Inovio Pharmaceuticals (INO) 10-Q 14 Nov 24 2024 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2024	Nov. 12, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		26,099,991
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001055726
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 21,687,480	$ 14,310,862
Short-term investments	63,117,288	130,982,913
Accounts receivable from affiliated entities	1,862,739	2,405,228
Prepaid expenses and other current assets	4,617,116	5,393,665
Prepaid expenses and other current assets from affiliated entity	0	20,432
Total current assets	91,284,623	153,113,100
Fixed assets, net	4,091,562	4,960,986
Investment in affiliated entity	2,644,226	2,780,287
Operating lease right-of-use assets	8,472,848	9,491,735
Other assets	566,415	605,315
Total assets	107,059,674	170,951,423
Current liabilities:
Accrued clinical trial expenses	4,496,568	2,365,382
Operating lease liability	2,425,112	2,406,522
Grant funding liability	0	87,489
Grant funding liability from affiliated entity	0	21,918
Convertible senior notes	0	16,770,654
Total current liabilities	23,499,137	42,570,228
Operating lease liability, net of current portion	10,020,227	11,032,066
Total liabilities	33,519,364	53,602,294
Stockholders’ equity:
Preferred stock	0	0
Common stock	26,051	22,792
Additional paid-in capital	1,784,975,303	1,740,954,074
Accumulated deficit	(1,710,837,583)	(1,622,965,136)
Accumulated other comprehensive loss	(623,461)	(662,601)
Total Inovio Pharmaceuticals, Inc. stockholders’ equity	73,540,310	117,349,129
Total liabilities and stockholders’ equity	107,059,674	170,951,423
Nonrelated Party
Current liabilities:
Accounts payable and accrued expenses	14,743,191	19,847,744
Related Party
Current liabilities:
Accounts payable and accrued expenses	$ 1,834,266	$ 1,070,519

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues:
Revenue from collaborative arrangements and other contracts		$ 0	$ 388,446	$ 100,762	$ 729,359
Operating expenses:
Research and development		18,733,584	15,503,032	62,734,891	69,423,513
General and administrative		8,613,895	9,925,055	29,395,232	37,338,763
Impairment of goodwill		0	10,513,371	0	10,513,371
Total operating expenses		27,347,479	35,941,458	92,130,123	117,275,647
Loss from operations		(27,347,479)	(35,553,012)	(92,029,361)	(116,546,288)
Other income (expense):
Interest income		1,106,758	1,938,745	3,914,406	6,314,149
Interest expense		0	(313,488)	(177,833)	(940,464)
Gain (loss) on investment in affiliated entity		324,251	214,374	(136,061)	987,758
Net unrealized gain (loss) on available-for-sale equity securities		1,330,811	(219,337)	1,810,868	3,921,819
Other (expense) income, net		(579,819)	2,854	(1,254,466)	(3,850,688)
Net loss		$ (25,165,478)	$ (33,929,864)	$ (87,872,447)	$ (110,113,714)
Net loss per share
Basic (in dollars per share)	[1]	$ (0.89)	$ (1.52)	$ (3.35)	$ (5.01)
Diluted (in dollars per share)	[1]	$ (0.89)	$ (1.52)	$ (3.35)	$ (5.01)
Weighted average number of common shares used to compute net loss per share
Basic (in shares)	[1]	28,140,497	22,385,229	26,216,983	21,986,840
Diluted (in shares)	[1]	28,140,497	22,385,229	26,216,983	21,986,840
[1]Share and per share amounts have been restated to reflect the 1-for-12 reverse stock split effected in January 2024 on a retroactive basis for all periods presented.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Parenthetical)		1 Months Ended
	Jan. 24, 2024	Jan. 31, 2024
Income Statement [Abstract]
Stock split, conversion ratio	0.083333	0.083333

