453,730	235,649	449,524
Other revenue
Revenues:
Total revenues	786,904	237,536	171,588
Other revenue from affiliated entities
Revenues:
Total revenues	$ 0	$ 1,800	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (167,474,914)	$ (120,551,777)	$ (96,967,830)
Other comprehensive income (loss):
Foreign currency translation	27,205	0	0
Unrealized gain (loss) on short-term investments, net of tax	(755,963)	1,001,475	(180,496)
Comprehensive loss	(168,203,672)	(119,550,302)	(97,148,326)
Comprehensive loss attributable to non-controlling interest	1,063,757	1,192,558	0
Comprehensive loss attributable to Inovio Pharmaceuticals, Inc.	$ (167,139,915)	$ (118,357,744)	$ (97,148,326)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	6.50% Convertible Senior Notes Due 2024	August 2019 Bonds	Cumulative Effect, Period of Adoption, Adjustment	[1]	Preferred stock	Common stock	Common stock6.50% Convertible Senior Notes Due 2024	Common stockAugust 2019 Bonds	Additional paid-in capital	Additional paid-in capital6.50% Convertible Senior Notes Due 2024	Additional paid-in capitalAugust 2019 Bonds	Accumulated deficit	Accumulated deficitCumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss)Cumulative Effect, Period of Adoption, Adjustment	[1]	Non- controlling interest
Beginning balance (in shares) at Dec. 31, 2017						23	90,357,644
Beginning balance at Dec. 31, 2017	$ 142,488,809			$ 0		$ 0	$ 90,358			$ 665,775,504			$ (523,356,317)	$ 231,366		$ (117,005)	$ (231,366)		$ 96,269
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash (in shares)							5,669,025
Issuance of common stock for cash	29,227,776						$ 5,669			29,222,107
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)							1,199,141
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments	1,809,526						$ 1,199			1,808,327
Stock-based compensation	10,654,622									10,988,277			(333,655)
Net loss attributable to common stockholders	(96,967,830)												(96,967,830)
Unrealized gain (loss) on short-term investments, net of tax	(180,496)															(180,496)
Foreign currency translation	0
Ending balance (in shares) at Dec. 31, 2018						23	97,225,810
Ending balance at Dec. 31, 2018	87,032,407					$ 0	$ 97,226			707,794,215			(620,426,436)			(528,867)			96,269
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash (in shares)							3,340,678
Issuance of common stock for cash	9,089,009						$ 3,340			9,085,669
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)							794,546
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments	(780,405)						$ 795			(781,200)
Equity component of issuance of convertible notes	15,752,698									15,752,698
Stock-based compensation	10,901,320									10,795,403									105,917
Acquisition of non-controlling interest in Geneos, net	2,960,131																		2,960,131
Net loss attributable to common stockholders	(120,551,777)												(119,359,219)						(1,192,558)
Unrealized gain (loss) on short-term investments, net of tax	1,001,475															1,001,475
Foreign currency translation	0
Ending balance (in shares) at Dec. 31, 2019						23	101,361,034
Ending balance at Dec. 31, 2019	5,404,858					$ 0	$ 101,361			742,646,785			(739,785,655)			472,608			1,969,759
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash (in shares)							66,064,886
Issuance of common stock for cash	454,486,400						$ 66,065			454,420,335
Conversion of preferred stock/senior notes to common stock (in shares)						(14)	5,147	11,535,660	4,962,364
Conversion of preferred stock/senior notes to common stock	0	$ 43,694,386	$ 102,671,310				$ 5	$ 11,536	$ 4,961	(5)	$ 43,682,850	$ 102,666,349
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)							2,922,402
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments	8,241,624						$ 2,923			8,238,701
Stock-based compensation	15,647,523									15,655,585									(8,062)
Acquisition of non-controlling interest in Geneos, net	2,379,969																		2,379,969
Deconsolidation of Geneos	(3,181,640)																		(3,181,640)
Net loss attributable to common stockholders	(167,474,914)												(166,411,157)						(1,063,757)
Dissolution of majority-owned subsidiary VGX Animal Health, Inc.	0									96,269									(96,269)
Unrealized gain (loss) on short-term investments, net of tax	(755,963)															(755,963)
Foreign currency translation	27,205															27,205
Ending balance (in shares) at Dec. 31, 2020						9	186,851,493
Ending balance at Dec. 31, 2020	$ 461,140,758					$ 0	$ 186,851			$ 1,367,406,869			$ (906,196,812)			$ (256,150)			$ 0
[1]	Upon adoption of ASU 2016-01 on January 1, 2018, the Company began to measure and record equity investments, except those accounted for under the equity method of accounting that have a readily determinable fair value, at fair value and began to recognize the changes in fair value in its consolidated statements of operations, instead of recognizing unrealized gains and losses through accumulated other comprehensive income (loss), as done under the previous guidance. The Company recorded a $231,000 cumulative effect adjustment to reclassify the cumulative unrealized gain, net of tax effect, from its investment in an affiliated entity, PLS, from accumulated other comprehensive loss to accumulated deficit.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (167,474,914)	$ (120,551,777)	$ (96,967,830)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	3,038,996	3,598,388	3,747,183
Amortization of intangible assets	547,081	1,066,294	1,249,584
Amortization of operating lease right-of-use assets	1,041,713	851,760
Change in fair value of common stock warrants	0	0	(360,795)
Change in fair value of derivative liability	75,670,977	1,763,652	0
Stock-based compensation	15,647,523	10,901,320	10,654,622
Non-cash interest expense	4,077,686	5,230,954	0
Amortization of premiums on investments	0	1,962	72,561
Deferred taxes	0	5,397	0
Loss (gain) on short-term investments	588,270	(476,368)	1,342,005
Settlement of receivable with shares of common stock from affiliated entity (PLS)	(1,713,770)	0	0
Gain on deconsolidation of Geneos	(4,121,075)	0	0
Loss on disposal of fixed assets	26,913	5,889	14,529
(Gain) loss on equity investment in affiliated entities	(36,556,658)	3,090,557	1,988,567
Share of net loss in Geneos	4,584,610	0	0
Net unrealized gain on available-for-sale equity securities	(1,695,497)	0	0
Tax benefit from other unrealized gains on short-term investments	0	(266,215)	0
Unrealized transaction loss on foreign-currency denominated debt	15,902	471,172	0
Changes in operating assets and liabilities:
Accounts receivable	(17,859,894)	2,616,288	2,686,844
Accounts receivable from affiliated entities	844,423	(593,461)	(251,964)
Prepaid expenses and other current assets	(38,849,572)	(178,008)	1,194,316
Prepaid expenses and other current assets from affiliated entities	374,107	70,665	725,202
Other assets	(23,285,424)	(2,026)	(30,644)
Accounts payable and accrued expenses	3,115,828	(4,337,829)	550,407
Accrued clinical trial expenses	5,962,381	(1,622,037)	(2,940,128)
Accounts payable and accrued expenses due to affiliated entities	135,650	(248,063)	50,849
Deferred revenue	(68,078)	(180,450)	(1,016,836)
Deferred revenue from affiliated entities	5,725	(1,800)	(140,535)
Deferred rent	0	0	(398,357)
Operating lease right-of-use assets and liabilities, net	(2,091,855)	(1,733,599)
Grant funding liability	1,409,098	1,899,364	4,165,848
Grant funding liability from affiliated entities	(784,925)	816,342	27,083
Other liabilities	20,720	(48,507)	87,333
Net cash used in operating activities	(177,979,046)	(97,850,136)	(73,550,156)
Cash flows from investing activities:
Purchases of investments	(156,216,677)	(100,950,301)	(88,155,046)
Proceeds from sale of or maturity of investments	62,991,023	92,893,232	132,659,976
Purchases of capital assets	(1,520,665)	(987,926)	(2,085,022)
Proceeds from sale of investment	40,125,418	0	0
Decrease of cash resulting from the deconsolidation of Geneos	(2,774,851)	0	0
Investment in Geneos	(1,399,999)	0	0
Net cash (used in) provided by investing activities	(58,795,751)	(9,044,995)	42,419,908
Cash flows from financing activities:
Proceeds from issuances of convertible senior notes and convertible bonds	0	97,443,617	0
Costs related to issuances of convertible senior notes and convertible bonds	0	(3,314,757)	0
Proceeds from issuance of common stock, net of issuance costs	454,486,400	9,089,010	29,227,776
Proceeds from stock option and warrant exercises, net of tax payments	12,269,801	112,522	2,421,136
Taxes paid related to net share settlement of equity awards, net of proceeds from option exercises	(4,028,177)	(892,928)	(611,610)
Acquisition of non-controlling interest	2,379,969	2,960,131	0
Proceeds from Geneos issuance of note payable	171,620	0	0
Net cash provided by financing activities	465,279,613	105,397,595	31,037,302
Effect of exchange rate changes on cash and cash equivalents	27,205	0	0
Increase (decrease) in cash and cash equivalents	228,532,021	(1,497,536)	(92,946)
Cash and cash equivalents, beginning of period	22,196,097	23,693,633	23,786,579
Cash and cash equivalents, end of period	250,728,118	22,196,097	23,693,633
Supplemental disclosure:
Amounts accrued for purchases of property and equipment	136,711	0	559,646
Interest paid	4,624,764	2,717,585	0
Equity component of issuance of convertible notes	0	15,752,698	0
Right-of-use assets obtained in exchange for lease obligations	0	14,634,769
August 2019 Bonds
Adjustments to reconcile net loss to net cash used in operating activities:
Gain (loss) on extinguishment of debt	8,177,043	0	0
6.50% Convertible Senior Notes Due 2024
Adjustments to reconcile net loss to net cash used in operating activities:
Gain (loss) on extinguishment of debt	$ (8,762,030)	$ 0	$ 0

The Company

The Company	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company Inovio Pharmaceuticals, Inc. (the “Company” or “INOVIO”), is a biotechnology company focused on rapidly bringing to market precisely designed DNA medicines to treat and protect people from infectious diseases, cancer, and diseases associated with human papillomavirus (HPV). INOVIO's DNA medicines pipeline is comprised of three types of product candidates: DNA vaccines, DNA immunotherapies and DNA encoded monoclonal antibodies (dMAbs ® ). In clinical trials, INOVIO has demonstrated that DNA medicines can be delivered directly into cells in the body through its proprietary smart device to consistently activate robust and fully functional T cell and antibody responses against targeted pathogens and cancers. The Company's novel DNA medicine candidates are made using its proprietary SynCon ® technology that uses a computer algorithm designed to identify and optimize the DNA sequence of the target antigen (be it virus or a tumor). INOVIO then creates optimized plasmids, which are circular strands of DNA that instruct a cell to produce antigens to help the person’s immune system recognize and destroy cancerous or virally infected cells. INOVIO's patented CELLECTRA ® smart delivery devices provide optimized uptake of its DNA medicines within the cell, overcoming a key limitation of other DNA-based technology approaches. Human clinical trial data to date has shown a favorable safety profile of INOVIO's DNA medicines delivered directly into cells in the body using the CELLECTRA ® smart device in more than 7,000 administrations across more than 3,000 patients. INOVIO's corporate strategy is to advance, protect and, once approved, commercialize its novel DNA medicines to meet urgent and emerging global health needs. The Company continues to advance and clinically validate an array of DNA medicine candidates that target HPV-associated diseases, cancer, and infectious diseases, such as COVID-19 (SARS-CoV-2). The Company aims to advance these candidates through commercialization and continue to leverage third-party resources through collaborations and partnerships, including product license agreements. The Company's partners and collaborators include ApolloBio Corporation., AstraZeneca, Beijing Advaccine, The Bill & Melinda Gates Foundation, Coalition for Epidemic Preparedness Innovations (CEPI), The U.S. Department of Defense (DoD), Defense Advanced Research Projects Agency (DARPA), GeneOne Life Science, HIV Vaccines Trial Network, the U.S. Defense Threat Reduction Agency’s Medical CBRN Defense Consortium (MCDC), International Vaccine Institute (IVI), National Cancer Institute, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Ology Bioservices, the Parker Institute for Cancer Immunotherapy, Plumbline Life Sciences, Regeneron Pharmaceuticals, Inc., Richter-Helm BioLogics, Thermo Fisher Scientific, the University of Pennsylvania, the Walter Reed Army Institute of Research, and The Wistar Institute. The Company and its collaborators are currently conducting or planning clinical studies of its DNA medicines for HPV-associated precancers, including cervical, vulvar, and anal dysplasia; HPV-associated cancers, including head & neck, cervical, anal, penile, vulvar, and vaginal; other HPV-associated disorders, such as recurrent respiratory papillomatosis (RRP); glioblastoma multiforme (GBM); prostate cancer; HIV; Ebola; Middle East Respiratory Syndrome (MERS); Lassa fever; Zika virus; and the COVID-19 virus (coronavirus). INOVIO was incorporated in Delaware in June 2001 and has its principal executive offices in Plymouth Meeting, Pennsylvania.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Liquidity INOVIO incurred a net loss attributable to common stockholders of $166.4 million for the year ended December 31, 2020. INOVIO had working capital of $429.5 million and an accumulated deficit of $906.2 million as of December 31, 2020. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $411.6 million as of December 31, 2020 , are sufficient to support the Company's operations for a period of at least 12 months from the date it is issuing these financial statements. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements. In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings including use of potential future At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds under past Sales Agreements of $454.5 million during the year ended December 31, 2020, and net proceeds of $9.1 million under a Sales Agreement during the year ended December 31, 2019. The Company also received net proceeds of $75.7 million from a private placement of 6.50% convertible senior notes due 2024 (the “Notes”), net proceeds of $14.5 million from the private placement of 18 billion Korean Won (KRW) (approximately USD $15.0 million based on the exchange rate on the date of issuance) aggregate principal amount of its 1.0% convertible bonds due August 2024 (the "August 2019 Bonds"), and net proceeds of $4.0 million from the private placement of 4.7 billion KRW (approximately USD $4.1 million based on the exchange rate on the date of issuance) aggregate principal amount of its 1.0% convertible bonds due December 2024 (the "December 2019 Bonds" and, together with the August 2019 Bonds, the “Bonds”) during the year ended December 31, 2019. However, sufficient funding may not be available in the future, or if available, may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders. If adequate funds are not available, the Company may need to delay, reduce the scope of or put on hold one or more of its clinical and/or preclinical programs. In June 2020, the Company formed a wholly-owned subsidiary, Inovio Asia LLC, under the laws of South Korea, through which the Company intends to advance its corporate development projects and other functions in South Korea and other Asian countries. From time to time, the Company may be subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal proceedings, including litigation, government investigations and enforcement actions, could result in material costs, occupy significant management resources and entail civil and criminal penalties, even if the Company ultimately prevails. Any of the foregoing consequences could result in serious harm to the Company’s business, results of operations and financial condition. The Company’s ability to continue its operations is dependent upon its ability to obtain additional capital in the future and achieve profitable operations. The Company expects to continue to rely on outside sources of financing to meet its capital needs and the Company may never achieve positive cash flow. Risks and Uncertainties The global pandemic resulting from COVID-19, caused by a novel strain of coronavirus, SARS-CoV-2, has caused national and global economic and financial market disruptions. The impact of this pandemic has been and will likely continue to be extensive in many aspects of society, which has resulted in and will continue to cause significant disruptions to the global economy, as well as businesses and capital markets around the world. The Company is closely monitoring the impact of the COVID-19 pandemic on its employees, collaborators and service providers. The extent to which the pandemic will impact the Company's business and operations will depend on future developments, including the duration of the outbreak, travel restrictions and social distancing in the United States and other countries, and the effectiveness of actions taken in the United States and other countries to contain and treat the disease, that are highly uncertain. Consolidation The consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiaries. As of December 31, 2020 the Company consolidated its wholly-owned subsidiary Inovio Asia LLC. On December 31, 2020, former wholly-owned subsidiaries Genetronics, Inc. and VGX Pharmaceuticals Inc. and former majority -owned subsidiary VGX Animal Health, Inc. were merged into Inovio Pharmaceuticals, Inc. All intercompany accounts and transactions have been eliminated upon consolidation. As of June 1, 2020, the Company deconsolidated its former subsidiary Geneos Therapeutics, Inc. ("Geneos"), as the Company no longer held a controlling financial interest. Refer to Footnote 19 for further discussion of Geneos. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one segment operating primarily within the United States. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and short-term investments. The Company limits its exposure to credit loss by placing its cash and investments with high credit quality financial institutions. Additionally, the Company has established guidelines regarding diversification of its investments and their maturities which are designed to maintain principal and maximize liquidity. The Company has contracts with certain of its customers that have represented more than 10% of the Company's total revenues, as discussed in Note 7. Fair Value of Financial Instruments The Company’s financial instruments consist principally of cash equivalents, short-term investments and investments in affiliated entities. The carrying amounts of cash equivalents approximate the related fair values due to the short-term maturities of these instruments. Investments are recorded at fair value, based on current market valuations. The Company carries convertible notes and bonds at face value less unamortized debt discount and issuance costs on its consolidated balance sheet, and it presents the fair value of such convertible notes and bonds for disclosure purposes only. Cash and Cash Equivalents Cash equivalents are considered by the Company to be highly liquid investments purchased with original maturities of three months or less from the date of purchase. Cash and cash equivalents included certain money market accounts and U.S. treasury securities at December 31, 2020 and money market accounts at December 31, 2019. Investments The Company defines investments as income-yielding securities that can be readily converted into cash or equity investments classified as available-for-sale. Investments included mutual funds, U.S. treasury securities, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2020. Investments included mutual funds and an equity investment in the Company's affiliated entities, PLS and GeneOne, at December 31, 2019. Accounts Receivable Accounts receivable are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers’ financial condition. Credit is extended to customers as deemed necessary and generally does not require collateral. Management believes that the risk of loss is significantly reduced due to the quality and financial position of the Company's customers. No allowance for doubtful accounts was deemed necessary at December 31, 2020 and 2019. Fixed Assets Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful life of the assets, generally three Long-Lived Assets All long-lived assets are reviewed for impairment in value when changes in circumstances dictate, based upon undiscounted future operating cash flows, and appropriate losses are recognized and reflected in current earnings, to the extent the carrying amount of an asset exceeds its estimated fair value determined by the use of appraisals, discounted cash flow analyses or comparable fair values of similar assets. The Company has not recognized any losses on long-lived assets through December 31, 2020. Valuation of Intangible Assets and Goodwill Intangible assets are amortized over their estimated useful lives ranging from two Historically, the Company has recorded patents at cost and amortized these costs using the straight-line method over the expected useful lives of the patents or 17 years, whichever is less. Patent cost consists of the consideration paid for patents and related legal costs. New patent costs are expensed as incurred, with patent costs capitalized as of that date continuing to be amortized over the expected life of the patent. License costs are recorded based on the fair value of consideration paid and are amortized using the straight-line method over the shorter of the expected useful life of the underlying patents or the term of the related license agreement to the extent the license has an alternative future use. As of December 31, 2019 and 2018, the Company’s intangible assets resulting from acquisitions and additional intangibles including previously capitalized patent costs and license costs, net of accumulated amortization, totaled $3.1 million and $3.7 million, respectively. The determination of the value of intangible assets requires management to make estimates and assumptions that affect the Company’s consolidated financial statements. The Company assesses potential impairments to intangible assets when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recovered. The Company’s judgments regarding the existence of impairment indicators and future cash flows related to intangible assets are based on operational performance of its acquired businesses, market conditions and other factors. If impairment is indicated, the Company will reduce the carrying value of the intangible asset to fair value. While current and historical operating and cash flow losses are potential indicators of impairment, the Company believes the future cash flows to be received from its intangible assets will exceed the intangible assets’ carrying value, and accordingly, the Company has not recognized any impairment losses through December 31, 2020. Goodwill represents the excess of acquisition cost over the fair value of the net assets of acquired businesses. Goodwill is reviewed for impairment at least annually at November 30, or more frequently if an event occurs indicating the potential for impairment. During its goodwill impairment review, the Company may assess qualitative factors to determine whether it is more likely than not that the fair value of its reporting unit is less than its carrying amount, including goodwill. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance of the Company. If, after assessing the totality of these qualitative factors, the Company determines that it is not more likely than not that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company proceeds to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the Company performs the second step of the goodwill impairment test to determine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. The Company may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of the goodwill impairment test. The Company performed its annual assessment for goodwill impairment as of November 30, 2020, identifying no impairment. Although there are inherent uncertainties in this assessment process, the estimates and assumptions the Company is using are consistent with its internal planning. If these estimates or their related assumptions change in the future, the Company may be required to record an impairment charge on all or a portion of its goodwill and intangible assets. Furthermore, the Company cannot predict the occurrence of future impairment triggering events nor the impact such events might have on its reported asset values. Future events could cause the Company to conclude that impairment indicators exist and that goodwill or other intangible assets associated with its acquired businesses are impaired. Any resulting impairment loss could have an adverse impact on the Company’s results of operations. See Note 10 for further discussion of the Company’s goodwill and intangible assets. Income Taxes The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities along with net operating loss and tax credit carry forwards. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. Valuation allowances against the Company’s deferred tax assets were $159.7 million and $137.2 million at December 31, 2020 and 2019, respectively. Changes in the valuation allowances, when they are recognized in the provision for income taxes, are included as a component of the estimated annual effective tax rate. Collaboration Agreements The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808, the Company assesses whether the payments between the Company and the collaboration partner are subject to other accounting literature. If payments from the collaboration partner to the Company represent consideration from a customer, then the Company accounts for those payments within the scope of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“Topic 606”). However, if the Company concludes that its collaboration partner is not a customer for certain activities, such as for certain collaborative research and development activities, the Company presents such payments as a reduction of research and development expense. Revenue Recognition The Company recognizes revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which it expects to be entitled in exchange for those goods or services. To determine revenue recognition for contracts with customers, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies its performance obligations. At contract inception, the Company assesses the goods or services agreed upon within each contract and assess whether each good or service is distinct and determine those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Collaborative Arrangements The Company enters into collaborative arrangements with partners that typically include payment of one or more of the following: (i) license fees; (ii) product supply services; (iii) milestone payments related to the achievement of developmental, regulatory, or commercial goals; and (iv) royalties on net sales of licensed products. Where a portion of non-refundable, upfront fees or other payments received are allocated to continuing performance obligations under the terms of a collaborative arrangement, they are recorded as deferred revenue and recognized as revenue when (or as) the underlying performance obligation is satisfied. As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment of management to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligation. The standalone selling price may include items such as forecasted revenues, development timelines, discount rates and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. License Fees If a license to intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Product Supply Services Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the licensee’s discretion are generally considered as options. The Company assesses if these options provide a material right to the licensee and if so, they are accounted for as separate performance obligations. The Company evaluates whether it is the principal or agent in the arrangement. The Company had determined that it is the principal in the current arrangements as the Company controls the product supply before it is transferred to the customer. Milestone Payments At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company's or its collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achieving such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration or other revenues and earnings in the period of adjustment. Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its collaborative arrangements. Grants The Company accounts for various grant agreements under the contributions guidance under Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition , which is outside the scope of Topic 606, as the government agencies granting the Company funds are not receiving reciprocal value for their contributions. All contributions received from current grant agreements are recorded as a contra-expense as opposed to revenue on the consolidated statement of operations. Derivative Liabilities The Company evaluates its debt and equity issuances to determine if those contracts or embedded components of those contracts qualify as derivatives requiring separate recognition in the Company's financial statements. The result of this accounting treatment is that the fair value of the embedded derivative is revalued at each balance sheet date and recorded as a liability, and the change in fair value during the reporting period is recorded in other income (expense) in the consolidated statements of operations. In circumstances where the embedded conversion option in a convertible instrument is required to be bifurcated and there are also other embedded derivative instruments in the convertible instrument that are required to be bifurcated, the bifurcated derivative instruments are accounted for as a single, compound derivative instrument. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is reassessed at the end of each reporting period. Derivative instrument liabilities are classified in the balance sheet as current or non-current based on whether or not net-cash settlement of the derivative instrument is expected within twelve months of the balance sheet date. Foreign Currency Transactions The functional and presentation currency of the Company is the U.S. dollar. Transactions denominated in a currency other than the functional currency are recorded on the initial recognition at the exchange rate at the date of the transaction. After initial recognition, monetary assets and liabilities denominated in foreign currency are remeasured at the end of each reporting period into the functional currency at the exchange rate at that date. Exchange differences are included in general and administrative expenses in the consolidated statement of operations. Non-monetary assets and liabilities measured at cost are remeasured at the exchange rate at the date of the transaction. Variable Interest Entities (VIE) The Company evaluates its ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether the Company is the primary beneficiary of the VIE. In determining whether the Company is the primary beneficiary of a VIE and therefore required to consolidate the VIE, the Company applies a qualitative approach that determines whether it has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. The Company will continuously perform this assessment, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of a VIE. Equity Investments Under ASC Topic 321, Investments - Equity Securities, the Company must measure equity investments (except those accounted for under the equity method, those that result in consolidation of the investee and certain other investments) at fair value and recognize any changes in fair value in the consolidated statement of operations. The Company can elect a measurement alternative for equity investments that do not have readily determinable fair values and do not qualify for the practical expedient in ASC Topic 820, Fair Value Measurement, to estimate fair value using the net asset value per share (or its equivalent). The Company's equity investments that do not have readily determinable fair values and do not qualify for the net asset value practical expedient for estimating fair value are measured at cost, less any impairments, plus or minus changes resulting from observable price changes in orderly transactions for identifiable or similar investments of the same issuer. Research and Development Expenses The Company’s activities have largely consisted of research and development efforts related to developing electroporation delivery technologies, DNA vaccines, DNA immunotherapies and dMAbs. Research and development expenses consist of expenses incurred in performing research and development activities including salaries and benefits, facilities and other overhead expenses, clinical trials, contract services and other outside expenses. Research and development expenses are charged to operations as they are incurred. These expenses result from the Company's independent research and development efforts as well as efforts associated with collaborations and licensing arrangements. The Company reviews and accrues clinical trial expense based on work performed, which relies on estimates of total trial management costs, sites activated, patients enrolled, and number of patient visits. The Company follows this method since reasonably dependable estimates of the costs applicable to various stages of a research agreement or clinical trial can be made. Accrued clinical trial costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a trial could result in a charge to the Company's results of operations. Net Loss Per Share Basic net loss per share is computed by dividing the net loss for the year by the weighted average number of common shares outstanding during the year. Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding stock options and restricted stock units and reflects the potential dilution that would occur if securities or other contracts to issue common stock were exercised or converted to common stock. The dilutive impact of the outstanding Notes and Bonds issued by the Company (discussed in Note 11) has been considered using the "if-converted" method. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the options or other securities and the presumed exercise of such securities are dilutive to net loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of such securities from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any. For the years ended December 31, 2020, 2019 and 2018, basic and diluted net loss per share are the same, as the assumed exercise or settlement of stock options, restricted stock units and the potentially dilutive shares issuable upon conversion of the Notes and Bonds are antidilutive. The following table summarizes potential shares of common stock that were excluded from diluted net loss per share calculation because of their anti-dilutive effect: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 8,906,624 9,265,390 8,752,677 Service-based restricted stock units 2,558,052 2,069,936 1,688,017 Performance-based restricted stock units 663,353 — — Convertible preferred stock 3,309 8,456 8,456 Convertible notes 3,049,980 14,585,653 — August 2019 Bonds — 3,799,071 — December 2019 Bonds 1,009,450 1,009,450 — Total 16,190,768 30,737,956 10,449,150 Leases For its long-term operating leases, the Company recognized an operating lease right-of-use asset and an operating lease liability on its consolidated balance sheets. The lease liability is determined as the present value of future lease payments using an estimated rate of interest that the Company would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. The right-of-use asset is based on the liability adjusted for any prepaid or deferred rent. The Company determines the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise. Fixed rent expense for the Company's operating leases is recognized on a straight-line basis over the term of the lease and is included in operating expenses on the consolidated statements of operations. Variable lease payments including lease operating expenses are recorded as incurred. Stock-Based Compensation The Company incurs stock-based compensation expense related to restricted stock units and stock options. The fair value of restricted stock is determined by the closing price of the Company's common stock reported on the Nasdaq Global Select Market on the date of grant. The Company estimates the fair value of stock options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of subjective assumptions, including the expected stock price volatility and expected option life. The Company amortizes the fair value of the awards on a straight-line basis over the requisite vesting period of the awards. Expected volatility is based on historical volatility. The expected life of options granted is based on historical expected life. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield is based on the fact that no dividends have been paid historically and none are currently expected to be paid in the foreseeable future. The Company recognizes forfeitures as they occur. The weighte

