Inovio Pharmaceuticals (INO) 10-K 1 Mar 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2021	Feb. 25, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
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			$ 1.9
Entity Common Stock, Shares Outstanding		217,403,287
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 2022 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, 2021.
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0001055726

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Audit Information [Abstract]
Auditor Location	San Diego, California
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 71,143,778	$ 250,728,118
Short-term investments	330,170,940	160,914,935
Accounts receivable	5,466,850	18,559,967
Accounts receivable from affiliated entities	2,565,194	503,782
Prepaid expenses and other current assets	38,836,991	40,357,456
Prepaid expenses and other current assets from affiliated entities	261,192	106,432
Total current assets	448,444,945	471,170,690
Fixed assets, net	17,453,206	11,348,144
Investments in affiliated entity	3,906,796	4,460,366
Investment in Geneos	0	434,387
Intangible assets, net	2,626,355	3,146,770
Goodwill	10,513,371	10,513,371
Operating lease right-of-use assets	11,571,026	12,741,296
Other assets	1,425,794	25,957,448
Total assets	495,941,493	539,772,472
Current liabilities:
Accounts payable and accrued expenses	47,644,530	21,203,808
Accounts payable and accrued expenses due to affiliated entities	548,032	642,969
Accrued clinical trial expenses	10,326,266	9,950,345
Deferred revenue	21,628	46,628
Operating lease liability	2,603,956	2,329,394
Grant funding liability	4,559,721	7,474,310
Grant funding liability from affiliated entities	37,500	58,500
Total current liabilities	65,741,633	41,705,954
Deferred revenue, net of current portion	64,361	79,214
Operating lease liability, net of current portion	15,459,559	18,063,515
Deferred tax liabilities	32,046	32,046
Grant funding liability from affiliated entity, net of current portion	0	37,500
Other liabilities	14,826	57,663
Total liabilities	96,272,072	78,631,714
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, 2021 and 2020	0	0
Common stock—par value $0.001; Authorized shares: 600,000,000 at December 31, 2021 and 2020, issued and outstanding: 217,382,887 at December 31, 2021 and 186,851,493 at December 31, 2020	217,382	186,851
Additional paid-in capital	1,609,589,797	1,367,406,869
Accumulated deficit	(1,209,855,522)	(906,196,812)
Accumulated other comprehensive income (loss)	(282,236)	(256,150)
Total Inovio Pharmaceuticals, Inc. stockholders’ equity	399,669,421	461,140,758
Total liabilities and stockholders’ equity	495,941,493	539,772,472
6.50% Convertible Senior Notes Due 2024
Current liabilities:
Convertible debt	14,959,647	14,139,988
Convertible Bonds
Current liabilities:
Convertible debt	$ 0	$ 4,515,834

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
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	9
Preferred stock, shares outstanding (in shares)	9	9
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)	217,382,887	186,851,493
Common stock, shares outstanding (in shares)	217,382,887	186,851,493

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Total revenues	$ 1,774,758	$ 7,411,220	$ 4,111,930
Operating expenses:
Research and development	249,240,324	94,245,436	88,017,319
General and administrative	53,752,353	37,247,828	27,203,156
Total operating expenses	302,992,677	131,493,264	115,220,475
Loss from operations	(301,217,919)	(124,082,044)	(111,108,545)
Other income (expense):
Interest income	3,363,080	3,311,846	2,605,981
Interest expense	(1,936,447)	(8,702,450)	(7,948,539)
Change in fair value of derivative liability	0	(75,670,977)	(1,763,652)
Gain (loss) on investment in affiliated entities	(553,570)	36,556,658	(3,090,557)
Net unrealized gain (loss) on available-for-sale equity securities	(3,222,838)	1,695,497	0
Other income (expense), net	343,371	(704,896)	496,200
Gain on deconsolidation of Geneos	0	4,121,075	0
Net loss before income tax benefit	(303,224,323)	(162,890,304)	(120,809,112)
Income tax benefit	0	0	257,335
Share in net loss of Geneos	(434,387)	(4,584,610)	0
Net loss	(303,658,710)	(167,474,914)	(120,551,777)
Net loss attributable to non-controlling interest	0	1,063,757	1,192,558
Net loss attributable to Inovio Pharmaceuticals, Inc.	$ (303,658,710)	$ (166,411,157)	$ (119,359,219)
Net loss per share attributable to Inovio Pharmaceuticals, Inc. stockholders
Basic (in USD per share)	$ (1.45)	$ (1.07)	$ (1.21)
Diluted (in USD per share)	$ (1.45)	$ (1.07)	$ (1.21)
Weighted average number of common shares outstanding
Basic (in shares)	208,829,801	155,126,857	98,717,999
Diluted (in shares)	208,829,801	155,126,857	98,717,999
Convertible Bonds
Other income (expense):
Gain (loss) on extinguishment of convertible bonds and senior notes	$ 0	$ (8,177,043)	$ 0
6.50% Convertible Senior Notes Due 2024
Other income (expense):
Gain (loss) on extinguishment of convertible bonds and senior notes	0	8,762,030	0
Revenue under collaborative research and development arrangements
Revenues:
Total revenues	902,260	5,170,586	3,636,945
Revenue under collaborative research and development arrangements from affiliated entities
Revenues:
Total revenues	245,310	1,453,730	235,649
Other revenue
Revenues:
Total revenues	627,188	786,904	237,536
Other revenue from affiliated entities
Revenues:
Total revenues	$ 0	$ 0	$ 1,800

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (303,658,710)	$ (167,474,914)	$ (120,551,777)
Other comprehensive income (loss):
Foreign currency translation	(30,134)	27,205	0
Unrealized gain (loss) on short-term investments, net of tax	4,048	(755,963)	1,001,475
Comprehensive loss	(303,684,796)	(168,203,672)	(119,550,302)
Comprehensive loss attributable to non-controlling interest	0	1,063,757	1,192,558
Comprehensive loss attributable to Inovio Pharmaceuticals, Inc.	$ (303,684,796)	$ (167,139,915)	$ (118,357,744)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	6.50% Convertible Senior Notes Due 2024	August 2019 Bonds	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 other comprehensive income (loss)	Non- controlling interest
Beginning balance (in shares) at Dec. 31, 2018				23	97,225,810
Beginning 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, net of capital raising related expenses (in shares)					3,340,678
Issuance of common stock for cash, net of capital raising related expenses	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, net of capital raising related expenses (in shares)					66,064,886
Issuance of common stock for cash, net of capital raising related expenses	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of capital raising related expenses (in shares)					27,310,341
Issuance of common stock for cash, net of capital raising related expenses	209,441,410				$ 27,310			209,414,100
Conversion of preferred stock/senior notes to common stock (in shares)							1,009,450
Conversion of preferred stock/senior notes to common stock			$ 4,377,892				$ 1,009			$ 4,376,883
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)					2,211,603
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments	2,057,393				$ 2,212			2,055,181
Stock-based compensation	26,336,764							26,336,764					0
Net loss attributable to common stockholders	(303,658,710)										(303,658,710)		0
Unrealized gain/loss on short-term investments, net of tax	4,048											4,048
Foreign currency translation	(30,134)											(30,134)
Ending balance (in shares) at Dec. 31, 2021				9	217,382,887
Ending balance at Dec. 31, 2021	$ 399,669,421			$ 0	$ 217,382			$ 1,609,589,797			$ (1,209,855,522)	$ (282,236)	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (303,658,710)	$ (167,474,914)	$ (120,551,777)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	3,040,096	3,038,996	3,598,388
Amortization of intangible assets	520,415	547,081	1,066,294
Amortization of operating lease right-of-use assets	1,170,270	1,041,713	851,760
Change in fair value of derivative liability	0	75,670,977	1,763,652
Stock-based compensation	26,336,764	15,647,523	10,901,320
Non-cash interest expense	858,644	4,077,686	5,230,954
Amortization of premiums on investments	1,633,286	0	1,962
Deferred taxes	0	0	5,397
Loss (gain) on short-term investments	5,397	588,270	(476,368)
Settlement of receivable with shares of common stock from affiliated entity (PLS)	0	(1,713,770)	0
Gain on deconsolidation of Geneos	0	(4,121,075)	0
Loss on disposal of fixed assets	0	26,913	5,889
Loss (gain) on equity investment in affiliated entities	553,570	(36,556,658)	3,090,557
Share of net loss in Geneos	434,387	4,584,610	0
Net unrealized loss (gain) on available-for-sale equity securities	3,222,838	(1,695,497)	0
Tax benefit from other unrealized gains on short-term investments	0	0	(266,215)
Unrealized transaction (gain) loss on foreign-currency denominated debt	(176,927)	15,902	471,172
Changes in operating assets and liabilities:
Accounts receivable	13,093,117	(17,859,894)	2,616,288
Accounts receivable from affiliated entities	(2,061,412)	844,423	(593,461)
Prepaid expenses and other current assets	(6,188,872)	(38,849,572)	(178,008)
Prepaid expenses and other current assets from affiliated entities	(154,760)	374,107	70,665
Other assets	24,531,654	(23,285,424)	(2,026)
Accounts payable and accrued expenses	26,235,907	3,115,828	(4,337,829)
Accrued clinical trial expenses	375,921	5,962,381	(1,622,037)
Accounts payable and accrued expenses due to affiliated entities	(94,937)	135,650	(248,063)
Deferred revenue	(39,853)	(68,078)	(180,450)
Deferred revenue from affiliated entities	0	5,725	(1,800)
Operating lease right-of-use assets and liabilities, net	(2,329,394)	(2,091,855)	(1,733,599)
Grant funding liability	(2,914,589)	1,409,098	1,899,364
Grant funding liability from affiliated entities	(58,500)	(784,925)	816,342
Other liabilities	(42,837)	20,720	(48,507)
Net cash used in operating activities	(215,708,525)	(177,979,046)	(97,850,136)
Cash flows from investing activities:
Purchases of investments	(348,953,236)	(156,216,677)	(100,950,301)
Proceeds from sale of or maturity of investments	174,839,758	62,991,023	92,893,232
Purchases of capital assets	(1,231,006)	(1,520,665)	(987,926)
Proceeds from sale of investment of GeneOne	0	40,125,418	0
Decrease in cash resulting from the deconsolidation of Geneos	0	(2,774,851)	0
Investment in Geneos	0	(1,399,999)	0
Net cash used in investing activities	(175,344,484)	(58,795,751)	(9,044,995)
Cash flows from financing activities:
Proceeds from issuances of convertible senior notes and convertible bonds	0	0	97,443,617
Costs related to issuances of convertible senior notes and convertible bonds	0	0	(3,314,757)
Proceeds from issuance of common stock, net of issuance costs	209,441,410	454,486,400	9,089,010
Proceeds from stock option exercises, net of tax payments	6,668,741	12,269,801	112,522
Taxes paid related to net share settlement of equity awards, net of proceeds from option exercises	(4,611,348)	(4,028,177)	(892,928)
Acquisition of non-controlling interest	0	2,379,969	2,960,131
Proceeds from Geneos issuance of note payable	0	171,620	0
Net cash provided by financing activities	211,498,803	465,279,613	105,397,595
Effect of exchange rate changes on cash and cash equivalents	(30,134)	27,205	0
Increase (decrease) in cash and cash equivalents	(179,584,340)	228,532,021	(1,497,536)
Cash and cash equivalents, beginning of period	250,728,118	22,196,097	23,693,633
Cash and cash equivalents, end of period	71,143,778	250,728,118	22,196,097
Supplemental disclosure:
Amounts accrued for purchases of property and equipment	204,815	136,711	0
Interest paid	1,077,803	4,624,764	2,717,585
Change in prepaid expenses and other current assets included in fixed assets	7,709,337	0	0
Equity component of issuance of convertible notes	0	0	15,752,698
Right-of-use assets obtained in exchange for lease obligations	0	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	0	8,177,043	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	$ 0	$ (8,762,030)	$ 0