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (25,165,478)	$ (33,929,864)	$ (87,872,447)	$ (110,113,714)
Other comprehensive loss:
Foreign currency translation	0	(2,109)	32,403	(4,403)
Unrealized gain (loss) on short-term investments, net of tax	66,075	(57,703)	6,737	(47,930)
Comprehensive loss	$ (25,099,403)	$ (33,989,676)	$ (87,833,307)	$ (110,166,047)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($)		Total	Preferred stock	Common stock		Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss
Beginning balance (in shares) at Dec. 31, 2022			9	21,090,938	[1]
Beginning balance at Dec. 31, 2022		$ 222,362,756	$ 0	$ 21,090	[1]	$ 1,710,888,191	$ (1,487,847,784)	$ (698,741)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			760,083
Issuance of common stock for cash, net of financing costs		14,000,000		$ 760	[1]	13,999,240
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			43,901
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(424,704)		$ 44	[1]	(424,748)
Stock-based compensation		3,809,003				3,809,003
Net loss		(40,649,317)					(40,649,317)
Unrealized gain (loss) on short-term investments, net of tax		117,862						117,862
Foreign currency translation		(1,918)						(1,918)
Ending balance (in shares) at Mar. 31, 2023			9	21,894,922	[1]
Ending balance at Mar. 31, 2023		199,213,682	$ 0	$ 21,894	[1]	1,728,271,686	(1,528,497,101)	(582,797)
Beginning balance (in shares) at Dec. 31, 2022			9	21,090,938	[1]
Beginning balance at Dec. 31, 2022		222,362,756	$ 0	$ 21,090	[1]	1,710,888,191	(1,487,847,784)	(698,741)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(110,113,714)
Unrealized gain (loss) on short-term investments, net of tax		(47,930)
Foreign currency translation		(4,403)
Ending balance (in shares) at Sep. 30, 2023			9	22,477,618	[1]
Ending balance at Sep. 30, 2023		138,159,713	$ 0	$ 22,476	[1]	1,736,849,809	(1,597,961,498)	(751,074)
Beginning balance (in shares) at Mar. 31, 2023			9	21,894,922	[1]
Beginning balance at Mar. 31, 2023		199,213,682	$ 0	$ 21,894	[1]	1,728,271,686	(1,528,497,101)	(582,797)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			425,429
Issuance of common stock for cash, net of financing costs		2,915,179		$ 425	[1]	2,914,754
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			19,077
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(32,292)		$ 19	[1]	(32,311)
Stock-based compensation		2,917,997				2,917,997
Net loss		(35,534,533)					(35,534,533)
Unrealized gain (loss) on short-term investments, net of tax		(108,089)						(108,089)
Foreign currency translation		(376)						(376)
Ending balance (in shares) at Jun. 30, 2023			9	22,339,428	[1]
Ending balance at Jun. 30, 2023		169,371,568	$ 0	$ 22,338	[1]	1,734,072,126	(1,564,031,634)	(691,262)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			134,418
Issuance of common stock for cash, net of financing costs		708,283		$ 134	[1]	708,149
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			3,772
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(9,650)		$ 4	[1]	(9,654)
Stock-based compensation		2,079,188				2,079,188
Net loss		(33,929,864)					(33,929,864)
Unrealized gain (loss) on short-term investments, net of tax		(57,703)						(57,703)
Foreign currency translation		(2,109)						(2,109)
Ending balance (in shares) at Sep. 30, 2023			9	22,477,618	[1]
Ending balance at Sep. 30, 2023		138,159,713	$ 0	$ 22,476	[1]	1,736,849,809	(1,597,961,498)	(751,074)
Beginning balance (in shares) at Dec. 31, 2023			9	22,793,075	[1]
Beginning balance at Dec. 31, 2023		117,349,129	$ 0	$ 22,792	[1]	1,740,954,074	(1,622,965,136)	(662,601)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			543,620
Issuance of common stock for cash, net of financing costs		5,225,133		$ 544	[1]	5,224,589
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			34,558
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(174,248)		$ 34	[1]	(174,282)
Stock-based compensation		2,525,433				2,525,433
Net loss		(30,469,871)					(30,469,871)
Unrealized gain (loss) on short-term investments, net of tax		(46,016)						(46,016)
Foreign currency translation		32,403						32,403
Ending balance (in shares) at Mar. 31, 2024			9	23,371,253	[1]
Ending balance at Mar. 31, 2024		94,441,963	$ 0	$ 23,370	[1]	1,748,529,814	(1,653,435,007)	(676,214)
Beginning balance (in shares) at Dec. 31, 2023			9	22,793,075	[1]
Beginning balance at Dec. 31, 2023		117,349,129	$ 0	$ 22,792	[1]	1,740,954,074	(1,622,965,136)	(662,601)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(87,872,447)
Unrealized gain (loss) on short-term investments, net of tax		6,737
Foreign currency translation		32,403
Ending balance (in shares) at Sep. 30, 2024			9	26,052,452	[1]
Ending balance at Sep. 30, 2024		73,540,310	$ 0	$ 26,051	[1]	1,784,975,303	(1,710,837,583)	(623,461)
Beginning balance (in shares) at Mar. 31, 2024			9	23,371,253	[1]
Beginning balance at Mar. 31, 2024		94,441,963	$ 0	$ 23,370	[1]	1,748,529,814	(1,653,435,007)	(676,214)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			2,536,258
Issuance of common stock for cash, net of financing costs		17,059,668		$ 2,536	[1]	17,057,132
Issuance of pre-funded warrants for cash, net of financing costs		16,146,397				16,146,397
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			56,033
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(172,454)		$ 56	[1]	(172,510)
Stock-based compensation		1,514,053				1,514,053
Net loss		(32,237,098)					(32,237,098)
Unrealized gain (loss) on short-term investments, net of tax		(13,322)						(13,322)
Ending balance (in shares) at Jun. 30, 2024			9	25,963,544	[1]
Ending balance at Jun. 30, 2024		96,739,207	$ 0	$ 25,962	[1]	1,783,074,886	(1,685,672,105)	(689,536)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for cash, net of financing costs (in shares)	[1]			86,361
Issuance of common stock for cash, net of financing costs		667,066		$ 86	[1]	666,980
Exercise of stock options for cash and vesting of RSUs, net of tax payments (in shares)	[1]			2,547
Exercise of stock options for cash and vesting of RSUs, net of tax payments		(6,418)		$ 3	[1]	(6,421)
Stock-based compensation		1,239,858				1,239,858
Net loss		(25,165,478)					(25,165,478)
Unrealized gain (loss) on short-term investments, net of tax		66,075						66,075
Foreign currency translation		0
Ending balance (in shares) at Sep. 30, 2024			9	26,052,452	[1]
Ending balance at Sep. 30, 2024		$ 73,540,310	$ 0	$ 26,051	[1]	$ 1,784,975,303	$ (1,710,837,583)	$ (623,461)
[1]All share amounts in this column, including appropriate reclassifications between common stock and additional paid-in capital, have been restated to reflect the 1-for-12 reverse stock split effected in January 2024 on a retroactive basis for all periods presented.

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical)		1 Months Ended
	Jan. 24, 2024	Jan. 31, 2024
Statement of Stockholders' Equity [Abstract]
Stock split, conversion ratio	0.083333	0.083333