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition During the year ended December 31, 2020, the Company recognized total revenue under license and other agreements of $5.0 million from Advaccine, $1.4 million from its affiliated entity Plumbline Life Sciences, Inc. ("PLS"), and $1.0 million from various other contracts. Of the total revenue recognized during the year ended December 31, 2020, $127,000 was in deferred revenue as of December 31, 2019. During the year ended December 31, 2019, the Company recognized revenue of $293,000 that was included in deferred revenue at December 31, 2018. Performance obligations are generally satisfied within 12 months of the initial contract date.

Collaborative Agreements

Collaborative Agreements	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Agreements	Collaborative Agreements Advaccine Biopharmaceuticals Suzhou Co., Ltd. (Advaccine) On December 31, 2020, the Company entered into a Collaboration and License Agreement (the “Agreement”) with Advaccine. Under the terms of the Agreement, the Company has granted to Advaccine the exclusive right to develop, manufacture and commercialize the Company’s vaccine candidate INO-4800 within the territories of China, Taiwan, Hong Kong and Macau (referred to collectively as “Greater China”). Advaccine will not have the right to grant sublicenses, other than to affiliated entities, without the Company’s express prior written consent. As part of the collaboration, Advaccine has also granted to the Company a non-exclusive license to certain DNA vaccine manufacturing processes. The Company and Advaccine have collaborated since January 2020 to leverage Advaccine’s clinical development expertise to conduct an early-stage clinical trial in China in parallel with the Company’s clinical development efforts in the United States and South Korea. In December 2020, the Company and Advaccine announced that they had dosed the first subject in a Phase 2 clinical trial of INO-4800 in China. This trial is independent of the Company’s ongoing clinical trial of INO-4800, called INNOVATE, being conducted in the United States. Under the Agreement, Advaccine made an upfront payment to the Company of $3.0 million subsequent to December 31, 2020. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of $108.0 million upon the achievement of specified milestones related to the development, regulatory approval and commercialization of INO-4800, including the achievement of specified net sales thresholds for INO-4800 in Greater China, if approved. As of December 31, 2020 the Company had earned a $2.0 million milestone payment based on the enrollment of the first subject in the Phase 2 clinical trial for the product in the Advaccine territory. The Company will also be entitled to receive a royalty equal to a high single-digit percentage of annual net sales in each region within Greater China, subject to reduction in the event of competition from biosimilar products in a particular region and in other specified circumstances. Advaccine’s obligation to pay royalties will continue, on a licensed product-by-licensed product basis and region-by-region basis, for ten years after the first commercial sale in a particular region within Greater China or, if later, until the expiration of the last-to-expire patent covering a given licensed product in a given region. Under the Agreement, Advaccine will be responsible for the development and commercialization of the licensed products at its own cost and expense and shall use commercially reasonable efforts to develop, obtain and maintain regulatory approval of INO-4800, as well as the Company’s CELLECTRA ® device and arrays for use in connection with the administration of INO-4800, in each region in Greater China. In the event that the Company has not initiated the planned Phase 3 segment of its ongoing clinical trial of INO-4800 in the United States within one year after entering into the Agreement, Advaccine may elect to conduct a Phase 3 clinical trial outside of Greater China at its own cost and expense for the purposes of obtaining regulatory approval in China, subject to the Company’s right to review and approve the protocols and design of such a trial. Under the Agreement, the Company will supply Advaccine’s clinical requirements of INO-4800 and devices, although Advaccine may manufacture INO-4800 for its clinical use and may procure alternate suppliers. Advaccine is responsible for the manufacture and supply of INO-4800 itself or through a contract manufacturer for commercial use. Upon Advaccine’s reasonable request, the parties may negotiate a separate clinical and/or commercial supply agreement. The Company evaluated the terms of the Advaccine Agreement under ASC Topics 606 and 808, and determined that the contract was with a customer and therefore should be accounted for under ASC Topic 606. The license to INO-4800 in the territories was identified as the only distinct performance obligation on a standalone basis as of the inception of the agreement. The Company concluded that the license was distinct from potential future manufacturing and supply obligations. The Company further determined that the transaction price under the agreement consisted of the $3.0 million upfront payment plus the initial $2.0 million milestone payment which was achieved upon contract signing. The future potential milestone amounts were not included in the transaction price, as they were all determined to be fully constrained. As part of the evaluation of the development and regulatory milestones constraint, the Company determined that the achievement of such milestones is contingent upon success in future clinical trials and regulatory approvals, each of which is uncertain at this time. Future potential milestone amounts may be recognized as revenue under the Advaccine Agreement, as well as under other collaborative research and development arrangements, if unconstrained. Reimbursable program costs will be recognized proportionately with the performance of the underlying services or delivery of drug supply and are excluded from the transaction price. The Agreement will continue in force on a region-by-region basis until Advaccine has no remaining royalty obligations in such region. Either party may terminate the Agreement (i) in the event the other party shall have materially breached its obligations thereunder and such default shall have continued for a specified period after written notice thereof or (ii) upon the bankruptcy or insolvency of the other party. In addition, the Company may terminate the agreement, upon prior written notice, if Advaccine (i) ceases all development or commercialization activities for at least nine months, subject to certain exceptions, or (ii) challenges the validity, enforceability or scope of any of the patents licensed by the Company to Advaccine under the Agreement, subject to certain conditions. Advaccine may terminate the Agreement at any time for convenience upon nine months’ written notice to the Company, if such notice is provided before the first commercial sale of INO-4800 in Greater China, or 18 months’ written notice thereafter; provided that the Company may accelerate the effectiveness of such termination to the extent permitted by law. Under Topic 606, the entire transaction price of $5.0 million was allocated to the license performance obligation. The Company determined that as of December 31, 2020, the transfer of technology has occurred for the use and benefit of the license and accordingly, the performance obligation was fully satisfied. The Company accordingly has recognized $5.0 million in revenue under collaborative research and development arrangements on the consolidated statement of operations during the year ended December 31, 2020. As of December 31, 2020, the Company had an accounts receivable balance of $7.1 million from Advaccine. ApolloBio Corporation On December 29, 2017, the Company entered into an Amended and Restated License and Collaboration Agreement (the "ApolloBio Agreement"), with ApolloBio Corporation ("ApolloBio"), with an effective date of March 20, 2018. Under the terms of the ApolloBio Agreement, the Company granted to ApolloBio the exclusive right to develop and commercialize VGX-3100, its DNA immunotherapy product candidate designed to treat pre-cancers caused by HPV, within the territories of China, Hong Kong, Macao, Taiwan, and may include Korea in the event that no patent covering VGX-3100 is issued in China within the three years following the effective date of the ApolloBio Agreement. Under the ApolloBio Agreement, the Company received proceeds of $19.4 million in March 2018, which comprised the upfront payment of $23.0 million less $2.2 million in foreign income taxes and $1.4 million in certain foreign non-income taxes. The foreign income taxes were recorded as a provision for income taxes and the foreign non-income taxes were recorded as a general and administrative expense, on the consolidated statement of operations. The Company also incurred advisory fees of $960,000 in connection with receiving the upfront payment from ApolloBio. These fees were determined to be incremental costs of obtaining the contract. The Company applied the practical expedient that permits a company to expense incremental costs to obtain a contract when the expected amortization period is one year or less and recorded the fees in general and administrative expense during the quarter ended March 31, 2018. No additional advisory fees are due related to the ApolloBio Agreement. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of $20.0 million, less required income, withholding or other taxes, upon the achievement of specified milestones related to the regulatory approval of VGX-3100 in the United States, China and Korea. In the event that VGX-3100 is approved for marketing, the Company will be entitled to receive royalty payments based on a tiered percentage of annual net sales, with such percentage being in the low- to mid-teens, subject to reduction in the event of generic competition in a particular territory. ApolloBio’s obligation to pay royalties will continue for 10 years after the first commercial sale in a particular territory or, if later, until the expiration of the last-to-expire patent covering the licensed products in the specified territory. The Company evaluated the terms of the ApolloBio Agreement under ASC Topic 606, and the license to VGX-3100 in the territories was identified as the only distinct performance obligation on a standalone basis as of the inception of the agreement. The Company concluded that the license was distinct from potential future manufacturing and supply obligations. The Company further determined that the transaction price under the agreement consisted of the $23.0 million upfront payment. The future potential milestone amounts were not included in the transaction price, as they were all determined to be fully constrained. As part of the evaluation of the development and regulatory milestones constraint, the Company determined that the achievement of such milestones is contingent upon success in future clinical trials and regulatory approvals, each of which is uncertain at this time. Future potential milestone amounts may be recognized as revenue under the ApolloBio Agreement, as well as under other collaborative research and development arrangements, if unconstrained. Reimbursable program costs will be recognized proportionately with the performance of the underlying services or delivery of drug supply and are excluded from the transaction price . As of December 31, 2020 there have been no significant reimbursable program costs under the ApolloBio Agreement. The ApolloBio Agreement will continue in force until ApolloBio has no remaining royalty obligations. Either party may terminate the ApolloBio Agreement in the event the other party shall materially breach or default in the performance of its material obligations thereunder and such default continues for a specified period after written notice thereof. In addition, ApolloBio may terminate the ApolloBio Agreement at any time beginning one year after the effective date for any reason upon 90 days written notice to the Company. Under Topic 606, the entire transaction price of $23.0 million was allocated to the license performance obligation. The Company determined that during the quarter ended June 30, 2018, the transfer of technology occurred and accordingly, the performance obligation was fully satisfied. The Company has recorded the gross upfront payment received from ApolloBio of $23.0 million as license revenue on the consolidated statement of operations during the year ended December 31, 2018. AstraZeneca On August 7, 2015, the Company entered into a license and collaboration agreement with MedImmune, the global biologics research and development arm of AstraZeneca ("AstraZeneca"). Under the agreement, AstraZeneca acquired exclusive rights to the Company's INO-3112 immunotherapy, renamed as MEDI0457, which targets cancers caused by human papillomavirus (HPV) types 16 and 18, with the ability to sublicense those license rights. AstraZeneca made an upfront payment of $27.5 million to the Company in September 2015. AstraZeneca may be obligated to make potential future development and regulatory event-based payments to the Company totaling up to $125 million and potential future commercial event-based payments totaling up to $115 million, in each case upon the achievement of specified milestones related to MEDI0457 set forth in the license and collaboration agreement. AstraZeneca will fund all development costs associated with MEDI0457 immunotherapy. The Company is entitled to receive up to mid-single to double-digit tiered royalties on MEDI0457 product sales. Under the agreement, AstraZeneca can also request the Company to provide certain clinical manufacturing at an agreed upon price. The Company determined these options did not represent material rights at the inception of the agreement. As of December 31, 2017, the Company had recognized all of the $27.5 million upfront payment as revenue, as all identified materia l performance obligations had been met with respect to that payment. In both December 2018 and March 2019, the Company recognized as revenue $2.0 million in milestone payments from AstraZeneca triggered by AstraZeneca’s initiation of the Phase 2 portion of ongoing clinical trials in the second and third major indication, respectively, under the agreement. Coalition for Epidemic Preparedness Innovations On April 11, 2018, the Company entered into agreements with CEPI, pursuant to which the Company intends to develop vaccine candidates against Lassa fever and MERS. The goal of the collaboration between the Company and CEPI is to conduct research and development so that investigational stockpiles will be ready for clinical efficacy trial testing during potential disease outbreaks. The agreements with CEPI contemplate preclinical studies, as well as Phase 1 and Phase 2 clinical trials, occurring over multiple years. As part of the arrangement between the parties, CEPI has agreed to fund up to an aggregate of $56 million of costs over a five-year period for preclinical studies, as well as planned Phase 1 and Phase 2 clinical trials, to be conducted by the Company and collaborators, with funding from CEPI based on the achievement of identified milestones. During the years ended December 31, 2020 and 2019, the Company received funding of $6.4 million and $6.3 million, respectively, related to these grants and recorded those payments as contra-research and development expense. As of December 31, 2020, the Company had a grant funding liability balance related to the CEPI grant of $2.6 million recorded as grant funding liability on the consolidated balance sheet related to the CEPI grant. In January 2020, CEPI awarded the Company a grant of up to $9.0 million to develop a vaccine against COVID-19. This initial CEPI funding is intended to support preclinical and clinical development through Phase 1 human testing in the United States of INO-4800, the Company's COVID-19 vaccine candidate against COVID-19. In April 2020, CEPI awarded the Company a grant of $6.9 million to work with the International Vaccine Institute ("IVI") and the Korea National Institute of Health ("KNIH") to conduct clinical trials of INO-4800 in South Korea, a grant of $5.0 million to accelerate development of the Company's next-generation intradermal electroporation device, known as CELLECTRA ® 3PSP, for the intradermal delivery of INO-4800, and a grant of $1.3 million to support large-scale manufacturing of INO-4800. During the year ended December 31, 2020, the Company received funding of $10.0 million from CEPI related to these grants for INO-4800 and recorded such amounts as contra-research and development expense. As of December 31, 2020 the Company had $3.4 million recorded as deferred grant funding on the consolidated balance sheet related to the CEPI grants related to INO-4800. Bill & Melinda Gates Foundation In October 2018, the Bill & Melinda Gates Foundation (“Gates”) awarded and funded the Company a grant of $2.2 million to advance the development of dMAbs to address issues in infectious disease prevention and therapy. This technology has high relevance for the control of influenza and HIV. This next-generation approach to the delivery of monoclonal antibodies would make the technology accessible to low and middle-income countries. In August 2019, Gates funded an additional $1.1 million for the project. During the years ended December 31, 2020 and 2019, the Company recorded $463,000 and $2.1 million, respectively, as contra-research and development expense related to the Gates dMAb grant. As of December 31, 2020, the Company had $575,000 recorded as deferred grant funding on the consolidated balance sheet related to the grant. In March 2020, Gates awarded and funded the Company a grant of $5.0 million to accelerate the development of the CELLECTRA ® 3PSP device for the intradermal delivery of INO-4800. During the year ended December 31, 2020, the Company recorded $4.1 million as contra-research and development expense and had $884,000 recorded as deferred grant funding on the consolidated balance sheet related to this Gates grant. Department of Defense (DoD) In June 2020, the Company entered into an Other Transaction Authority for Prototype Agreement (the “OTA Agreement”) with the DoD to fund the Company’s efforts in developing the CELLECTRA ® 3PSP device and associated arrays to be used for delivery of INO-4800 against COVID-19. Under the OTA Agreement, the Company intends to develop the CELLECTRA ® 3PSP device and arrays for use in the U.S. military population and the U.S. population as a whole, subject to approval of the device by the U.S. Food and Drug Administration (the “FDA”). The OTA Agreement is also expected to support large-scale manufacturing of the CELLECTRA ® 3PSP device, as well as large-scale DNA plasmid production for manufacture and supply of a specified number of doses of INO-4800 in support of FDA approval of the device. The total amount of funding being made available to the Company under the OTA Agreement is approximately $54.5 million. The Company has determined that the OTA Agreement should be considered under Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition , which is outside the scope of Topic 606, as the government agency granting the Company funds is not receiving reciprocal value for their contributions. The Company will record contra-research development expense on the consolidated statement of operations in the same period that the underlying expenses are incurred. Additionally, in June 2020, the Company was awarded a fixed-price contract (the “Procurement Contract”) from the DoD for the purchase of the Company’s intradermal CELLECTRA ® 2000 device and accessories. The CELLECTRA ® 2000 devices will be used to inject INO-4800 in the Company’s planned later-stage clinical trials. The total purchase price under the Procurement Contract is approximately $16.6 million. The Company has determined that the Procurement Contract does not currently fall under the scope of ASC Topic 606 as contingencies remain regarding INO-4800 which does not give the Company the ability to satisfy its obligations under the arrangement. During the year ended December 31, 2020, the Company recorded $21.2 million as contra-research and development expense related to these agreements with the DoD. As of December 31, 2020, the Company had an accounts receivable balance of $11.4 million on the consolidated balance sheet from the DoD. In November 2020, the Company announced that the DoD has also agreed to provide funding for the Phase 2/3 clinical trial for INO-4800, called INNOVATE ( IN OVIO I NO -4800 Va ccine T rial for E fficacy) . These expenses will be paid directly by the DoD.

Short-term Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Short-term Investments	Short-term Investments Short-term investments at December 31, 2020 consisted of mutual funds, certificates of deposit and U.S. agency mortgage-backed securities. Short-term investments at December 31, 2019 consisted of mutual funds. Short-term investments are recorded at fair value, based on current market valuations. Unrealized gains and losses on the Company's debt securities are excluded from earnings and reported as a separate component of other comprehensive loss until realized. Realized gains and losses and unrealized gains and losses on available-for-sale equity securities are included in non-operating other income (expense) on the consolidated statements of operations and are derived using the specific identification method for determining the cost of the securities sold. During the years ended December 31, 2020 and 2019, the Company recorded gross realized ga in on investments of $744,000 and $594,000, respectively, and gross realized loss on investments of $1.3 million and $118,000, respectively. During the year ended December 31, 2020, the Company recorded net unrealized gain on available for sale equity securities of $1.7 million. There was no material unrealized gain or loss on available-for-sale equity securities recorded during the year ended December 31, 2019. No material balances were reclassified out of accumulated other comprehensive income (loss) for the years ended December 31, 2020, 2019 and 2018. Interest and dividends on investments classified as available-for-sale are included in interest income in the consolidated statements of operations. As of December 31, 2020, the Company had 12 available-for-sale securities in a gross unrealized loss position, of which none were in such position for longer than 12 months. The following is a summary of available-for-sale securities as of December 31, 2020 and 2019: As of December 31, 2020 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 153,177,675 $ 2,339,639 $ (644,140) $ 154,873,174 Certificates of deposit Less than 1 3,000,000 26,260 (10,000) 3,016,260 U.S. agency mortgage-backed securities * 3,062,256 — (36,755) 3,025,501 $ 159,239,931 $ 2,365,899 $ (690,895) $ 160,914,935 As of December 31, 2019 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 66,599,219 $ 754,709 $ (15,911) $ 67,338,017 *No single maturity date. The Company periodically reviews its portfolio of available-for-sale debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For the debt securities where the fair value of the investment is less than the amortized cost basis, the Company has assessed at the individual security level for various quantitative factors including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses on available-for-sale debt securities as of December 31, 2020 were primarily due to changes in interest rates, including credit spreads from perceived increased credit risks as a result of the COVID-19 global pandemic, and not due to increased credit risks associated with specific securities. The Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity. Based on the credit quality of the available-for-sale debt securities that are in an unrealized loss position, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. Accordingly, at December 31, 2020, the Company has not recorded an allowance for credit losses related to its available-for-sale debt securities.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The guidance regarding fair value measurements establishes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets that are accessible at the measurement date; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Assets are, and prior to September 30, 2020 liabilities were, classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The Company did not have any transfer of assets and liabilities between Level 1, Level 2 and Level 3 of the fair value hierarchy during the years ended December 31, 2020 and 2019. All liabilities in the fair value hierarchy were extinguished as of September 30, 2020 as described below. The following table presents the Company’s assets that are measured at fair value on a recurring basis, and are determined using the following inputs as of December 31, 2020: Fair Value Measurements at December 31, 2020 Total Quoted Prices Significant Significant Assets: Cash and cash equivalents U.S. treasury securities $ 59,996,800 $ 59,996,800 $ — $ — Short-term investments Mutual funds 154,873,174 154,873,174 — — Certificates of deposit 3,016,260 — 3,016,260 — U.S. agency mortgage-backed securities 3,025,501 — 3,025,501 — Total short-term investments 160,914,935 154,873,174 6,041,761 — Investment in affiliated entity 4,460,366 4,460,366 — — Total assets measured at fair value $ 225,372,101 $ 219,330,340 $ 6,041,761 $ — The following table presents the Company’s assets and liabilities that are measured at fair value on a recurring basis, and are determined using the following inputs as of December 31, 2019: Fair Value Measurements at December 31, 2019 Total Quoted Prices Significant Significant Assets: Cash and cash equivalents Money market funds $ 2,349,729 $ 2,349,729 $ — $ — Short-term investments Mutual funds 67,338,017 67,338,017 — — Investments in affiliated entities 6,315,356 6,315,356 — — Total assets measured at fair value $ 76,003,102 $ 76,003,102 $ — $ — Liabilities: Derivative liability $ 8,819,023 $ — $ — $ 8,819,023 Total liabilities measured at fair value $ 8,819,023 $ — $ — $ 8,819,023 Level 1 assets at December 31, 2020 consisted of mutual funds and U.S. treasury securities held by the Company that are valued at quoted market prices, as well as the Company’s investment in its affiliated entity, PLS. Level 1 assets at December 31, 2019 consisted of money market funds and mutual funds held by the Company that are valued at quoted market prices, as well as the Company’s investments in its affiliates, GeneOne and PLS. The Company accounts for its investment in 597,808 common shares of PLS as an equity investment with a fair value based on the closing price of the shares on the Korea New Exchange Market on the applicable balance sheet date. Unrealized gains and losses on the Company's equity securities are reported in the consolidated statement of operations as unrealized gain (loss) on available-for-sale equity securities or as a gain (loss) on investment in affiliated entities. In August 2020, the Company sold its investment in 1,644,155 common shares of its affiliated entity GeneOne for net proceeds of $40.1 million, resulting in a gain on investment in affiliated entity of $36.7 million. Previously, the Company accounted for its investment in GeneOne based on the closing price of the shares on the KOSDAQ Market of the Korea Exchange (KOSDAQ) on the applicable balance sheet date. Level 2 assets at December 31, 2020 consisted of certificates of deposit and U.S. agency mortgage-backed securities. Level 2 assets held by the Company that are initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing market observable data. The Company obtains the fair value of its Level 2 assets from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or inputs other than quoted prices that are observable either directly or indirectly. The professional pricing service gathers quoted market prices and observable inputs from a variety of industry data providers. The valuation techniques used to measure the fair value of the Company's Level 2 financial instruments were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models such as discounted cash flow techniques. The Company validates the quoted market prices provided by the primary pricing service by comparing the service's assessment of the fair values of the Company's investment portfolio balance against the fair values of the Company's investment portfolio balance obtained from an independent source. There were no Level 3 assets held as of December 31, 2020 and 2019. There were no Level 3 liabilities held at December 31, 2020 due to the full conversion of the August 2019 Bonds into shares of the Company's common stock. Level 3 liabilities held as of December 31, 2019 consisted of the embedded conversion option contained in the August 2019 Bonds that met the criteria to be bifurcated and accounted for separately from the August 2019 Bonds (the "derivative liability") (see Note 11 below for more information). The derivative liability was recorded at fair value of $7.1 million upon the issuance of the August 2019 Bonds, and is subsequently remeasured to fair value at each reporting period. The derivative liability was initially valued and remeasured using a "with-and-without" method. The "with-and-without" methodology involves valuing the whole instrument on an as-is basis and then valuing the instrument without the embedded conversion option. The difference between the entire instrument with the embedded conversion option compared to the instrument without the embedded conversion option is the fair value of the derivative, recorded as the derivative liability. There was no derivative liability associated with the issuance of the December 2019 Bonds. The fair value of the August 2019 Bonds with the conversion option is estimated using a Monte Carlo simulation approach. The key inputs to valuing the August 2019 Bonds with the conversion option on the date of issuance and as of August 3, 2020 conversion date included the Company’s stock price on the valuation date; the expected annual volatility of the Company’s common stock, and the discount yield, which was derived by making the fair value of the August 2019 Bonds equal to the face value on the issuance date. Fair value measurements are highly sensitive to changes in these inputs and significant changes in these inputs could result in a significantly higher or lower fair value. The following table presents the changes in fair value of the derivative liability for the year ended December 31, 2020: Balance at December 31, 2019 $ 8,819,023 Change in fair value 75,670,977 Derecognition of the derivative liability upon conversion (84,490,000) Balance at December 31, 2020 $ —