The Company

The Company	12 Months Ended
	Dec. 31, 2021
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 bringing to market precisely designed DNA medicines and vaccines to help protect people from infectious diseases, including COVID-19, and to help treat people with cancer, and conditions associated with human papillomavirus ("HPV"). INOVIO has shown in clinical trials that its DNA vaccine candidates can be delivered into cells in the body via a proprietary smart device allowing the nucleic-acid delivered gene products to activate functional T cell and antibody responses against targeted pathogens and cancers. The Company's DNA medicines pipeline is comprised of three types of product candidates: prophylactic DNA vaccines, therapeutic DNA immunotherapies, and DNA encoded monoclonal and bispecific antibodies ("dMAbs" and “dBTAs”), all of which utilize the two components of INOVIO's integrated platform, SynCon ® and CELLECTRA®. The Company's proprietary SynCon ® technology creates optimized plasmids, which are circular strands of DNA that instruct a cell to produce proteins or antigens to help the person’s immune system respond with antibodies and immune cells which recognize and then help block viruses and destroy cancerous or pre-cancerous cells. INOVIO's patented CELLECTRA ® smart delivery devices facilitate uptake of its DNA medicines into the cell, which has been a key limitation of historical DNA-based technology approaches. Human clinical trial data from more than 15,000 CELLECTRA® smart device administrations across more than 5,000 participants to date have shown a tolerable safety profile. INOVIO's corporate strategy is to develop, seek regulatory approval for and commercialize its novel DNA medicines to address unmet global health needs. The Company continues to advance and clinically validate an array of DNA medicine candidates that target infectious diseases, such as COVID-19, as well as HPV-associated diseases and cancer. The Company's partners and collaborators include ApolloBio Corporation, AstraZeneca, Beijing Advaccine, The Bill & Melinda Gates Foundation (Gates), Coalition for Epidemic Preparedness Innovations ("CEPI"), The U.S. Department of Defense ("DoD"), Defense Advanced Research Projects Agency ("DARPA"), HIV Vaccines Trial Network, the U.S. Defense Threat Reduction Agency’s Medical CBRN Defense Consortium ("MCDC"), International Vaccine Institute ("IVI"), Kaneka Eurogentec, 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 evaluating the feasibility of, conducting or planning clinical studies of DNA medicines for COVID-19, which includes both homologous and heterologous boosting approaches; Middle East Respiratory Syndrome, or MERS; Lassa fever; Ebola; as well as 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, or RRP; glioblastoma multiforme, or GBM; and prostate cancer. 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, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Liquidity The Company incurred a net loss attributable to common stockholders of $303.7 million for the year ended December 31, 2021. The Company had working capital of $382.7 million and an accumulated deficit of $1.2 billion as of December 31, 2021. 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 $401.3 million as of December 31, 2021 , 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. 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 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 of $162.1 million from a January 2021 underwritten public offering, net proceeds of $47.7 million under a Sales Agreement during the year ended December 31, 2021, net proceeds of $454.5 million under Sales Agreements 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. 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. These consolidated financial statements do not include any adjustments to the specific amounts and classifications of assets and liabilities, which might be necessary should Inovio be unable to continue as a going concern. The Company's consolidated financial statements as of and for the year ended December 31, 2021 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business for the foreseeable future. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements. The Company is and, from time to time, may in the future 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. 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 continues to closely monitor the impact of the COVID-19 pandemic on its employees, collaborators and service providers. The extent to which the pandemic will continue to impact the Company's business and operations will depend on future developments, including travel restrictions to, from and within 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, including mass vaccination efforts, that are highly uncertain as of the date the Company is issuing these financial statements. Consolidation 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. The consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiary. As of December 31, 2021 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 16 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 3. Fair Value of Financial Instruments 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. The Company’s financial instruments include cash equivalents, short-term investments, investments in affiliated entities, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses, and convertible senior notes. The carrying amounts of cash equivalents, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses approximate the related fair values due to the short-term maturities of these instruments. Short-term investments are recorded at fair value on a recurring basis, based on current market valuations. The Company carries convertible senior notes 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, 2021 and 2020. Short-term 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, commercial paper, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2021 and 2020. Short-term investments are recorded at fair value, based on current market valuations. Unrealized gains and losses on the Company's short-term debt investments 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. 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, 2021 and 2020. 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, 2021. Valuation of Intangible Assets and Goodwill Intangible assets are amortized over their estimated useful lives ranging from two 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, 2021 and 2020, the Company’s intangible assets resulting from the acquisition of Inovio AS and Bioject Medical Technologies, Inc. ("Bioject"), and additional intangibles including license costs, net of accumulated amortization, totaled $2.6 million and $3.1 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, 2021. 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 likely 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 likely that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company will proceed to perform the impairment test in which the fair value of the reporting unit is compared with its carrying amount, and an impairment charge will be recorded for the amount by which the carrying amount exceeds the reporting unit's fair value, if any. The Company performed its annual assessment for goodwill impairment as of November 30, 2021, 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 8 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 $237.2 million and $159.7 million at December 31, 2021 and 2020, 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 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 and the Company concludes that its collaboration partner is not a customer, the Company presents such payments as a reduction of research and development expense. 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”). 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 translated at the end of each reporting period into the functional currency at the exchange rate at that date. The cumulative translation adjustment is included in the accumulated other comprehensive income (loss) within the statement of stockholders' equity. 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 costs incurred based on participant enrollment, completion of studies and other events. 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. Advance payments for goods or services to be rendered in the future for use in research and development activities are deferred and included in prepaid expenses and other assets. The deferred amounts are expensed as the related goods are delivered or the services are performed. 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 9) 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, 2021, 2020 and 2019, 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, 2021 2020 2019 Options to purchase common stock 10,488,993 8,906,624 9,265,390 Service-based restricted stock units 2,448,868 2,558,052 2,069,936 Performance-based restricted stock units 663,353 663,353 — Convertible preferred stock 3,309 3,309 8,456 Convertible notes 3,049,980 3,049,980 14,585,653 August 2019 Bonds — — 3,799,071 December 2019 Bonds — 1,009,450 1,009,450 Total 16,654,503 16,190,768 30,737,956 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 r

Revenue Recognition and Concent

Revenue Recognition and Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition and Concentration of Credit Risk	Revenue Recognition and Concentration of Credit RiskDuring the years ended December 31, 2021, 2020 and 2019, the Company recognized revenue from various license and other agreements. The following table indicates the percentage of total revenues in excess of 10% with any single customer: Customer 2021 Revenue % of Total 2020 Revenue % of Total 2019 Revenue % of Total AstraZeneca $ 41,659 2 % $ 170,587 2 % $ 3,194,877 78 % Advaccine — — 5,000,000 68 — — Plumbline Life Sciences, Inc. (affiliated entity) 245,310 14 1,370,396 18 — — Department of Defense 754,853 43 — — — — All other, including affiliated entities 732,936 41 870,237 12 917,053 22 Total revenue $ 1,774,758 100 % 1 $ 7,411,220 100 % $ 4,111,930 100 % Of the total revenue recognized during the year ended December 31, 2021, $46,000 was in deferred revenue as of December 31, 2020. During the year ended December 31, 2020, the Company recognized revenue of $127,000 that was included in deferred revenue at December 31, 2019. Performance obligations are generally satisfied within 12 months of the initial contract date. As of December 31, 2021, $3.6 million, or 65%, and $1.9 million, or 34%, of the Company's accounts receivable was attributable to the DoD and the CEPI MERS grant, respectively. 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. There is minimal credit risk with these customers based upon collection history, their size and financial condition. Accordingly, the Company does not consider it necessary to record a reserve for uncollectible accounts receivable.

Collaborative Agreements

Collaborative Agreements	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Agreements	Collaborative Agreements Advaccine Biopharmaceuticals Suzhou Co., Ltd. On December 31, 2020, the Company entered into a Collaboration and License Agreement with Advaccine Biopharmaceuticals Suzhou Co., Ltd. (“Advaccine”), which was amended and restated on June 7, 2021 (as amended and restated, the “Advaccine Agreement”). Under the terms of the Advaccine Agreement, the Company 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”) and 33 additional countries in Asia. Advaccine does 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 also granted to the Company a non-exclusive license to certain DNA vaccine manufacturing processes. The June 2021 amendment relates to the collaboration between the Company and Advaccine to jointly conduct the global Phase 3 segment of the Company’s ongoing Phase 2/3 trial of INO-4800 and expand the existing collaboration to include the planned global Phase 3 trial. The parties will jointly participate in the trial and will equally share the global development costs for the trial, including the Company’s manufacturing costs to supply INO-4800. In certain instances, the Company will have the right to convert the exclusive license to a non-exclusive license in the licensed territories, other than Greater China, unless Advaccine agrees to pay the Company its full share of development costs in excess of a specified maximum. Notwithstanding the foregoing, Advaccine will be fully responsible for conducting the trial in Greater China, including its costs and expenses incurred. The Company will be fully responsible for its costs and expenses, if any, incurred solely as a result of its activities in connection with the performance of the trial in the United States. The parties may continue to conduct clinical trials of INO-4800 outside of the territories covered by the Advaccine Agreement. In the event that a global purchasing entity desires to enter into a purchase agreement for INO-4800 in both parties’ territories, the parties will enter into good faith negotiations for an arrangement to supply INO-4800 to such entity. In addition, the Company is permitted to enter into an agreement with a global purchasing entity to authorize the entity to conduct a portion of the global Phase 3 trial in the licensed territory outside of Greater China. Under the Advaccine Agreement, Advaccine made an upfront payment to the Company of $3.0 million in January 2021. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of $206.0 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 and the additional covered territories, if approved. As of December 31, 2020 the Company had earned a $2.0 million milestone payment based on the enrollment of the first participant 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 the licensed territory, 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. Beginning in the first calendar year following the first commercial sale of INO-4800 in the licensed territory outside of Greater China, Advaccine will pay the Company an annual maintenance fee of $1.5 million for a period of five years, which fee will be creditable against any royalties payable by Advaccine with respect to sales outside of Greater China. Under the Advaccine 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 Advaccine 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 Advaccine 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 Advaccine Agreement, subject to certain conditions. Advaccine may terminate the Advaccine 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 the licensed territory, or 18 months’ written notice thereafter; provided that the Company may accelerate the effectiveness of such termination to the extent permitted by law. The Company evaluated the terms of the Advaccine Agreement under ASC Topics 606 and 808 at inception 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 Advaccine 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 Advaccine Agreement consisted of the $3.0 million upfront payment received in January 2021 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. 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. 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 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. There has been no additional revenue earned under this collaboration agreement with Advaccine for the year ended December 31, 2021. In connection with the June 2021 amendment, the Company determined that the Global Phase 3 trial component of the agreement is a collaboration and not a contract with a customer and therefore concluded to account for the June 2021 amendment under ASC Topic 808. Reimbursements from Advaccine will be recognized as contra-research development expense on the condensed consolidated statement of operations once earned and collectibility is assured. During the year ended December 31, 2021 , the Company received funding of $4.5 million from Advaccine that was recorded as contra-research and development expense. 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 agreed upon territories. 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 accordance with the ApolloBio Agreement. 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 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. 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, 2021 there have been no significant reimbursable program costs under the ApolloBio Agreement. 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. 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 was obligated to make potential future development and regulatory event-based payments to the Company and potential future commercial event-based payments, in each case upon the achievement of specified milestones related to MEDI0457 set forth in the license and collaboration agreement. AstraZeneca was funding all development costs associated with MEDI0457 immunotherapy. The Company was entitled to receive up to mid-single to double-digit tiered royalties on MEDI0457 product sales. Under the agreement, AstraZeneca could 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. On October 28, 2021, AstraZeneca provided notice to the Company to terminate the INO-3112 / MEDI0457 development program under the agreement. As a result of the termination, the agreement has been terminated in its entirety and the Company has no further obligations under the collaboration. 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, 2021 and 2020, the Company received funding of $10.0 million and $6.4 million, respectively, related to these grants and recorded those payments as contra-research and development expense. As of December 31, 2021, the Company had an accounts receivable balance of $1.9 million and recorded $23,000 as deferred grant funding on the consolidated balance sheet related to these CEPI grants. In January 2020, CEPI awarded the Company a grant of up to $9.0 million to support preclinical and clinical development of INO-4800 through Phase 1 human testing in the United States. 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 years ended December 31, 2021 and 2020 , the Company received funding of $6.9 million and $10.0 million, respectively, from CEPI related to these grants for INO-4800 and recorded such amounts as contra-research and development expense. As of December 31, 2021 the Company had $1.8 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, 2021 and 2020, the Company recorded $182,000 and $463,000, respectively, as contra-research and development expense related to the Gates dMAb grant. As of December 31, 2021, the Company had $384,000 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 years ended December 31, 2021 and 2020, the Company recorded $893,000 and $4.1 million, respectively, as contra-research and development expense 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 $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 later-stage clinical trials. The total purchase price under the Procurement Contract is expected to be approximately $10.7 million. As of December 31, 2021, t he Company determined that the Procurement Contract falls under the scope of ASC Topic 606 as the contract is with a customer and the Company is able to satisfy its obligations under the arrangement as the Phase 3 clinical trials of INO-4800 are underway. Performance obligations under the Procurement Contract consist of the delivery of a specified number of CELLECTRA ® 2000 devices and accessories. The total transaction price was allocated to the individual performance obligations based on the determined standalone selling price for the devices and accessories. The Company will recognize revenue on the consolidated statement of operations upon shipment of the purchased devices and accessories. During the year ended December 31, 2021, the Company recorded revenue of $755,000 from the Procurement Contract. This revenue was recognized at a 100% margin as the sale was for products whose related inventory had previously been written down to zero. During the years ended December 31, 2021 and 2020, the Company recorded $27.1 million and $21.2 million, respectively, as contra-research and development expense related to the OTA agreement. As of December 31, 2021, the Company had an accounts receivable balance of $3.6 million on the consolidated balance sheet from the DoD. As of December 31, 2021, the Company had $2.3 million recorded as deferred grant funding on the consolidated balance sheet related to the Procurement Contract. In April 2021, the Company announced that the DoD had notified the Company that it will discontinue funding f or the Phase 3 segment of the Company's clinical trial of INO-4800 in the United States, while continuing funding under the OTA Agreement and Procurement Contract.