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Cash flows from operating activities:
Net loss	$ (25,165,478)	$ (30,469,871)	$ (33,929,864)	$ (40,649,317)	$ (87,872,447)	$ (110,113,714)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation					1,335,326	2,051,962
Amortization of intangible assets					0	145,417
Amortization of operating lease right-of-use assets					1,018,887	1,130,932
Impairment of goodwill	0		10,513,371		0	10,513,371
Impairment of intangible assets					0	1,984,444
Non-cash stock-based compensation					5,279,344	8,806,188
Non-cash interest on senior convertible notes					(355,654)	(126,511)
Amortization of discounts on investments					(1,510,276)	(3,641,765)
Loss on sales of short-term investments					1,278,959	3,853,691
Loss on disposal of fixed assets					21,930	364,422
Loss (gain) on equity investment in affiliated entity	(324,251)		(214,374)		136,061	(987,758)
Net unrealized gain on available-for-sale equity securities	(1,330,811)		219,337		(1,810,868)	(3,921,819)
Changes in operating assets and liabilities:
Accounts receivable from affiliated entities					542,489	9,594,021
Prepaid expenses and other current assets, including from affiliated entities					796,981	39,285,174
Other assets					38,900	78,729
Accounts payable and accrued expenses, including due to affiliated entities					(4,340,806)	(50,641,862)
Accrued clinical trial expenses					2,131,186	(5,582,888)
Operating lease right-of-use assets and liabilities, net					(993,249)	(2,147,175)
Grant funding liability, including from affiliated entity					(109,407)	1,265,375
Net cash used in operating activities					(84,412,644)	(98,089,766)
Cash flows from investing activities:
Purchases of investments					(54,138,027)	(174,250,213)
Proceeds from sale or maturity of investments					124,052,574	235,912,707
Purchases of capital assets					(487,832)	(320,898)
Proceeds from sale of capital assets					0	6,071,000
Net cash provided by investing activities					69,426,715	67,412,596
Cash flows from financing activities:
Repayment of convertible senior notes					(16,415,000)	0
Proceeds from issuance of pre-funded warrants, net of issuance costs					16,146,397	0
Proceeds from issuance of common stock, net of issuance costs					22,951,867	3,623,462
Proceeds from stock option exercises					67,675	0
Taxes paid related to net share settlement of equity awards					(420,795)	(466,646)
Net cash provided by financing activities					22,330,144	3,156,816
Effect of exchange rate changes on cash and cash equivalents					32,403	(4,403)
Increase in cash and cash equivalents					7,376,618	(27,524,757)
Cash and cash equivalents, beginning of period		$ 14,310,862		$ 46,329,359	14,310,862	46,329,359	$ 46,329,359
Cash and cash equivalents, end of period	$ 21,687,480		$ 18,804,602		21,687,480	18,804,602	$ 14,310,862
Supplemental disclosures:
Interest paid					533,487	1,066,975
Issuance of common stock as part of litigation settlement					$ 0	$ 14,000,000

Organization and Operations

Organization and Operations	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	Organization and Operations Inovio Pharmaceuticals, Inc. (the “Company” or “INOVIO”) is a clinical-stage biotechnology company focused on developing and commercializing DNA medicines to help treat and protect people from diseases associated with human papillomavirus (HPV), cancer, and infectious diseases. INOVIO's platform harnesses the power of in vivo protein production, featuring optimized design and delivery of DNA medicines that teach the body to manufacture its own disease-fighting tools. INOVIO uses proprietary technology to design DNA plasmids, which are small circular DNA molecules that work like software the body’s cells can download to produce specific proteins to target and fight disease. The Company's proprietary investigational CELLECTRA delivery devices are designed to optimally deliver the plasmids into the body's cells. INOVIO's lead candidate is INO-3107 for the treatment of recurrent respiratory papillomatosis (RRP), a life-long, rare disease of the respiratory tract caused by HPV infection. In its completed Phase 1/2 clinical trial of INO-3107 for the treatment of HPV-6 and HPV-11-associated RRP, 81.3% of patients experienced a reduction in the number of surgical interventions in the year following administration of INO-3107, when compared with the year prior to treatment. In addition to its development efforts with INO-3107, INOVIO is actively developing or planning to develop DNA medicines for other indications, including HPV-related oropharyngeal squamous cell carcinoma (OPSCC) and anal dysplasia; glioblastoma multiforme (GBM), a deadly form of brain cancer; and a potential vaccine booster to protect against the Ebola virus. The Company was previously conducting clinical trials of a DNA medicine candidate for the treatment of HPV-related cervical high-grade squamous intraepithelial lesions (HSIL) but announced in August 2023 that it was ceasing development for this indication in the United States. However, its collaborator ApolloBio Corporation continues to conduct a Phase 3 clinical trial of this candidate in China and plans to seek regulatory approval for and potentially commercialize the candidate in that jurisdiction. The Company's partners and collaborators include Advaccine Biopharmaceuticals Suzhou Co, ApolloBio Corporation, AstraZeneca, The Bill & Melinda Gates Foundation (Gates), Coalition for Epidemic Preparedness Innovations (CEPI), Coherus Biosciences, Defense Advanced Research Projects Agency (DARPA), The U.S. Department of Defense (DoD), HIV Vaccines Trial Network, International Vaccine Institute (IVI), Kaneka Eurogentec, National Cancer Institute (NCI), National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), Plumbline Life Sciences, Regeneron Pharmaceuticals, Richter-Helm BioLogics, Thermo Fisher Scientific, the University of Pennsylvania, the Walter Reed Army Institute of Research, and The Wistar Institute. INOVIO was incorporated in Delaware in June 2001 and has its principal executive offices in Plymouth Meeting, Pennsylvania.