Major Customers and Concentrati

Major Customers and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Major Customers and Concentration of Credit Risk	Major Customers and Concentration of Credit Risk Customer 2020 Revenue % of Total 2019 Revenue % of Total 2018 Revenue % of Total ApolloBio $ — — % $ — — % $ 23,000,000 75 % AstraZeneca 170,587 2 3,194,877 78 6,850,424 23 Advaccine 5,000,000 68 — — — — Plumbline Life Sciences, Inc. 1,370,396 18 — — — — All other, including affiliated entities 870,237 12 917,053 22 631,473 2 Total revenue $ 7,411,220 100 % 1 $ 4,111,930 100 % $ 30,481,897 100 % During the years ended December 31, 2020, 2019 and 2018, the Company recognized revenue from various license and other agreements. As of December 31, 2020, $11.4 million, or 62%, and $7.1 million, or 38%, of the Company's accounts receivable was attributable to the DoD and Advaccine, respectively. As of December 31, 2019, $469,000, or 67%, and $161,000, or 23%, of the Company's accounts receivable was attributable to MCDC and AstraZeneca, respectively.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets at December 31, 2020 and 2019 consisted of the following: 2020 2019 Prepaid manufacturing expenses (a) $ 35,661,947 $ — Other prepaid expenses 4,695,509 1,584,598 $ 40,357,456 $ 1,584,598 (a) Prepaid manufacturing expenses related to deposits made to reserve capacity for the manufacturing of INO-4800 expected in 2021. In the event that the manufacturing does not occur in 2021 the deposits will be forfeited.

Fixed Assets

Fixed Assets	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Fixed Assets	Fixed Assets Fixed assets at December 31, 2020 and 2019 consisted of the following: Cost Accumulated Net Book As of December 31, 2020 Leasehold improvements $ 15,179,447 $ (6,549,418) $ 8,630,029 Laboratory equipment 4,788,678 (3,727,508) 1,061,170 Office furniture and fixtures 2,828,675 (2,296,942) 531,733 Computer equipment and other 4,544,915 (3,419,703) 1,125,212 $ 27,341,715 $ (15,993,571) $ 11,348,144 As of December 31, 2019 Leasehold improvements $ 15,007,935 $ (4,996,777) $ 10,011,158 Laboratory equipment 4,102,467 (3,229,357) 873,110 Office furniture and fixtures 3,048,053 (1,944,293) 1,103,760 Computer equipment and other 3,781,020 (2,996,031) 784,989 $ 25,939,475 $ (13,166,458) $ 12,773,017 Depreciation expense for the years ended December 31, 2020, 2019 and 2018 was $3.0 million, $3.6 million and $3.7 million, respectively. The Company determined that the carrying value of these long-lived assets was not impaired during the periods presented. During the year ended December 31, 2020 the Company disposed of fixed assets with a net book value of $227,000 and accumulated depreciation of $200,000.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets The following sets forth goodwill and intangible assets by major asset class: December 31, 2020 December 31, 2019 Weighted Average Useful Gross Accumulated Net Book Gross Accumulated Net Book Indefinite lived: Goodwill(a) $ 10,513,371 $ — $ 10,513,371 $ 10,513,371 $ — $ 10,513,371 Definite lived: Licenses 10 1,323,761 (1,276,852) 46,909 1,323,761 (1,248,104) 75,657 Bioject (b) 12 5,100,000 (2,468,889) 2,631,111 5,100,000 (2,175,556) 2,924,444 Other (c) 18 4,050,000 (3,581,250) 468,750 4,050,000 (3,356,250) 693,750 Total intangible assets 11 10,473,761 (7,326,991) 3,146,770 10,473,761 (6,779,910) 3,693,851 Total goodwill and intangible assets $ 20,987,132 $ (7,326,991) $ 13,660,141 $ 20,987,132 $ (6,779,910) $ 14,207,222 (a) Goodwill was recorded from the acquisition of other companies and assets. (b) Bioject intangible assets represent the estimated fair value of developed technology and intellectual property which were recorded from an asset acquisition. (c) Other intangible assets represent the estimated fair value of acquired intellectual property. Aggregate amortization expense on intangible assets was $547,000, $1.1 million and $1.2 million for the years ended December 31, 2020, 2019 and 2018, respectively. Amortization expense related to intangible assets at December 31, 2020 is expected to be incurred as follows: Year ending December 31, 2021 $ 521,000 2022 493,000 2023 276,000 2024 253,000 2025 253,000 Thereafter 1,351,000 $ 3,147,000 There were no impairment or impairment indicators present and no losses were recorded during the years ended December 31, 2020, 2019 and 2018, respectively.

Convertible Debt

Convertible Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Convertible Debt	Convertible Debt Convertible Senior Notes On February 19, 2019 and March 1, 2019, the Company completed a private placement of $78.5 million aggregate principal amount of its 6.50% convertible senior notes due 2024 (the “Notes”). The Notes were sold in a private offering to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended. Net proceeds from the offering were approximately $75.7 million. The Notes are senior unsecured obligations of the Company and accrue interest payable in cash semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2019, at a rate of 6.50% per annum. The Notes will mature on March 1, 2024, unless earlier converted, redeemed or repurchased. Prior to the close of business on the business day immediately preceding November 1, 2023, the Notes will be convertible at the option of the holders only upon the satisfaction of certain circumstances. Thereafter, the Notes will be convertible at the option of the holders at any time until the close of business on the scheduled trading day immediately before the maturity date. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at its election. The initial conversion rate will be 185.8045 shares per $1,000 principal amount of Notes (equivalent to an initial conversion price of approximately $5.38 per share), subject to adjustment upon the occurrence of specified events. The Company may not redeem the Notes prior to March 1, 2022. On or after March 1, 2022, the Company may redeem all, or any portion, of the Notes for cash if the last reported sale price per share of the Company's common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the trading day immediately before the Company sends the related redemption notice; and (ii) the trading day immediately before the date the Company sends such redemption notice. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. The Company evaluated the accounting for the issuance of the Notes and concluded that the embedded conversion features meet the requirements for a derivative scope exception for instruments that are both indexed to an entity’s own stock and classified in stockholders’ equity in its consolidated balance sheet, and that the cash conversion guidance applies. Therefore, the Notes issuance proceeds of $78.5 million are allocated first to the liability component based on the fair value of non-convertible debt with otherwise identical residual terms with the residual proceeds allocated to equity for the conversion features. The Company determined that the fair value of the non-convertible debt upon issuance of the Notes was $62.2 million and recorded this amount as a liability and the offsetting amount as a debt discount as a reduction to the carrying value of the Notes on the closing date. The debt issuance costs associated with the Notes of $2.8 million are allocated to the liability and equity component in the same proportion as the issuance proceeds. The Company determined that all other features of the Notes were clearly and closely associated with a debt host and did not require bifurcation as a derivative liability, or the fair value of the feature was immaterial to the Company's consolidated financial statements. The Company determined that the expected life of the Notes was equal to the period through November 1, 2023 as this represents the point at which the Notes are initially subject to repurchase by the Company at the option of the holders. Accordingly, the total debt discount of $18.6 million, inclusive of the fair value of the embedded conversion feature derivative at issuance, is being amortized using the effective interest method through November 1, 2023. The effective interest rate of the liability component is 13.1%. During the year ended December 31, 2020, the Company received notices for the conversion of $62.1 million of principal amount of the Notes, which were settled into an aggregate of 11,535,660 shares of the Company's common stock. The fair value of the Notes at the date of conversion was $43.7 million compared to the carrying value of $52.5 million, resulting in a $8.8 million gain on extinguishment of debt. Thi s gain was recorded in the consolidated statement of operations. To measure the fair value of the converted Notes as of the conversion dates, the Company engaged a third-party valuation expert and utilized a binomial lattice model. The balance of the Notes at December 31, 2020 is as follows: Principal amount $ 78,500,000 Principal amount converted into common shares (62,085,000) Unamortized debt discount on the liability component (2,312,404) Unamortized debt issuance cost (318,266) Accrued interest 355,658 Net carrying amount $ 14,139,988 For the years ended December 31, 2020 and 2019, the Company recognized $6.9 million and $7.0 million, respectively, of interest expense related to the Notes, of which $4.1 million and $4.4 million, respectively, related to the contractual interest coupon. August 2019 Convertible Bonds On August 1, 2019, the Company closed a private placement of the August 2019 Bonds with an aggregate principal amount of 18 billion KRW (approximately USD $15.0 million based on the exchange rate on the date of issuance) issued to institutional investors led by Korea Investment Partners (KIP), a global venture capital and private equity firm based in Seoul, Korea. Net proceeds from the offering were approximately $14.5 million. The August 2019 Bonds, which are unsecured obligations of the Company, were issued on August 1, 2019 and accrued interest at a coupon rate of 1.00% per annum, payable quarterly. The August 2019 Bonds were scheduled to mature on July 31, 2024, unless earlier converted or repurchased. On August 3, 2020 the August 2019 Bonds were converted in full into an aggregate of 4,962,364 shares of the Company's common stock, leaving no further August 2019 Bonds outstanding. The initial conversion rate was 211.0595 shares per KRW1,000,000 in principal amount (equivalent to an initial conversion price of approximately USD $4.00 per share based on the exchange rate as of July 30, 2019), subject to adjustment upon the occurrence of specified events. The conversion rate was reset on January 2, 2020 and was subject to reset quarterly thereafter if the current market price was lower than the conversion price then in effect. The conversion rate as of the date of conversion on August 1, 2020 was 275.6873 shares per KRW1,000,000 in principal amount (equivalent to a conversion price of approximately USD $3.14 per share). The Company evaluated the accounting for the issuance of the August 2019 Bonds and concluded that the embedded conversion feature was considered a derivative requiring bifurcation from the August 2019 Bonds as it did not meet the equity scope exception due to the fact that it was denominated in a currency other than the Company's functional currency. The fair value of the conversion feature at August 1, 2019 was $7.1 million, which was recorded as a reduction to the carrying value of the debt. This debt discount was being amortized to interest expense over the term of the debt using the effective interest method. The conversion option was accounted for as a derivative liability, which was revalued each reporting period with the resulting change in fair value reflected in other income (expense), net, in the consolidated statements of operations. The Company determined that all other features of the August 2019 Bonds were clearly and closely associated with a debt host and did not require bifurcation as a derivative liability, or the fair value of the feature was immaterial to the Company's consolidated financial statements. At their issuance, the Company determined that the expected life of the August 2019 Bonds was equal to the period through August 1, 2022 as this represented the point at which the August 2019 Bonds were initially subject to repurchase by the Company at the option of the holders. Accordingly, the total debt discount of $7.3 million, inclusive of the fair value of the embedded conversion feature derivative at issuance, was being amortized using the effective interest method through August 1, 2022. For the years ended December 31, 2020 and 2019, the Company recognized $1.6 million and $982,000, respectively, of interest expense related to the August 2019 Bonds, of which $87,000 and $65,000, respectively, related to the contractual interest coupon. In August 2020, all outstanding August 2019 Bonds were converted into common stock. Immediately prior to the conversion, the derivative liability was revalued at $84.5 million. The change in fair value of the derivative liability was an increase of $75.7 million, which was recorded on the consolidated statement of operations. To measure the fair value of the derivative liability as of the conversion date, the Company engaged a third-party valuation expert. Upon conversion, a loss on extinguishment of $8.2 million was recorded on the consolidated statement of operations. This loss represents the difference between (a) the calculated fair value of the derivative liability immediately prior to its derecognition plus the carrying amount of the debt component including any unamortized debt discount and issuance costs and (b) the fair value of the 4,692,364 shares of the Company's common stock issued upon conversion. December 2019 Convertible Bonds On December 26, 2019, the Company closed a private placement of convertible promissory notes (the “December 2019 Bonds”) with an aggregate principal amount of 4.7 billion KRW (approximately USD $4.1 million based on the exchange rate on the date of issuance) issued to a Korea-based institutional investor. Net proceeds from the offering were approximately $4.0 million. The December 2019 Bonds, which are unsecured obligations of the Company, were issued on December 31, 2019 and will accrue interest at a coupon rate of 1.00% per annum, payable quarterly. The December 2019 Bonds will mature on December 31, 2024, unless earlier converted or repurchased. The outstanding December 2019 Bonds will be repaid at maturity at a price equal to the principal of the outstanding bonds to be repaid plus a premium on such bonds to provide an internal rate of return with respect to such bonds of 6.00%. Commencing on December 31, 2020, the December 2019 Bonds are convertible until the date that is one month prior to maturity date. Upon conversion, the Company will deliver shares of common stock of the Company. The initial conversion rate was 214.7766 shares per KRW1,000,000 principal amount of Bonds (equivalent to an initial conversion price of approximately USD $4.00 per share based on the exchange rate as of December 19, 2019), subject to adjustment upon the occurrence of certain events. The conversion rate was subject to reset on July 2, 2020 and on each three month anniversary thereafter until the maturity date to the then current market price if the current market price is lower than the conversion price then in effect; provided that the conversion rate will not exceed 357.9611 shares per KRW1,000,000 (equivalent to a conversion price of approximately USD $2.40 per share based on the exchange rate as of December 19, 2019). The conversion rate has not been reset as of December 31, 2020 from the initial conversion rate. The December 2019 Bonds will be subject to repurchase by the Company at the option of the bondholders from and including December 31, 2022 up to the date that is one month prior to the maturity date at a repurchase price equal to the principal of the December 2019 Bonds to be repurchased plus a premium on the Bonds in order to ensure an internal rate of return with respect to the Bonds equal to 6.00%. In addition, upon the occurrence of a fundamental change (as defined in the Subscription Agreement) the Company will be required to offer to repurchase the Bonds at a repurchase price equal to the principal amount thereof plus accrued and unpaid interest thereon to but excluding the applicable repurchase date. If certain bankruptcy and insolvency-related events of default occur, the principal of, and accrued and unpaid interest on, all of the then outstanding December 2019 Bonds shall automatically become due and payable. If any other event of default occurs and is continuing, the holders of at least 25% of the in aggregate principal amount of the December 2019 Bonds by notice to the Company may declare the principal of, and accrued and unpaid interest on, all of the then-outstanding December 2019 Bonds to be due and payable. The Company evaluated the accounting for the issuance of the December 2019 Bonds and concluded that the embedded conversion feature does not require bifurcation from the December 2019 Bonds. Although the embedded conversion feature meets the definition of a derivative, it qualifies for the equity scope exception for instruments that are both indexed to an entity’s own stock and classified in stockholders’ equity in its consolidated balance sheet. The December 2019 Bonds are denominated in a foreign currency other than the Company’s functional currency, which would typically violate the settlement provision criteria when analyzing whether the conversion option is indexed to an entity’s own stock. However, per the terms of the agreement, the functional currency rate required to be used in a conversion scenario is fixed as of the date preceding the date of issuance of the Bonds. Therefore, the fluctuation in functional currency does not impact the settlement of the conversion option. Further, as there is no cash conversion feature or beneficial conversion feature on the date of issuance, and the Bonds were not issued at a substantial premium, all of the proceeds were recorded as a liability. The Company determined that all other features of the December 2019 Bonds were clearly and closely associated with a debt host and did not require bifurcation as a derivative liability, or the fair value of the feature was immaterial to the Company's consolidated financial statements. The balance of the December 2019 Bonds at December 31, 2020 is as follows: Principal amount $ 4,327,370 Unamortized debt issuance cost (36,525) Accretion of premium associated with the December 2019 Bonds 214,171 Accrued interest 10,818 Net carrying amount $ 4,515,834 The Company determined that the expected life of the December 2019 Bonds was equal to the period through December 31, 2022 as this represents the point at which the December 2019 Bonds are initially subject to repurchase by the Company at the option of the holders. The effective interest rate of the December 2019 Bonds is 6.2%. For the year ended December 31, 2020, the Company recognized $253,000 of interest expense related to the December 2019 Bonds, of which $40,000 related to the contractual interest coupon. As of December 31, 2020, there have not been any conversions or redemptions of the December 2019 Bonds. As of December 31, 2020, future minimum payments due under the Company's convertible debt instruments are as follows: Year ending December 31, Convertible Notes (1) December 2019 Bonds (2) Total 2021 $ 1,067,000 $ 43,000 $ 1,110,000 2022 1,067,000 43,000 1,110,000 2023 1,067,000 44,000 1,111,000 2024 16,948,000 5,571,000 22,519,000 Total $ 20,149,000 $ 5,701,000 $ 25,850,000 (1) Amounts represent contractual amounts due under the Notes, including interest based on the fixed rate of 6.5% per year.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts Payable and Accrued Expenses Accounts payable and accrued expenses at December 31, 2020 and 2019 consisted of the following: 2020 2019 Trade accounts payable $ 825,516 $ 6,919,081 Accrued compensation 13,127,257 8,967,897 Accrued subcontract costs 247,796 273,508 Other accrued expenses 7,003,239 2,076,772 $ 21,203,808 $ 18,237,258