Short-term Investments and Fair

Short-term Investments and Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Short-term Investments and Fair Value Measurements	Short-term Investments and Fair Value Measurements The following is a summary of available-for-sale securities as of December 31, 2021 and 2020: As of December 31, 2021 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 192,966,772 $ 87,069 $ (1,614,411) $ 191,439,430 U.S. treasury securities Less than 1 94,193,441 — (9,921) 94,183,520 Commercial paper Less than 1 39,967,853 — — 39,967,853 Certificates of deposit Less than 1 2,976,210 15,618 (338) 2,991,490 U.S. agency mortgage-backed securities * 1,608,137 4,508 (23,998) 1,588,647 $ 331,712,413 $ 107,195 $ (1,648,668) $ 330,170,940 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 *No single maturity date. During the years ended December 31, 2021 and 2020, the Company recorded gross realized ga in on investments of $394,000 and $744,000, respectively, and gross realized loss on investments of $399,000 and $1.3 million, respectively. During the years ended December 31, 2021 and 2020, the Company recorded net unrealized (loss) gain on available-for-sale equity securities of $(3.2) million and $1.7 million, respectively. No material balances were reclassified out of accumulated other comprehensive income (loss) for the years ended December 31, 2021, 2020 and 2019. 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, 2021, the Company had 24 available-for-sale securities in a gross unrealized loss position, of which six with an aggregate total unrealized loss of $766,000 were in such position for longer than 12 months. 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, 2021 were primarily due to changes in interest rates, 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 basis, 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, 2021, the Company has not recorded an allowance for credit losses related to its available-for-sale debt securities. The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2021: Fair Value Measurements at December 31, 2021 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 191,439,430 $ 191,439,430 $ — $ — U.S. treasury securities 94,183,520 94,183,520 — — Commercial paper 39,967,853 — 39,967,853 — Certificates of deposit 2,991,490 — 2,991,490 — U.S. agency mortgage-backed securities 1,588,647 — 1,588,647 — Total short-term investments 330,170,940 285,622,950 44,547,990 — Investment in affiliated entity 3,906,796 3,906,796 — — Total assets measured at fair value $ 334,077,736 $ 289,529,746 $ 44,547,990 $ — The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2020: Fair Value Measurements at December 31, 2020 Total Quoted Prices Significant Significant 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 — Investments in affiliated entity 4,460,366 4,460,366 — — Total assets measured at fair value $ 225,372,101 $ 219,330,340 $ 6,041,761 $ — Level 1 assets at December 31, 2021 and 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. The Company accounts for its investment in 597,808 common shares of PLS 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 ope rations as unrealized gain (loss) on available-for-sale equity securities or as a gain (loss) on investment in affiliated entity. Level 2 assets at December 31, 2021 consisted of commercial paper, certificates of deposit and U.S. agency mortgage-backed securities 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. Level 2 assets at December 31, 2020 consisted of certificates of deposit and U.S. agency mortgage-backed securities. The Company obtains the fair value of its Level 2 assets from a
Short-term Investments and Fair Value Measurements	Short-term Investments and Fair Value Measurements The following is a summary of available-for-sale securities as of December 31, 2021 and 2020: As of December 31, 2021 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 192,966,772 $ 87,069 $ (1,614,411) $ 191,439,430 U.S. treasury securities Less than 1 94,193,441 — (9,921) 94,183,520 Commercial paper Less than 1 39,967,853 — — 39,967,853 Certificates of deposit Less than 1 2,976,210 15,618 (338) 2,991,490 U.S. agency mortgage-backed securities * 1,608,137 4,508 (23,998) 1,588,647 $ 331,712,413 $ 107,195 $ (1,648,668) $ 330,170,940 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 *No single maturity date. During the years ended December 31, 2021 and 2020, the Company recorded gross realized ga in on investments of $394,000 and $744,000, respectively, and gross realized loss on investments of $399,000 and $1.3 million, respectively. During the years ended December 31, 2021 and 2020, the Company recorded net unrealized (loss) gain on available-for-sale equity securities of $(3.2) million and $1.7 million, respectively. No material balances were reclassified out of accumulated other comprehensive income (loss) for the years ended December 31, 2021, 2020 and 2019. 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, 2021, the Company had 24 available-for-sale securities in a gross unrealized loss position, of which six with an aggregate total unrealized loss of $766,000 were in such position for longer than 12 months. 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, 2021 were primarily due to changes in interest rates, 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 basis, 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, 2021, the Company has not recorded an allowance for credit losses related to its available-for-sale debt securities. The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2021: Fair Value Measurements at December 31, 2021 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 191,439,430 $ 191,439,430 $ — $ — U.S. treasury securities 94,183,520 94,183,520 — — Commercial paper 39,967,853 — 39,967,853 — Certificates of deposit 2,991,490 — 2,991,490 — U.S. agency mortgage-backed securities 1,588,647 — 1,588,647 — Total short-term investments 330,170,940 285,622,950 44,547,990 — Investment in affiliated entity 3,906,796 3,906,796 — — Total assets measured at fair value $ 334,077,736 $ 289,529,746 $ 44,547,990 $ — The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2020: Fair Value Measurements at December 31, 2020 Total Quoted Prices Significant Significant 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 — Investments in affiliated entity 4,460,366 4,460,366 — — Total assets measured at fair value $ 225,372,101 $ 219,330,340 $ 6,041,761 $ — Level 1 assets at December 31, 2021 and 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. The Company accounts for its investment in 597,808 common shares of PLS 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 ope rations as unrealized gain (loss) on available-for-sale equity securities or as a gain (loss) on investment in affiliated entity. Level 2 assets at December 31, 2021 consisted of commercial paper, certificates of deposit and U.S. agency mortgage-backed securities 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. Level 2 assets at December 31, 2020 consisted of certificates of deposit and U.S. agency mortgage-backed securities. The Company obtains the fair value of its Level 2 assets from a

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2021
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, 2021 and 2020 consisted of the following: 2021 2020 Prepaid manufacturing expenses (a) $ 27,474,159 $ 35,661,947 Other prepaid expenses 11,362,832 4,695,509 $ 38,836,991 $ 40,357,456 (a) Includes prepaid manufacturing expenses related to deposits made to reserve capacity for the manufacture of INO-4800. The Company deposited a total of $50.0 million to reserve manufacturing capacity, of which $30.0 million was paid in 2020 and the remainder paid in the first quarter of 2021. Of these deposits, $35.0 million was included in research and development expenses in December 2021.

Fixed Assets

Fixed Assets	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Fixed Assets	Fixed Assets Fixed assets at December 31, 2021 and 2020 consisted of the following: Cost Accumulated Net Book As of December 31, 2021 Leasehold improvements $ 15,803,108 $ (8,258,608) $ 7,544,500 Laboratory equipment 12,392,916 (4,279,816) 8,113,100 Office furniture and fixtures 2,827,476 (2,599,643) 227,833 Computer equipment and other 5,374,084 (3,806,311) 1,567,773 $ 36,397,584 $ (18,944,378) $ 17,453,206 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 Depreciation expense for the years ended December 31, 2021, 2020 and 2019 was $3.0 million, $3.0 million and $3.6 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, 2021 the Company disposed of fixed assets with a net book value of $89,000 and accumulated depreciation of $89,000.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2021
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, 2021 December 31, 2020 Weighted Average Useful Gross Accumulated Net Book Gross Accumulated Net Book Indefinite lived: Goodwill $ 10,513,371 $ — $ 10,513,371 $ 10,513,371 $ — $ 10,513,371 Definite lived: Licenses 10 1,323,761 (1,305,600) 18,161 1,323,761 (1,276,852) 46,909 Bioject (a) 12 5,100,000 (2,735,556) 2,364,444 5,100,000 (2,468,889) 2,631,111 Other (b) 18 4,050,000 (3,806,250) 243,750 4,050,000 (3,581,250) 468,750 Total intangible assets 11 10,473,761 (7,847,406) 2,626,355 10,473,761 (7,326,991) 3,146,770 Total goodwill and intangible assets $ 20,987,132 $ (7,847,406) $ 13,139,726 $ 20,987,132 $ (7,326,991) $ 13,660,141 (a) Bioject intangible assets represent the estimated fair value of developed technology and intellectual property which were recorded from an asset acquisition. (b) Other intangible assets represent the estimated fair value of acquired intellectual property. Aggregate amortization expense on intangible assets was $520,000, $547,000 and $1.1 million for the years ended December 31, 2021, 2020 and 2019, respectively. Amortization expense related to intangible assets at December 31, 2021 is expected to be incurred as follows: Year ending December 31, 2022 $ 493,000 2023 276,000 2024 253,000 2025 253,000 2026 253,000 Thereafter 1,098,000 $ 2,626,000 There were no impairment or impairment indicators present and no losses were recorded during the years ended December 31, 2021, 2020 and 2019, respectively.

Convertible Debt

Convertible Debt	12 Months Ended
	Dec. 31, 2021
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 $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 was 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 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, 2021 is as follows: Principal amount $ 78,500,000 Principal amount converted into common shares (62,085,000) Unamortized debt discount on the liability component (1,591,909) Unamortized debt issuance cost (219,101) Accrued interest 355,657 Net carrying amount $ 14,959,647 For the years ended December 31, 2021 and 2020, the Company recognized $1.9 million and $6.9 million, respectively, of interest expense related to the Notes, of which $1.1 million and $4.1 million, respectively, related to the contractual interest coupon. As of December 31, 2021, future minimum payments due under the Notes, representing contractual amounts due, including interest based on the fixed rate of 6.5% per annum, are as follows: 2022 $ 1,067,000 2023 1,067,000 2024 16,948,000 Total $ 19,082,000 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 Korean Won (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 $14.5 million. The August 2019 Bonds, which were 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 275.69 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 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 year ended December 31, 2020, the Company recognized $1.6 million of interest expense related to the August 2019 Bonds, of which $87,000 related to the contractual interest coupon. Immediately prior to the August 2020 conversion in full of the August 2019 Bonds, the derivative liability associated with the August 2019 Bonds 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 for the year ended December 31, 2020. 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 for the year ended December 31, 2020. 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 $4.0 million. The December 2019 Bonds, which were unsecured obligations of the Company, were issued on December 31, 2019 and accrue interest at a coupon rate of 1.00% per annum, payable quarterly. The December 2019 Bonds were scheduled to mature on December 31, 2024, unless earlier converted or repurchased. On March 17, 2021, the December 2019 Bonds were converted in full into an aggregate of 1,009,450 shares of the Company's common stock, leaving no further December 2019 Bonds outstanding. 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. As of the conversion date of March 17, 2021, the conversion rate had not been reset from the initial conversion rate. The Company evaluated the accounting for the issuance of the December 2019 Bonds and concluded that the embedded conversion feature did not require bifurcation from the December 2019 Bonds. Although the embedded conversion feature met the definition of a derivative, it qualified 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 were 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 was fixed as of the date preceding the date of issuance of the Bonds. Therefore, the fluctuation in functional currency did not impact the settlement of the conversion option. Further, as there was 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. At their issuance, the Company determined that the expected life of the December 2019 Bonds was through December 31, 2022 as this represented the point at which the December 2019 Bonds were 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 years ended December 31, 2021 and 2020, the Company recognized $50,000 and $253,000, respectively, of interest expense related to the December 2019 Bonds, of which $9,000 and $40,000, respectively, related to the contractual interest coupon. As of December 31, 2021, all outstanding December 2019 Bonds were converted into 1,009,450 shares of the Company's common stock. Upon conversion, the $4.4 million carrying value of the December 2019 Bonds was reclassified to stockholders' equity.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Accounts Payable and Accrued Expenses	Accounts Payable and Accrued Expenses Accounts payable and accrued expenses at December 31, 2021 and 2020 consisted of the following: 2021 2020 Trade accounts payable $ 24,213,673 $ 825,516 Accrued compensation 16,112,912 13,127,257 Accrued subcontract costs 11,602 247,796 Other accrued expenses 7,306,343 7,003,239 $ 47,644,530 $ 21,203,808