Basis of Presentation, Liquidit

Basis of Presentation, Liquidity and Risks and Uncertainties	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation, Liquidity and Risks and Uncertainties	Basis of Presentation, Liquidity and Risks and Uncertainties Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Inovio have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) as contained in the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") for interim financial information and with instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The condensed consolidated balance sheet as of September 30, 2024, the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive loss and the condensed consolidated statements of stockholders' equity for the three and nine months ended September 30, 2024 and 2023 and the condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023 are unaudited, but include all adjustments (consisting of normal recurring adjustments) that the Company considers necessary for a fair presentation of the financial position, results of operations, cash flows and changes in stockholders' equity for the periods presented. The results of operations for the three and nine months ended September 30, 2024 shown herein are not necessarily indicative of the results that may be expected for the year ending December 31, 2024, or for any other period. These unaudited financial statements, and notes thereto, should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2023, included in the Company's Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on March 6, 2024. The balance sheet at December 31, 2023 has been derived from the audited financial statements at that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These unaudited condensed consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiary. As of September 30, 2024 and December 31, 2023, the Company consolidated its wholly-owned subsidiary Inovio Asia LLC. All intercompany accounts and transactions were eliminated upon consolidation. Liquidity The Company incurred a net loss of $25.2 million and $87.9 million for the three and nine months ended September 30, 2024, respectively. The Company had working capital of $67.8 million and an accumulated deficit of $1.7 billion as of September 30, 2024. 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. On April 18, 2024, the Company closed an underwritten registered direct offering (the “Offering”) relating to the issuance and sale of 2,536,258 shares (the “Shares”) of its common stock, par value $0.001 per share, at a price of $7.693 per share and pre-funded warrants to purchase up to 2,135,477 shares of common stock (the “Pre-Funded Warrants”) at a price of $7.692 per Pre-Funded Warrant, which represents the per share price for the Shares less the $0.001 per share exercise price for each Pre-Funded Warrant. The net proceeds from the Offering were $33.2 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company. Going Concern The Company’s cash, cash equivalents and short-term investments of $84.8 million as of September 30, 2024 are expected to be sufficient to support the Company's planned operations into the third quarter of 2025. The Company's current financial resources may not be sufficient to support its planned operations beyond this date without securing additional financing. 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 Offering described above, and the receipt of net proceeds of $667,000 and $5.5 million under Sales Agreements during the nine months ended September 30, 2024 and year ended December 31, 2023, respectively. 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. In light of these factors, management believes that there is substantial doubt about the Company's ability to continue as a going concern beyond the third quarter of 2025. The Company's condensed consolidated financial statements as of and for the three and nine months ended September 30, 2024 do not include any adjustments that might result from the outcome of this uncertainty. The Company has evaluated subsequent events after the balance sheet date through the date it issued these condensed 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. Reverse Stock Split On January 24, 2024, the Company filed with the Secretary of State of the State of Delaware a certificate of amendment to its certificate of incorporation, as previously amended, to effect a 1-for-12 reverse stock split of its common stock (the “Reverse Stock Split”). As a result of the Reverse Stock Split, every 12 issued and outstanding shares of the Company's common stock were automatically combined into one issued and outstanding share of common stock. The reverse stock split was reflected on the Nasdaq Capital Market beginning with the opening of trading on January 25, 2024. Accordingly, an amount equal to the par value of the decreased shares resulting from the reverse stock split was reclassified from "Additional paid-in capital" to "Common stock" on the balance sheet and statement of changes in stockholders’ equity. Any fractional post-split shares as a result of the reverse stock split were eliminated by the payment of cash for the value of such fractional share. As a result of the Reverse Stock Split, proportionate adjustments were made to the number of shares underlying, and the

Critical Accounting Policies

Critical Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Critical Accounting Policies	Critical Accounting Policies Collaboration Agreements and Revenue Recognition The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808 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”). Research and Development Expenses - Clinical Trial Accruals The Company's activities have largely consisted of research and development efforts related to developing its proprietary device technology and DNA medicine candidates. For clinical trial expenses, judgements used in estimating accruals rely 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.