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock Shares Outstanding as of Shares Authorized Shares Issued 2020 2019 Series C Preferred Stock, par $0.001 1,091 1,091 9 23 In June 2020, 14 shares of the Company’s Series C preferred stock were converted into an aggregate of 5,147 shares of the Company’s common stock. The holder of any share or shares of Series C Preferred Stock has the right at any time, at such holder’s option, to convert all or any lesser portion of such holder’s shares of the Preferred Stock into fully paid and non-assessable shares of Common Stock. As of December 31, 2020, the Conversion Value w as $27.20 per share, such that the outstanding shares of Series C Preferred Stock were convertible into an aggregate of 3,309 shares of common stock. Common Stock In May 2018, the Company entered into the Sales Agreement with an outside placement agent (the “Placement Agent”) to sell shares of its common stock w ith aggregate gross proceeds of up to $100.0 million, from time to time, through an “at-the-market” equity offering program under which the Placement Agent will act as sales agent. During the first quarter of 2020, the Company and the Placement Agent entered into a first and second amendment to the Sales Agreement (the "Prior Sales Agreement") to increase the amount of common stock that may be sold under the Sales Agreement from $100.0 million to $250.0 million. As of March 31, 2020, there was no remaining capacity under the Prior Sales Agreement. On April 3, 2020, the Company and the Placement Agent entered into a new Sales Agreement (the "New Sales Agreement") to sell shares of its common stock . On April 3, 2020 and May 12, 2020, the Company filed prospectus supplements pursuant to the New Sales Agreement for the offer and sale of its Common Stock for aggregate gross proceeds of up to an aggregate of $250.0 million. Under the New Sales Agreement, the Company will set the parameters for the sale of shares, inclu ding the number of shares to be issued, the time period during which sales are requested to be made, limitation on the number of shares that may be sold in any one trading day and any minimum price below which sales may not be made. The New Sales Agreement provides that the Placement Agent will be entitled to compensation for its services in an amount equal to up to 3.0% of the gross proceeds from the sales of shares sold through the Placement Agent under the New Sales Agreement. The Company has no obligation to sell any shares under the New Sales Agreement, and could at any time suspend solicitation and offers under the New Sales Agreement. During the three months ended March 31, 2020, the Company sold 43,148,952 shares of its common stock under the Prior Sales Agreement. The sales were made at a weighted average price of $4.92 per share, resulting in aggregate net proceeds of $208.2 million. As of March 31, 2020, there was no remaining capacity under the Prior Sales Agreement. During the year ended December 31, 2020, the Company sold a total of 22,915,934 shares of common stock under the New Sales Agreement. The sales were made at a weighted average price of $10.91 per share resulting in aggregate net proceeds of $246.2 million. As of December 31, 2020, t here was no remaining capacity under the New Sales Agreement. Stock Options and Restricted Stock Units The Company has a stock-based incentive plan, the 2016 Omnibus Incentive Plan (as amended to date, the "2016 Incentive Plan"), pursuant to which the Company may grant stock options, restricted stock awards, restricted stock units and other stock-based awards or short-term cash incentive awards to employees, directors and consultants. The 2016 Incentive Plan was originally approved by the Company's stockholders on May 13, 2016, and an amendment to the plan to increase the number of shares available for issuance was approved by the stockholders on May 8, 2019. The maximum number of shares of the Company’s common stock available for issuance over the term of the 2016 Incentive Plan may not exceed 18,000,000 shares, provided that commencing with the first business day of each calendar year beginning January 1, 2020, such maximum number of shares shall be increased by 2,000,000 shares of common stock unless the Board determines, prior to January 1 for any such calendar year, to increase such maximum amount by a fewer number of shares or not to increase the maximum amount at all for such year. On January 1, 2021, the maximum number of shares to be issued increased by 2,000,000. At December 31, 2020, there were 18,000,000 shares of common stock reserved for issuance upon exercise of incentive awards granted and to be granted at future dates under the 2016 Incentive Plan. At December 31, 2020, the Company had 6,739,577 shares of common stock available for future grant under the 2016 Incentive Plan, 2,558,052 shares underlying outstanding but unvested restricted stock units and options outstanding to purchase 5,742,109 shares of common stock under the 2016 Incentive Plan. The awards granted and available for future grant under the 2016 Incentive Plan generally vest over three years and have a maximum contractual term of ten years. The 2016 Incentive Plan terminates by its terms on March 9, 2026. The Amended and Restated 2007 Omnibus Incentive Plan (the "2007 Incentive Plan") was adopted on March 31, 2007 and terminated by its terms on March 31, 2017. At December 31, 2020, the Company had options outstanding to purchase 3,164,515 shares of common stock under the 2007 Incentive Plan. The awards granted under the 2007 Incentive Plan generally vest over three years and have a maximum contractual term of ten years. Total employee and director stock-based compensation expense recognized in the consolidated statements of operations for the years ended December 31, 2020, 2019 and 2018 was $14.5 million, $9.8 million and $10.2 million, respectively, of which $8.0 million, $5.9 million and $5.9 million was included in research and development expenses and $6.5 million, $3.9 million and $4.3 million was included in general and administrative expenses, respectively. At December 31, 2020 and 2019, there was $4.4 million and $3.4 million, respectively, of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 1.4 years and 1.7 years, respectively. At December 31, 2020 and 2019, there was $10.9 million and $4.3 million, respectively, of total unrecognized compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted-average period of 1.9 years and 1.6 years, respectively. The fair value of stock options granted to non-employees was estimated using the Black-Scholes pricing model. Total stock-based compensation expense for stock options and restricted stock units granted to non-employees for the years ended December 31, 2020, 2019 and 2018 was $1.2 million, $970,000 and $302,000, respectively. As of December 31, 2020, options to purchase 845,375 shares of common stock granted to non-employees remained outstanding. The following table summarizes total stock options outstanding at December 31, 2020: Options Outstanding Options Exercisable Exercise Price Shares Underlying Options Weighted-Average Weighted Shares Underlying Options Weighted Average $1.48-$3.00 452,749 2.5 $ 2.24 428,231 $ 2.23 $3.01-$6.00 3,261,410 7.4 $ 3.85 1,975,426 $ 3.98 $6.01-$9.00 3,879,209 6.5 $ 7.59 2,864,794 $ 7.33 $9.01-$12.00 365,223 7.2 $ 10.42 233,282 $ 10.08 $12.01-$15.00 833,282 5.9 $ 13.46 546,723 $ 13.14 $15.01-$25.62 114,751 9.6 $ 20.57 31,041 $ 20.59 8,906,624 6.6 $ 6.78 6,079,497 $ 6.58 At December 31, 2020, the aggregate intrinsic value of options outstanding was $24.2 million, the aggregate intrinsic value of options exercisable was $16.8 million, and the weighted average remaining contractual term of options exercisable was 5.7 years. At December 31, 2020, the aggregate intrinsic value of unvested restricted stock units was $22.6 million and the aggregate intrinsic value of restricted stock units which vested during the year ended December 31, 2020 was $13.5 million. At December 31, 2020, options to purchase 8,906,624 shares of common stock and 2,558,052 restricted stock units were expected to vest. Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2020 was as follows: Number of Weighted-Average Balance, December 31, 2019 9,265,390 $ 5.72 Granted 2,126,182 10.17 Exercised (2,178,252) 5.63 Cancelled (306,696) 6.40 Balance, December 31, 2020 8,906,624 $ 6.78 Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2020 was as follows: Number of Balance, December 31, 2019 2,069,936 Granted 1,586,280 Vested (1,040,628) Cancelled (57,536) Balance, December 31, 2020 2,558,052 The weighted average exercise price per share was $4.44 for the 78,750 options which expired during the year ended December 31, 2020, $6.27 for the 324,502 options which expired during the year ended December 31, 2019 and $5.17 for the 119,091 options which expired during the year ended December 31, 2018. The weighted average grant date fair value per share was $6.87, $2.19 and $2.86 for options granted during the years ended December 31, 2020, 2019 and 2018, respectively. The weighted average grant date fair value was $9.12, $3.09 and $4.31 per share for restricted stock units granted during the years ended December 31, 2020, 2019 and 2018, respectively. The Company received $12.3 million, $113,000 and $1.5 million in proceeds from the exercise of stock options during the years ended December 31, 2020, 2019 and 2018, respectively. The aggregate intrinsic value of options exercised was $14.2 million, $25,000 and $910,000 during the years ended December 31, 2020, 2019 and 2018, respectively. On August 28, 2020, the Company granted 663,353 performance-based RSUs to key employees under the 2016 Incentive Plan. The RSUs will vest in two tranches as follows: 50% of the shares in each tranche will vest upon achievement of the predetermined performance milestones and the remaining 50% of the shares in each tranche will vest upon subsequent completion of a one-year service period. The grant date fair value of the performance-based RSUs was $8.0 million based on the grant date closing price per share of $12.06. As of December 31, 2020 , the underlying performance milestones of the RSUs were not probable of achievement, and no stock-based compensation expense was recognized for the performance-based RSUs for the year then ended.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases The Company leases approximately 82,200 square feet of office, laboratory, and manufacturing space in San Diego, California and 57,360 square feet of office space in Plymouth Meeting, Pennsylvania under various non-cancellable operating lease agreements with remaining lease terms of 2.9 years to 9.0 years, which represent the non-cancellable periods of the leases. The Company has excluded the extension options from its lease terms in the calculation of future lease payments as they are not reasonably certain to be exercised. The Company's lease payments consist primarily of fixed rental payments for the right to use the underlying leased assets over the lease terms as well as payments for common area maintenance and administrative services. The Company has received customary incentives from its landlords, such as reimbursements for tenant improvements and rent abatement periods, which effectively reduce the total lease payments owed for these leases. The Company performed an evaluation of its contracts with customers and suppliers in accordance with ASC Topic 842 and determined that, except for the real estate leases described above and various copier leases, none of its other contracts contain a right-of-use asset. Operating lease right-of-use assets and liabilities on the consolidated balance sheet represents the present value of the remaining lease payments over the remaining lease terms. Payments for additional monthly fees to cover the Company's share of certain facility expenses are not included in operating lease right-of-use assets and liabilities. The Company uses its incremental borrowing rate to calculate the present value of its lease payments, as the implicit rates in the leases are not readily determinable. As of December 31, 2020, the maturities of the Company's operating lease liabilities were as follows: Year ending December 31, 2021 $ 3,968,000 2022 4,045,000 2023 4,023,000 2024 3,001,000 2025 3,063,000 Thereafter 9,888,000 Total remaining lease payments 27,988,000 Less: present value adjustment (7,595,000) Total operating lease liabilities 20,393,000 Less: current portion (2,329,000) Long-term operating lease liabilities $ 18,064,000 Weighted-average remaining lease term 7.4 years Weighted-average discount rate 8.5 % Lease costs included in operating expenses in the consolidated statements of operations for the years ended December 31, 2020, 2019 and 2018 were $3.4 million, $3.2 million and $3.4 million, respectively. Operating lease costs consisting of the fixed lease payments included in operating lease liabilities are recorded on a straight-line basis over the lease terms. Variable lease costs are recorded as incurred. In the fourth quarter of 2019, the Company entered into two agreements to sublease a total of approximately 13,500 square feet in its Plymouth Meeting headquarters through periods between December 31, 2022 and March 31, 2025. In the normal course of business, the Company is a party to a variety of agreements pursuant to which it may be obligated to indemnify the other party. It is not possible to predict the maximum potential amount of future payments under these types of agreements due to the conditional nature of the Company's obligations and the unique facts and circumstances involved in each particular agreement. Historically, payments made by the Company under these types of agreements have not had a material effect on its business, consolidated results of operations or financial condition.

Investment in Affiliated Entity

Investment in Affiliated Entity	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Investment in Affiliated Entity	Investment in Affiliated Entity As of December 31, 2020 and 2019, the Company held 597,808 and 395,758 common shares in PLS, representing a 19.7% and 15.0% ownership interest, respectively. On August 27, 2020, the Company sold 1,644,155 shares of common stock in GeneOne for net proceeds of approximately 47.4 billion KRW (approximately USD $40.1 million based on the exchange rate on the date of sale). The Company no longer holds an investment in GeneOne shares and GeneOne is no longer considered a related party to the Company under ASC Topic 850. Please see further information as discussed in Note 2 and Note 6.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In accordance with the guidance pursuant to accounting for income taxes, a deferred tax asset or liability is determined based on the difference between the financial statement and tax basis of assets and liabilities as measured by the enacted tax rates which will be in effect when these differences reverse. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax asset will be realized. The components of pretax loss from operations are as follows: Year Ended December 31, 2020 2019 2018 U.S. Domestic $ (162,664,355) $ (120,809,112) $ (94,798,019) Foreign (225,949) — — Pretax loss from operations $ (162,890,304) $ (120,809,112) $ (94,798,019) The components of the provision for (benefit from) income taxes are presented in the following table: Year Ended December 31, 2020 2019 2018 Current: Federal $ — $ 4,000 $ — State — 2,000 — Foreign — — 2,170,000 — 6,000 2,170,000 Deferred: Federal — (263,000) State — — — Foreign — — — — (263,000) — $ — $ (257,000) $ 2,170,000 The reconciliation of income taxes attributable to continuing operations computed at the statutory tax rates to income tax expense (benefit), using a 21% statutory tax rate for December 31, 2020, 2019 and 2018, is as follows: Year Ended December 31, 2020 2019 2018 Income (benefit) taxes at statutory rates $ (34,207,000) $ (25,370,000) $ (19,908,000) State income tax, net of federal benefit — — (4,000) Foreign income taxes — — 2,170,000 Change in valuation allowance 21,428,000 25,457,000 20,898,000 Nondeductible loss on extinguishment of debt 14,450,000 — — Research and development tax credits (2,650,000) (3,838,000) (3,170,000) Change in fair value of warrants — — (76,000) Stock-based compensation (1,953,000) 1,114,000 1,094,000 Uncertain tax positions 1,068,000 1,537,000 1,268,000 Deconsolidation of subsidiary 853,000 — — Expired NOLs and credits 468,000 616,000 2,176,000 Limited NOLs and credits (368,000) (616,000) (2,176,000) Change in tax rates — 12,000 — Foreign tax rate differential (9,000) — — Other 920,000 831,000 (102,000) $ — $ (257,000) $ 2,170,000 The income tax benefit recorded during the year ended December 31, 2019 of $257,000 was principally due to a requirement under ASC Topic 740, Accounting for Income Taxes , that a company must consider all sources of income in order to determine the tax benefit resulting from a loss from continuing operations. As a result of the requirement under ASC 740-20-45-7, the pretax income which the Company generated from other comprehensive income was a source of income which resulted in the partial realization of the current year loss from continuing operations. Adoption of ASU 2019-12 The Company early adopted ASU No. 2019-12 as of January 1, 2020. Among other provisions, ASU 2019-12 eliminated the requirement under ASC 740-20-45-7 to consider all sources of income in order to determine the tax benefit resulting from a loss from continuing operations. Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are shown below: As of December 31, 2020 2019 Deferred tax assets: Capitalized research expense $ 5,250,000 $ 6,300,000 NOL carryforwards 127,835,000 110,788,000 Research and development and other tax credits 13,242,000 11,737,000 Deferred revenue 1,628,000 1,506,000 Stock-based compensation 3,256,000 3,255,000 Acquired intangibles 757,000 889,000 Derivative liability — 1,852,000 Interest expense 564,000 1,122,000 Investment in affiliated entity 542,000 645,000 Lease liability 4,283,000 4,722,000 Other 6,127,000 2,413,000 163,484,000 145,229,000 Valuation allowance (159,705,000) (137,159,000) Total deferred tax assets 3,779,000 8,070,000 Deferred tax liabilities: Acquired intangibles (179,000) (160,000) Right of use asset (2,676,000) (2,894,000) Note discount (469,000) (2,862,000) Convertible note — (1,381,000) Fixed assets (487,000) (805,000) Net deferred tax liabilities $ (32,000) $ (32,000) As of December 31, 2020, the Company had federal, California and Pennsylvania tax net operating loss (NOL) carryforwards of $566.2 million, $68.6 million and $75.3 million, respectively, net of the net operating losses that will expire due to IRC Section 382 limitations. The aggregate federal net operating losses generated in 2018 and after for the amount of $270.3 million will carryforward indefinitely and be available to offset up to 80% of future taxable income each year, subject to certain modifications made by the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) enacted in 2020. The federal NOL carryforward began to expire in 2021, and the California and Pennsylvania NOL carryforwards will begin and have begun to expire in 2028 and 2020, respectively, unless previously utilized. In addition, as of December 31, 2020, the Company had federal and state research and development (R&D) tax credit carryforwards of $19.8 million and $3.2 million, respectively. The federal tax credit carryforwards will begin to expire in 2029. The California research tax credits do not expire. Based upon statute, federal and state losses and credits are expected to expire as follows (in millions): Expiration Date: Federal NOLs State NOLs Federal R&D State R&D 2021 $ 2.3 $ 0.3 $ — $ — 2022 6.1 0.4 — — 2023 5.3 1.2 — — 2024 14.5 9.1 — — 2025 and thereafter 267.7 132.9 19.8 — Indefinite 270.3 — — 3.2 $ 566.2 $ 143.9 $ 19.8 $ 3.2 Pursuant to Internal Revenue Code (IRC) Sections 382 and 383, annual use of the Company’s NOL and R&D credit carryforwards may be limited in the event that a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has completed an IRC Section 382/383 analysis regarding the limitation of NOL and R&D credit carryforwards as of December 31, 2020. As a result of the analysis, the Company estimates that approximately $10.2 million of tax benefits related to NOL and R&D carryforwards will expire unused. Accordingly, the related NOL and R&D credit carryforwards have been removed from deferred tax assets, accompanied by a corresponding reduction of the valuation allowance. Due to the existence of the valuation allowance, limitations created by current and future ownership changes, if any, related to the Company's operations in the United States will not impact its effective tax rate. Any additional ownership changes may further limit the ability to use the NOL and R&D carryforwards. The Tax Cuts and Jobs Act of 2017 subjects a U.S. stockholder to tax on Global Intangible Low-Taxed Income (GILTI) earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity can make an accounting policy election to recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. The Company has elected to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. For 2020, the Company did not generate any GILTI due to losses earned by its foreign subsidiary. On March 27, 2020, the CARES Act was enacted in response to the COVID-19 pandemic. The CARES Act, among other things, permits federal NOL carryovers and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. In addition, the CARES Act allows federal NOLs incurred in 2018, 2019, and 2020 to be carried back to each of the five preceding taxable years to generate a refund of previously paid income taxes. Due to the Company's history of net operating losses, the CARES Act is not expected to have a material impact on the Company's financial statements. The following table summarizes the activity related to the Company's unrecognized tax benefits: Year ended December 31, 2020 2019 2018 Balance at beginning of the year $ 11,204,000 $ 9,632,000 $ 8,313,000 Increases related to current year tax positions 1,043,000 1,575,000 1,319,000 Increases (decreases) related to prior year tax positions 27,000 (3,000) — Other (64,000) — — Balance at end of the year $ 12,210,000 $ 11,204,000 $ 9,632,000 The amount of unrecognized tax benefits that, if recognized and realized, would affect the effective tax rate was $10.9 million, $9.9 million and $8.3 million as of December 31, 2020, 2019 and 2018, respectively, subject to valuation allowances. The Company has not recorded any interest and penalties on the unrecognized tax positions as the Company has continued to generate net operating losses after accounting for the unrecognized tax benefits. The Company does not anticipate that the total amount of unrecognized tax benefits will significantly increase or decrease within twelve months of the reporting date. The Company and its subsidiaries are subject to U.S. federal income tax as well as income tax in multiple state jurisdictions. With few exceptions, the Company is no longer subject to United States federal income tax examinations for years before 2017 and state and local income tax examinations before 2016. However, to the extent allowed by law, the tax authorities may have the right to examine prior periods where net operating losses were generated and carried forward, and make adjustments up to the amount of the NOL carryforward amount. The Company is not currently under Internal Revenue Service (“IRS”), state or local tax examination.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
401(k) Plan	401(k) PlanThe Company has adopted a 401(k) Profit Sharing Plan covering substantially all of its employees. The defined contribution plan allows the employees to contribute a percentage of their compensation each year. The Company currently matches 50% of its employees’ contributions, up to 6% of their annual compensation. The Company’s contributions are recorded as expense in the accompanying consolidated statements of operations and totaled $1.1 million, $1.2 million and $1.2 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transactions	Related Party Transactions GeneOne Life Sciences On August 27, 2020, the Company sold 1,644,155 shares of common stock in GeneOne for net proceeds of approximately 47.4 billion KRW (approximately USD $40.1 million based on the exchange rate on the date of sale). The Company no longer holds an investment in GeneOne shares and GeneOne is no longer considered a related party to the Company under ASC 850. The Company's consolidated balance sheet as of December 31, 2020 no longer reflects GeneOne’s portion in accounts receivable and accounts payable and accrued expenses with affiliated entities, whereas the Company’s balance sheet as of December 31, 2019 reflects $128,000 and $511,000 in accounts receivable and accounts payable and accrued expenses with affiliated entities, respectively, related to GeneOne. Revenues recognized from GeneOne will no longer be presented as revenue with affiliated entity on the consolidated statement of operations after the change in related party designation in August 2020. Revenue recognized from GeneOne for the years ended December 31, 2020, 2019 and 2018 consisting of patent, device maintenance and licensing fees was $125,000, $127,000 and $342,000, respectively. Operating expenses recorded from transactions with GeneOne related primarily to biologics manufacturing and were $4.7 million, $2.5 million and $7.0 million for the years ended December 31, 2020, 2019 and 2018, respectively. Plumbline Life Sciences, Inc. The Company owned 597,808 shares of common stock in Plumbline Life Sciences, Inc. ("PLS") as of December 31, 2020 and one of the Company's directors, Dr. David B. Weiner, acts as a consultant to PLS. On February 20, 2020, the Company entered into a Debt and Share Subscription Agreement with PLS under which the Company received 202,050 shares of PLS common stock in exchange for a portion of the outstanding accounts receivable balance due from PLS. Following the issuance of these shares and as of December 31, 2020, the Company held a 19.7% ownership interest in PLS. Revenue recognized from PLS consists of milestone, license and patent fees. For the years ended December 31, 2020 and 2019, the Company recognized revenue from PLS of $1.4 million and $111,000, respectively. At December 31, 2020 and 2019, the Company had an accounts receivable balance of $67,000 and $589,000, respectively, related to PLS. The Wistar Institute The Company's director Dr. David B. Weiner is a director of the Vaccine Center of The Wistar Institute ("Wistar"). Dr. Weiner is also the Executive Vice President of Wistar. In March 2016, the Company entered into collaborative research agreements with Wistar for preventive and therapeutic DNA-based immunotherapy applications and products developed by Dr. Weiner and Wistar for the treatment of cancers and infectious diseases. Under the terms of the agreement, the Company will reimburse Wistar for all direct and indirect costs incurred in the conduct of the collaborative research, not to exceed $3.1 million during the five-year term of the agreement. The Company will have the exclusive right to in-license new intellectual property developed in this agreement. In November 2016, the Company rece ived a $6.1 million sub-grant through Wistar to develop a DMAb against the Zika infection, with fun ding through December 2020. The Company is also a collaborator with Wistar on an Integrated Preclinical/Clinical AIDS Vaccine Development grant from the NIAID, with funding through February 2021. In 2020, the Company received a $10.7 million sub-grant through Wistar for the preclinical development and translational studies of DMAbs as countermeasures for COVID-19, with funding through September 2022. The sub-grant also includes an option for an additional $6.0 million in funding through September 2024. Deferred grant funding recognized from Wistar and recorded as contra-research and development expense is related to work performed by the Company on the research sub-contract agreements. For the years ended December 31, 2020 and 2019, the Company recorded $1.9 million and $2.2 million, respectively, as contra-research and development expense from Wistar. Research and development expenses recorded from Wistar relate primarily to the collaborative research agreements and sub-contract agreements related to Gates and CEPI (see Note 4). Research and development expenses recorded from Wistar for the years ended December 31, 2020 and 2019 were $2.3 million and $1.5 million, respectively. At December 31, 2020 and 2019, the Company had an accounts receivable balance of $425,000 and $616,000, respectively, and an accounts payable and accrued liability balance of $643,000 and $219,000, respectively, related to Wistar. As of December 31, 2020, the Company had $96,000 recorded as grant funding liability on its consolidated balance sheet related to Wistar.

Geneos Therapeutics, Inc.