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock Shares Outstanding as of Shares Authorized Shares Issued 2021 2020 Series C Preferred Stock, par $0.001 1,091 1,091 9 9 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 a 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, 2021, 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 On November 9, 2021, the Company entered into an ATM Equity Offering SM Sales Agreement (the “2021 Sales Agreement”) with outside sales agents (collectively, the “Sales Agents”) for the offer and sale of its common stock for an aggregate offering price of up to $300.0 million. The 2021 Sales Agreement provides that the Sales Agents will be entitled to compensation in an amount equal to up to 3.0% of the gross sales proceeds of any common stock sold through the Sales Agents under the 2021 Sales Agreement. For the year ended December 31, 2021, the Company sold 6,955,341 shares of its common stock under the 2021 Sales Agreement. The sales were made at a weighted average price of $6.96 per share, resulting in aggregate net proceeds of $47.7 million. As of December 31, 2021 there was $251.6 million of remaining capacity under the 2021 Sales Agreement. On January 25, 2021, the Company closed an underwritten public offering of 20,355,000 shares of 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 offering expenses, were $162.1 million. On April 3, 2020, the Company and the Placement Agent entered into a new Sales Agreement (the "2020 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 2020 Sales Agreement for the offer and sale of its Common Stock for aggregate gross proceeds of up to an aggregate of $250.0 million. During the year ended December 31, 2020, the Company sold a total of 22,919,934 shares of its common stock under the 2020 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, there was no remaining capacity under the 2020 Sales Agreement. In May 2018, the Company entered into a Sales Agreement with an outside placement agent (the “Placement Agent”) to sell shares of its common stock with 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 amendments to the Sales Agreement (as so amended, the "2018 Sales Agreement") to increase the amount of common stock that could be sold under the 2018 Sales Agreement from $100.0 million to $250.0 million. During the three months ended March 31, 2020, the Company sold 43,148,952 shares of its common stock under the 2018 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 2018 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. As of December 31, 2021, the maximum number of shares of the Company’s common stock available for issuance over the term of the 2016 Incentive Plan was 20,000,000 shares. On the first business day of each calendar year, 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, 2022, the maximum number of shares increased by 2,000,000. At December 31, 2021, the Company had 4,481,745 shares of common stock available for future grant under the 2016 Incentive Plan, 2,448,868 shares underlying outstanding but unvested restricted stock units and options outstanding to purchase 8,060,957 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, 2021, the Company had options outstanding to purchase 2,428,036 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, 2021, 2020 and 2019 was $25.0 million, $14.5 million and $9.8 million, respectively, of which $13.4 million, $8.0 million and $5.9 million was included in research and development expenses and $11.6 million, $6.5 million and $3.9 million was included in general and administrative expenses, respectively. At December 31, 2021 and 2020, there was $16.5 million and $4.4 million, respectively, of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.0 years and 1.4 years, respectively. At December 31, 2021 and 2020, there was $13.4 million and $10.9 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 1.8 years and 1.9 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, 2021, 2020 and 2019 was $1.4 million, $1.2 million and $970,000, respectively. As of December 31, 2021, options to purchase 632,375 shares of common stock granted to non-employees remained outstanding. The following table summarizes total stock options outstanding at December 31, 2021: Options Outstanding Options Exercisable Exercise Price Shares Underlying Options Weighted-Average Weighted Shares Underlying Options Weighted Average $1.60-$3.00 272,063 1.8 $ 2.25 262,148 $ 2.24 $3.01-$6.00 2,583,652 6.8 $ 3.80 2,137,202 $ 3.88 $6.01-$9.00 4,148,238 6.4 $ 7.60 2,848,150 $ 7.48 $9.01-$12.00 2,562,668 8.8 $ 10.95 827,259 $ 10.77 $12.01-$15.00 824,184 5.1 $ 13.54 663,646 $ 13.40 $15.01-$25.62 98,188 8.6 $ 20.64 52,227 $ 20.67 10,488,993 6.9 $ 7.93 6,790,632 $ 7.22 At December 31, 2021, the aggregate intrinsic value of options outstanding was $3.8 million, the aggregate intrinsic value of options exercisable was $3.1 million, and the weighted average remaining contractual term of options exercisable was 5.9 years. At December 31, 2021, the aggregate intrinsic value of unvested restricted stock units was $12.2 million and the aggregate intrinsic value of restricted stock units which vested during the year ended December 31, 2021 was $12.7 million. At December 31, 2021, options to purchase 10,488,993 shares of common stock and 2,448,868 restricted stock units were expected to vest. Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2021 was as follows: Number of Weighted-Average Balance, December 31, 2020 8,906,624 $ 6.78 Granted 3,483,118 10.29 Exercised (1,310,263) 5.09 Cancelled (590,486) 10.81 Balance, December 31, 2021 10,488,993 $ 7.93 Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2021 was as follows: Number of Balance, December 31, 2020 2,558,052 Granted 1,392,124 Vested (1,387,384) Cancelled (113,924) Balance, December 31, 2021 2,448,868 The weighted average exercise price per share was $4.56 for the 7,000 options which expired during the year ended December 31, 2021, $4.44 for the 78,750 options which expired during the year ended December 31, 2020 and $6.27 for the 324,502 options which expired during the year ended December 31, 2019. The weighted average grant date fair value per share was $7.61, $6.87 and $2.19 for options granted during the years ended December 31, 2021, 2020 and 2019, respectively. The weighted average grant date fair value was $10.37, $9.12 and $3.09 per share for restricted stock units granted during the years ended December 31, 2021, 2020 and 2019, respectively. The Company received $6.7 million, $12.3 million and $113,000 in proceeds from the exercise of stock options during the years ended December 31, 2021, 2020 and 2019, respectively. The aggregate intrinsic value of options exercised was $7.0 million, $14.2 million and $25,000 during the years ended December 31, 2021, 2020 and 2019, 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, 2021 , 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.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Commitments and Contingencies	Commitments and Contingencies 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 as of December 31, 2021 of 1.9 years to 8.0 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, 2021, the maturities of the Company's operating lease liabilities were as follows: Year ending December 31, 2022 $ 4,085,000 2023 4,089,000 2024 3,050,000 2025 3,063,000 2026 3,139,000 Thereafter 6,749,000 Total remaining lease payments 24,175,000 Less: present value adjustment (6,111,000) Total operating lease liabilities 18,064,000 Less: current portion (2,604,000) Long-term operating lease liabilities $ 15,460,000 Weighted-average remaining lease term 6.6 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, 2021, 2020 and 2019 were $3.4 million, $3.4 million and $3.2 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. Other Commitments The Company has existing supply agreements with contract manufacturers to manufacture INO-4800 drug substance. Under the terms of the agreements, the Company is committed to certain minimum purchases in 2022. At December 31, 2021, the Company had a $47.4 million minimum purchase obligation in connection with these agreements. Legal Proceedings Securities Litigation On March 12, 2020, a purported shareholder class action complaint, McDermid v. Inovio Pharmaceuticals, Inc. and J. Joseph Kim, was filed in the United States District Court for the Eastern District of Pennsylvania, naming the Company and J. Joseph Kim, the Company’s Chief Executive Officer, as defendants. The lawsuit alleges that the Company made materially false and misleading statements regarding its development of a vaccine for COVID-19 in its public disclosures in violation of certain federal securities laws. The plaintiff seeks unspecified monetary damages on behalf of the putative class and an award of costs and expenses, including reasonable attorneys’ fees. On August 3, 2020, the lead plaintiff filed a consolidated complaint, naming the Company and three of its officers as defendants. On September 21, 2020, the lead plaintiff and another purported stockholder filed a first amended complaint, naming the Company and three of its officers as defendants. Defendants filed a motion to dismiss plaintiff’s first amended complaint on November 5, 2020. On February 16, 2021, the court issued an order granting in part, and denying in part, the defendants’ motion to dismiss. The court granted the defendants’ motion to dismiss, and dismissed with prejudice, the claims premised on certain of the Company’s statements. The court denied defendants’ motion to dismiss as to the remaining statements. On March 9, 2021, the defendants filed their answer to the complaint. The case is currently in discovery. On July 29, 2021, the plaintiffs moved to certify the class action. That motion is fully briefed and remains pending. On February 17, 2022, the court granted Plaintiffs’ motion for leave to amend their complaint, and further ordered that the amended complaint is deemed filed as of February 17. Defendants intend to move to dismiss the new allegations in the amended complaint. On April 20, 2020, a purported shareholder derivative complaint, Behesti v. Kim, et al., was filed in the United States District Court for the Eastern District of Pennsylvania, naming eight current and former directors of the Company as defendants. The lawsuit asserts state and federal claims and is based on the same alleged misstatements as the shareholder class action complaint. The lawsuit accuses the Company’s board of directors of failing to exercise reasonable and prudent supervision over the Company’s management, policies, practices, and internal controls. The plaintiff seeks unspecified monetary damages on behalf of the Company as well as governance reforms. On June 5, 2020, the court stayed the Beheshti action pending resolution of a forthcoming motion to dismiss the McDermid securities class action or until any party provides notice that they no longer consent to the stay. On June 12, 2020 and June 15, 2020, two additional shareholder derivative complaints were filed in the United States District Court for the Eastern District of Pennsylvania, captioned Isman v. Benito, et al. and Devarakonda et al. v Kim, et. al. The complaints assert substantially similar claims as the Beheshti action and name the Company’s current directors as defendants. The Devarakonda complaint also names one of the Company’s former directors as a defendant. On July 21, 2020, the court consolidated the three derivative cases under the caption In re Inovio Pharmaceuticals, Inc. Derivative Litigation. The consolidated action is stayed. On July 7, 2020, a fourth shareholder derivative complaint, Fettig v. Kim et al., was filed in the United States District Court for the Eastern District of Pennsylvania, naming eight current and former directors of the Company as defendants. The complaint asserts substantially similar claims as those in the consolidated derivative action. On August 27, 2020, the Fettig action was consolidated with the other derivative cases, which remain stayed as explained above. The Company intends to defend these actions vigorously. VGXI Litigation On June 3, 2020, the Company filed a complaint in the Court of Common Pleas of Montgomery County, Pennsylvania against VGXI, Inc. and GeneOne Life Science, Inc., or GeneOne, and together with VGXI, Inc. collectively referred to as VGXI, alleging that VGXI had materially breached the Company’s supply agreement with them. The complaint seeks declaratory judgments, specific performance of the agreement, injunctive relief, an accounting, damages, attorneys’ fees, interest, costs and other relief from VGXI. On June 3, 2020, the Company filed a petition for preliminary injunction, which was denied on June 25, 2020. On June 26, 2020, the Company filed notice of appeal of the denial of the petition with the Pennsylvania Superior Court. On July 7, 2020, VGXI filed an answer, new matter and counterclaims against the Company, alleging that the Company had breached the supply agreement, as well as misappropriation of trade secrets and unjust enrichment. The counterclaims seek injunctive relief, damages, attorneys’ fees, interest, costs and other relief from the Company. Also, on July 7, 2020, VGXI filed a third-party complaint against Ology Bioservices, Inc., a contract manufacturing organization that the Company had engaged to provide services similar to those that were being provided by VGXI. On July 27, 2020, the Company filed an answer to VGXI’s counterclaims, disputing the allegations and the claims raised in VGXI’s filing. On October 1, 2020, the Company filed a notice of discontinuance of appeal with the Pennsylvania Superior Court. A trial date for the litigation has not been set. The Company intends to aggressively prosecute the claims set forth in its complaint against VGXI and to vigorously defend itself against VGXI’s counterclaims. GeneOne Litigation On December 7, 2020, GeneOne filed a complaint in the Court of Common Pleas of Montgomery County, Pennsylvania against the Company, alleging that the Company had breached the CELLECTRA Device License Agreement, or the Agreement, between the Company and GeneOne. The Company terminated the Agreement on October 9, 2020. The complaint asserts claims for breach of contract, declaratory judgment, unfair competition, and unjust enrichment. The complaint seeks injunctive relief, an accounting, damages, disgorgement of profits, attorneys’ fees, interest, and other relief from the Company. On January 29, 2021, the Company filed preliminary objections to the complaint. On August 23, 2021, the court overruled the Company’s preliminary objections to the complaint. On September 13, 2021, the Company filed an answer to the complaint, new matter, and counterclaims. The Company’s counterclaims allege that GeneOne breached the Agreement and assert claims for breach of contract and declaratory judgment. The counterclaims seek damages, interest, expenses, attorney’s fees, and costs. On October 18, 2021, GeneOne filed its answer to the Company’s counterclaims and new matter. On November 8, 2021, we filed our answer to GeneOne’s new matter. A trial date for this litigation has not been set. The Company intends to aggressively prosecute the claims set forth in its counterclaims against GeneOne and to vigorously defend itself against the claims in GeneOne’s complaint. Other Matters From time to time, the Company may be involved in disputes, including litigation, relating to claims arising out of operations in the normal course of our business. Any of these claims could subject the Company to costly legal expenses and, while the Company generally believes that it has adequate insurance to cover many different types of liabilities, its insurance carriers may deny coverage or its policy limits may be inadequate to fully satisfy any damage awards or settlements. If this were to happen, the payment of any such awards could have a material adverse effect on the Company's consolidated results of operations and financial position. Additionally, any such claims, whether or not successful, could damage the Company's reputation and business. Except as described above, the Company is not a party to any legal proceedings, the adverse outcome of which, in management’s opinion, individually or in the aggregate, would be reasonably expected to have a material adverse effect on the Company’s consolidated results of operations or financial position.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In accordance with the accounting guidance 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 before equity method investment are as follows: Year Ended December 31, 2021 2020 2019 U.S. Domestic $ (302,614,003) $ (162,664,355) $ (120,809,112) Foreign (610,320) (225,949) — Pretax loss from operations before equity method investment $ (303,224,323) $ (162,890,304) $ (120,809,112) There was no provision for (benefit from) income taxes for the years ended December 31, 2021 and 2020. There was an income tax benefit of $(257,000) for the year ended December 31, 2019. 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, 2021, 2020 and 2019, is as follows: Year Ended December 31, 2021 2020 2019 Income (benefit) taxes at statutory rates $ (63,677,000) $ (34,207,000) $ (25,370,000) State income tax, net of federal benefit (3,447,000) — — Change in valuation allowance 77,424,000 21,428,000 25,457,000 Nondeductible loss on extinguishment of debt — 14,450,000 — Research and development tax credits (16,523,000) (2,650,000) (3,838,000) Stock-based compensation 483,000 (1,953,000) 1,114,000 Uncertain tax positions 6,509,000 1,068,000 1,537,000 Deconsolidation of subsidiary — 853,000 — Expired NOLs and credits 616,000 468,000 616,000 Limited NOLs and credits (542,000) (368,000) (616,000) Change in tax rates — — 12,000 Foreign tax rate differential (24,000) (9,000) — Other (819,000) 920,000 831,000 $ — $ — $ (257,000) 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. Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are shown below: As of December 31, 2021 2020 Deferred tax assets: Capitalized research expense $ 4,200,000 $ 5,250,000 NOL carryforwards 197,144,000 127,835,000 Research and development and other tax credits 23,005,000 13,242,000 Deferred revenue 987,000 1,628,000 Stock-based compensation 3,599,000 3,256,000 Acquired intangibles 637,000 757,000 Interest expense 83,000 564,000 Investment in affiliated entity 750,000 542,000 Lease liability 3,793,000 4,283,000 Other 5,973,000 6,127,000 240,171,000 163,484,000 Valuation allowance (237,205,000) (159,705,000) Total deferred tax assets 2,966,000 3,779,000 Deferred tax liabilities: Acquired intangibles (194,000) (179,000) Right of use asset (2,430,000) (2,676,000) Note discount (321,000) (469,000) Fixed assets (53,000) (487,000) Net deferred tax liabilities $ (32,000) $ (32,000) As of December 31, 2021, the Company had federal, California and Pennsylvania tax net operating loss (NOL) carryforwards of $864.5 million, $146.5 million and $89.0 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 $568.9 million will carryforward indefinitely and be available to offset up to 80% of future taxable income each year. 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 2021, respectively, unless previously utilized. The Company also has Korean NOL carryforwards of $806,000 as of December 31, 2021. The Korean NOLs are available to offset up to 60% of future taxable income and will begin to expire in 2030, unless previously utilized. In addition, as of December 31, 2021, the Company had federal and state research and development (R&D) tax credit carryforwards of $35.1 million and $4.4 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 Foreign NOLs Federal R&D State R&D 2022 $ 6.1 $ 0.4 $ — $ — $ — 2023 5.3 1.2 — — — 2024 16.5 9.1 — — — 2025 and thereafter 267.7 224.9 0.8 35.1 — Indefinite 568.9 — — — 4.4 $ 864.5 $ 235.6 $ 0.8 $ 35.1 $ 4.4 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, 2021. As a result of the analysis, the Company estimates that approximately $9.7 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 2021, 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 2019, 2020, and 2021 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, 2021 2020 2019 Balance at beginning of the year $ 12,210,000 $ 11,204,000 $ 9,632,000 Increases related to current year tax positions 6,602,000 1,043,000 1,575,000 Increases (decreases) related to prior year tax positions 7,000 27,000 (3,000) Other — (64,000) — Balance at end of the year $ 18,819,000 $ 12,210,000 $ 11,204,000 The amount of unrecognized tax benefits that, if recognized and realized, would affect the effective tax rate was $17.4 million, $10.9 million and $9.9 million as of December 31, 2021, 2020 and 2019, 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 and foreign jurisdictions. With few exceptions, the Company is no longer subject to United States federal income tax examinations for years before 2018 and state and local income tax examinations before 2017. 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 subject to examinations for tax years beginning in 2020 in Korea. The Company is not currently under Internal Revenue Service (“IRS”), state, local or foreign tax examination.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2021
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 $1.5 million, $1.1 million and $1.2 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transactions	Related Party Transactions Plumbline Life Sciences, Inc. T he Company owned 597,808 shares of common stock in Plumbline Life Sciences, Inc. ("PLS") as of December 31, 2021 and 2020, representing a 18.9% and 19.7% ownership interest, respectively. One of the Company's directors, Dr. David B. Weiner, acts as a consultant to PLS. Revenue recognized from PLS consists of milestone, license and patent fees. For the years ended December 31, 2021 and 2020, the Company recognized revenue from PLS of $245,000 and $1.4 million, respectively. At December 31, 2021 and 2020, the Company had an accounts receivable balance of $25,000 and $67,000, 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 reimbursed 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. In March 2021, upon expiration of the March 2016 agreements, the Company entered into new collaborative research agreements with Wistar with the same terms. The Company will have the exclusive right to in-license new intellectual property developed in this agreement. In 2021, the Company entered into collaborative research agreements with Wistar in support of the clinical development of INO-4800. Under the terms of these collaborative research agreements, the Company will reimburse Wistar for all direct and indirect costs incurred in the conduct of the collaborative research, not to exceed $1.9 million during the two-year term of the agreements. In November 2016, the Company rece ived a $6.1 million sub-grant through Wistar to develop a DMAb against the Zika infectio n, with funding through December 2021. The Company is also a collaborator with Wistar on an Integrated Preclinical/Clinical AIDS Vaccine Development grant from the NIAID, with funding through February 2022. In 2020, the Company received a $10.7 million sub-grant through Wistar, which was amended in 2021 to $13.5 million, 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, of which $3.3 million has been exercised as of December 31, 2021. 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, 2021 and 2020, the Company recorded $3.0 million and $1.9 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, 2021 and 2020 were $2.9 million and $2.3 million, respectively. At December 31, 2021 and 2020, the Company had an accounts receivable balance of $2.6 million and $425,000, respectively, and an accounts payable and accrued liability balance of $548,000 and $643,000, respectively, related to Wistar. As of December 31, 2021, the Company had a prepaid expense balance of $261,000 and recorded $37,000 as deferred grant funding on its consolidated balance sheet related to Wistar.