Short-term Investments and Fair

Short-term Investments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024 and December 31, 2023: As of September 30, 2024 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 36,127,635 $ — $ (1,712,020) $ 34,415,615 U.S. treasury securities Less than 1 24,812,301 16,999 — 24,829,300 Certificates of deposit Less than 1 2,979,932 10,242 (285) 2,989,889 U.S. agency mortgage-backed securities * 1,270,330 — (387,846) 882,484 $ 65,190,198 $ 27,241 $ (2,100,151) $ 63,117,288 As of December 31, 2023 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 55,389,289 $ — $ (3,522,888) $ 51,866,401 U.S. treasury securities Less than 1 75,164,782 24,938 — 75,189,720 Certificates of deposit Less than 1 2,978,917 11,709 (300) 2,990,326 U.S. agency mortgage-backed securities * 1,340,439 — (403,973) 936,466 $ 134,873,427 $ 36,647 $ (3,927,161) $ 130,982,913 *No single maturity date. During the three and nine months ended September 30, 2024, the Company recorded gross realized gains on investments of $200 and $700, respectively, and gross realized losses on investments of $587,000 and $1.3 million, respectively. During the three and nine months ended September 30, 2023, the Company recorded gross realized gains on investments of $300 and $800, respectively, and gross realized losses on investments of $500 and $3.9 million, respectively. During the three and nine months ended September 30, 2024, the Company recorded net unrealized gains on available-for-sale equity securities of $1.3 million and $1.8 million, respectively. During the three and nine months ended September 30, 2023, the Company recorded net unrealized (losses) gains on available-for-sale equity securities of $(219,000) and $3.9 million, respectively. No material balances were reclassified out of accumulated other comprehensive loss for the three and nine months ended September 30, 2024 and 2023. Interest and dividends on investments classified as available-for-sale are included in interest income in the condensed consolidated statements of operations. As of September 30, 2024, the Company had 19 available-for-sale securities with an aggregate total unrealized loss of $2.1 million. Of these securities, all had been in a loss position for longer than 12 months as of September 30, 2024. 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 September 30, 2024 were primarily due to changes in interest rates , and not due to increased credit risks associated with specific securities. 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 September 30, 2024, 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 September 30, 2024: Fair Value Measurements at September 30, 2024 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 34,415,615 $ 34,415,615 $ — $ — U.S. treasury securities 24,829,300 24,829,300 — — Certificates of deposit 2,989,889 — 2,989,889 — U.S. agency mortgage-backed securities 882,484 — 882,484 — Total short-term investments 63,117,288 59,244,915 3,872,373 — Investment in affiliated entity 2,644,226 2,644,226 — — Total assets measured at fair value $ 65,761,514 $ 61,889,141 $ 3,872,373 $ — 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, 2023: Fair Value Measurements at December 31, 2023 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 51,866,401 $ 51,866,401 $ — $ — U.S. treasury securities 75,189,720 75,189,720 — — Certificates of deposit 2,990,326 — 2,990,326 — U.S. agency mortgage-backed securities 936,466 — 936,466 — Total short-term investments 130,982,913 127,056,121 3,926,792 — Investment in affiliated entity 2,780,287 2,780,287 — — Total assets measured at fair value $ 133,763,200 $ 129,836,408 $ 3,926,792 $ — Level 1 assets at September 30, 2024 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 or loss on available-for-sale equity securities or as a gain or loss on investment in affiliated entity. Level 2 assets at September 30, 2024 consisted of 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. The Company obtains the fair value of its Level 2 assets from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or inputs other than quoted prices that are observable either directly or indirectly. The professional pricing service gathers quoted market prices and observable inputs from a variety of industry data providers. The valuation techniques used to measure the fair value of the Company's Level 2 financial instruments were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models such as discounted cash flow techniques. The Company validates the quoted market prices provided by the primary pricing service by comparing the service's assessment of the fair values of the Company's investment portfolio balance against the fair values of the Company's investment portfolio balance obtained from an independent source. There were no Level 3 assets held as of September 30, 2024 or December 31, 2023.
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 September 30, 2024 and December 31, 2023: As of September 30, 2024 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 36,127,635 $ — $ (1,712,020) $ 34,415,615 U.S. treasury securities Less than 1 24,812,301 16,999 — 24,829,300 Certificates of deposit Less than 1 2,979,932 10,242 (285) 2,989,889 U.S. agency mortgage-backed securities * 1,270,330 — (387,846) 882,484 $ 65,190,198 $ 27,241 $ (2,100,151) $ 63,117,288 As of December 31, 2023 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 55,389,289 $ — $ (3,522,888) $ 51,866,401 U.S. treasury securities Less than 1 75,164,782 24,938 — 75,189,720 Certificates of deposit Less than 1 2,978,917 11,709 (300) 2,990,326 U.S. agency mortgage-backed securities * 1,340,439 — (403,973) 936,466 $ 134,873,427 $ 36,647 $ (3,927,161) $ 130,982,913 *No single maturity date. During the three and nine months ended September 30, 2024, the Company recorded gross realized gains on investments of $200 and $700, respectively, and gross realized losses on investments of $587,000 and $1.3 million, respectively. During the three and nine months ended September 30, 2023, the Company recorded gross realized gains on investments of $300 and $800, respectively, and gross realized losses on investments of $500 and $3.9 million, respectively. During the three and nine months ended September 30, 2024, the Company recorded net unrealized gains on available-for-sale equity securities of $1.3 million and $1.8 million, respectively. During the three and nine months ended September 30, 2023, the Company recorded net unrealized (losses) gains on available-for-sale equity securities of $(219,000) and $3.9 million, respectively. No material balances were reclassified out of accumulated other comprehensive loss for the three and nine months ended September 30, 2024 and 2023. Interest and dividends on investments classified as available-for-sale are included in interest income in the condensed consolidated statements of operations. As of September 30, 2024, the Company had 19 available-for-sale securities with an aggregate total unrealized loss of $2.1 million. Of these securities, all had been in a loss position for longer than 12 months as of September 30, 2024. 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 September 30, 2024 were primarily due to changes in interest rates , and not due to increased credit risks associated with specific securities. 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 September 30, 2024, 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 September 30, 2024: Fair Value Measurements at September 30, 2024 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 34,415,615 $ 34,415,615 $ — $ — U.S. treasury securities 24,829,300 24,829,300 — — Certificates of deposit 2,989,889 — 2,989,889 — U.S. agency mortgage-backed securities 882,484 — 882,484 — Total short-term investments 63,117,288 59,244,915 3,872,373 — Investment in affiliated entity 2,644,226 2,644,226 — — Total assets measured at fair value $ 65,761,514 $ 61,889,141 $ 3,872,373 $ — 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, 2023: Fair Value Measurements at December 31, 2023 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 51,866,401 $ 51,866,401 $ — $ — U.S. treasury securities 75,189,720 75,189,720 — — Certificates of deposit 2,990,326 — 2,990,326 — U.S. agency mortgage-backed securities 936,466 — 936,466 — Total short-term investments 130,982,913 127,056,121 3,926,792 — Investment in affiliated entity 2,780,287 2,780,287 — — Total assets measured at fair value $ 133,763,200 $ 129,836,408 $ 3,926,792 $ — Level 1 assets at September 30, 2024 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 or loss on available-for-sale equity securities or as a gain or loss on investment in affiliated entity. Level 2 assets at September 30, 2024 consisted of 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. The Company obtains the fair value of its Level 2 assets from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or inputs other than quoted prices that are observable either directly or indirectly. The professional pricing service gathers quoted market prices and observable inputs from a variety of industry data providers. The valuation techniques used to measure the fair value of the Company's Level 2 financial instruments were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models such as discounted cash flow techniques. The Company validates the quoted market prices provided by the primary pricing service by comparing the service's assessment of the fair values of the Company's investment portfolio balance against the fair values of the Company's investment portfolio balance obtained from an independent source. There were no Level 3 assets held as of September 30, 2024 or December 31, 2023.

Certain Balance Sheet Items

Certain Balance Sheet Items	9 Months Ended
	Sep. 30, 2024
Certain Balance Sheet Items [Abstract]
Certain Balance Sheet Items	Certain Balance Sheet Items Prepaid and other current assets consisted of the following: September 30, 2024 December 31, 2023 Prepaid clinical expenses (a) $ 2,264,051 $ 3,410,442 Other prepaid expenses 2,353,065 1,983,223 $ 4,617,116 $ 5,393,665 Accounts payable and accrued expenses consisted of the following: September 30, 2024 December 31, 2023 Trade accounts payable $ 3,551,234 $ 3,577,826 Accrued compensation 9,918,354 9,837,104 Other accrued expenses (b) 1,273,603 6,432,814 $ 14,743,191 $ 19,847,744 (a) As of September 30, 2024 and December 31, 2023, balance included $95,000 and $1.5 million, respectively, of prepaid manufacturing expenses. (b) As of September 30, 2024 and December 31, 2023, balance included $0 and $4.3 million, respectively, of liability for unused grant funding.