Geneos Therapeutics, Inc.	12 Months Ended
	Dec. 31, 2020
Noncontrolling Interest [Abstract]
Geneos Therapeutics, Inc.	Geneos Therapeutics, Inc. In August 2016, the Company formed Geneos to develop and commercialize neoantigen-based personalized cancer therapies. Geneos was considered a variable interest entity (VIE) for which the Company was the primary beneficiary. In February 2019, Geneos completed the initial closing of a Series A preferred stock financing. The Company invested $1.2 million in the Series A preferred stock financing, which was led by an outside investor. Following this transaction, the Company held 61% of the outstanding equity, on an as-converted to common stock basis, of Geneos and continued to consolidate its investment in Geneos under ASC 810, Consolidation . In January 2020, Geneos completed the second closing of the Series A preferred stock financing, in which the Company invested $800,000. Following this transaction, as of March 31, 2020, the Company held 52% of the outstanding equity, on an as-converted to common stock basis, of Geneos and continued to consolidate its investment in Geneos. In June 2020, Geneos closed an additional Series A preferred stock financing round, in which the Company invested $800,000. Following this transaction, the Company owned 47% of the outstanding equity of Geneos on an as-converted to common stock basis. This transaction triggered a VIE reconsideration, as the Company no longer held a controlling financial interest. Based on the Company’s assessment, Geneos continued to be a VIE as it did not have sufficient equity at risk to finance its activities without additional subordinated financial support. However, the Company was not the primary beneficiary of Geneos, as it did not have the power to direct the activities that most significantly impact Geneos’ economic performance. Accordingly, the Company deconsolidated its investment in Geneos as of June 1, 2020, resulting in a gain of $4.1 million, of which $2.4 million related to the remeasurement of the retained noncontrolling interest investment to fair value. The gain has been recorded separately on the Company's consolidated statement of operations. The following table shows the amounts related to the deconsolidation accounting: Working capital (excluding cash) $ (59,992) Note payable 171,620 Fixed assets, net of accumulated depreciation (16,340) Carrying value of noncontrolling interest 3,181,640 Fair value of investment in Geneos retained 3,618,998 Gain on deconsolidation of Geneos (4,121,075) Decrease in cash resulting from the deconsolidation of Geneos $ 2,774,851 The details of the Company’s 47% retained equity investment in Geneos are shown in the table below, with fair values calculated as of June 1, 2020, the date of deconsolidation. Geneos Share Class Shares Price per Share Fair Value Common 3,000,000 $ 0.273 $ 819,000 Preferred 2,113,206 $ 1.325 $ 2,799,998 Total 5,113,206 $ 3,618,998 The fair value of Geneos Series A preferred stock was based on the per share price paid by third-party investors in connection with the most recent closing of the Series A preferred stock financing for Geneos on June 1, 2020. The fair value of Geneos common stock was determined by a third-party valuation, as there is no public market for such stock. Geneos’s enterprise value, which was estimated using a market approach that derived an implied total equity value from a transaction involving its own securities, was allocated to all classes of equity using the option pricing method. Under the option pricing method, each equity class was modeled as having a call option with a distinct claim on the total value of Geneos. Each option’s exercise price was based on the total value available for each participating security holder. The characteristics of each class of ownership determined the claim on the total value for that class of ownership. The estimated value allocated to common stock included assumptions related to the fair value of the enterprise, expected volatility, expected term, and risk-free interest rate. Expected volatility was based on historical asset volatilities derived from daily stock price changes of guideline public companies. The estimated expected term was based on a weighted average of the estimated time to Geneos's next financing and successful exit timing assumption. The risk-free interest rate was based on the yield of U.S. Treasury with a comparable term. Geneos’s common stock is classified as a Level 3 financial instrument. The assumptions used in the fair value calculation as of June 1, 2020 are presented below: Expected term (years) 2.92 Volatility 70% Risk-free interest rate 2.46% Geneos enterprise value $4,966,531 The Company applies the equity method to investments in common stock and to other investments in entities that have risk and reward characteristics that are substantially similar to an investment in the investee’s common stock. Since the Company’s Series A preferred stock investment in Geneos has a substantive liquidation preference, it is not substantially similar to the Company’s common stock investment and will therefore be recorded as an equity security under ASC 321. As of June 1, 2020, the Company accounts for its common stock investment in Geneos, in which the Company lacks control but does have the ability to exercise significant influence over operating and financial policies, using the equity method. Generally, the ability to exercise significant influence is presumed when the investor possesses more than 20% of the voting interests of the investee. This presumption may be overcome based on specific facts and circumstances that demonstrate that the ability to exercise significant influence is restricted. In applying the equity method, the Company records the investment at cost unless the initial recognition is the result of the deconsolidation of a subsidiary, in which case it is recorded at fair value. The Company's proportionate share of net loss of Geneos is recorded in equity in net earnings of Geneos in the Company's consolidated statements of operations. The Company's equity method investments are reviewed for indicators of impairment at each reporting period and are written down to fair value if there is evidence of a loss in value that is other-than-temporary. Any difference between the carrying amount of the Company’s investment and the amount of underlying equity in Geneos’s net assets is amortized into income or expense accordingly. There were no basis differences identified as of the deconsolidation date that would need to be amortized. Upon deconsolidation, the Company recorded its Series A preferred stock investment at fair value based on the per share price paid by third party investors in connection with the Series A preferred stock financing on June 1, 2020. The Company has determined that its Series A preferred stock investment in Geneos does not have a readily determinable fair value and has therefore elected the measurement alternative in ASC 321 to subsequently record the investment at cost, less any impairments, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. When fair value becomes determinable, from observable price changes in orderly transactions, the Company’s investment will be marked to fair value. There have been no observable price changes or impairments identified since the deconsolidation date. In November 2020, Geneos completed the closing of a Series A-1 preferred stock financing. The Company invested $1.4 million in the Series A-1 preferred stock financing, which was led by outside investors. The date of this transaction was determined to be a VIE reconsideration event; based on the Company’s assessment, Geneos continues to be a VIE as it does not have sufficient equity at risk to finance its activities without additional subordinated financial support. The Company continues to not be the primary beneficiary of Geneos, as it does not have the power to direct the activities that most significantly impact Geneos’s economic performance and should not consolidate Geneos. Following this transaction, the Company held approximately 36% of the outstanding equity, on an as-converted to common stock basis. Accordingly, the Company continues to account for its common stock investment in Geneos as an equity method investment under ASC 323 and its preferred stock investments as equity securities under ASC 321. The fair value of Geneos’s Series A-1 preferred stock was based on the per share price paid by third-party investors in connection with the closing on November 12, 2020. The Company has concluded that its Series A-1 preferred stock investment is not similar to its prior Series A preferred stock investment due to certain material rights held solely by Series A preferred stockholders. Therefore, the Company will continue to record its Series A preferred stock investment in Geneos at cost, as there have been no observable price changes or impairments identified since the deconsolidation date. The Company’s share of net losses of Geneos for the period from June 1, 2020 through December 31, 2020 w as $4.6 million. O f this amount, $819,000 has been allocated to the equity method investment, thereby reducing the balance to $0 as of December 31, 2020 . The remaining $3.8 million loss has been allocated to the Company’s Series A and Series A-1 preferred stock investments in Geneos, on a ratable basis, thereby reducing the investment balance t o $434,000 as of December 31, 2020 as shown in the table below: Investment in Geneos upon deconsolidation $ 3,618,998 Investment in Geneos Series A-1 preferred stock 1,399,999 Share in net loss of Geneos (4,584,610) Investment in Geneos as of December 31, 2020 $ 434,387 The Company continues to exclusively license its SynCon ® immunotherapy and CELLECTRA ® technology platform to Geneos to be used in the field of personalized, neoantigen-based therapy for cancer. The license agreement provides for potential royalty payments to the Company in the event that Geneos commercializes any products using the licensed technology. The Company is not obligated to use any of its assets to fund the future operations of Geneos.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information (Unaudited)	Quarterly Financial Information (Unaudited) The following is a summary of the quarterly results of operations of the Company for the years ended December 31, 2020 and 2019 (unaudited): Quarter Ended Quarter Ended Quarter Ended Quarter Ended December 31, September 30, June 30, March 31, Consolidated Statements of Operations: Revenues: Revenue under collaborative research and development arrangements $ 5,003,494 $ 21,490 $ 74,102 $ 71,500 Revenue under collaborative research and development arrangements from affiliated entities 82,774 103,684 95,146 1,172,126 Other revenue, including from affiliated entities 494,313 111,004 97,939 83,648 Total revenues 5,580,581 236,178 267,187 1,327,274 Operating Expenses: Research and development 26,302,561 26,455,112 22,376,575 19,111,188 General and administrative 8,617,458 10,110,506 11,071,510 7,448,354 Total operating expenses 34,920,019 36,565,618 33,448,085 26,559,542 Loss from operations (29,339,438) (36,329,440) (33,180,898) (25,232,268) Interest income 931,168 896,710 1,067,399 416,569 Interest expense (1,068,008) (1,984,046) (2,846,641) (2,803,755) Change in fair value of derivative liability — 35,306,000 (97,755,000) (13,221,977) Gain (loss) on investment in affiliated entities 306,317 26,951,898 (3,883,176) 13,181,619 Net unrealized gain on available-for-sale equity securities 1,070,975 1,315,980 4,358,634 (5,050,092) Other income (expense), net 9,350 (136,644) (152,102) (425,500) Gain on deconsolidation of Geneos — — 4,121,075 — Loss on extinguishment of convertible bonds — (8,177,043) — — Gain on extinguishment of convertible senior notes 5,674,435 3,087,595 — — Net income (loss) before income tax benefit and share in net loss of Geneos $ (22,415,201) $ 20,931,010 $ (128,270,709) $ (33,135,404) Share in net loss of Geneos (1,923,179) (1,759,674) (901,757) — Net income (loss) $ (24,338,380) $ 19,171,336 $ (129,172,466) $ (33,135,404) Net loss attributable to non-controlling interest — — 469,407 594,350 Net income (loss) attributable to Inovio Pharmaceuticals, Inc. $ (24,338,380) $ 19,171,336 $ (128,703,059) $ (32,541,054) Net income (loss) per share Basic $ (0.14) $ 0.12 $ (0.83) $ (0.26) Diluted $ (0.14) $ 0.11 $ (0.83) $ (0.26) Quarter Ended Quarter Ended Quarter Ended Quarter Ended December 31, September 30, June 30, March 31, Consolidated Statements of Operations: Revenues: Revenue under collaborative research and development arrangements $ 184,523 $ 617,427 $ 64,283 $ 2,770,712 Revenue under collaborative research and development arrangements from affiliated entities 55,665 53,014 71,390 55,579 Other revenue, including from affiliated entities 39,300 196,422 — 3,614 Total revenues 279,488 866,863 135,673 2,829,905 Operating Expenses: Research and development 22,003,955 19,137,209 22,486,266 24,389,888 General and administrative 8,696,586 5,681,441 5,850,101 6,975,029 Total operating expenses 30,700,541 24,818,650 28,336,367 31,364,917 Loss from operations (30,421,053) (23,951,787) (28,200,694) (28,535,012) Interest income 587,679 637,438 755,330 625,535 Interest expense (2,668,837) (2,428,671) (2,194,783) (656,248) Change in fair value of derivative liability (4,315,105) 2,551,453 — — Loss from investment in affiliated entities (1,681,401) (485,841) (173,212) (750,103) Other income (expense), net 263,571 140,956 127,512 (35,839) Net loss before income tax benefit (38,235,146) (23,536,452) (29,685,847) (29,351,667) Income tax benefit 87,764 — 106,771 62,800 Net loss (38,147,382) (23,536,452) (29,579,076) (29,288,867) Net loss attributable to non-controlling interest 485,344 445,759 191,850 69,605 Net loss attributable to Inovio Pharmaceuticals, Inc. $ (37,662,038) $ (23,090,693) $ (29,387,226) $ (29,219,262) Net loss per share Basic $ (0.38) $ (0.23) $ (0.30) $ (0.30) Diluted $ (0.38) $ (0.25) $ (0.30) $ (0.30)

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn January 25, 2021, the Company closed an underwritten public offering of 20,355,000 shares of the Company's common stock at a public offering price of $8.50 per share. The net proceeds to the Company, after deducting the underwriters' discounts and commissions and other estimated offering expenses, were $162.1 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Liquidity	Basis of Presentation and Liquidity INOVIO incurred a net loss attributable to common stockholders of $166.4 million for the year ended December 31, 2020. INOVIO had working capital of $429.5 million and an accumulated deficit of $906.2 million as of December 31, 2020. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $411.6 million as of December 31, 2020 , are sufficient to support the Company's operations for a period of at least 12 months from the date it is issuing these financial statements. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements. In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings including use of potential future At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds under past Sales Agreements of $454.5 million during the year ended December 31, 2020, and net proceeds of $9.1 million under a Sales Agreement during the year ended December 31, 2019. The Company also received net proceeds of $75.7 million from a private placement of 6.50% convertible senior notes due 2024 (the “Notes”), net proceeds of $14.5 million from the private placement of 18 billion Korean Won (KRW) (approximately USD $15.0 million based on the exchange rate on the date of issuance) aggregate principal amount of its 1.0% convertible bonds due August 2024 (the "August 2019 Bonds"), and net proceeds of $4.0 million from the private placement of 4.7 billion KRW (approximately USD $4.1 million based on the exchange rate on the date of issuance) aggregate principal amount of its 1.0% convertible bonds due December 2024 (the "December 2019 Bonds" and, together with the August 2019 Bonds, the “Bonds”) during the year ended December 31, 2019. However, sufficient funding may not be available in the future, or if available, may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders. If adequate funds are not available, the Company may need to delay, reduce the scope of or put on hold one or more of its clinical and/or preclinical programs. In June 2020, the Company formed a wholly-owned subsidiary, Inovio Asia LLC, under the laws of South Korea, through which the Company intends to advance its corporate development projects and other functions in South Korea and other Asian countries. From time to time, the Company may be subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal proceedings, including litigation, government investigations and enforcement actions, could result in material costs, occupy significant management resources and entail civil and criminal penalties, even if the Company ultimately prevails. Any of the foregoing consequences could result in serious harm to the Company’s business, results of operations and financial condition. The Company’s ability to continue its operations is dependent upon its ability to obtain additional capital in the future and achieve profitable operations. The Company expects to continue to rely on outside sources of financing to meet its capital needs and the Company may never achieve positive cash flow. Risks and Uncertainties The global pandemic resulting from COVID-19, caused by a novel strain of coronavirus, SARS-CoV-2, has caused national and global economic and financial market disruptions. The impact of this pandemic has been and will likely continue to be extensive in many aspects of society, which has resulted in and will continue to cause significant disruptions to the global economy, as well as businesses and capital markets around the world. The Company is closely monitoring the impact of the COVID-19 pandemic on its employees, collaborators and service providers. The extent to which the pandemic will impact the Company's business and operations will depend on future developments, including the duration of the outbreak, travel restrictions and social distancing in the United States and other countries, and the effectiveness of actions taken in the United States and other countries to contain and treat the disease, that are highly uncertain.
Consolidation	ConsolidationThe consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiaries. As of December 31, 2020 the Company consolidated its wholly-owned subsidiary Inovio Asia LLC. On December 31, 2020, former wholly-owned subsidiaries Genetronics, Inc. and VGX Pharmaceuticals Inc. and former majority -owned subsidiary VGX Animal Health, Inc. were merged into Inovio Pharmaceuticals, Inc. All intercompany accounts and transactions have been eliminated upon consolidation. As of June 1, 2020, the Company deconsolidated its former subsidiary Geneos Therapeutics, Inc. ("Geneos"), as the Company no longer held a controlling financial interest.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one segment operating primarily within the United States.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit RiskFinancial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and short-term investments. The Company limits its exposure to credit loss by placing its cash and investments with high credit quality financial institutions. Additionally, the Company has established guidelines regarding diversification of its investments and their maturities which are designed to maintain principal and maximize liquidity.
Fair value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments consist principally of cash equivalents, short-term investments and investments in affiliated entities. The carrying amounts of cash equivalents approximate the related fair values due to the short-term maturities of these instruments. Investments are recorded at fair value, based on current market valuations. The Company carries convertible notes and bonds at face value less unamortized debt discount and issuance costs on its consolidated balance sheet, and it presents the fair value of such convertible notes and bonds for disclosure purposes only.
Cash and Cash Equivalents	Cash and Cash EquivalentsCash equivalents are considered by the Company to be highly liquid investments purchased with original maturities of three months or less from the date of purchase. Cash and cash equivalents included certain money market accounts and U.S. treasury securities at December 31, 2020 and money market accounts at December 31, 2019.
Investments	InvestmentsThe Company defines investments as income-yielding securities that can be readily converted into cash or equity investments classified as available-for-sale. Investments included mutual funds, U.S. treasury securities, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2020. Investments included mutual funds and an equity investment in the Company's affiliated entities, PLS and GeneOne, at December 31, 2019.
Accounts Receivable	Accounts ReceivableAccounts receivable are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers’ financial condition. Credit is extended to customers as deemed necessary and generally does not require collateral. Management believes that the risk of loss is significantly reduced due to the quality and financial position of the Company's customers.
Fixed Assets	Fixed Assets Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful life of the assets, generally three
Long-Lived Assets	Long-Lived AssetsAll long-lived assets are reviewed for impairment in value when changes in circumstances dictate, based upon undiscounted future operating cash flows, and appropriate losses are recognized and reflected in current earnings, to the extent the carrying amount of an asset exceeds its estimated fair value determined by the use of appraisals, discounted cash flow analyses or comparable fair values of similar assets.
Valuation of Intangible Assets and Goodwill	Valuation of Intangible Assets and Goodwill Intangible assets are amortized over their estimated useful lives ranging from two Historically, the Company has recorded patents at cost and amortized these costs using the straight-line method over the expected useful lives of the patents or 17 years, whichever is less. Patent cost consists of the consideration paid for patents and related legal costs. New patent costs are expensed as incurred, with patent costs capitalized as of that date continuing to be amortized over the expected life of the patent. License costs are recorded based on the fair value of consideration paid and are amortized using the straight-line method over the shorter of the expected useful life of the underlying patents or the term of the related license agreement to the extent the license has an alternative future use. As of December 31, 2019 and 2018, the Company’s intangible assets resulting from acquisitions and additional intangibles including previously capitalized patent costs and license costs, net of accumulated amortization, totaled $3.1 million and $3.7 million, respectively. The determination of the value of intangible assets requires management to make estimates and assumptions that affect the Company’s consolidated financial statements. The Company assesses potential impairments to intangible assets when there is evidence that events or changes in circumstances indicate that the carrying amount of an asset may not be recovered. The Company’s judgments regarding the existence of impairment indicators and future cash flows related to intangible assets are based on operational performance of its acquired businesses, market conditions and other factors. If impairment is indicated, the Company will reduce the carrying value of the intangible asset to fair value. While current and historical operating and cash flow losses are potential indicators of impairment, the Company believes the future cash flows to be received from its intangible assets will exceed the intangible assets’ carrying value, and accordingly, the Company has not recognized any impairment losses through December 31, 2020. Goodwill represents the excess of acquisition cost over the fair value of the net assets of acquired businesses. Goodwill is reviewed for impairment at least annually at November 30, or more frequently if an event occurs indicating the potential for impairment. During its goodwill impairment review, the Company may assess qualitative factors to determine whether it is more likely than not that the fair value of its reporting unit is less than its carrying amount, including goodwill. The qualitative factors include, but are not limited to, macroeconomic conditions, industry and market considerations, and the overall financial performance of the Company. If, after assessing the totality of these qualitative factors, the Company determines that it is not more likely than not that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company proceeds to perform the two-step test for goodwill impairment. The first step involves comparing the estimated fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the Company performs the second step of the goodwill impairment test to determine the amount of loss, which involves comparing the implied fair value of the goodwill to the carrying value of the goodwill. The Company may also elect to bypass the qualitative assessment in a period and elect to proceed to perform the first step of the goodwill impairment test. The Company performed its annual assessment for goodwill impairment as of November 30, 2020, identifying no impairment.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities along with net operating loss and tax credit carry forwards. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. Valuation allowances against the Company’s deferred tax assets were $159.7 million and $137.2 million at December 31, 2020 and 2019, respectively. Changes in the valuation allowances, when they are recognized in the provision for income taxes, are included as a component of the estimated annual effective tax rate.
Collaboration Agreements	Collaboration Agreements The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808, the Company assesses whether the payments between the Company and the collaboration partner are subject to other accounting literature. If payments from the collaboration partner to the Company represent consideration from a customer, then the Company accounts for those payments within the scope of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“Topic 606”). However, if the Company concludes that its collaboration partner is not a customer for certain activities, such as for certain collaborative research and development activities, the Company presents such payments as a reduction of research and development expense.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which it expects to be entitled in exchange for those goods or services. To determine revenue recognition for contracts with customers, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies its performance obligations. At contract inception, the Company assesses the goods or services agreed upon within each contract and assess whether each good or service is distinct and determine those that are performance obligations. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Collaborative Arrangements The Company enters into collaborative arrangements with partners that typically include payment of one or more of the following: (i) license fees; (ii) product supply services; (iii) milestone payments related to the achievement of developmental, regulatory, or commercial goals; and (iv) royalties on net sales of licensed products. Where a portion of non-refundable, upfront fees or other payments received are allocated to continuing performance obligations under the terms of a collaborative arrangement, they are recorded as deferred revenue and recognized as revenue when (or as) the underlying performance obligation is satisfied. As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment of management to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligation. The standalone selling price may include items such as forecasted revenues, development timelines, discount rates and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. License Fees If a license to intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Product Supply Services Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the licensee’s discretion are generally considered as options. The Company assesses if these options provide a material right to the licensee and if so, they are accounted for as separate performance obligations. The Company evaluates whether it is the principal or agent in the arrangement. The Company had determined that it is the principal in the current arrangements as the Company controls the product supply before it is transferred to the customer. Milestone Payments At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company's or its collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achieving such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration or other revenues and earnings in the period of adjustment. Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of its collaborative arrangements.
Grants	Grants The Company accounts for various grant agreements under the contributions guidance under Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition
Derivative Liabilities	Derivative Liabilities The Company evaluates its debt and equity issuances to determine if those contracts or embedded components of those contracts qualify as derivatives requiring separate recognition in the Company's financial statements. The result of this accounting treatment is that the fair value of the embedded derivative is revalued at each balance sheet date and recorded as a liability, and the change in fair value during the reporting period is recorded in other income (expense) in the consolidated statements of operations. In circumstances where the embedded conversion option in a convertible instrument is required to be bifurcated and there are also other embedded derivative instruments in the convertible instrument that are required to be bifurcated, the bifurcated derivative instruments are accounted for as a single, compound derivative instrument. The classification of derivative instruments, including whether such instruments should be recorded as liabilities or as equity, is reassessed at the end of each reporting period. Derivative instrument liabilities are classified in the balance sheet as current or non-current based on whether or not net-cash settlement of the derivative instrument is expected within twelve months of the balance sheet date.
Foreign Currency Transactions	Foreign Currency Transactions The functional and presentation currency of the Company is the U.S. dollar. Transactions denominated in a currency other than the functional currency are recorded on the initial recognition at the exchange rate at the date of the transaction. After initial recognition, monetary assets and liabilities denominated in foreign currency are remeasured at the end of each reporting period into the functional currency at the exchange rate at that date. Exchange differences are included in general and administrative expenses in the consolidated statement of operations. Non-monetary assets and liabilities measured at cost are remeasured at the exchange rate at the date of the transaction. Variable Interest Entities (VIE) The Company evaluates its ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether the Company is the primary beneficiary of the VIE. In determining whether the Company is the primary beneficiary of a VIE and therefore required to consolidate the VIE, the Company applies a qualitative approach that determines whether it has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. The Company will continuously perform this assessment, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of a VIE. Equity Investments Under ASC Topic 321, Investments - Equity Securities, the Company must measure equity investments (except those accounted for under the equity method, those that result in consolidation of the investee and certain other investments) at fair value and recognize any changes in fair value in the consolidated statement of operations. The Company can elect a measurement alternative for equity investments that do not have readily determinable fair values and do not qualify for the practical expedient in ASC Topic 820, Fair Value Measurement,
Research and Development Expenses	Research and Development Expenses The Company’s activities have largely consisted of research and development efforts related to developing electroporation delivery technologies, DNA vaccines, DNA immunotherapies and dMAbs. Research and development expenses consist of expenses incurred in performing research and development activities including salaries and benefits, facilities and other overhead expenses, clinical trials, contract services and other outside expenses. Research and development expenses are charged to operations as they are incurred. These expenses result from the Company's independent research and development efforts as well as efforts associated with collaborations and licensing arrangements. The Company reviews and accrues clinical trial expense based on work performed, which relies on estimates of total trial management costs, sites activated, patients enrolled, and number of patient visits. The Company follows this method since reasonably dependable estimates of the costs applicable to various stages of a research agreement or clinical trial can be made. Accrued clinical trial costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a trial could result in a charge to the Company's results of operations.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss for the year by the weighted average number of common shares outstanding during the year. Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding stock options and restricted stock units and reflects the potential dilution that would occur if securities or other contracts to issue common stock were exercised or converted to common stock. The dilutive impact of the outstanding Notes and Bonds issued by the Company (discussed in Note 11) has been considered using the "if-converted" method. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the options or other securities and the presumed exercise of such securities are dilutive to net loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of such securities from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any.
Leases	Leases For its long-term operating leases, the Company recognized an operating lease right-of-use asset and an operating lease liability on its consolidated balance sheets. The lease liability is determined as the present value of future lease payments using an estimated rate of interest that the Company would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. The right-of-use asset is based on the liability adjusted for any prepaid or deferred rent. The Company determines the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise. Fixed rent expense for the Company's operating leases is recognized on a straight-line basis over the term of the lease and is included in operating expenses on the consolidated statements of operations. Variable lease payments including lease operating expenses are recorded as incurred.
Stock-Based Compensation	Stock-Based CompensationThe Company incurs stock-based compensation expense related to restricted stock units and stock options. The fair value of restricted stock is determined by the closing price of the Company's common stock reported on the Nasdaq Global Select Market on the date of grant. The Company estimates the fair value of stock options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of subjective assumptions, including the expected stock price volatility and expected option life. The Company amortizes the fair value of the awards on a straight-line basis over the requisite vesting period of the awards. Expected volatility is based on historical volatility. The expected life of options granted is based on historical expected life. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield is based on the fact that no dividends have been paid historically and none are currently expected to be paid in the foreseeable future. The Company recognizes forfeitures as they occur.
Recent Accounting Pronouncements - Recently Adopted	Recent Accounting Pronouncements - Recently Adopted The recent accounting pronouncements below may have a significant effect on the Company's financial statements. Recent accounting pronouncements that are not anticipated to have an impact on or are unrelated to the Company's financial condition, results of operations, or related disclosures are not discussed. ASU No. 2019-12. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes . FASB issued this Update as part of its simplification initiative to improve areas of GAAP and reduce cost and complexity while maintaining usefulness. The main provision that impacts the Company is the removal of the exception to the incremental approach of intra-period tax allocation when there is a loss from continuing operations and income or gain from other items (for example, discontinued operations and other comprehensive income). ASU 2019-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2020. Early adoption is permitted, including adoption in an interim period. The Company has elected to early adopt ASU 2019-12. By early adopting, ASU 2019-12 became effective as of the beginning of 2020; however, there was no cumulative effect to be recognized with the early adoption. As of December 31, 2020, there was a loss from continuing operations and a cumulative loss in other comprehensive income and there was therefore no effect on the tax provision for the period ended December 31, 2020. ASU No. 2016-13 . In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments (Topic 326) , which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available for sale debt securities. This standard includes the Company's financial instruments, such as accounts receivable and investments that are generally of high credit quality. Previously, when credit losses were measured under GAAP, an entity generally only considered past events and current conditions in measuring the incurred loss. The new guidance requires the Company to identify, analyze, document and support new methodologies for quantifying expected credit loss estimates for its financial instruments, using information such as historical experience and current economic conditions, plus the use of reasonably supportable forecast information. The Company adopted ASU 2016-13 on January 1, 2020, and there was no material impact to its consolidated financial statements. The Company will continue to monitor the impact of the coronavirus, SARS-CoV-2 (“COVID-19”) outbreak on expected credit losses. ASU No. 2018-13 . In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement , which amends certain disclosure requirements over fair value measurements. Under the new guidance, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, or valuation processes for Level 3 fair value measurements. However, public companies will be required to disclose the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and related changes in unrealized gains and losses included in other comprehensive income. The Company adopted this guidance on January 1, 2020, and there was no material impact to its consolidated financial statement disclosures (see Note 6 for more information about the Company’s fair value classifications). ASU No. 2018-18 . In November 2018, the FASB issued ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 , which clarified the interaction between Topic 808, Collaborative Arrangements , and Topic 606, Revenue from Contracts with Customers . The Company adopted this guidance on January 1, 2020, and there was no material impact to its consolidated financial statements. ASU 2017-04. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect	The following table summarizes potential shares of common stock that were excluded from diluted net loss per share calculation because of their anti-dilutive effect: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 8,906,624 9,265,390 8,752,677 Service-based restricted stock units 2,558,052 2,069,936 1,688,017 Performance-based restricted stock units 663,353 — — Convertible preferred stock 3,309 8,456 8,456 Convertible notes 3,049,980 14,585,653 — August 2019 Bonds — 3,799,071 — December 2019 Bonds 1,009,450 1,009,450 — Total 16,190,768 30,737,956 10,449,150
Summary of assumptions used to estimate the fair value of stock options	The weighted average assumptions used in the Black-Scholes model for option grants to employees and directors are presented below: Year Ended December 31, 2020 2019 2018 Risk-free interest rate 0.63% 2.42% 2.73% Expected volatility 78% 70% 72% Expected life in years 6 6 6 Dividend yield — — — The weighted average assumptions used in the Black-Scholes model for option grants to non-employees are presented below: Year Ended December 31, 2020 2019 2018 Risk-free interest rate 0.82% 2.45% 2.71% Expected volatility 76% 88% 78% Expected life in years 10 10 9 Dividend yield — — —