Geneos Therapeutics, Inc.

Geneos Therapeutics, Inc.	12 Months Ended
	Dec. 31, 2021
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 closing 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 and for the three months ended March 31, 2021 was $1.5 million; however, only $434,000 was recorded, reducing the Company's total investment in Geneos to $0. O f this amount, $819,000 has been allocated to the equity method investment, thereby reducing the balance to $0 as of March 31, 2021 . The remaining $4.2 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 $0 as of March 31, 2021 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 from June 30, 2020 - December 31, 2020 (4,584,610) Share in net loss of Geneos for the three months ended March 31, 2021 (434,387) Investment in Geneos as of March 31, 2021 $ — The Company will not reduce its investment below $0 and will not record its share of further net losses of Geneos as the Company has no obligation to fund Geneos. In February 2021, Geneos completed a second closing of the Series A-1 preferred stock financing, in which the Company did not participate. Following this transaction, the Company held approximately 35% of the outstanding equity, on an as-converted to common stock basis. 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Liquidity	Basis of Presentation and Liquidity The Company incurred a net loss attributable to common stockholders of $303.7 million for the year ended December 31, 2021. The Company had working capital of $382.7 million and an accumulated deficit of $1.2 billion as of December 31, 2021. 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 $401.3 million as of December 31, 2021 , 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. 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 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 of $162.1 million from a January 2021 underwritten public offering, net proceeds of $47.7 million under a Sales Agreement during the year ended December 31, 2021, net proceeds of $454.5 million under Sales Agreements 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. 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. These consolidated financial statements do not include any adjustments to the specific amounts and classifications of assets and liabilities, which might be necessary should Inovio be unable to continue as a going concern. The Company's consolidated financial statements as of and for the year ended December 31, 2021 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business for the foreseeable future. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements.
Consolidation	Consolidation 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. The consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiary. As of December 31, 2021
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 EstimatesThe 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 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. The Company’s financial instruments include cash equivalents, short-term investments, investments in affiliated entities, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses, and convertible senior notes. The carrying amounts of cash equivalents, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses approximate the related fair values due to the short-term maturities of these instruments. Short-term investments are recorded at fair value on a recurring basis, based on current market valuations. The Company carries convertible senior notes 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 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, 2021 and 2020.
Short Term Investments	Short-term 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, commercial paper, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2021 and 2020. Short-term investments are recorded at fair value, based on current market valuations. Unrealized gains and losses on the Company's short-term debt investments 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
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 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
Valuation of Intangible Assets and Goodwill	Valuation of Intangible Assets and Goodwill Intangible assets are amortized over their estimated useful lives ranging from two 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, 2021 and 2020, the Company’s intangible assets resulting from the acquisition of Inovio AS and Bioject Medical Technologies, Inc. ("Bioject"), and additional intangibles including license costs, net of accumulated amortization, totaled $2.6 million and $3.1 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, 2021. 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 likely 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 likely that the fair value of its reporting unit is less than its carrying amount, then no additional assessment is deemed necessary. Otherwise, the Company will proceed to perform the impairment test in which the fair value of the reporting unit is compared with its carrying amount, and an impairment charge will be recorded for the amount by which the carrying amount exceeds the reporting unit's fair value, if any. The Company performed its annual assessment for goodwill impairment as of November 30, 2021, 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 $237.2 million and $159.7 million at December 31, 2021 and 2020, 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 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 and the Company concludes that its collaboration partner is not a customer, the Company presents such payments as a reduction of research and development expense. 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
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
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 translated at the end of each reporting period into the functional currency at the exchange rate at that date. The cumulative translation adjustment is included in the accumulated other comprehensive income (loss) within the statement of stockholders' equity. 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)	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 Method Investments	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
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 9) 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 Compensation The Company incurs stock-based compensation expense related to restricted stock units ("RSUs") 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 - Pending Adoption 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. 2020-06. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
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, 2021 2020 2019 Options to purchase common stock 10,488,993 8,906,624 9,265,390 Service-based restricted stock units 2,448,868 2,558,052 2,069,936 Performance-based restricted stock units 663,353 663,353 — Convertible preferred stock 3,309 3,309 8,456 Convertible notes 3,049,980 3,049,980 14,585,653 August 2019 Bonds — — 3,799,071 December 2019 Bonds — 1,009,450 1,009,450 Total 16,654,503 16,190,768 30,737,956
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, 2021 2020 2019 Risk-free interest rate 0.91% 0.63% 2.42% Expected volatility 93% 78% 70% 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, 2021 2020 2019 Risk-free interest rate 1.45% 0.82% 2.45% Expected volatility 87% 76% 88% Expected life in years 10 10 10 Dividend yield — — —

Revenue Recognition and Conce_2

Revenue Recognition and Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Revenue from External Customers	The following table indicates the percentage of total revenues in excess of 10% with any single customer: Customer 2021 Revenue % of Total 2020 Revenue % of Total 2019 Revenue % of Total AstraZeneca $ 41,659 2 % $ 170,587 2 % $ 3,194,877 78 % Advaccine — — 5,000,000 68 — — Plumbline Life Sciences, Inc. (affiliated entity) 245,310 14 1,370,396 18 — — Department of Defense 754,853 43 — — — — All other, including affiliated entities 732,936 41 870,237 12 917,053 22 Total revenue $ 1,774,758 100 % 1 $ 7,411,220 100 % $ 4,111,930 100 %

Short-term Investments and Fa_2

Short-term Investments and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of Investments	The following is a summary of available-for-sale securities as of December 31, 2021 and 2020: As of December 31, 2021 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 192,966,772 $ 87,069 $ (1,614,411) $ 191,439,430 U.S. treasury securities Less than 1 94,193,441 — (9,921) 94,183,520 Commercial paper Less than 1 39,967,853 — — 39,967,853 Certificates of deposit Less than 1 2,976,210 15,618 (338) 2,991,490 U.S. agency mortgage-backed securities * 1,608,137 4,508 (23,998) 1,588,647 $ 331,712,413 $ 107,195 $ (1,648,668) $ 330,170,940 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 *No single maturity date.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2021: Fair Value Measurements at December 31, 2021 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 191,439,430 $ 191,439,430 $ — $ — U.S. treasury securities 94,183,520 94,183,520 — — Commercial paper 39,967,853 — 39,967,853 — Certificates of deposit 2,991,490 — 2,991,490 — U.S. agency mortgage-backed securities 1,588,647 — 1,588,647 — Total short-term investments 330,170,940 285,622,950 44,547,990 — Investment in affiliated entity 3,906,796 3,906,796 — — Total assets measured at fair value $ 334,077,736 $ 289,529,746 $ 44,547,990 $ — The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2020: Fair Value Measurements at December 31, 2020 Total Quoted Prices Significant Significant 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 — Investments in affiliated entity 4,460,366 4,460,366 — — Total assets measured at fair value $ 225,372,101 $ 219,330,340 $ 6,041,761 $ —

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2021
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, 2021 and 2020 consisted of the following: 2021 2020 Prepaid manufacturing expenses (a) $ 27,474,159 $ 35,661,947 Other prepaid expenses 11,362,832 4,695,509 $ 38,836,991 $ 40,357,456 (a) Includes prepaid manufacturing expenses related to deposits made to reserve capacity for the manufacture of INO-4800. The Company deposited a total of $50.0 million to reserve manufacturing capacity, of which $30.0 million was paid in 2020 and the remainder paid in the first quarter of 2021. Of these deposits, $35.0 million was included in research and development expenses in December 2021.