Convertible Debt

Convertible Debt	9 Months Ended
	Sep. 30, 2024
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 were senior unsecured obligations of the Company and accrued interest payable in cash semi-annually in arrears on March 1 and September 1 of each year at a rate of 6.50% per annum. The Notes matured on March 1, 2024 and the Company paid the then remaining $16.9 million obligation in full, including accrued interest. For the nine months ended September 30, 2024, the Company recognized $178,000 of interest expense related to the Notes, all of which related to the contractual interes t coupon. For the three and nine months ended September 30, 2023 , the Company recognized $313,000 and $940,000, respectively, of interest expense related to the Notes, of which $267,000 and $800,000, respectively, related to the contractual interest coupon.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity The following is a summary of the Company's authorized and issued common and preferred stock as of September 30, 2024 and December 31, 2023: Outstanding as of Authorized Issued September 30, 2024 December 31, 2023 Common Stock, par value $0.001 per share 600,000,000 26,052,452 26,052,452 22,793,075 Series C Preferred Stock, par value $0.001 per share 1,091 1,091 9 9 Offering of Common Stock and Pre-Funded Warrants On April 18, 2024, the Company closed the Offering of Shares and Pre-Funded Warrants (see “Liquidity” in Note 2 above). As the Pre-Funded Warrants are indexed to the Company's own shares of common stock (and otherwise meet the requirements to be classified in equity), the Company recorded the consideration received from the issuance of the Pre-Funded Warrants as additional paid-in capital on the Company's condensed consolidated balance sheet as of June 30, 2024. Each Pre-Funded Warrant has an initial exercise price per share of $0.001, subject to certain adjustments. The Pre-Funded Warrants may be exercised at any time until exercised in full. A holder (together with its affiliates and other attribution parties) may not exercise any portion of a Pre-Funded Warrant to the extent that immediately prior to or after giving effect to such exercise the holder would own more than 9.99% of the Company’s outstanding Common Stock immediately after exercise, which percentage may be changed at the holder’s election to a lower or higher percentage not in excess of 19.99% upon 61 days’ notice to the Company subject to the terms of the Pre-Funded Warrants. As of September 30, 2024, no Pre-Funded Warrants had been exercised. At-The-Market Sales Agreements On August 13, 2024, the Company entered into an Equity Distribution Agreement (the "2024 Sales Agreement") with an outside sales agent (the "Sales Agent") for the offer and sale of its common stock for an aggregate offering price of up to $60.0 million. The 2024 Sales Agreement provides that the Sales Agent is 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 Agent under the 2024 Sales Agreement, and the Company has provided the Sales Agent with certain indemnification rights. During the three months ended September 30, 2024, the Company sold 86,361 shares of its common stock under the 2024 Sales Agreement. The sales were made at a weighted average price of $7.84 per share, resulting in aggregate net proceeds of $667,000. As of September 30, 2024, there was $59.3 million of remaining capacity under the 2024 Sales Agreement. 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 were 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. During the three months ended March 31, 2024, the Company sold 543,620 shares of its common stock under the 2021 Sales Agreement at a weighted average price of $9.76 per share, resulting in aggregate net proceeds of $5.2 million. During the year ended December 31, 2023, the Company sold 875,305 shares of its common stock under the 2021 Sales Agreement at a weighted average price of $6.33 per share, resulting in aggregate net proceeds of $5.5 million. The 2021 Sales Agreement was terminated in August 2024 in connection with the entry into the 2024 Sales Agreement described above. Other Issuances of Common Stock During the three months ended March 31, 2023, the Company issued 760,083 shares of common stock pursuant to the securities class action settlement, as described in Note 11. Stock Options and Restricted Stock Units The Board of Directors adopted the 2023 Omnibus Incentive Plan (the “2023 Plan”) on March 24, 2023, pursuant to which the Company may grant stock options, restricted stock awards, restricted stock units ("RSUs") and other stock-based awards or short-term cash incentive awards to employees, directors and consultants. The 2023 Plan was approved by stockholders on May 16, 2023. The aggregate number of shares of the Company’s common stock that may be issued under the 2023 Plan will not exceed the sum of 1,166,666 shares plus any shares that may return from time to time from the 2016 Omnibus Incentive Plan (as amended, the “2016 Plan”) as a result of expirations, terminations or forfeitures of awards outstanding under the 2016 Plan as of May 16, 2023. At September 30, 2024, the Company had 873,434 shares of common stock available for future grant under the 2023 Plan, 176,279 shares underlying outstanding RSUs and 265,191 shares underlying options outstanding to purchase common stock under the 2023 Plan. The awards granted and available for future grant under the 2023 Plan generally vest over three years and have a maximum contractual term of ten years. The 2023 Plan terminates by its terms on March 24, 2033. At September 30, 2024, the Company had 129,000 shares underlying outstanding but unvested RSUs and options outstanding to purchase 905,952 shares of common stock under the 2016 Plan. The outstanding awards granted under the 2016 Plan generally vest over three years and have a maximum contractual term of ten years. Following adoption of the 2023 Plan, no further awards may be made under the 2016 Plan, but outstanding awards continue to be governed by their existing terms. On June 24, 2022, the Company's board of directors adopted a stock-based incentive plan (the "2022 Inducement Plan"), which provides for the discretionary grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, RSU awards, performance awards, and other awards to individuals as a material inducement to entering into employment with the Company. The aggregate number of shares of the Company’s common stock that may be issued under the 2022 Inducement Plan will not exceed 166,666 shares. At September 30, 2024, the Company had 85,994 shares of common stock available for future grant under the 2022 Inducement Plan, 20,829 shares underlying outstanding but unvested RSUs and options outstanding to purchase 52,018 shares of common stock under the 2022 Inducement Plan. The 2022 Inducement Plan can be terminated by the Company's board of directors at any time. The Amended and Restated 2007 Omnibus Incentive Plan (the "2007 Incentive Plan") was adopted on M

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding during the period. The outstanding Pre-Funded Warrants (see Note 7) are included in the weighted-average common shares outstanding in the basic net loss per share calculation for the three and nine months ended September 30, 2024 given their nominal exercise price. Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding stock options and RSUs and refle cts the potential dilution that would occur if securities or other con tracts to issue common stock were exercised or converted to common stock. The dilutive impact of the Notes previously issued by the Company (discussed in Note 6) was 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 the 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 three and nine months ended September 30, 2024 and 2023, basic and diluted net loss per share were the same, as the assumed exercise or settlement of stock options, service-based RSUs, performance-and market-based RSUs and the potentially dilutive shares issuable upon conversion of the Notes prior to their repayment on March 1, 2024 would have been anti-dilutive. Basic and diluted net loss per share for the three and nine months ended September 30, 2024 and 2023 are calculated as follows: Three Months Ended September 30, 2024 2023 Numerator: Net loss $ (25,165,478) $ (33,929,864) Denominator: Shares used to compute net loss per share, basic and diluted Weighted-average common shares outstanding 26,005,020 22,385,229 Weighted-average pre-funded warrants 2,135,477 — Weighted-average common shares outstanding used to compute basic and diluted net loss per share 28,140,497 22,385,229 Net loss per share Basic and diluted $ (0.89) $ (1.52) Nine Months Ended September 30, 2024 2023 Numerator: Net loss $ (87,872,447) $ (110,113,714) Denominator: Shares used to compute net loss per share, basic and diluted Weighted-average common shares outstanding 24,923,227 21,986,840 Weighted-average pre-funded warrants 1,293,756 — Weighted-average common shares outstanding used to compute basic and diluted net loss per share 26,216,983 21,986,840 Net loss per share Basic and diluted $ (3.35) $ (5.01) The following table summarizes potential shares of common stock that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect: Three and Nine Months Ended September 30 2024 2023 Options to purchase common stock 1,319,769 1,209,989 Service-based restricted stock units 326,108 277,440 Performance-and market-based restricted stock units 83,800 — Convertible preferred stock 275 275 Convertible notes — 254,165 Total 1,729,952 1,741,869