Short-term Investments (Tables)

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Summary of investments	The following is a summary of available-for-sale securities as of December 31, 2020 and 2019: As of December 31, 2020 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 153,177,675 $ 2,339,639 $ (644,140) $ 154,873,174 Certificates of deposit Less than 1 3,000,000 26,260 (10,000) 3,016,260 U.S. agency mortgage-backed securities * 3,062,256 — (36,755) 3,025,501 $ 159,239,931 $ 2,365,899 $ (690,895) $ 160,914,935 As of December 31, 2019 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 66,599,219 $ 754,709 $ (15,911) $ 67,338,017 *No single maturity date.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	The following table presents the Company’s assets that are measured at fair value on a recurring basis, and are determined using the following inputs as of December 31, 2020: Fair Value Measurements at December 31, 2020 Total Quoted Prices Significant Significant Assets: Cash and cash equivalents U.S. treasury securities $ 59,996,800 $ 59,996,800 $ — $ — Short-term investments Mutual funds 154,873,174 154,873,174 — — Certificates of deposit 3,016,260 — 3,016,260 — U.S. agency mortgage-backed securities 3,025,501 — 3,025,501 — Total short-term investments 160,914,935 154,873,174 6,041,761 — Investment in affiliated entity 4,460,366 4,460,366 — — Total assets measured at fair value $ 225,372,101 $ 219,330,340 $ 6,041,761 $ — The following table presents the Company’s assets and liabilities that are measured at fair value on a recurring basis, and are determined using the following inputs as of December 31, 2019: Fair Value Measurements at December 31, 2019 Total Quoted Prices Significant Significant Assets: Cash and cash equivalents Money market funds $ 2,349,729 $ 2,349,729 $ — $ — Short-term investments Mutual funds 67,338,017 67,338,017 — — Investments in affiliated entities 6,315,356 6,315,356 — — Total assets measured at fair value $ 76,003,102 $ 76,003,102 $ — $ — Liabilities: Derivative liability $ 8,819,023 $ — $ — $ 8,819,023 Total liabilities measured at fair value $ 8,819,023 $ — $ — $ 8,819,023
Changes in fair value of the financial liabilities	The following table presents the changes in fair value of the derivative liability for the year ended December 31, 2020: Balance at December 31, 2019 $ 8,819,023 Change in fair value 75,670,977 Derecognition of the derivative liability upon conversion (84,490,000) Balance at December 31, 2020 $ —

Major Customers and Concentra_2

Major Customers and Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Schedule of major customers and concentration risks	Customer 2020 Revenue % of Total 2019 Revenue % of Total 2018 Revenue % of Total ApolloBio $ — — % $ — — % $ 23,000,000 75 % AstraZeneca 170,587 2 3,194,877 78 6,850,424 23 Advaccine 5,000,000 68 — — — — Plumbline Life Sciences, Inc. 1,370,396 18 — — — — All other, including affiliated entities 870,237 12 917,053 22 631,473 2 Total revenue $ 7,411,220 100 % 1 $ 4,111,930 100 % $ 30,481,897 100 %

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule Of Prepaid Expenses And Other Current Assets	Prepaid expenses and other current assets at December 31, 2020 and 2019 consisted of the following: 2020 2019 Prepaid manufacturing expenses (a) $ 35,661,947 $ — Other prepaid expenses 4,695,509 1,584,598 $ 40,357,456 $ 1,584,598 (a) Prepaid manufacturing expenses related to deposits made to reserve capacity for the manufacturing of INO-4800 expected in 2021. In the event that the manufacturing does not occur in 2021 the deposits will be forfeited.

Fixed Assets (Tables)

Fixed Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of fixed assets	Fixed assets at December 31, 2020 and 2019 consisted of the following: Cost Accumulated Net Book As of December 31, 2020 Leasehold improvements $ 15,179,447 $ (6,549,418) $ 8,630,029 Laboratory equipment 4,788,678 (3,727,508) 1,061,170 Office furniture and fixtures 2,828,675 (2,296,942) 531,733 Computer equipment and other 4,544,915 (3,419,703) 1,125,212 $ 27,341,715 $ (15,993,571) $ 11,348,144 As of December 31, 2019 Leasehold improvements $ 15,007,935 $ (4,996,777) $ 10,011,158 Laboratory equipment 4,102,467 (3,229,357) 873,110 Office furniture and fixtures 3,048,053 (1,944,293) 1,103,760 Computer equipment and other 3,781,020 (2,996,031) 784,989 $ 25,939,475 $ (13,166,458) $ 12,773,017

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of intangible assets by major asset class	The following sets forth goodwill and intangible assets by major asset class: December 31, 2020 December 31, 2019 Weighted Average Useful Gross Accumulated Net Book Gross Accumulated Net Book Indefinite lived: Goodwill(a) $ 10,513,371 $ — $ 10,513,371 $ 10,513,371 $ — $ 10,513,371 Definite lived: Licenses 10 1,323,761 (1,276,852) 46,909 1,323,761 (1,248,104) 75,657 Bioject (b) 12 5,100,000 (2,468,889) 2,631,111 5,100,000 (2,175,556) 2,924,444 Other (c) 18 4,050,000 (3,581,250) 468,750 4,050,000 (3,356,250) 693,750 Total intangible assets 11 10,473,761 (7,326,991) 3,146,770 10,473,761 (6,779,910) 3,693,851 Total goodwill and intangible assets $ 20,987,132 $ (7,326,991) $ 13,660,141 $ 20,987,132 $ (6,779,910) $ 14,207,222 (a) Goodwill was recorded from the acquisition of other companies and assets. (b) Bioject intangible assets represent the estimated fair value of developed technology and intellectual property which were recorded from an asset acquisition. (c) Other intangible assets represent the estimated fair value of acquired intellectual property.
Schedule of finite-lived intangible assets, future amortization expense	Amortization expense related to intangible assets at December 31, 2020 is expected to be incurred as follows: Year ending December 31, 2021 $ 521,000 2022 493,000 2023 276,000 2024 253,000 2025 253,000 Thereafter 1,351,000 $ 3,147,000

Convertible Debt (Tables)

Convertible Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of convertible debt	The balance of the Notes at December 31, 2020 is as follows: Principal amount $ 78,500,000 Principal amount converted into common shares (62,085,000) Unamortized debt discount on the liability component (2,312,404) Unamortized debt issuance cost (318,266) Accrued interest 355,658 Net carrying amount $ 14,139,988 The balance of the December 2019 Bonds at December 31, 2020 is as follows: Principal amount $ 4,327,370 Unamortized debt issuance cost (36,525) Accretion of premium associated with the December 2019 Bonds 214,171 Accrued interest 10,818 Net carrying amount $ 4,515,834
Schedule of maturities of long-term debt	As of December 31, 2020, future minimum payments due under the Company's convertible debt instruments are as follows: Year ending December 31, Convertible Notes (1) December 2019 Bonds (2) Total 2021 $ 1,067,000 $ 43,000 $ 1,110,000 2022 1,067,000 43,000 1,110,000 2023 1,067,000 44,000 1,111,000 2024 16,948,000 5,571,000 22,519,000 Total $ 20,149,000 $ 5,701,000 $ 25,850,000 (1) Amounts represent contractual amounts due under the Notes, including interest based on the fixed rate of 6.5% per year.

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of accounts payable and accrued expenses	Accounts payable and accrued expenses at December 31, 2020 and 2019 consisted of the following: 2020 2019 Trade accounts payable $ 825,516 $ 6,919,081 Accrued compensation 13,127,257 8,967,897 Accrued subcontract costs 247,796 273,508 Other accrued expenses 7,003,239 2,076,772 $ 21,203,808 $ 18,237,258

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Summary of preferred stock authorized, issued and outstanding	Shares Outstanding as of Shares Authorized Shares Issued 2020 2019 Series C Preferred Stock, par $0.001 1,091 1,091 9 23
Schedule of shares authorized under stock option plans, by exercise price range	The following table summarizes total stock options outstanding at December 31, 2020: Options Outstanding Options Exercisable Exercise Price Shares Underlying Options Weighted-Average Weighted Shares Underlying Options Weighted Average $1.48-$3.00 452,749 2.5 $ 2.24 428,231 $ 2.23 $3.01-$6.00 3,261,410 7.4 $ 3.85 1,975,426 $ 3.98 $6.01-$9.00 3,879,209 6.5 $ 7.59 2,864,794 $ 7.33 $9.01-$12.00 365,223 7.2 $ 10.42 233,282 $ 10.08 $12.01-$15.00 833,282 5.9 $ 13.46 546,723 $ 13.14 $15.01-$25.62 114,751 9.6 $ 20.57 31,041 $ 20.59 8,906,624 6.6 $ 6.78 6,079,497 $ 6.58
Schedule of stock options, activity	Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2020 was as follows: Number of Weighted-Average Balance, December 31, 2019 9,265,390 $ 5.72 Granted 2,126,182 10.17 Exercised (2,178,252) 5.63 Cancelled (306,696) 6.40 Balance, December 31, 2020 8,906,624 $ 6.78
Schedule of restricted stock unit activity	Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2020 was as follows: Number of Balance, December 31, 2019 2,069,936 Granted 1,586,280 Vested (1,040,628) Cancelled (57,536) Balance, December 31, 2020 2,558,052

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Maturities of operating lease liabilities	As of December 31, 2020, the maturities of the Company's operating lease liabilities were as follows: Year ending December 31, 2021 $ 3,968,000 2022 4,045,000 2023 4,023,000 2024 3,001,000 2025 3,063,000 Thereafter 9,888,000 Total remaining lease payments 27,988,000 Less: present value adjustment (7,595,000) Total operating lease liabilities 20,393,000 Less: current portion (2,329,000) Long-term operating lease liabilities $ 18,064,000 Weighted-average remaining lease term 7.4 years Weighted-average discount rate 8.5 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of components of pretax loss from operations	The components of pretax loss from operations are as follows: Year Ended December 31, 2020 2019 2018 U.S. Domestic $ (162,664,355) $ (120,809,112) $ (94,798,019) Foreign (225,949) — — Pretax loss from operations $ (162,890,304) $ (120,809,112) $ (94,798,019)
Schedule of components of income tax expense (benefit)	The components of the provision for (benefit from) income taxes are presented in the following table: Year Ended December 31, 2020 2019 2018 Current: Federal $ — $ 4,000 $ — State — 2,000 — Foreign — — 2,170,000 — 6,000 2,170,000 Deferred: Federal — (263,000) State — — — Foreign — — — — (263,000) — $ — $ (257,000) $ 2,170,000
Schedule of effective income tax rate reconciliation	The reconciliation of income taxes attributable to continuing operations computed at the statutory tax rates to income tax expense (benefit), using a 21% statutory tax rate for December 31, 2020, 2019 and 2018, is as follows: Year Ended December 31, 2020 2019 2018 Income (benefit) taxes at statutory rates $ (34,207,000) $ (25,370,000) $ (19,908,000) State income tax, net of federal benefit — — (4,000) Foreign income taxes — — 2,170,000 Change in valuation allowance 21,428,000 25,457,000 20,898,000 Nondeductible loss on extinguishment of debt 14,450,000 — — Research and development tax credits (2,650,000) (3,838,000) (3,170,000) Change in fair value of warrants — — (76,000) Stock-based compensation (1,953,000) 1,114,000 1,094,000 Uncertain tax positions 1,068,000 1,537,000 1,268,000 Deconsolidation of subsidiary 853,000 — — Expired NOLs and credits 468,000 616,000 2,176,000 Limited NOLs and credits (368,000) (616,000) (2,176,000) Change in tax rates — 12,000 — Foreign tax rate differential (9,000) — — Other 920,000 831,000 (102,000) $ — $ (257,000) $ 2,170,000
Schedule of deferred tax assets and liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2020 and 2019 are shown below: As of December 31, 2020 2019 Deferred tax assets: Capitalized research expense $ 5,250,000 $ 6,300,000 NOL carryforwards 127,835,000 110,788,000 Research and development and other tax credits 13,242,000 11,737,000 Deferred revenue 1,628,000 1,506,000 Stock-based compensation 3,256,000 3,255,000 Acquired intangibles 757,000 889,000 Derivative liability — 1,852,000 Interest expense 564,000 1,122,000 Investment in affiliated entity 542,000 645,000 Lease liability 4,283,000 4,722,000 Other 6,127,000 2,413,000 163,484,000 145,229,000 Valuation allowance (159,705,000) (137,159,000) Total deferred tax assets 3,779,000 8,070,000 Deferred tax liabilities: Acquired intangibles (179,000) (160,000) Right of use asset (2,676,000) (2,894,000) Note discount (469,000) (2,862,000) Convertible note — (1,381,000) Fixed assets (487,000) (805,000) Net deferred tax liabilities $ (32,000) $ (32,000)
Schedule of operating loss and tax credit carryforward expirations	Based upon statute, federal and state losses and credits are expected to expire as follows (in millions): Expiration Date: Federal NOLs State NOLs Federal R&D State R&D 2021 $ 2.3 $ 0.3 $ — $ — 2022 6.1 0.4 — — 2023 5.3 1.2 — — 2024 14.5 9.1 — — 2025 and thereafter 267.7 132.9 19.8 — Indefinite 270.3 — — 3.2 $ 566.2 $ 143.9 $ 19.8 $ 3.2
Schedule of unrecognized tax benefits rollforward	The following table summarizes the activity related to the Company's unrecognized tax benefits: Year ended December 31, 2020 2019 2018 Balance at beginning of the year $ 11,204,000 $ 9,632,000 $ 8,313,000 Increases related to current year tax positions 1,043,000 1,575,000 1,319,000 Increases (decreases) related to prior year tax positions 27,000 (3,000) — Other (64,000) — — Balance at end of the year $ 12,210,000 $ 11,204,000 $ 9,632,000

Geneos Therapeutics, Inc. (Tabl

Geneos Therapeutics, Inc. (Tables)	12 Months Ended
	Dec. 31, 2020
Noncontrolling Interest [Abstract]
Schedule of equity method investments	The following table shows the amounts related to the deconsolidation accounting: Working capital (excluding cash) $ (59,992) Note payable 171,620 Fixed assets, net of accumulated depreciation (16,340) Carrying value of noncontrolling interest 3,181,640 Fair value of investment in Geneos retained 3,618,998 Gain on deconsolidation of Geneos (4,121,075) Decrease in cash resulting from the deconsolidation of Geneos $ 2,774,851 The details of the Company’s 47% retained equity investment in Geneos are shown in the table below, with fair values calculated as of June 1, 2020, the date of deconsolidation. Geneos Share Class Shares Price per Share Fair Value Common 3,000,000 $ 0.273 $ 819,000 Preferred 2,113,206 $ 1.325 $ 2,799,998 Total 5,113,206 $ 3,618,998 $3.8 million loss has been allocated to the Company’s Series A and Series A-1 preferred stock investments in Geneos, on a ratable basis, thereby reducing the investment balance t o $434,000 as of December 31, 2020 as shown in the table below: Investment in Geneos upon deconsolidation $ 3,618,998 Investment in Geneos Series A-1 preferred stock 1,399,999 Share in net loss of Geneos (4,584,610) Investment in Geneos as of December 31, 2020 $ 434,387
Schedule of fair value measurement inputs and valuation techniques	The assumptions used in the fair value calculation as of June 1, 2020 are presented below: Expected term (years) 2.92 Volatility 70% Risk-free interest rate 2.46% Geneos enterprise value $4,966,531

Quarterly Financial Informati_2

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial information (unaudited)	The following is a summary of the quarterly results of operations of the Company for the years ended December 31, 2020 and 2019 (unaudited): Quarter Ended Quarter Ended Quarter Ended Quarter Ended December 31, September 30, June 30, March 31, Consolidated Statements of Operations: Revenues: Revenue under collaborative research and development arrangements $ 5,003,494 $ 21,490 $ 74,102 $ 71,500 Revenue under collaborative research and development arrangements from affiliated entities 82,774 103,684 95,146 1,172,126 Other revenue, including from affiliated entities 494,313 111,004 97,939 83,648 Total revenues 5,580,581 236,178 267,187 1,327,274 Operating Expenses: Research and development 26,302,561 26,455,112 22,376,575 19,111,188 General and administrative 8,617,458 10,110,506 11,071,510 7,448,354 Total operating expenses 34,920,019 36,565,618 33,448,085 26,559,542 Loss from operations (29,339,438) (36,329,440) (33,180,898) (25,232,268) Interest income 931,168 896,710 1,067,399 416,569 Interest expense (1,068,008) (1,984,046) (2,846,641) (2,803,755) Change in fair value of derivative liability — 35,306,000 (97,755,000) (13,221,977) Gain (loss) on investment in affiliated entities 306,317 26,951,898 (3,883,176) 13,181,619 Net unrealized gain on available-for-sale equity securities 1,070,975 1,315,980 4,358,634 (5,050,092) Other income (expense), net 9,350 (136,644) (152,102) (425,500) Gain on deconsolidation of Geneos — — 4,121,075 — Loss on extinguishment of convertible bonds — (8,177,043) — — Gain on extinguishment of convertible senior notes 5,674,435 3,087,595 — — Net income (loss) before income tax benefit and share in net loss of Geneos $ (22,415,201) $ 20,931,010 $ (128,270,709) $ (33,135,404) Share in net loss of Geneos (1,923,179) (1,759,674) (901,757) — Net income (loss) $ (24,338,380) $ 19,171,336 $ (129,172,466) $ (33,135,404) Net loss attributable to non-controlling interest — — 469,407 594,350 Net income (loss) attributable to Inovio Pharmaceuticals, Inc. $ (24,338,380) $ 19,171,336 $ (128,703,059) $ (32,541,054) Net income (loss) per share Basic $ (0.14) $ 0.12 $ (0.83) $ (0.26) Diluted $ (0.14) $ 0.11 $ (0.83) $ (0.26) Quarter Ended Quarter Ended Quarter Ended Quarter Ended December 31, September 30, June 30, March 31, Consolidated Statements of Operations: Revenues: Revenue under collaborative research and development arrangements $ 184,523 $ 617,427 $ 64,283 $ 2,770,712 Revenue under collaborative research and development arrangements from affiliated entities 55,665 53,014 71,390 55,579 Other revenue, including from affiliated entities 39,300 196,422 — 3,614 Total revenues 279,488 866,863 135,673 2,829,905 Operating Expenses: Research and development 22,003,955 19,137,209 22,486,266 24,389,888 General and administrative 8,696,586 5,681,441 5,850,101 6,975,029 Total operating expenses 30,700,541 24,818,650 28,336,367 31,364,917 Loss from operations (30,421,053) (23,951,787) (28,200,694) (28,535,012) Interest income 587,679 637,438 755,330 625,535 Interest expense (2,668,837) (2,428,671) (2,194,783) (656,248) Change in fair value of derivative liability (4,315,105) 2,551,453 — — Loss from investment in affiliated entities (1,681,401) (485,841) (173,212) (750,103) Other income (expense), net 263,571 140,956 127,512 (35,839) Net loss before income tax benefit (38,235,146) (23,536,452) (29,685,847) (29,351,667) Income tax benefit 87,764 — 106,771 62,800 Net loss (38,147,382) (23,536,452) (29,579,076) (29,288,867) Net loss attributable to non-controlling interest 485,344 445,759 191,850 69,605 Net loss attributable to Inovio Pharmaceuticals, Inc. $ (37,662,038) $ (23,090,693) $ (29,387,226) $ (29,219,262) Net loss per share Basic $ (0.38) $ (0.23) $ (0.30) $ (0.30) Diluted $ (0.38) $ (0.25) $ (0.30) $ (0.30)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	Dec. 26, 2019USD ($)	Aug. 01, 2019USD ($)	Mar. 01, 2019USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2019KRW (₩)	Dec. 26, 2019KRW (₩)	Aug. 01, 2019KRW (₩)
Property, Plant and Equipment [Line Items]
Net loss from operations				$ 24,338,380	$ (19,171,336)	$ 128,703,059	$ 32,541,054	$ 37,662,038	$ 23,090,693	$ 29,387,226	$ 29,219,262	$ 166,411,157	$ 119,359,219	$ 96,967,830
Working capital				429,500,000								429,500,000
Accumulated deficit				906,196,812				739,785,655				906,196,812	739,785,655
Cash, cash equivalents, and short-term investments				411,600,000								411,600,000
Proceeds from issuance of common stock												$ 454,486,400	9,089,010	$ 29,227,776
Number of operating segments | segment												1
Allowance for doubtful accounts				0				0				$ 0	0
Finite lived intangible assets, net				3,146,770				3,693,851				3,146,770	3,693,851
Deferred tax assets, valuation allowance				159,705,000				$ 137,159,000				$ 159,705,000	137,159,000
Minimum
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life												3 years
Intangible asset, useful life												2 years
Maximum
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, useful life												5 years
Intangible asset, useful life												18 years
6.50% Convertible Senior Notes Due 2024
Property, Plant and Equipment [Line Items]
Debt instrument, face amount				78,500,000								$ 78,500,000
December 2019 Bonds
Property, Plant and Equipment [Line Items]
Debt instrument, face amount				$ 4,327,370								$ 4,327,370
Convertible Debt | 6.50% Convertible Senior Notes Due 2024
Property, Plant and Equipment [Line Items]
Proceeds from issuance of debt			$ 75,700,000										$ 75,700,000
Stated interest rate			6.50%	6.50%				6.50%				6.50%	6.50%		6.50%
Debt instrument, face amount			$ 78,500,000
Convertible Debt | August 2019 Bonds
Property, Plant and Equipment [Line Items]
Proceeds from issuance of debt		$ 14,500,000											$ 14,500,000
Stated interest rate		1.00%		1.00%				100.00%				1.00%	100.00%		100.00%		1.00%
Debt instrument, face amount		$ 15,000,000						$ 15,000,000					$ 15,000,000		₩ 18,000,000,000		₩ 18,000,000,000
Convertible Debt | December 2019 Bonds
Property, Plant and Equipment [Line Items]
Proceeds from issuance of debt	$ 4,000,000												$ 4,000,000
Stated interest rate	1.00%							1.00%					1.00%		1.00%	1.00%
Debt instrument, face amount	$ 4,100,000							$ 4,100,000					$ 4,100,000		₩ 4,700,000,000	₩ 4,700,000,000
Common stock | Sales Agreement
Property, Plant and Equipment [Line Items]
Proceeds from issuance of common stock												$ 454,500,000	$ 9,100,000
Patents
Property, Plant and Equipment [Line Items]
Intangible asset, useful life												17 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Antidilutive Securities Table (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	16,190,768	30,737,956	10,449,150
Options to purchase common stock
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	8,906,624	9,265,390	8,752,677
Service-based restricted stock units
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	2,558,052	2,069,936	1,688,017
Performance-based restricted stock units
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	663,353	0	0
Convertible preferred stock
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	3,309	8,456	8,456
6.50% Convertible Senior Notes Due 2024 | Convertible Debt Securities
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	3,049,980	14,585,653	0
August 2019 Bonds | Convertible Debt Securities
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	0	3,799,071	0
December 2019 Bonds | Convertible Debt Securities
Summary of common shares that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect
Total antidilutive securities (shares)	1,009,450	1,009,450	0