Fixed Assets (Tables)

Fixed Assets (Tables)	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Schedule of fixed assets	Fixed assets at December 31, 2021 and 2020 consisted of the following: Cost Accumulated Net Book As of December 31, 2021 Leasehold improvements $ 15,803,108 $ (8,258,608) $ 7,544,500 Laboratory equipment 12,392,916 (4,279,816) 8,113,100 Office furniture and fixtures 2,827,476 (2,599,643) 227,833 Computer equipment and other 5,374,084 (3,806,311) 1,567,773 $ 36,397,584 $ (18,944,378) $ 17,453,206 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

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2021
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, 2021 December 31, 2020 Weighted Average Useful Gross Accumulated Net Book Gross Accumulated Net Book Indefinite lived: Goodwill $ 10,513,371 $ — $ 10,513,371 $ 10,513,371 $ — $ 10,513,371 Definite lived: Licenses 10 1,323,761 (1,305,600) 18,161 1,323,761 (1,276,852) 46,909 Bioject (a) 12 5,100,000 (2,735,556) 2,364,444 5,100,000 (2,468,889) 2,631,111 Other (b) 18 4,050,000 (3,806,250) 243,750 4,050,000 (3,581,250) 468,750 Total intangible assets 11 10,473,761 (7,847,406) 2,626,355 10,473,761 (7,326,991) 3,146,770 Total goodwill and intangible assets $ 20,987,132 $ (7,847,406) $ 13,139,726 $ 20,987,132 $ (7,326,991) $ 13,660,141 (a) Bioject intangible assets represent the estimated fair value of developed technology and intellectual property which were recorded from an asset acquisition. (b) 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, 2021 is expected to be incurred as follows: Year ending December 31, 2022 $ 493,000 2023 276,000 2024 253,000 2025 253,000 2026 253,000 Thereafter 1,098,000 $ 2,626,000

Convertible Debt (Tables)

Convertible Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of convertible debt	The balance of the Notes at December 31, 2021 is as follows: Principal amount $ 78,500,000 Principal amount converted into common shares (62,085,000) Unamortized debt discount on the liability component (1,591,909) Unamortized debt issuance cost (219,101) Accrued interest 355,657 Net carrying amount $ 14,959,647
Schedule of maturities of long-term debt	As of December 31, 2021, future minimum payments due under the Notes, representing contractual amounts due, including interest based on the fixed rate of 6.5% per annum, are as follows: 2022 $ 1,067,000 2023 1,067,000 2024 16,948,000 Total $ 19,082,000

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2021
Payables and Accruals [Abstract]
Schedule of accounts payable and accrued expenses	Accounts payable and accrued expenses at December 31, 2021 and 2020 consisted of the following: 2021 2020 Trade accounts payable $ 24,213,673 $ 825,516 Accrued compensation 16,112,912 13,127,257 Accrued subcontract costs 11,602 247,796 Other accrued expenses 7,306,343 7,003,239 $ 47,644,530 $ 21,203,808

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Summary of preferred stock authorized, issued and outstanding	Shares Outstanding as of Shares Authorized Shares Issued 2021 2020 Series C Preferred Stock, par $0.001 1,091 1,091 9 9
Schedule of shares authorized under stock option plans, by exercise price range	The following table summarizes total stock options outstanding at December 31, 2021: Options Outstanding Options Exercisable Exercise Price Shares Underlying Options Weighted-Average Weighted Shares Underlying Options Weighted Average $1.60-$3.00 272,063 1.8 $ 2.25 262,148 $ 2.24 $3.01-$6.00 2,583,652 6.8 $ 3.80 2,137,202 $ 3.88 $6.01-$9.00 4,148,238 6.4 $ 7.60 2,848,150 $ 7.48 $9.01-$12.00 2,562,668 8.8 $ 10.95 827,259 $ 10.77 $12.01-$15.00 824,184 5.1 $ 13.54 663,646 $ 13.40 $15.01-$25.62 98,188 8.6 $ 20.64 52,227 $ 20.67 10,488,993 6.9 $ 7.93 6,790,632 $ 7.22
Schedule of stock options, activity	Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2021 was as follows: Number of Weighted-Average Balance, December 31, 2020 8,906,624 $ 6.78 Granted 3,483,118 10.29 Exercised (1,310,263) 5.09 Cancelled (590,486) 10.81 Balance, December 31, 2021 10,488,993 $ 7.93
Schedule of restricted stock unit activity	Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2021 was as follows: Number of Balance, December 31, 2020 2,558,052 Granted 1,392,124 Vested (1,387,384) Cancelled (113,924) Balance, December 31, 2021 2,448,868

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Schedule of maturities of operating lease liabilities	As of December 31, 2021, the maturities of the Company's operating lease liabilities were as follows: Year ending December 31, 2022 $ 4,085,000 2023 4,089,000 2024 3,050,000 2025 3,063,000 2026 3,139,000 Thereafter 6,749,000 Total remaining lease payments 24,175,000 Less: present value adjustment (6,111,000) Total operating lease liabilities 18,064,000 Less: current portion (2,604,000) Long-term operating lease liabilities $ 15,460,000 Weighted-average remaining lease term 6.6 years Weighted-average discount rate 8.5 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of components of pretax loss from operations	The components of pretax loss from operations before equity method investment are as follows: Year Ended December 31, 2021 2020 2019 U.S. Domestic $ (302,614,003) $ (162,664,355) $ (120,809,112) Foreign (610,320) (225,949) — Pretax loss from operations before equity method investment $ (303,224,323) $ (162,890,304) $ (120,809,112)
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, 2021, 2020 and 2019, is as follows: Year Ended December 31, 2021 2020 2019 Income (benefit) taxes at statutory rates $ (63,677,000) $ (34,207,000) $ (25,370,000) State income tax, net of federal benefit (3,447,000) — — Change in valuation allowance 77,424,000 21,428,000 25,457,000 Nondeductible loss on extinguishment of debt — 14,450,000 — Research and development tax credits (16,523,000) (2,650,000) (3,838,000) Stock-based compensation 483,000 (1,953,000) 1,114,000 Uncertain tax positions 6,509,000 1,068,000 1,537,000 Deconsolidation of subsidiary — 853,000 — Expired NOLs and credits 616,000 468,000 616,000 Limited NOLs and credits (542,000) (368,000) (616,000) Change in tax rates — — 12,000 Foreign tax rate differential (24,000) (9,000) — Other (819,000) 920,000 831,000 $ — $ — $ (257,000)
Schedule of deferred tax assets and liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are shown below: As of December 31, 2021 2020 Deferred tax assets: Capitalized research expense $ 4,200,000 $ 5,250,000 NOL carryforwards 197,144,000 127,835,000 Research and development and other tax credits 23,005,000 13,242,000 Deferred revenue 987,000 1,628,000 Stock-based compensation 3,599,000 3,256,000 Acquired intangibles 637,000 757,000 Interest expense 83,000 564,000 Investment in affiliated entity 750,000 542,000 Lease liability 3,793,000 4,283,000 Other 5,973,000 6,127,000 240,171,000 163,484,000 Valuation allowance (237,205,000) (159,705,000) Total deferred tax assets 2,966,000 3,779,000 Deferred tax liabilities: Acquired intangibles (194,000) (179,000) Right of use asset (2,430,000) (2,676,000) Note discount (321,000) (469,000) Fixed assets (53,000) (487,000) 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 Foreign NOLs Federal R&D State R&D 2022 $ 6.1 $ 0.4 $ — $ — $ — 2023 5.3 1.2 — — — 2024 16.5 9.1 — — — 2025 and thereafter 267.7 224.9 0.8 35.1 — Indefinite 568.9 — — — 4.4 $ 864.5 $ 235.6 $ 0.8 $ 35.1 $ 4.4
Schedule of unrecognized tax benefits rollforward	The following table summarizes the activity related to the Company's unrecognized tax benefits: Year ended December 31, 2021 2020 2019 Balance at beginning of the year $ 12,210,000 $ 11,204,000 $ 9,632,000 Increases related to current year tax positions 6,602,000 1,043,000 1,575,000 Increases (decreases) related to prior year tax positions 7,000 27,000 (3,000) Other — (64,000) — Balance at end of the year $ 18,819,000 $ 12,210,000 $ 11,204,000

Geneos Therapeutics, Inc. (Tabl

Geneos Therapeutics, Inc. (Tables)	12 Months Ended
	Dec. 31, 2021
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 $4.2 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 $0 as of March 31, 2021 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 from June 30, 2020 - December 31, 2020 (4,584,610) Share in net loss of Geneos for the three months ended March 31, 2021 (434,387) Investment in Geneos as of March 31, 2021 $ —
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

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	Dec. 26, 2019USD ($)	Aug. 01, 2019USD ($)	Feb. 28, 2019USD ($)	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2019KRW (₩)	Dec. 26, 2019KRW (₩)	Aug. 01, 2019KRW (₩)	Mar. 01, 2019USD ($)
Property, Plant and Equipment [Line Items]
Net loss from operations				$ 303,658,710	$ 166,411,157	$ 119,359,219
Working capital				382,700,000
Accumulated deficit				1,209,855,522	906,196,812
Cash, cash equivalents, and short-term investments				401,300,000
Proceeds from issuance of common stock				$ 209,441,410	454,486,400	9,089,010
Number of operating segments | segment				1
Allowance for doubtful accounts				$ 0	0
Finite lived intangible assets, net				2,626,355	3,146,770
Deferred tax assets, valuation allowance				$ 237,205,000	159,705,000
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
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
Debt interest based on the fixed rate				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
Debt interest based on the fixed rate		1.00%				100.00%	100.00%		1.00%
Debt instrument, face amount		$ 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
Debt interest based on the fixed rate	1.00%					1.00%	1.00%	1.00%
Debt instrument, face amount	$ 4,100,000					$ 4,100,000	₩ 4,700,000,000	₩ 4,700,000,000
Common stock | Underwritten Public Offering
Property, Plant and Equipment [Line Items]
Proceeds from issuance of common stock				$ 162,100,000
Common stock | Sales Agreement
Property, Plant and Equipment [Line Items]
Proceeds from issuance of common stock				$ 47,700,000	$ 454,500,000	$ 9,100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Antidilutive Securities Table (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
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)	16,654,503	16,190,768	30,737,956
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)	10,488,993	8,906,624	9,265,390
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)	2,448,868	2,558,052	2,069,936
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	663,353	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	3,309	8,456
Convertible Debt Securities | 6.50% Convertible Senior Notes Due 2024
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	3,049,980	14,585,653
Convertible Debt Securities | August 2019 Bonds
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	0	3,799,071
Convertible Debt Securities | December 2019 Bonds
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	1,009,450	1,009,450

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Stock-Based Compensation Assumptions (Details) - Stock Options	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employees and Directors
Summary of assumptions used to estimate the fair value of stock options
Risk-free interest rate	0.91%	0.63%	2.42%
Expected volatility	93.00%	78.00%	70.00%
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	1.45%	0.82%	2.45%
Expected volatility	87.00%	76.00%	88.00%
Expected life in years	10 years	10 years	10 years
Dividend yield	0.00%	0.00%	0.00%

Revenue Recognition and Conce_3

Revenue Recognition and Concentration of Credit Risk- Revenue from External Customers (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,774,758	$ 7,411,220	$ 4,111,930
Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	100.00%	100.00%	100.00%
AstraZeneca
Disaggregation of Revenue [Line Items]
Total revenues	$ 41,659	$ 170,587	$ 3,194,877
AstraZeneca | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	2.00%	2.00%	78.00%
Advaccine
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 5,000,000	$ 0
Advaccine | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	0.00%	68.00%	0.00%
Plumbline Life Sciences, Inc. (affiliated entity)
Disaggregation of Revenue [Line Items]
Total revenues	$ 245,310	$ 1,370,396	$ 0
Plumbline Life Sciences, Inc. (affiliated entity) | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	14.00%	18.00%	0.00%
Department of Defense
Disaggregation of Revenue [Line Items]
Total revenues	$ 754,853	$ 0	$ 0
Department of Defense | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	43.00%	0.00%	0.00%
All other, including affiliated entities
Disaggregation of Revenue [Line Items]
Total revenues	$ 732,936	$ 870,237	$ 917,053
All other, including affiliated entities | Revenue from Contract with Customer Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
% of Total Revenue	41.00%	12.00%	22.00%

Revenue Recognition and Conce_4

Revenue Recognition and Concentration of Credit Risk - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized from deferred revenue	$ 46	$ 127
Department of Defense | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Accounts receivable	$ 3,600	$ 11,400
Department of Defense | Customer Concentration Risk | Accounts Receivable
Disaggregation of Revenue [Line Items]
% of Total Revenue	65.00%	62.00%
CEPI MERS | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Accounts receivable	$ 1,900
CEPI MERS | Customer Concentration Risk | Accounts Receivable
Disaggregation of Revenue [Line Items]
% of Total Revenue	34.00%
Advaccine | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Accounts receivable		$ 7,100
Advaccine | Customer Concentration Risk | Accounts Receivable
Disaggregation of Revenue [Line Items]
% of Total Revenue		38.00%

Collaborative Agreements (Detai

Collaborative Agreements (Details) - USD ($)

Apr. 11, 2018

Dec. 31, 2017

Jan. 31, 2021

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

Jun. 30, 2018

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Total revenues

$ 1,774,758

$ 7,411,220

$ 4,111,930

Deferred grant funding

4,559,721

7,474,310

Revenue under collaborative research and development arrangements

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Total revenues

902,260

5,170,586

3,636,945

Advaccine

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Total revenues

0

5,000,000

$ 0

Advaccine | Customer Concentration Risk

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Accounts receivable

7,100,000

Advaccine | Collaborative Arrangement

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Upfront payment received

$ 3,000,000

4,500,000

Additional revenue to be achieved

206,000,000

Collaboration agreement, payment earned

$ 2,000,000

2,000,000

Obligation period to pay royalties

10 years

Cost, Maintenance

$ 1,500,000

Annual Maintenance Period

5 years

Total revenues

$ 5,000,000

Agreement, number of days written notice before termination

18 months

Advaccine | Collaborative Arrangement | Revenue under collaborative research and development arrangements

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Total revenues

5,000,000

ApolloBio | Collaborative Arrangement

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Upfront payment received

$ 23,000,000

$ 23,000,000

$ 23,000,000

Additional revenue to be achieved

$ 20,000,000

Obligation period to pay royalties

10 years

Proceeds from collaborative agreement

19,400,000

Advisory fees

$ 960,000

Agreement period from effective date for termination

1 year

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, 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

$ 10,000,000

6,400,000

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

23,000

Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement | Lassa Fever And MERS Vaccine

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Accounts receivable

1,900,000

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

6,900,000

10,000,000

Deferred grant funding

1,800,000

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

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

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

893,000

4,100,000

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

182,000

463,000

Deferred grant funding

384,000

Department Of Defence | Collaborative Arrangement

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Collaborative agreement, funding to be received

$ 54,500,000

Collaborative Arrangement , Revenue from the Procurement Contract

755,000,000

Grant proceeds received

27,100,000

$ 21,200,000

Accounts receivable

3,600,000

Grants Receivable

2,300,000

Department Of Defence | Collaborative Arrangement | CELLECTRA 3PSP Proprietary Smart Device

Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]

Purchase price, procurement contract

$ 10,700,000

Short-term Investments and Fa_3

Short-term Investments and Fair Value Measurements - Summary of Available-for-sale Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	$ 331,712,413	$ 159,239,931
Gross Unrealized Gains	107,195	2,365,899
Gross Unrealized Losses	(1,648,668)	(690,895)
Fair Market Value	330,170,940	160,914,935
Mutual funds
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	192,966,772	153,177,675
Gross Unrealized Gains	87,069	2,339,639
Gross Unrealized Losses	(1,614,411)	(644,140)
Fair Market Value	$ 191,439,430	154,873,174
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity	1 year
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	$ 94,193,441
Gross Unrealized Gains	0
Gross Unrealized Losses	(9,921)
Fair Market Value	$ 94,183,520
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity	1 year
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	$ 39,967,853
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Market Value	39,967,853
Certificates of deposit
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	2,976,210	3,000,000
Gross Unrealized Gains	15,618	26,260
Gross Unrealized Losses	(338)	(10,000)
Fair Market Value	$ 2,991,490	$ 3,016,260
Certificates of deposit | Maximum
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity	1 year	1 year
U.S. agency mortgage-backed securities
Debt Securities, Available-for-sale, Sale [Abstract]
Cost	$ 1,608,137	$ 3,062,256
Gross Unrealized Gains	4,508	0
Gross Unrealized Losses	(23,998)	(36,755)
Fair Market Value	$ 1,588,647	$ 3,025,501

Short-term Investments and Fa_4

Short-term Investments and Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	$ 330,170,940	$ 160,914,935
Mutual funds
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	191,439,430	154,873,174
Commercial paper
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	39,967,853
Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	2,991,490	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	1,588,647	3,025,501
Fair Value, Measurements, Recurring
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	330,170,940	160,914,935
Investments in affiliated entity	3,906,796	4,460,366
Total assets measured at fair value	334,077,736	225,372,101
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	285,622,950	154,873,174
Investments in affiliated entity	3,906,796	4,460,366
Total assets measured at fair value	289,529,746	219,330,340
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	44,547,990	6,041,761
Investments in affiliated entity	0	0
Total assets measured at fair value	44,547,990	6,041,761
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	0
Investments in affiliated entity	0	0
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring | Mutual funds
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	191,439,430	154,873,174
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	191,439,430	154,873,174
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 | U.S. treasury securities
Financial assets and liabilities that are measured at fair value on recurring basis
Cash and cash equivalents		59,996,800
Short-term investments	94,183,520
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
Short-term investments	94,183,520
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
Short-term investments	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
Short-term investments	0
Fair Value, Measurements, Recurring | Commercial paper
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	39,967,853
Fair Value, Measurements, Recurring | Commercial paper | 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 | Commercial paper | Significant Other Unobservable Inputs (Level 2)
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	39,967,853
Fair Value, Measurements, Recurring | Commercial paper | 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 | Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	2,991,490	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	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	2,991,490	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	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	1,588,647	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	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	1,588,647	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	$ 0

Short-term Investments and Fa_5

Short-term Investments and Fair Value Measurements - Narrative (Details)	12 Months Ended
	Dec. 31, 2021USD ($)investmentshares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, realized gain	$ 394,000	$ 744,000
Debt securities, available-for-sale, realized gain	399,000	1,300,000
Net unrealized gain on available-for-sale equity securities	$ (3,222,838)	$ 1,695,497	$ 0
Number of securities in a gross unrealized loss position | investment	24
Number of securities in a gross unrealized loss position for more than twelve months | investment	6
Unrealized gain (loss) on investments	$ 766,000
Fair Value, Inputs, Level 1 | Common stock
Debt Securities, Available-for-sale [Line Items]
Number of shares owned (in shares) | shares	597,808

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid manufacturing expenses	$ 27,474,159	$ 35,661,947
Other prepaid expenses	11,362,832	4,695,509
Prepaid expenses and other current assets	$ 38,836,991	$ 40,357,456

Prepaid Expenses and Other Cu_4

Prepaid Expenses and Other Current Assets - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deposits		$ 50
Deposit payments		$ 30
Deposits forfeited	$ 35

Fixed Assets (Details)

Fixed Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Cost	$ 36,397,584	$ 27,341,715
Accumulated Depreciation and Amortization	(18,944,378)	(15,993,571)
Net Book Value	17,453,206	11,348,144
Depreciation	3,040,096	3,038,996	$ 3,598,388
Property, plant and equipment disposed of	89,000
Accumulated depreciation written off due to disposal of property plant and equipment	89,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	15,803,108	15,179,447
Accumulated Depreciation and Amortization	(8,258,608)	(6,549,418)
Net Book Value	7,544,500	8,630,029
Laboratory equipment
Property, Plant and Equipment [Line Items]
Cost	12,392,916	4,788,678
Accumulated Depreciation and Amortization	(4,279,816)	(3,727,508)
Net Book Value	8,113,100	1,061,170
Office furniture and fixtures
Property, Plant and Equipment [Line Items]
Cost	2,827,476	2,828,675
Accumulated Depreciation and Amortization	(2,599,643)	(2,296,942)
Net Book Value	227,833	531,733
Computer equipment and other
Property, Plant and Equipment [Line Items]
Cost	5,374,084	4,544,915
Accumulated Depreciation and Amortization	(3,806,311)	(3,419,703)
Net Book Value	$ 1,567,773	$ 1,125,212

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Summary of Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Indefinite lived:
Goodwill	$ 10,513,371	$ 10,513,371
Definite lived:
Intangible assets, Gross	10,473,761	10,473,761
Intangible assets, Accumulated Amortization	(7,847,406)	(7,326,991)
Intangible assets, Net Book Value	2,626,355	3,146,770
Total goodwill and intangible assets, Gross	20,987,132	20,987,132
Total goodwill and intangible assets, Net Book Value	$ 13,139,726	13,660,141
Weighted Average Useful Life (Yrs)
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	(1,305,600)	(1,276,852)
Intangible assets, Net Book Value	$ 18,161	46,909
Licenses | Weighted Average Useful Life (Yrs)
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	(2,735,556)	(2,468,889)
Intangible assets, Net Book Value	$ 2,364,444	2,631,111
Bioject | Weighted Average Useful Life (Yrs)
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	(3,806,250)	(3,581,250)
Intangible assets, Net Book Value	$ 243,750	$ 468,750
Other | Weighted Average Useful Life (Yrs)
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, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 520,415	$ 547,081	$ 1,066,294
Impairment	0	0	0
Goodwill, Impairment Loss	$ 0	$ 0	$ 0

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Amortization Expense (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 493,000
2023	276,000
2024	253,000
2025	253,000
2026	253,000
Thereafter	1,098,000
Intangible assets, Net Book Value	$ 2,626,355	$ 3,146,770

Convertible Debt - Narrative (D

Convertible Debt - Narrative (Details)	Aug. 03, 2020$ / sharesshares	Dec. 26, 2019USD ($)$ / shares	Aug. 01, 2019USD ($)	Feb. 28, 2019USD ($)	Aug. 31, 2020USD ($)shares	Dec. 31, 2021USD ($)day$ / sharesshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Dec. 31, 2019KRW (₩)	Dec. 26, 2019KRW (₩)	Aug. 01, 2019KRW (₩)	Mar. 01, 2019USD ($)
Debt Instrument [Line Items]
Interest expense						$ 1,936,447	$ 8,702,450	$ 7,948,539
Change in fair value of derivative liability						0	(75,670,977)	(1,763,652)
6.50% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Debt instrument, face amount						78,500,000
Debt issuance costs, net						219,101
Debt instrument, unamortized discount						1,591,909
Gain (loss) on extinguishment of convertible bonds and senior notes						$ 0	8,762,030	$ 0
6.50% Convertible Senior Notes Due 2024 | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount												$ 78,500,000
Debt interest based on the fixed rate						6.50%		6.50%	6.50%			6.50%
Proceeds from issuance of debt				$ 75,700,000				$ 75,700,000
Debt instrument, convertible, conversion price (in USD per share) | $ / shares						$ 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%
Debt instrument, convertible, conversion ratio				0.1858045
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
Debt instrument, convertible, carrying amount of equity component							52,500,000
Gain (loss) on extinguishment of convertible bonds and senior notes							8,800,000
Interest expense						$ 1,900,000	6,900,000
Interest expense, debt						1,100,000	4,100,000
August 2019 Bonds
Debt Instrument [Line Items]
Gain (loss) on extinguishment of convertible bonds and senior notes						$ 0	(8,177,043)	0
August 2019 Bonds | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount			$ 15,000,000					$ 15,000,000	₩ 18,000,000,000		₩ 18,000,000,000
Debt interest based on the fixed rate			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 convertible bonds and senior notes					$ (8,200,000)
Interest expense							1,600,000
Interest expense, debt							87,000
Fair value of derivative liability					84,500,000
Change in fair value of derivative liability					$ 75,700,000
August 2019 Bonds | Convertible Debt | Initial Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion price (in USD per share) | $ / shares	$ 4
Debt instrument, convertible, conversion ratio	0.0002110595
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 | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount		$ 4,100,000						$ 4,100,000	₩ 4,700,000,000	₩ 4,700,000,000
Debt interest based on the fixed rate		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%
Debt conversion, converted instrument, shares issued (in shares) | shares						1,009,450
Interest expense						$ 50,000	253,000
Interest expense, debt						9,000	$ 40,000
Stock Issued During Period, Value, Conversion of Units						$ 4,400,000
December 2019 Bonds | Convertible Debt | Initial Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion price (in USD per share) | $ / shares		$ 4
Debt instrument, convertible, conversion ratio		0.0002147766
December 2019 Bonds | Convertible Debt | After July 2, 2020 Conversion Price
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio		0.0003579611

Convertible Debt - Balance Of C

Convertible Debt - Balance Of Convertible Debt (Details) - 6.50% Convertible Senior Notes Due 2024	Dec. 31, 2021USD ($)
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	(1,591,909)
Unamortized debt issuance cost	(219,101)
Accrued interest	355,657
Total	$ 14,959,647

Convertible Debt - Schedule of

Convertible Debt - Schedule of Maturities (Details) - 6.50% Convertible Senior Notes Due 2024 - USD ($)	Dec. 31, 2021	Dec. 31, 2019	Mar. 01, 2019
Debt Instrument [Line Items]
Total	$ 14,959,647
Convertible Debt
Debt Instrument [Line Items]
Debt interest based on the fixed rate	6.50%	6.50%	6.50%
2022	$ 1,067,000
2023	1,067,000
2024	16,948,000
Total	$ 19,082,000

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Trade accounts payable	$ 24,213,673	$ 825,516
Accrued compensation	16,112,912	13,127,257
Accrued subcontract costs	11,602	247,796
Other accrued expenses	7,306,343	7,003,239
Accounts payable and accrued liabilities	$ 47,644,530	$ 21,203,808

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Preferred Stock (Details) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
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	9
Preferred stock, shares outstanding (in shares)	9	9
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	9

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)

Nov. 09, 2021

Jan. 25, 2021

Aug. 28, 2020

May 12, 2020

Jun. 30, 2020

May 31, 2018

Mar. 31, 2021

Mar. 31, 2020

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2019

Jan. 01, 2022

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

$ 26,336,764

$ 15,647,523

$ 10,901,320

Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized

$ 16,500,000

$ 4,400,000

Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition

2 years

1 year 4 months 24 days

Number of options outstanding to purchase common stock (in shares)

10,488,993

8,906,624

Aggregate intrinsic value of options outstanding

$ 3,800,000

Aggregate intrinsic value for options exercisable

$ 3,100,000

Options exercisable, remaining contractual term

5 years 10 months 24 days

Number of options expected to vest (in shares)

10,488,993

Options, expirations in period, weighted average exercise price (in USD per share)

$ 4.56

$ 4.44

$ 6.27

Options, expirations in period (in shares)

7,000

78,750

324,502

Options, grants in period, weighted average grant date fair value (in USD per share)

$ 7.61

$ 6.87

$ 2.19

Proceeds from stock options exercised

$ 6,700,000

$ 12,300,000

$ 113,000

Options, exercises in period, aggregate intrinsic value

7,000,000

14,200,000

$ 25,000

Restricted Stock Units (RSUs)

Class of Stock [Line Items]

Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized

$ 13,400,000

$ 10,900,000

Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition

1 year 9 months 18 days

1 year 10 months 24 days

Aggregate intrinsic value of unvested

$ 12,200,000

Aggregate intrinsic value of vested

$ 12,700,000

RSU's expected to vest (in shares)

2,448,868

Weighted average grant date fair value (in USD per share)

$ 10.37

$ 9.12

$ 3.09

Granted (in shares)

1,392,124

Employee

Class of Stock [Line Items]

Share-based compensation

$ 25,000,000

$ 14,500,000

$ 9,800,000

Research and Development Expense

Class of Stock [Line Items]

Share-based compensation

13,400,000

8,000,000

5,900,000

General and Administrative Expense

Class of Stock [Line Items]

Share-based compensation

11,600,000

6,500,000

3,900,000

Non Employee

Class of Stock [Line Items]

Allocated share-based compensation expense

$ 1,400,000

$ 1,200,000

$ 970,000

Number of options outstanding to purchase common stock (in shares)

632,375

2016 Incentive Plan

Class of Stock [Line Items]

Reserved number of shares under the Incentive Plan (in shares)