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company incurs stock-based compensation expense related to service-based RSUs, performance-based 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 Capital Market on the date of grant. The Company estimates the fair value of stock options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of subjective assumptions, including the expected stock price volatility and expected option life. The Company amortizes the fair value of the awards on a straight-line basis over the requisite vesting period of the awards. Expected volatility is based on historical volatility. The expected life of options granted is based on historical expected life. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield is based on the fact that no dividends have been paid historically and none are currently expected to be paid in the foreseeable future. The Company recognizes forfeitures as they occur. The weighted average assumptions used in the Black-Scholes model for option grants to employees and directors are presented below: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Risk-free interest rate 3.86% 4.11% 4.21% 4.05% Expected volatility 106% 101% 105% 100% Expected life in years 5.6 5.6 5.5 5.5 Dividend yield — — — — Total employee and director stock-based compensation expense recognized in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024 was $1.2 million and $5.1 million, respectively, of which $581,000 and $2.2 million, respectively, was included in research and development expenses, and $619,000 and $2.9 million, respectively, was included in general and administrative expenses. Total employee and director stock-based compensation expense recognized in the condensed consolidated statements of operations for the three and nine months ended September 30, 2023 was $1.9 million and $8.3 million, respectively, of which $846,000 and $3.5 million, respectively, was included in research and development expenses, and $1.1 million and $4.8 million, respectively, was included in general and administrative expenses. At September 30, 2024, there was $2.8 million of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 1.5 years. The weighted average grant date fair value per share, calculated using the Black-Scholes option pricing model, was $7.96 and $7.01 for employee and director stock options granted during the three and nine months ended September 30, 2024, respectively, and $5.04 and $11.28 for the three and nine months ended September 30, 2023, respectively. At September 30, 2024, there was $2.6 million of total unrecognized compensation expense related to unvested service-based RSUs, which is expected to be recognized over a weighted-average period of 1.7 years. The weighted average grant date fair value per share was $9.97 and $8.68 for service-based RSUs granted during the three and nine months ended September 30, 2024, respectively and $6.36 and $10.32 for the three and nine months ended September 30, 2023, 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 RSUs granted to non-employees for the three and nine months ended September 30, 2024 was $40,000 and $186,000, respectively. Total stock-based compensation expense for stock options and RSUs granted to non-employees for the three and nine months ended September 30, 2023 was $153,000 and $519,000, respectively. Performance-and Market-Based RSUs In 2024, the Company granted performance-and market-based RSUs (such performance-based grants, the "PSU Awards") to key employees under the 2023 Plan. Each PSU was expressed as a target number of RSUs. With respect to the PSU Awards, the Company's Board of Directors established specified performance goals and corresponding performance periods over which the goals must be attained, the satisfaction of which are conditions to earning the PSU Awards and vesting of the underlying RSUs. As of September 30, 2024, 83,800 performance-and market-based RSU's were outstanding. Of the target number of RSUs underlying each PSU Award, up to 70% (the "Milestone-based RSUs") will vest based on the achievement of specified milestones relating to the development, regulatory status and commercialization of the Company’s lead product candidate INO-3107 (each, a "Milestone," and collectively, the "Milestones"). Each Milestone has a specified deadline for achievement ranging between the end of 2025 and the end of 2027. The remaining 30% of the target number of RSUs underlying each PSU Award (the "Market-based RSUs") will be eligible to vest based on the Company’s achievement of total stockholder return relative to a peer group consisting of companies in the Russell 2000 Biotechnology Subsector index (the “Relative TSR”) over the period beginning on June 1, 2024 and ending on December 31, 2027 (the “Performance Period”), expressed as a percentile ranking. The number of Market-based RSUs, if any, actually earned based on the achievement of the Relative TSR goal may range from 50% of the target number of RSUs for performance at a specified threshold percentile, to 100% of the target number of RSUs for performance at the target percentile, and up to 150% of the target number of RSUs for performance at or above a specified maximum percentile. In the event that actual Relative TSR performance is between the threshold and target levels or between the target and maximum levels, the number of RSUs earned based on Relative TSR will be determined based on linear interpolation between the specified percentiles. If the Company’s actual Relative TSR performance is below the threshold percentile, then no RSUs would be earned based on Relative TSR. The number of RSUs earned based on Relative TSR may not exceed the target number of RSUs eligible to vest based on Relative TSR if the Company’s total stockholder return is negative for the Performance Period. The Company values the Milestone-based RSUs based on the grant date closing price per share. The Company recognizes stock-based compensation expense over the performance period, if it is probable that the performance condition will be achieved. Adjustments to stock-based compensation expense are made, as needed, each reporting period based on changes in the Company's estimate of the number of units that are probable of vesting. The Company values the Market-based RSUs on the grant date using the Monte Carlo simulation method, a generally accepted statistical technique used to simulate a range of possible future stock prices for the Company and the peer group. The determination of fair value is affected by the Company's stock price and a number of assumptions including the expected volatility and the risk-free interest rate. The Company will recognize stock-based compensation expense ratably over the performance period of the award. The market-based RSUs will cliff-vest at the end of the three-year period ranging from 0 percent to 150 percent of the target number of awards granted. The significant assumptions used in the Monte Carlo simulation method were as follows: Risk-free interest rate 4.60% Expected volatility 90% Expected life in years 3.61 Dividend yield — The grant date fair value of the Milestone-based RSUs was $629,000 based on the grant date closing price per share of $10.96. As of September 30, 2024, the underlying performance milestones of the Milestone-based RSUs were determined to be not probable of achievement, and no stock-based compensation expense was recognized for the three and nine months then ended.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2024