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Stock-Based Compensation Assumptions (Details) - Stock Options	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employees and Directors
Summary of assumptions used to estimate the fair value of stock options
Risk-free interest rate	0.63%	2.42%	2.73%
Expected volatility	78.00%	70.00%	72.00%
Expected life in years	6 years	6 years	6 years
Dividend yield	0.00%	0.00%	0.00%
Non Employee
Summary of assumptions used to estimate the fair value of stock options
Risk-free interest rate	0.82%	2.45%	2.71%
Expected volatility	76.00%	88.00%	78.00%
Expected life in years	10 years	10 years	9 years
Dividend yield	0.00%	0.00%	0.00%

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 5,580,581	$ 236,178	$ 267,187	$ 1,327,274	$ 279,488	$ 866,863	$ 135,673	$ 2,829,905	$ 7,411,220	$ 4,111,930	$ 30,481,897
Revenue recognized from deferred revenue beginning balance									127,000	$ 293,000
Advaccine
Disaggregation of Revenue [Line Items]
Total revenues									5,000,000
Plumbline Life Sciences
Disaggregation of Revenue [Line Items]
Total revenues									1,400,000
Other Counterparty
Disaggregation of Revenue [Line Items]
Total revenues									$ 1,000,000

Collaborative Agreements (Detai

Collaborative Agreements (Details) - USD ($)	Mar. 01, 2021	Apr. 11, 2018	Dec. 31, 2017	Dec. 29, 2017	Jun. 30, 2020	Apr. 30, 2020	Mar. 31, 2020	Jan. 31, 2020	Aug. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Oct. 31, 2018	Mar. 31, 2018	Sep. 30, 2015	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues															$ 5,580,581	$ 236,178	$ 267,187	$ 1,327,274	$ 279,488	$ 866,863	$ 135,673	$ 2,829,905		$ 7,411,220	$ 4,111,930	$ 30,481,897
Revenues															5,580,581	236,178	267,187	1,327,274	279,488	866,863	135,673	2,829,905		7,411,220	4,111,930	30,481,897
Deferred grant funding															7,474,310				6,065,212					7,474,310	6,065,212
Revenue under collaborative research and development arrangements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues															5,003,494	21,490	74,102	71,500	184,523	617,427	64,283	2,770,712		5,170,586	3,636,945	29,860,785
Revenues															5,003,494	$ 21,490	$ 74,102	$ 71,500	$ 184,523	$ 617,427	$ 64,283	$ 2,770,712		5,170,586	3,636,945	29,860,785
Advaccine
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues																								5,000,000
Revenues																								5,000,000
Advaccine | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received																								3,000,000
Additional revenue to be achieved																								108,000,000
Collaboration agreement, payment earned																								$ 2,000,000
Obligation period to pay royalties																								10 years
Agreement period from effective date for termination																								1 year
Total revenues																								$ 5,000,000
Revenues																								5,000,000
Advaccine | Collaborative Arrangement | Revenue under collaborative research and development arrangements
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues																								5,000,000
Revenues																								5,000,000
Advaccine | Collaborative Arrangement | Subsequent Event
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received	$ 3,000,000
ApolloBio | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received													$ 23,000,000										$ 23,000,000	23,000,000		$ 23,000,000
Additional revenue to be achieved																								$ 20,000,000
Obligation period to pay royalties																								10 years
Agreement period from effective date for termination																								1 year
Territory expansion option period				3 years
Proceeds from collaborative agreement													19,400,000
Advisory fees													960,000
Agreement, number of days written notice before termination																								90 days
ApolloBio | Collaborative Arrangement | Foreign Tax Authority
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, corporate income tax													2,200,000
Collaborative agreement, foreign non-income Taxes													$ 1,400,000
AstraZeneca | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received			$ 27,500,000											$ 27,500,000
Agreement anticipated development and regulatory event based payment receivable milestones																								$ 125,000,000
Agreement, anticipated commercial event based payment receivable milestones																								115,000,000
Agreement, milestone payment, revenue recognized										$ 2,000,000	$ 2,000,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received																								6,400,000	6,300,000
Collaborative agreement, funding to be received		$ 56,000,000				$ 6,900,000
Collaborative agreement, period to receive funding for research and development		5 years
Deferred grant funding															2,600,000									2,600,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement | COVID19 Vaccine
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received								$ 9,000,000																10,000,000
Deferred grant funding															3,400,000									3,400,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement | IN O4800
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received						1,300,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement | CELLECTRA 3PSP Proprietary Smart Device
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received						$ 5,000,000
Bill And Melinda Gates Foundation | Collaborative Arrangement | CELLECTRA 3PSP Proprietary Smart Device
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received							$ 5,000,000																	4,100,000
Deferred grant funding															884,000									884,000
Bill And Melinda Gates Foundation | Collaborative Arrangement | D N A Encoded Monoclonal Antibody Technology
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received									$ 1,100,000			$ 2,200,000												463,000	$ 2,100,000
Deferred grant funding															575,000									575,000
Department Of Defence | Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received					$ 54,500,000
Grant proceeds received																								21,200,000
Accounts receivable															$ 11,400,000									$ 11,400,000
Department Of Defence | Collaborative Arrangement | CELLECTRA 3PSP Proprietary Smart Device
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Purchase price, procurement contract					$ 16,600,000

Short-term Investments - Narrat

Short-term Investments - Narrative (Details)	3 Months Ended				12 Months Ended
	Dec. 31, 2020USD ($)investment	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)investment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Investments, Debt and Equity Securities [Abstract]
Debt securities, available-for-sale, realized gain					$ 744,000	$ 594,000
Debt securities, available-for-sale, realized gain					1,300,000	118,000
Net unrealized gain on available-for-sale equity securities	$ 1,070,975	$ 1,315,980	$ 4,358,634	$ (5,050,092)	$ 1,695,497	$ 0	$ 0
Number of securities in a gross unrealized loss position | investment	12				12
Number of securities in a gross unrealized loss position for more than twelve months | investment	0				0

Short-term Investments - Summar

Short-term Investments - Summary of Available-for-sale Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	$ 159,239,931
Gross Unrealized Gains	2,365,899
Gross Unrealized Losses	(690,895)
Fair Market Value	160,914,935
Mutual funds
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	153,177,675	$ 66,599,219
Gross Unrealized Gains	2,339,639	754,709
Gross Unrealized Losses	(644,140)	(15,911)
Fair Market Value	154,873,174	$ 67,338,017
Certificates of deposit
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	3,000,000
Gross Unrealized Gains	26,260
Gross Unrealized Losses	(10,000)
Fair Market Value	3,016,260
U.S. agency mortgage-backed securities
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	3,062,256
Gross Unrealized Gains	0
Gross Unrealized Losses	(36,755)
Fair Market Value	$ 3,025,501
Maximum | Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity	1 year

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	$ 160,914,935
Investments in affiliated entities	4,460,366	$ 6,315,356
Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Derivative liability	7,100,000
Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Liabilities, fair value	0
Mutual funds
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	154,873,174	67,338,017
Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,016,260
U.S. agency mortgage-backed securities
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,025,501
Fair Value, Measurements, Recurring
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	160,914,935
Investments in affiliated entities	4,460,366	6,315,356
Assets, fair value	225,372,101	76,003,102
Derivative liability		8,819,023
Liabilities, fair value		8,819,023
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	154,873,174
Investments in affiliated entities	4,460,366	6,315,356
Assets, fair value	219,330,340	76,003,102
Derivative liability		0
Liabilities, fair value		0
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	6,041,761
Investments in affiliated entities	0	0
Assets, fair value	6,041,761	0
Derivative liability		0
Liabilities, fair value		0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0
Investments in affiliated entities	0	0
Assets, fair value	0	0
Derivative liability		8,819,023
Liabilities, fair value		8,819,023
Fair Value, Measurements, Recurring | U.S. treasury securities
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents	59,996,800
Fair Value, Measurements, Recurring | U.S. treasury securities | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents	59,996,800
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents	0
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents	0
Fair Value, Measurements, Recurring | Money market funds
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents		2,349,729
Fair Value, Measurements, Recurring | Money market funds | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents		2,349,729
Fair Value, Measurements, Recurring | Money market funds | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents		0
Fair Value, Measurements, Recurring | Money market funds | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents		0
Fair Value, Measurements, Recurring | Mutual funds
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	154,873,174	67,338,017
Fair Value, Measurements, Recurring | Mutual funds | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	154,873,174	67,338,017
Fair Value, Measurements, Recurring | Mutual funds | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0	0
Fair Value, Measurements, Recurring | Mutual funds | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0	$ 0
Fair Value, Measurements, Recurring | Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,016,260
Fair Value, Measurements, Recurring | Certificates of deposit | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0
Fair Value, Measurements, Recurring | Certificates of deposit | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,016,260
Fair Value, Measurements, Recurring | Certificates of deposit | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,025,501
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Quoted Prices in Active Markets (Level 1)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	0
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	3,025,501
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Significant Unobservable Inputs (Level 3)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proceeds from sale of investment		$ 40,125,418	$ 0	$ 0
Gain on investments		(588,270)	476,368	$ (1,342,005)
GeneOne (affiliated entity)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proceeds from sale of investment	$ 40,100,000
Realized gain on sale of investment	$ 36,700,000
Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liability		7,100,000
Fair Value, Inputs, Level 1 | GeneOne (affiliated entity)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of shares held in an affiliated entity (in shares)	1,644,155
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets held-in-trust		0	$ 0
Liabilities held		$ 0
Common stock | Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of shares owned (shares)		597,808

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of the Company's Derivative Liability (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of year	$ 8,819,023
Change in fair value	75,670,977
Derecognition of the derivative liability upon conversion	(84,490,000)
Balance at end of year	$ 0

Major Customers and Concentra_3

Major Customers and Concentration of Credit Risk (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Total revenues	$ 5,580,581	$ 236,178	$ 267,187	$ 1,327,274	$ 279,488	$ 866,863	$ 135,673	$ 2,829,905	$ 7,411,220	$ 4,111,930	$ 30,481,897
Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									100.00%	100.00%	100.00%
ApolloBio
Concentration Risk [Line Items]
Total revenues									$ 0	$ 0	$ 23,000,000
ApolloBio | Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									0.00%	0.00%	75.00%
AstraZeneca
Concentration Risk [Line Items]
Total revenues									$ 170,587	$ 3,194,877	$ 6,850,424
AstraZeneca | Customer Concentration Risk
Concentration Risk [Line Items]
Accounts receivable					161,000					$ 161,000
AstraZeneca | Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									2.00%	78.00%	23.00%
AstraZeneca | Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage										23.00%
Advaccine
Concentration Risk [Line Items]
Total revenues									$ 5,000,000	$ 0	$ 0
Advaccine | Customer Concentration Risk
Concentration Risk [Line Items]
Accounts receivable	7,100,000								$ 7,100,000
Advaccine | Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									68.00%	0.00%	0.00%
Advaccine | Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									38.00%
Plumbline Life Sciences, Inc.
Concentration Risk [Line Items]
Total revenues									$ 1,370,396	$ 0	$ 0
Plumbline Life Sciences, Inc. | Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									18.00%	0.00%	0.00%
All other, including affiliated entities
Concentration Risk [Line Items]
Total revenues									$ 870,237	$ 917,053	$ 631,473
All other, including affiliated entities | Revenue | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									12.00%	22.00%	2.00%
DoD | Customer Concentration Risk
Concentration Risk [Line Items]
Accounts receivable	$ 11,400,000								$ 11,400,000
DoD | Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage									62.00%
MCDC | Customer Concentration Risk
Concentration Risk [Line Items]
Accounts receivable					$ 469,000					$ 469,000
MCDC | Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage										67.00%

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid manufacturing expenses	$ 35,661,947	$ 0
Other prepaid expenses	4,695,509	1,584,598
Prepaid expenses and other current assets	$ 40,357,456	$ 1,584,598

Fixed Assets (Details)

Fixed Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Cost	$ 27,341,715	$ 25,939,475
Accumulated Depreciation and Amortization	(15,993,571)	(13,166,458)
Net Book Value	11,348,144	12,773,017
Depreciation	3,038,996	3,598,388	$ 3,747,183
Property, plant and equipment disposed of	227,000
Accumulated depreciation written off due to disposal of property plant and equipment	200,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	15,179,447	15,007,935
Accumulated Depreciation and Amortization	(6,549,418)	(4,996,777)
Net Book Value	8,630,029	10,011,158
Laboratory equipment
Property, Plant and Equipment [Line Items]
Cost	4,788,678	4,102,467
Accumulated Depreciation and Amortization	(3,727,508)	(3,229,357)
Net Book Value	1,061,170	873,110
Office furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost	2,828,675	3,048,053
Accumulated Depreciation and Amortization	(2,296,942)	(1,944,293)
Net Book Value	531,733	1,103,760
Computer equipment and other
Property, Plant and Equipment [Line Items]
Cost	4,544,915	3,781,020
Accumulated Depreciation and Amortization	(3,419,703)	(2,996,031)
Net Book Value	$ 1,125,212	$ 784,989

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Indefinite lived:
Goodwill	$ 10,513,371	$ 10,513,371
Definite lived:
Intangible assets, Gross	10,473,761	10,473,761
Intangible assets, Accumulated Amortization	(7,326,991)	(6,779,910)
Intangible assets, Net Book Value	3,146,770	3,693,851
Total goodwill and intangible assets, Gross	20,987,132	20,987,132
Total goodwill and intangible assets, Net Book Value	$ 13,660,141	14,207,222
Weighted Average
Schedule of intangible assets by major asset class
Intangible asset, useful life	11 years
Licenses
Definite lived:
Intangible assets, Gross	$ 1,323,761	1,323,761
Intangible assets, Accumulated Amortization	(1,276,852)	(1,248,104)
Intangible assets, Net Book Value	$ 46,909	75,657
Licenses | Weighted Average
Schedule of intangible assets by major asset class
Intangible asset, useful life	10 years
Bioject
Definite lived:
Intangible assets, Gross	$ 5,100,000	5,100,000
Intangible assets, Accumulated Amortization	(2,468,889)	(2,175,556)
Intangible assets, Net Book Value	$ 2,631,111	2,924,444
Bioject | Weighted Average
Schedule of intangible assets by major asset class
Intangible asset, useful life	12 years
Other
Definite lived:
Intangible assets, Gross	$ 4,050,000	4,050,000
Intangible assets, Accumulated Amortization	(3,581,250)	(3,356,250)
Intangible assets, Net Book Value	$ 468,750	$ 693,750
Other | Weighted Average
Schedule of intangible assets by major asset class
Intangible asset, useful life	18 years

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 547,081	$ 1,066,294	$ 1,249,584
Impairment	$ 0	$ 0	$ 0

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Amortization Expense (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 521,000
2022	493,000
2023	276,000
2024	253,000
2025	253,000
Thereafter	1,351,000
Intangible assets, Net Book Value	$ 3,146,770	$ 3,693,851

Convertible Debt - Narrative (D

Convertible Debt - Narrative (Details)	Aug. 03, 2020$ / sharesshares	Dec. 26, 2019USD ($)$ / shares	Aug. 01, 2019USD ($)	Mar. 01, 2019USD ($)	Aug. 31, 2020USD ($)shares	Dec. 31, 2020USD ($)$ / shares	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)day$ / sharesshares	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2019KRW (₩)	Dec. 26, 2019KRW (₩)	Aug. 01, 2019KRW (₩)
Debt Instrument [Line Items]
Interest expense						$ 1,068,008	$ 1,984,046	$ 2,846,641	$ 2,803,755	$ 2,668,837	$ 2,428,671	$ 2,194,783	$ 656,248	$ 8,702,450	$ 7,948,539	$ 0
Change in fair value of derivative liability						0	35,306,000	(97,755,000)	(13,221,977)	$ (4,315,105)	$ 2,551,453	$ 0	$ 0	(75,670,977)	(1,763,652)	0
6.50% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Debt instrument, face amount						78,500,000								78,500,000
Debt issuance costs, net						318,266								318,266
Debt instrument, unamortized discount						2,312,404								2,312,404
Gain (loss) on extinguishment of debt						$ 5,674,435	$ 3,087,595	$ 0	$ 0					$ 8,762,030	$ 0	0
6.50% Convertible Senior Notes Due 2024 | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount				$ 78,500,000
Stated interest rate				6.50%		6.50%				6.50%				6.50%	6.50%		6.50%
Proceeds from issuance of debt				$ 75,700,000											$ 75,700,000
Debt instrument, convertible, conversion ratio				0.1858045
Debt instrument, convertible, conversion price (in USD per share) | $ / shares						$ 5.38								$ 5.38
Debt instrument, convertible, threshold percentage of stock price trigger														130.00%
Debt instrument, convertible, threshold trading days | day														20
Debt instrument, convertible, threshold consecutive trading days | day														30
Debt instrument, redemption price, percentage														100.00%
Long-term debt, fair value				$ 62,200,000
Debt issuance costs, net				2,800,000
Debt instrument, unamortized discount				$ 18,600,000
Debt instrument, interest rate, effective percentage						13.10%								13.10%
Debt conversion, converted instrument principal amount														$ 62,100,000
Debt conversion, converted instrument, shares issued (in shares) | shares														11,535,660
Fair value of date conversion						$ 43,700,000								$ 43,700,000
Debt instrument, convertible, carrying amount of equity component						$ 52,500,000								52,500,000
Gain (loss) on extinguishment of debt														8,800,000
Interest expense														6,900,000	7,000,000
Interest expense, debt														4,100,000	4,400,000
August 2019 Bonds
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt														$ (8,177,043)	0	$ 0
August 2019 Bonds | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount			$ 15,000,000							$ 15,000,000					$ 15,000,000		₩ 18,000,000,000		₩ 18,000,000,000
Stated interest rate			1.00%			1.00%				100.00%				1.00%	100.00%		100.00%		1.00%
Proceeds from issuance of debt			$ 14,500,000												$ 14,500,000
Debt instrument, convertible, conversion price (in USD per share) | $ / shares	$ 3.14
Debt instrument, unamortized discount			7,300,000
Debt conversion, converted instrument, shares issued (in shares) | shares	4,962,364				4,692,364
Debt instrument, convertible, carrying amount of equity component			$ 7,100,000
Gain (loss) on extinguishment of debt					$ (8,200,000)
Interest expense														$ 1,600,000	982,000
Interest expense, debt														$ 87,000	65,000
Fair value of derivative liability					84,500,000
Change in fair value of derivative liability					$ 75,700,000
Debt instrument, convertible, internal rate of return						6.00%								6.00%
August 2019 Bonds | Convertible Debt | Initial Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	0.0002110595
Debt instrument, convertible, conversion price (in USD per share) | $ / shares	$ 4
August 2019 Bonds | Convertible Debt | After January 2, 2020 Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	0.0002756873
December 2019 Bonds
Debt Instrument [Line Items]
Debt instrument, face amount						$ 4,327,370								$ 4,327,370
Debt issuance costs, net						$ 36,525								$ 36,525
December 2019 Bonds | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount		$ 4,100,000								$ 4,100,000					$ 4,100,000		₩ 4,700,000,000	₩ 4,700,000,000
Stated interest rate		1.00%								1.00%					1.00%		1.00%	1.00%
Proceeds from issuance of debt		$ 4,000,000													$ 4,000,000
Debt instrument, interest rate, effective percentage						6.20%								6.20%
Interest expense														$ 253,000
Interest expense, debt														$ 40,000
Debt instrument, convertible, internal rate of return		6.00%																6.00%
Debt instrument, convertible, required bondholder approval, percentage		25.00%
December 2019 Bonds | Convertible Debt | Initial Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio		0.0002147766
Debt instrument, convertible, conversion price (in USD per share) | $ / shares		$ 4
December 2019 Bonds | Convertible Debt | After July 2, 2020 Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio		0.0003579611
December 2019 Bonds | Convertible Debt | After July 2, 2020 Conversion Price | Maximum
Debt Instrument [Line Items]
Debt instrument, convertible, conversion price (in USD per share) | $ / shares		$ 2.40

Convertible Debt - Balance Of C

Convertible Debt - Balance Of Convertible Debt (Details)	Dec. 31, 2020USD ($)
6.50% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Principal amount	$ 78,500,000
Principal amount converted into common shares	(62,085,000)
Unamortized debt discount on the liability component	(2,312,404)
Unamortized debt issuance cost	(318,266)
Accrued interest	355,658
Total	14,139,988
December 2019 Bonds
Debt Instrument [Line Items]
Principal amount	4,327,370
Unamortized debt issuance cost	(36,525)
Accretion of premium associated with the bonds	214,171
Accrued interest	10,818
Total	$ 4,515,834

Convertible Debt - Schedule of

Convertible Debt - Schedule of Maturities (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 26, 2019	Mar. 01, 2019
6.50% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Total	$ 14,139,988
December 2019 Bonds
Debt Instrument [Line Items]
Total	4,515,834
Convertible Debt
Debt Instrument [Line Items]
2021	1,110,000
2022	1,110,000
2023	1,111,000
2024	22,519,000
Total	25,850,000
Convertible Debt | 6.50% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
2021	1,067,000
2022	1,067,000
2023	1,067,000
2024	16,948,000
Total	$ 20,149,000
Stated interest rate	6.50%	6.50%		6.50%
Convertible Debt | December 2019 Bonds
Debt Instrument [Line Items]
2021	$ 43,000
2022	43,000
2023	44,000
2024	5,571,000
Total	$ 5,701,000
Stated interest rate		1.00%	1.00%
Debt instrument, convertible, internal rate of return			6.00%

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Trade accounts payable	$ 825,516	$ 6,919,081
Accrued compensation	13,127,257	8,967,897
Accrued subcontract costs	247,796	273,508
Other accrued expenses	7,003,239	2,076,772
Accounts payable and accrued liabilities	$ 21,203,808	$ 18,237,258

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Preferred Stock (Details) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Summary of common and preferred stock authorized, issued and outstanding
Preferred Stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	9	23
Preferred stock, shares outstanding (in shares)	9	23
Series C Preferred Stock
Summary of common and preferred stock authorized, issued and outstanding
Preferred Stock, par value (in USD per share)	$ 0.001
Preferred stock, shares authorized (in shares)	1,091
Preferred stock, shares issued (in shares)	1,091
Preferred stock, shares outstanding (in shares)	9	23

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	Aug. 28, 2020	Jun. 30, 2020	May 12, 2020	May 31, 2018	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2020	May 13, 2016
Class of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion, conversion price (in USD per share)						$ 27.20
Share-based compensation						$ 15,647,523	$ 10,901,320	$ 10,654,622
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized						$ 4,400,000	$ 3,400,000
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition						1 year 4 months 24 days	1 year 8 months 12 days
Number of options outstanding to purchase common stock (in shares)						8,906,624	9,265,390
Aggregate intrinsic value of options outstanding						$ 24,200,000
Aggregate intrinsic value for options exercisable						$ 16,800,000
Options exercisable, remaining contractual term						5 years 8 months 12 days
Number of options expected to vest (in shares)						8,906,624
Options, expirations in period, weighted average exercise price (in USD per share)						$ 4.44	$ 6.27	$ 5.17
Options, expirations in period (in shares)						78,750	324,502	119,091
Options, grants in period, weighted average grant date fair value (in USD per share)						$ 6.87	$ 2.19	$ 2.86
Proceeds from stock options exercised						$ 12,300,000	$ 113,000	$ 1,500,000
Options, exercises in period, aggregate intrinsic value						14,200,000	25,000	910,000
Employee
Class of Stock [Line Items]
Share-based compensation						14,500,000	9,800,000	10,200,000
Research and Development Expense
Class of Stock [Line Items]
Share-based compensation						8,000,000	5,900,000	5,900,000
General and Administrative Expense
Class of Stock [Line Items]
Share-based compensation						6,500,000	3,900,000	4,300,000
Non Employee
Class of Stock [Line Items]
Allocated share-based compensation expense						$ 1,200,000	970,000	$ 302,000
Number of options outstanding to purchase common stock (in shares)						845,375
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized						$ 10,900,000	$ 4,300,000
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition						1 year 10 months 24 days	1 year 7 months 6 days
Aggregate intrinsic value of unvested						$ 22,600,000
Aggregate intrinsic value of vested						$ 13,500,000
RSU's expected to vest (in shares)						2,558,052
Weighted average grant date fair value (in USD per share)						$ 9.12	$ 3.09	$ 4.31
Granted (in shares)						1,586,280
2016 Incentive Plan
Class of Stock [Line Items]
Reserved number of shares under the Incentive Plan (in shares)						18,000,000				18,000,000
Number of potential shares authorized for issuance under a share-based compensation plan (in shares)										2,000,000
Increase in number of shares authorized (in shares)									2,000,000
Number of shares available for grants under the Incentive Plan (in shares)						6,739,577
Number of shares of vested restricted stock outstanding under the plan (in shares)						2,558,052
Number of common stock shares outstanding under the Incentive Plan (in shares)						5,742,109
Vesting period of incentive plan						3 years
Contractual year term of incentive plan						10 years
Award vesting period (in years)						3 years
2016 Incentive Plan | Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Weighted average grant date fair value (in USD per share)	$ 12.06
Granted (in shares)	663,353
Grant date fair value	$ 8,000,000
2016 Incentive Plan | Restricted Stock Units (RSUs) | Tranche One
Class of Stock [Line Items]
Vesting percentage	50.00%
2016 Incentive Plan | Restricted Stock Units (RSUs) | Tranche Two
Class of Stock [Line Items]
Vesting period of incentive plan	1 year
Vesting percentage	50.00%
Award vesting period (in years)	1 year
2007 Incentive Plan
Class of Stock [Line Items]
Number of common stock shares outstanding under the Incentive Plan (in shares)						3,164,515
Vesting period of incentive plan						3 years
Contractual year term of incentive plan						10 years
Award vesting period (in years)						3 years
Series C Preferred Stock
Class of Stock [Line Items]
Conversion of stock, shares converted (in shares)		14
Convertible preferred stock, shares issued upon conversion (in shares)						3,309
Common stock
Class of Stock [Line Items]
Conversion of stock, shares issued (in shares)		5,147
Common stock | Sales Agreement
Class of Stock [Line Items]
Authorized amount				$ 100,000,000	$ 250,000,000
Common stock | Prior Sales Agreement
Class of Stock [Line Items]
Remaining authorized amount					$ 0	$ 0
Stock sale agreement, aggregate number of shares issued (in shares)					43,148,952
Sale of stock, price per share (in USD per share)					$ 4.92
Stock sale agreement, aggregate proceeds from issuance of stock					$ 208,200,000
Common stock | New Sales Agreement
Class of Stock [Line Items]
Authorized amount			$ 250,000,000
Remaining authorized amount						$ 0
Agent fee				3.00%
Stock sale agreement, aggregate number of shares issued (in shares)						22,915,934
Sale of stock, price per share (in USD per share)						$ 10.91
Stock sale agreement, aggregate proceeds from issuance of stock						$ 246,200,000