20,000,000

Number of potential shares authorized for issuance under a share-based compensation plan (in shares)

2,000,000

Number of shares available for grants under the Incentive Plan (in shares)

4,481,745

Number of shares of vested restricted stock outstanding under the plan (in shares)

2,448,868

Number of common stock shares outstanding under the Incentive Plan (in shares)

8,060,957

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 | Subsequent Event

Class of Stock [Line Items]

Increase in number of shares authorized (in shares)

2,000,000

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)

2,428,036

Vesting period of incentive plan

3 years

Contractual year term of incentive plan

10 years

Award vesting period (in years)

3 years

Common stock | Underwritten Public Offering

Class of Stock [Line Items]

Number of shares issued in transaction (in shares)

20,355,000

Sale of stock, price per share (in USD per share)

$ 8.50

Commissions and other estimated offering expenses

$ 162,100,000

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]

Common stock aggregate offering price

$ 300,000,000

Sales Agents will be entitled to compensation

3.00%

Stock sale agreement, aggregate number of shares issued (in shares)

6,955,341

Sales made at a weighted average price (in USD per share)

$ 6.96

Stock sale agreement, aggregate proceeds from issuance of stock

$ 47,700,000

Remaining authorized amount

$ 251,600,000

Common stock | Prior Sales Agreement

Class of Stock [Line Items]

Sale of stock, price per share (in USD per share)

$ 4.92

Common stock aggregate offering price

$ 100,000,000

$ 250,000,000

Stock sale agreement, aggregate number of shares issued (in shares)

43,148,952

Stock sale agreement, aggregate proceeds from issuance of stock

$ 208,200,000

Remaining authorized amount

$ 0

Common stock | New Sales Agreement

Class of Stock [Line Items]

Common stock aggregate offering price

$ 250,000,000

Stock sale agreement, aggregate number of shares issued (in shares)

22,919,934

Sales made at a weighted average price (in USD per share)

$ 10.91

Stock sale agreement, aggregate proceeds from issuance of stock

$ 246,200,000

Remaining authorized amount

$ 0

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding (in shares) | shares	10,488,993
Weighted-average remaining contractual life (in Years)	6 years 10 months 24 days
Weighted average exercise price (in USD per share)	$ 7.93
Options exercisable (in shares) | shares	6,790,632
Weighted average exercise price (in USD per share)	$ 7.22
$1.60-$3.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise price, lower range limit (in USD per share)	1.60
Exercise price, upper range limit (in USD per share)	$ 3
Options outstanding (in shares) | shares	272,063
Weighted-average remaining contractual life (in Years)	1 year 9 months 18 days
Weighted average exercise price (in USD per share)	$ 2.25
Options exercisable (in shares) | shares	262,148
Weighted average exercise price (in USD per share)	$ 2.24
$1.60-$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	2,583,652
Weighted-average remaining contractual life (in Years)	6 years 9 months 18 days
Weighted average exercise price (in USD per share)	$ 3.80
Options exercisable (in shares) | shares	2,137,202
Weighted average exercise price (in USD per share)	$ 3.88
$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	4,148,238
Weighted-average remaining contractual life (in Years)	6 years 4 months 24 days
Weighted average exercise price (in USD per share)	$ 7.60
Options exercisable (in shares) | shares	2,848,150
Weighted average exercise price (in USD per share)	$ 7.48
$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	2,562,668
Weighted-average remaining contractual life (in Years)	8 years 9 months 18 days
Weighted average exercise price (in USD per share)	$ 10.95
Options exercisable (in shares) | shares	827,259
Weighted average exercise price (in USD per share)	$ 10.77
$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	824,184
Weighted-average remaining contractual life (in Years)	5 years 1 month 6 days
Weighted average exercise price (in USD per share)	$ 13.54
Options exercisable (in shares) | shares	663,646
Weighted average exercise price (in USD per share)	$ 13.40
$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	98,188
Weighted-average remaining contractual life (in Years)	8 years 7 months 6 days
Weighted average exercise price (in USD per share)	$ 20.64
Options exercisable (in shares) | shares	52,227
Weighted average exercise price (in USD per share)	$ 20.67

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Stock Option Activity Under Equity Incentive Plan (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	8,906,624
Granted (in shares) | shares	3,483,118
Exercised (in shares) | shares	(1,310,263)
Cancelled (in shares) | shares	(590,486)
Ending balance (in shares) | shares	10,488,993
Weighted-Average Exercise Price
Beginning balance (in USD per share) | $ / shares	$ 6.78
Granted (in USD per share) | $ / shares	10.29
Exercised (in USD per share) | $ / shares	5.09
Cancelled (in USD per share) | $ / shares	10.81
Ending balance (in USD per share) | $ / shares	$ 7.93

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, 2021shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	2,558,052
Granted (in shares)	1,392,124
Vested (in shares)	(1,387,384)
Cancelled (in shares)	(113,924)
Ending balance (in shares)	2,448,868

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019ft²lease	Dec. 31, 2021USD ($)ft²	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Operating Leased Assets [Line Items]
Lessee, operating lease, area of land under lease	13,500
Lease, cost | $		$ 3.4	$ 3.4	$ 3.2
Number of lease agreements entered into | lease	2
Minimum purchase obligation | $		$ 47.4
Minimum
Operating Leased Assets [Line Items]
Operating lease, remaining lease term		1 year 10 months 24 days
Maximum
Operating Leased Assets [Line Items]
Operating lease, remaining lease term		8 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

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Maturities of Operating Lease Payments (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022	$ 4,085,000
2023	4,089,000
2024	3,050,000
2025	3,063,000
2026	3,139,000
Thereafter	6,749,000
Total remaining lease payments	24,175,000
Less: present value adjustment	(6,111,000)
Total operating lease liabilities	18,064,000
Less: current portion	(2,603,956)	$ (2,329,394)
Long-term operating lease liabilities	$ 15,459,559	$ 18,063,515
Weighted-average remaining lease term	6 years 7 months 6 days
Weighted-average discount rate	8.50%

Income Taxes - Components of Pr

Income Taxes - Components of Pretax Loss from Operations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S. Domestic	$ (302,614,003)	$ (162,664,355)	$ (120,809,112)
Foreign	(610,320)	(225,949)	0
Net loss before income tax benefit	$ (303,224,323)	$ (162,890,304)	$ (120,809,112)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income (benefit) taxes at statutory rates	$ (63,677)	$ (34,207)	$ (25,370)
State income tax, net of federal benefit	(3,447)	0	0
Change in valuation allowance	77,424	21,428	25,457
Nondeductible loss on extinguishment of debt	0	14,450	0
Research and development tax credits	(16,523)	(2,650)	(3,838)
Stock-based compensation	483	(1,953)	1,114
Uncertain tax positions	6,509	1,068	1,537
Deconsolidation of subsidiary	0	853	0
Expired NOLs and credits	616	468	616
Limited NOLs and credits	(542)	(368)	(616)
Change in tax rates	0	0	12
Foreign tax rate differential	(24)	(9)	0
Other	(819)	920	831
Income tax expense (benefit)	$ 0	$ 0	$ (257)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 0	$ 0	$ (257,335)
Tax benefits expired	9,700,000
Unrecognized tax benefits that would impact effective tax rate	17,400,000	$ 10,900,000	$ 9,900,000
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations	864,500,000
Net operating loss carryforwards				$ 568,900,000
Federal | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	35,100,000
California
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations	146,500,000
Pennsylvania
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations	89,000,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	235,600,000
State | Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward amount	4,400,000
Korean State Income Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards that will expire due to IRC Section 382 limitations	$ 806,000

Income Taxes Significant Compon

Income Taxes Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Capitalized research expense	$ 4,200	$ 5,250
NOL carryforwards	197,144	127,835
Research and development and other tax credits	23,005	13,242
Deferred revenue	987	1,628
Stock-based compensation	3,599	3,256
Acquired intangibles	637	757
Interest expense	83	564
Investment in affiliated entity	750	542
Lease liability	3,793	4,283
Other	5,973	6,127
Deferred tax assets, gross	240,171	163,484
Valuation allowance	(237,205)	(159,705)
Total deferred tax assets	2,966	3,779
Deferred tax liabilities:
Acquired intangibles	(194)	(179)
Right of use asset	(2,430)	(2,676)
Note discount	(321)	(469)
Fixed assets	(53)	(487)
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, 2021USD ($)
Federal
Expirations of Operating Loss Carryforwards, Components [Abstract]
2022	$ 6.1
2023	5.3
2024	16.5
2025 and thereafter	267.7
Indefinite	568.9
Total	864.5
State
Expirations of Operating Loss Carryforwards, Components [Abstract]
2022	0.4
2023	1.2
2024	9.1
2025 and thereafter	224.9
Indefinite	0
Total	235.6
Foreign Tax Authority
Expirations of Operating Loss Carryforwards, Components [Abstract]
2022	0
2023	0
2024	0
2025 and thereafter	0.8
Indefinite	0
Total	0.8
Research Tax Credit Carryforward | Federal
Expirations of Tax Credit Carryforwards [Abstract]
2022	0
2023	0
2024	0
2025 and thereafter	35.1
Indefinite	0
Total	35.1
Research Tax Credit Carryforward | State
Expirations of Tax Credit Carryforwards [Abstract]
2022	0
2023	0
2024	0
2025 and thereafter	0
Indefinite	4.4
Total	$ 4.4

Income Taxes Unrecognized Tax B

Income Taxes Unrecognized Tax Benefits Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 12,210	$ 11,204	$ 9,632
Increases related to current year tax positions	6,602	1,043	1,575
Increases (decreases) related to prior year tax positions	7	27
Increases (decreases) related to prior year tax positions			(3)
Other	0	(64)	0
Balance at end of the year	$ 18,819	$ 12,210	$ 11,204

401(k) Plan (Details)

401(k) Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Employer matching contribution, percent	50.00%
Maximum annual contribution per employee, percent	6.00%
Company's contribution to 401(k) plan	$ 1.5	$ 1.1	$ 1.2

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2016	Mar. 31, 2016	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Agreement amended amount			$ 13,500
Awarded option amount				$ 6,000
Awarded exercised amount			3,300
Director
Related Party Transaction [Line Items]
Grant proceeds received			$ 3,000	$ 1,900
Available-for-sale Securities | Plumbline Life Sciences
Related Party Transaction [Line Items]
Percentage of ownership			18.90%	19.70%
PLS (affiliated entity)
Related Party Transaction [Line Items]
Number of shares owned (in shares)			597,808
Revenue from related parties			$ 245	$ 1,400
Accounts receivable			25	67
The Wistar Institute
Related Party Transaction [Line Items]
Accounts receivable			2,600	425
Expenses to reimburse		$ 3,100
Term		5 years
Proceeds from sub-grant	$ 6,100
Awarded amount				10,700
Operating expenses related to affiliated entity			2,900	2,300
Due to related parties			548	643
Deferred grant funding from affiliate			37
Prepaid expense				$ 261
Director
Related Party Transaction [Line Items]
Expenses to reimburse			$ 1,900
Term			2 years

Geneos Therapeutics, Inc. - Nar

Geneos Therapeutics, Inc. - Narrative (Details) - USD ($)	Jun. 01, 2020	Nov. 30, 2020	Feb. 28, 2019	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Feb. 28, 2021	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020
Noncontrolling Interest [Line Items]
Payments to acquire additional interest in subsidiaries						$ 0	$ 1,399,999	$ 0
Gain on deconsolidation of Geneos						0	4,121,075	0
Share in net loss of Geneos						434,387	4,584,610	$ 0
Investment in Geneos					$ 434,387	$ 0	$ 434,387
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%							35.00%	47.00%	52.00%
Percentage of ownership						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
Loss from equity method investment, recorded and allocated to investment				$ 1,500,000	4,600,000
Share in net loss of Geneos				434,387	4,584,610
Investment in Geneos	3,618,998			0		$ 0			$ 0
Geneos Therapeutics, Inc. | Common stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos					819,000
Investment in Geneos	$ 819,000			$ 0
Geneos Therapeutics, Inc. | Series A-1 Preferred Stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos					$ 4,200,000
Investment in Geneos						$ 0

Geneos Therapeutics, Inc. - Dec

Geneos Therapeutics, Inc. - Deconsolidation Accounting (Details) - USD ($)	Jun. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Fixed assets, net of accumulated depreciation		$ (17,453,206)	$ (11,348,144)
Gain on deconsolidation of Geneos		0	(4,121,075)	$ 0
Decrease in cash resulting from the deconsolidation of Geneos		$ 0	$ 2,774,851	$ 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, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 01, 2020
Noncontrolling Interest [Line Items]
Fair Value	$ 0			$ 434,387
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Shares (in shares)					5,113,206
Fair Value	$ 0	$ 0	$ 0		$ 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
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Investment in Geneos upon deconsolidation	$ 434,387		$ 434,387
Share in net loss of Geneos from June 30, 2020 - December 31, 2020			434,387	$ 4,584,610	$ 0
Investment in Geneos as of March 31, 2021		$ 434,387	0	$ 434,387
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Share in net loss of Geneos from June 30, 2020 - December 31, 2020	434,387	4,584,610
Investment in Geneos as of March 31, 2021	$ 0		0
Geneos Therapeutics, Inc. | Series A-1 Preferred Stock
Noncontrolling Interest [Line Items]
Share in net loss of Geneos from June 30, 2020 - December 31, 2020		$ 4,200,000
Investment in Geneos as of March 31, 2021			$ 0