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding (in shares) | shares	8,906,624
Weighted-average remaining contractual life (in Years)	6 years 7 months 6 days
Weighted average exercise price (in USD per share)	$ 6.78
Options exercisable (in shares) | shares	6,079,497
Weighted average exercise price (in USD per share)	$ 6.58
$1.48-$3.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	1.48
Exercise price, upper range limit (in USD per share)	$ 3
Options outstanding (in shares) | shares	452,749
Weighted-average remaining contractual life (in Years)	2 years 6 months
Weighted average exercise price (in USD per share)	$ 2.24
Options exercisable (in shares) | shares	428,231
Weighted average exercise price (in USD per share)	$ 2.23
$1.48-$3.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	3.01
Exercise price, upper range limit (in USD per share)	$ 6
Options outstanding (in shares) | shares	3,261,410
Weighted-average remaining contractual life (in Years)	7 years 4 months 24 days
Weighted average exercise price (in USD per share)	$ 3.85
Options exercisable (in shares) | shares	1,975,426
Weighted average exercise price (in USD per share)	$ 3.98
$6.01-$9.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	6.01
Exercise price, upper range limit (in USD per share)	$ 9
Options outstanding (in shares) | shares	3,879,209
Weighted-average remaining contractual life (in Years)	6 years 6 months
Weighted average exercise price (in USD per share)	$ 7.59
Options exercisable (in shares) | shares	2,864,794
Weighted average exercise price (in USD per share)	$ 7.33
$9.01-$12.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	9.01
Exercise price, upper range limit (in USD per share)	$ 12
Options outstanding (in shares) | shares	365,223
Weighted-average remaining contractual life (in Years)	7 years 2 months 12 days
Weighted average exercise price (in USD per share)	$ 10.42
Options exercisable (in shares) | shares	233,282
Weighted average exercise price (in USD per share)	$ 10.08
$12.01-$15.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	12.01
Exercise price, upper range limit (in USD per share)	$ 15
Options outstanding (in shares) | shares	833,282
Weighted-average remaining contractual life (in Years)	5 years 10 months 24 days
Weighted average exercise price (in USD per share)	$ 13.46
Options exercisable (in shares) | shares	546,723
Weighted average exercise price (in USD per share)	$ 13.14
$15.01-$25.62
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	15.01
Exercise price, upper range limit (in USD per share)	$ 25.62
Options outstanding (in shares) | shares	114,751
Weighted-average remaining contractual life (in Years)	9 years 7 months 6 days
Weighted average exercise price (in USD per share)	$ 20.57
Options exercisable (in shares) | shares	31,041
Weighted average exercise price (in USD per share)	$ 20.59

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Stock Option Activity Under Equity Incentive Plan (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	9,265,390
Granted (in shares) | shares	2,126,182
Exercised (in shares) | shares	(2,178,252)
Cancelled (in shares) | shares	(306,696)
Ending balance (in shares) | shares	8,906,624
Weighted-Average Exercise Price
Beginning balance (in USD per share) | $ / shares	$ 5.72
Granted (in USD per share) | $ / shares	10.17
Exercised (in USD per share) | $ / shares	5.63
Cancelled (in USD per share) | $ / shares	6.40
Ending balance (in USD per share) | $ / shares	$ 6.78

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of RSU Activity Under Equity Incentive Plan (Details) - Performance-based restricted stock units	12 Months Ended
	Dec. 31, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	2,069,936
Granted (in shares)	1,586,280
Vested (in shares)	(1,040,628)
Cancelled (in shares)	(57,536)
Ending balance (in shares)	2,558,052

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2020ft²lease	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
Lessee, operating lease, area of land under lease	13,500
Lease, cost | $		$ 3.4	$ 3.2	$ 3.4
Number of lease agreements entered into | lease	2
Minimum
Operating Leased Assets [Line Items]
Operating lease, remaining lease term	2 years 10 months 24 days	2 years 10 months 24 days
Maximum
Operating Leased Assets [Line Items]
Operating lease, remaining lease term	9 years	9 years
San Diego, California
Operating Leased Assets [Line Items]
Lessee, operating lease, area of land under lease		82,200
Plymouth Meeting, Pennsylvania
Operating Leased Assets [Line Items]
Lessee, operating lease, area of land under lease		57,360

Leases - Summary of Maturities

Leases - Summary of Maturities of Operating Lease Payments (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 3,968,000
2022	4,045,000
2023	4,023,000
2024	3,001,000
2025	3,063,000
Thereafter	9,888,000
Total remaining lease payments	27,988,000
Less: present value adjustment	(7,595,000)
Total operating lease liabilities	20,393,000
Less: current portion	(2,329,394)	$ (2,074,842)
Long-term operating lease liabilities	$ 18,063,515	$ 20,409,922
Weighted-average remaining lease term	7 years 4 months 24 days
Weighted-average discount rate	8.50%

Investment in Affiliated Enti_2

Investment in Affiliated Entity (Details) ₩ in Billions	Aug. 27, 2020USD ($)shares	Aug. 27, 2020KRW (₩)shares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)
Related Party Transaction [Line Items]
Proceeds from issuance of common stock | $			$ 454,486,400	$ 9,089,010	$ 29,227,776
Plumbline Life Sciences
Related Party Transaction [Line Items]
Percentage of ownership			19.70%	15.00%
Plumbline Life Sciences | Common stock
Related Party Transaction [Line Items]
Number of shares owned (shares)			597,808	395,758
GeneOne Life Sciences
Related Party Transaction [Line Items]
Number of shares owned (shares)	1,644,155	1,644,155
Number of shares issued in transaction (in shares)	1,644,155	1,644,155
Proceeds from issuance of common stock	$ 40,100,000	₩ 47.4

Income Taxes - Components of Pr

Income Taxes - Components of Pretax Loss from Operations (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. Domestic									$ (162,664,355)	$ (120,809,112)	$ (94,798,019)
Foreign									(225,949)	0	0
Net loss before income tax benefit/(provision for income tax)	$ (22,415,201)	$ 20,931,010	$ (128,270,709)	$ (33,135,404)	$ (38,235,146)	$ (23,536,452)	$ (29,685,847)	$ (29,351,667)	$ (162,890,304)	$ (120,809,112)	$ (94,798,019)

Income Taxes - Summary of the P

Income Taxes - Summary of the Provision for Income Taxes (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal					$ 0	$ 4,000	$ 0
State					0	2,000	0
Foreign					0	0	2,170,000
Current income tax expense (benefit)					0	6,000	2,170,000
Deferred:
Federal					0	(263,000)
State					0	0	0
Foreign					0	0	0
Deferred income tax expense (benefit)					0	(263,000)	0
Income tax expense (benefit)	$ (87,764)	$ 0	$ (106,771)	$ (62,800)	$ 0	$ (257,335)	$ 2,169,811

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income (benefit) taxes at statutory rates	$ (34,207)	$ (25,370)	$ (19,908)
State income tax, net of federal benefit	0	0	(4)
Foreign income taxes	0	0	2,170
Change in valuation allowance	21,428	25,457	20,898
Nondeductible loss on extinguishment of debt	14,450	0	0
Research and development tax credits	(2,650)	(3,838)	(3,170)
Change in fair value of warrants	0	0	(76)
Stock-based compensation	(1,953)	1,114	1,094
Uncertain tax positions	1,068	1,537	1,268
Deconsolidation of subsidiary	853	0	0
Expired NOLs and credits	468	616	2,176
Limited NOLs and credits	(368)	(616)	(2,176)
Change in tax rates	0	12	0
Foreign tax rate differential	(9)	0	0
Other	920	831	(102)
Income tax expense (benefit)	$ 0	$ (257)	$ 2,170

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Income tax benefit	$ (87,764)	$ 0	$ (106,771)	$ (62,800)	$ 0	$ (257,335)	$ 2,169,811
Tax benefits expired					10,200,000
Unrecognized tax benefits that would impact effective tax rate	$ 9,900,000				10,900,000	$ 9,900,000	8,300,000
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations					566,200,000
Net operating loss carryforwards							$ 270,300,000
Federal | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount					19,800,000
California
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations					68,600,000
Pennsylvania
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations					75,300,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards					143,900,000
State | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount					$ 3,200,000

Income Taxes Significant Compon

Income Taxes Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Capitalized research expense	$ 5,250	$ 6,300
NOL carryforwards	127,835	110,788
Research and development and other tax credits	13,242	11,737
Deferred revenue	1,628	1,506
Stock-based compensation	3,256	3,255
Acquired intangibles	757	889
Derivative liability	0	1,852
Interest expense	564	1,122
Investment in affiliated entity	542	645
Lease liability	4,283	4,722
Other	6,127	2,413
Deferred tax assets, gross	163,484	145,229
Valuation allowance	(159,705)	(137,159)
Total deferred tax assets	3,779	8,070
Deferred tax liabilities:
Acquired intangibles	(179)	(160)
Right of use asset	(2,676)	(2,894)
Note discount	(469)	(2,862)
Convertible note	0	(1,381)
Fixed assets	(487)	(805)
Net deferred tax liabilities	$ (32)	$ (32)

Income Taxes Expected Expiratio

Income Taxes Expected Expirations of Federal and State Losses and Credits (Details) $ in Millions	Dec. 31, 2020USD ($)
Federal
Expirations of Operating Loss Carryforwards, Components [Abstract]
2021	$ 2.3
2022	6.1
2023	5.3
2024	14.5
2025 and thereafter	267.7
Indefinite	270.3
Total	566.2
State
Expirations of Operating Loss Carryforwards, Components [Abstract]
2021	0.3
2022	0.4
2023	1.2
2024	9.1
2025 and thereafter	132.9
Indefinite	0
Total	143.9
Research Tax Credit Carryforward | Federal
Expirations of Tax Credit Carryforwards [Abstract]
2021	0
2022	0
2023	0
2024	0
2025 and thereafter	19.8
Indefinite	0
Total	19.8
Research Tax Credit Carryforward | State
Expirations of Tax Credit Carryforwards [Abstract]
2021	0
2022	0
2023	0
2024	0
2025 and thereafter	0
Indefinite	3.2
Total	$ 3.2

Income Taxes Unrecognized Tax B

Income Taxes Unrecognized Tax Benefits Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 11,204	$ 9,632	$ 8,313
Increases related to current year tax positions	1,043	1,575	1,319
Increases (decreases) related to prior year tax positions	27
Increases (decreases) related to prior year tax positions		(3)	0
Other	(64)	0	0
Balance at end of the year	$ 12,210	$ 11,204	$ 9,632

401(k) Plan (Details)

401(k) Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Employer matching contribution, percent	50.00%
Maximum annual contribution per employee, percent	6.00%
Company's contribution to 401(k) plan	$ 1.1	$ 1.2	$ 1.2

Related Party Transactions (Det

Related Party Transactions (Details) ₩ in Billions	Aug. 27, 2020USD ($)shares	Aug. 27, 2020KRW (₩)shares	Nov. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Feb. 20, 2020shares
Related Party Transaction [Line Items]
Proceeds from issuance of common stock					$ 454,486,400	$ 9,089,010	$ 29,227,776
Awarded option amount					6,000,000
GeneOne (affiliated entity)
Related Party Transaction [Line Items]
Proceeds from issuance of common stock	$ 40,100,000	₩ 47.4
Accounts receivable						128,000
Due to related parties						511,000
GeneOne (affiliated entity)
Related Party Transaction [Line Items]
Number of shares owned (shares) | shares	1,644,155	1,644,155
Proceeds from issuance of common stock	$ 40,100,000	₩ 47.4
Revenue from related parties					125,000	127,000	342,000
Operating expenses related to affiliated entity					$ 4,700,000	2,500,000	$ 7,000,000
PLS (affiliated entity)
Related Party Transaction [Line Items]
Number of shares owned (shares) | shares					597,808
Accounts receivable					$ 67,000	589,000
Revenue from related parties					$ 1,400,000	111,000
Percentage of ownership					19.70%
PLS (affiliated entity) | Available-for-sale Securities
Related Party Transaction [Line Items]
Investment owned, additional shares acquired (in shares) | shares								202,050
The Wistar Institute
Related Party Transaction [Line Items]
Accounts receivable					$ 425,000	616,000
Due to related parties					643,000	219,000
Operating expenses related to affiliated entity					2,300,000	1,500,000
Expenses to reimburse				$ 3,100,000
Term				5 years
Proceeds from sub-grant			$ 6,100,000
Awarded amount					10,700,000
Grant proceeds received					1,900,000	$ 2,200,000
Deferred grant funding from affiliate					$ 96,000

Geneos Therapeutics, Inc. - Nar

Geneos Therapeutics, Inc. - Narrative (Details) - USD ($)	Jun. 01, 2020	Nov. 30, 2020	Feb. 28, 2019	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2020
Noncontrolling Interest [Line Items]
Payments to acquire additional interest in subsidiaries									$ 1,399,999	$ 0	$ 0
Gain on deconsolidation of Geneos				$ 0	$ 0	$ 4,121,075	$ 0		4,121,075	0	0
Share in net loss of Geneos				1,923,179	$ 1,759,674	$ 901,757	$ 0		4,584,610	0	$ 0
Investment in Geneos				$ 434,387				$ 434,387	$ 434,387	$ 0
Series A-1 Preferred Stock
Noncontrolling Interest [Line Items]
Investment in Geneos	$ 1,399,999
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by parent		36.00%	61.00%			47.00%	52.00%
Percentage of ownership				47.00%				47.00%	47.00%
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Payments to acquire additional interest in subsidiaries		$ 1,400,000	$ 1,200,000
Stock purchase agreement, commitment of additional investment						$ 800,000						$ 800,000
Gain on deconsolidation of Geneos	4,121,075
Deconsolidation gain, remeasurement of retained noncontrolling investment to fair value	2,400,000
Share in net loss of Geneos								$ 4,584,610
Investment in Geneos	3,618,998			$ 434,387				434,387	$ 434,387
Geneos Therapeutics, Inc. | Common stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos								819,000
Investment in Geneos	$ 819,000			0				0	0
Geneos Therapeutics, Inc. | Series A-1 Preferred Stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos								3,800,000
Investment in Geneos				$ 434,000				$ 434,000	$ 434,000

Geneos Therapeutics, Inc. - Dec

Geneos Therapeutics, Inc. - Deconsolidation Accounting (Details) - USD ($)	Jun. 01, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Fixed assets, net of accumulated depreciation		$ (11,348,144)				$ (11,348,144)	$ (12,773,017)
Carrying value of noncontrolling interest		0				0	1,969,759
Gain on deconsolidation of Geneos		$ 0	$ 0	$ (4,121,075)	$ 0	(4,121,075)	0	$ 0
Decrease in cash resulting from the deconsolidation of Geneos						$ 2,774,851	$ 0	$ 0
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Working capital (excluding cash)	$ (59,992)
Note payable	171,620
Fixed assets, net of accumulated depreciation	(16,340)
Carrying value of noncontrolling interest	3,181,640
Fair value of investment in Geneos retained	3,618,998
Gain on deconsolidation of Geneos	(4,121,075)
Decrease in cash resulting from the deconsolidation of Geneos	$ 2,774,851

Geneos Therapeutics, Inc. - Inv

Geneos Therapeutics, Inc. - Investment in Geneos (Details) - USD ($)	Dec. 31, 2020	Jun. 01, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Fair Value	$ 434,387		$ 0
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Shares (in shares)		5,113,206
Fair Value	434,387	$ 3,618,998
Geneos Therapeutics, Inc. | Common
Noncontrolling Interest [Line Items]
Shares (in shares)		3,000,000
Price per Share (in USD per share)		$ 0.273
Fair Value	$ 0	$ 819,000
Geneos Therapeutics, Inc. | Preferred
Noncontrolling Interest [Line Items]
Shares (in shares)		2,113,206
Price per Share (in USD per share)		$ 1.325
Fair Value		$ 2,799,998

Geneos Therapeutics, Inc. - Fai

Geneos Therapeutics, Inc. - Fair Value Assumptions (Details) - Geneos Therapeutics, Inc.	Jun. 01, 2020USD ($)
Noncontrolling Interest [Line Items]
Geneos enterprise value	$ 4,966,531,000
Expected term (years)
Noncontrolling Interest [Line Items]
Equity method investment, measurement input, expected term	2 years 11 months 1 day
Volatility
Noncontrolling Interest [Line Items]
Equity method investment, measurement input	0.70
Risk-free interest rate
Noncontrolling Interest [Line Items]
Equity method investment, measurement input	0.0246

Geneos Therapeutics, Inc. - Pre

Geneos Therapeutics, Inc. - Preferred Stock Investment (Details) - USD ($)	3 Months Ended				7 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Investment in Geneos upon deconsolidation				$ 0		$ 0
Share in net loss of Geneos	$ 1,923,179	$ 1,759,674	$ 901,757	$ 0		4,584,610	$ 0	$ 0
Investment in Geneos as of December 31, 2020	434,387				$ 434,387	434,387	$ 0
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Share in net loss of Geneos					4,584,610
Investment in Geneos as of December 31, 2020	434,387				434,387	434,387
Geneos Therapeutics, Inc. | Series A-1 Preferred Stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos					3,800,000
Investment in Geneos as of December 31, 2020	$ 434,000				$ 434,000	$ 434,000

Quarterly Financial Informati_3

Quarterly Financial Information (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 5,580,581	$ 236,178	$ 267,187	$ 1,327,274	$ 279,488	$ 866,863	$ 135,673	$ 2,829,905	$ 7,411,220	$ 4,111,930	$ 30,481,897
Research and development	26,302,561	26,455,112	22,376,575	19,111,188	22,003,955	19,137,209	22,486,266	24,389,888	94,245,436	88,017,319	95,257,876
General and administrative	8,617,458	10,110,506	11,071,510	7,448,354	8,696,586	5,681,441	5,850,101	6,975,029	37,247,828	27,203,156	29,315,159
Total operating expenses	34,920,019	36,565,618	33,448,085	26,559,542	30,700,541	24,818,650	28,336,367	31,364,917	131,493,264	115,220,475	124,573,035
Loss from operations	(29,339,438)	(36,329,440)	(33,180,898)	(25,232,268)	(30,421,053)	(23,951,787)	(28,200,694)	(28,535,012)	(124,082,044)	(111,108,545)	(94,091,138)
Interest income	931,168	896,710	1,067,399	416,569	587,679	637,438	755,330	625,535	3,311,846	2,605,981	2,264,747
Interest expense	(1,068,008)	(1,984,046)	(2,846,641)	(2,803,755)	(2,668,837)	(2,428,671)	(2,194,783)	(656,248)	(8,702,450)	(7,948,539)	0
Change in fair value of derivative liability	0	35,306,000	(97,755,000)	(13,221,977)	(4,315,105)	2,551,453	0	0	(75,670,977)	(1,763,652)	0
Gain (loss) on investment in affiliated entities	306,317	26,951,898	(3,883,176)	13,181,619	(1,681,401)	(485,841)	(173,212)	(750,103)	36,556,658	(3,090,557)	(1,988,567)
Net unrealized gain on available-for-sale equity securities	1,070,975	1,315,980	4,358,634	(5,050,092)					1,695,497	0	0
Other income (expense), net	9,350	(136,644)	(152,102)	(425,500)	263,571	140,956	127,512	(35,839)	(704,896)	496,200	(1,343,856)
Gain on deconsolidation of Geneos	0	0	4,121,075	0					4,121,075	0	0
Net loss before income tax benefit/(provision for income tax)	(22,415,201)	20,931,010	(128,270,709)	(33,135,404)	(38,235,146)	(23,536,452)	(29,685,847)	(29,351,667)	(162,890,304)	(120,809,112)	(94,798,019)
Income tax benefit					87,764	0	106,771	62,800	0	257,335	(2,169,811)
Share in net loss of Geneos	(1,923,179)	(1,759,674)	(901,757)	0					(4,584,610)	0	0
Net loss	(24,338,380)	19,171,336	(129,172,466)	(33,135,404)	(38,147,382)	(23,536,452)	(29,579,076)	(29,288,867)	(167,474,914)	(120,551,777)	(96,967,830)
Net loss attributable to non-controlling interest	0	0	469,407	594,350	485,344	445,759	191,850	69,605	1,063,757	1,192,558	0
Net loss attributable to Inovio Pharmaceuticals, Inc.	$ (24,338,380)	$ 19,171,336	$ (128,703,059)	$ (32,541,054)	$ (37,662,038)	$ (23,090,693)	$ (29,387,226)	$ (29,219,262)	(166,411,157)	(119,359,219)	(96,967,830)
Net income (loss) per share
Basic (in USD per share)	$ (0.14)	$ 0.12	$ (0.83)	$ (0.26)	$ (0.38)	$ (0.23)	$ (0.30)	$ (0.30)
Diluted (in USD per share)	$ (0.14)	$ 0.11	$ (0.83)	$ (0.26)	$ (0.38)	$ (0.25)	$ (0.30)	$ (0.30)
Convertible Bonds
Disaggregation of Revenue [Line Items]
Gain (loss) on extinguishment of debt	$ 0	$ (8,177,043)	$ 0	$ 0					(8,177,043)	0	0
6.50% Convertible Senior Notes Due 2024
Disaggregation of Revenue [Line Items]
Gain (loss) on extinguishment of debt	5,674,435	3,087,595	0	0					8,762,030	0	0
Revenue under collaborative research and development arrangements
Disaggregation of Revenue [Line Items]
Total revenues	5,003,494	21,490	74,102	71,500	$ 184,523	$ 617,427	$ 64,283	$ 2,770,712	5,170,586	3,636,945	29,860,785
Revenue under collaborative research and development arrangements from affiliated entities
Disaggregation of Revenue [Line Items]
Total revenues	82,774	103,684	95,146	1,172,126	55,665	53,014	71,390	55,579	1,453,730	235,649	449,524
Other revenue, including from affiliated entities
Disaggregation of Revenue [Line Items]
Total revenues	$ 494,313	$ 111,004	$ 97,939	$ 83,648	$ 39,300	$ 196,422	$ 0	$ 3,614	$ 0	$ 1,800	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event $ / shares in Units, $ in Millions	Jan. 25, 2021USD ($)$ / sharesshares
Subsequent Event [Line Items]
Underwritten public offering, common stock (in shares) | shares	20,355,000
Sale of stock, price per share (in USD per share) | $ / shares	$ 8.50
Commissions and other estimated offering expenses | $	$ 162.1

Uncategorized Items - ino-20201

Label	Element	Value
Accounting Standards Update [Extensible List]	us-gaap_AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201601Member