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Plumbline Life Sciences, Inc. The Company owned 597,808 shares of common stock in PLS as of September 30, 2024, representing an ownership interest of 17.8%, and one of the Company's directors, Dr. David B. Weiner, acts as a consultant to PLS. The Wistar Institute Dr. Weiner is a director of the Vaccine Center of The Wistar Institute ("Wistar") and an 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 agreements. 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 has the exclusive right to in-license new intellectual property developed under this agreement. In 2020, the Company received a $10.7 million sub-grant through Wistar, which was amended in 2021 to $13.6 million, for the preclinical development and translational studies of DMAbs as countermeasures for COVID-19. In August 2024, the sub-grant was amended to a total of $12.5 million in funding through September 2025. In December 2022, the Company received a $1.2 million sub-grant through Wistar, which was amended in 2024 to $2.4 million with funding through November 2024, with an option for an additional $4.2 million in funding that extends the sub-grant through November 2027. The Company will support the Wistar lead consortium in the research and development of synthetic DNA-launched nanoparticles (dLNPs) for vaccination against HIV infection. 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 three and nine months ended September 30, 2024, the Company recorded $153,000 and $302,000, respectively, and for the three and nine months ended September 30, 2023, the Company recorded $316,000 and $705,000, respectively, as contra-research and development expense from Wistar. Research and development expenses recorded from Wistar relate primarily to collaborative research agreements. Research and development expenses recorded from Wistar for the three and nine months ended September 30, 2024 were $296,000 and $1.3 million, respectively. Research and development expenses recorded from Wistar for the three and nine months ended September 30, 2023 were $407,000 and $1.3 million, respectively. At September 30, 2024 and December 31, 2023, the Company had an accounts receivable balance of $1.9 million and $2.4 million, respectively, and an accounts payable and accrued liability balance of $1.8 million and $1.1 million, respectively, related to Wistar. At September 30, 2024 and December 31, 2023, the Company recorded $0 and $22,000, respectively, as deferred grant funding on its condensed consolidated balance sheet related to Wistar.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company leases approximately 56,600 square feet of office, laboratory, and manufacturing space in San Diego, California and approximately 57,400 square feet of office space in Plymouth Meeting, Pennsylvania under various non-cancellable operating lease agreements with remaining lease terms as of September 30, 2024 of 2.7 to 5.3 ye ars, 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. In November 2023, the Company entered into a lease agreement for research and development laboratory space in San Diego, California. The total space under the lease is approximately 5,600 square feet. The term of the lease commenced on February 10, 2024 and the initial term is 4.3 years. The base rent adjusts periodically throughout the term of the lease. Rent payments under the lease will include base rent with an annual increase of approximately three percent, and additional monthly fees to cover the Company's share of certain facility expenses, including utilities, property taxes, insurance and maintenance. 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 condensed 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 September 30, 2024, the maturities of the Company's operating lease liabilities were as follows: Remainder of 2024 $ 873,000 2025 3,483,000 2026 3,555,000 2027 2,955,000 2028 2,310,000 Thereafter 2,132,000 Total remaining lease payments 15,308,000 Less: present value adjustment (2,863,000) Total operating lease liabilities 12,445,000 Less: current portion (2,425,000) Long-term operating lease liabilities $ 10,020,000 Weighted-average remaining lease term 4.6 years Weighted-average discount rate 9.0% Lease costs included in operating expenses in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024 were $662,000 and $2.0 million, respectively. Lease costs included in operating expenses in the condensed consolidated statements of operations for the three and nine months ended September 30, 2023 were $851,000 and $2.5 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 third and fourth quarters of 2023, the Company entered into agreements to sublease a total of approximately 4,400 and 7,000 square feet, respectively, in its Plymouth Meeting headquarters, in each case with sublease terms through December 31, 2026. 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, with one sublease term through March 31, 2025 and the other month-to-month. 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. Legal Proceedings Securities Litigation In March 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 its former President and Chief Executive Officer as defendants. The lawsuit alleged that the Company made materially false and misleading statements in violation of certain federal securities laws. The plaintiffs sought unspecified monetary damages on behalf of the putative class and an award of costs and expenses, including reasonable attorneys’ fees. The plaintiffs’ complaint was later amended to include certain of the Company’s other officers as defendants. After additional motions were filed in the case, in June 2022 the parties negotiated an agreement in principle to settle the shareholder class action complaint, which was approved by the court in January 2023. Under the settlement, the Company agreed to pay $30.0 million in cash and $14.0 million in shares of its common stock to settle all outstanding claims. The Company's insurance carriers paid the $30.0 million cash component of the settlement. During the three months ended March 31, 2023, the Company issued 760,083 shares of common stock pursuant to the securities class action settlement. Shareholder Derivative Litigation In April 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 asserted state and federal claims and was based on the same alleged misstatements as the shareholder class action complaint described above. The lawsuit accused 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 sought unspecified monetary damages on behalf of the Company as well as governance reforms. Between June 2020 and August 2020, additional shareholder derivative complaints were filed and later consolidated by the court. In March 2022, an additional shareholder derivative complaint was filed in the Delaware Court of Chancery, asserting substantially similar claims as those in the consolidated derivative action. In May 2022, the Delaware Court of Chancery entered a stay of the litigation. In March 2023, the parties submitted a joint status report to the Court of Chancery reporting that the parties agreed to a settlement in principle, which also provided for the resolution of the consolidated derivative action and certain stockholder demands. In April 2023, the plaintiffs in the consolidated derivative action filed a motion for preliminary approval of settlement with the United States District Court for the Eastern District of Pennsylvania. The proposed settlement provided for resolution of the consolidated derivative action, the derivative action pending in the Delaware Court of Chancery, and certain stockholder demands. In June 2023, the court entered an order preliminarily approving the proposed settlement of the derivative claims, in accordance with a Stipulation of Settlement. The Stipulation of Settlement contemplated that, following the settlement hearing and the final approval of the settlement by the court, the Company would implement certain corporate governance reforms described in the Stipulation of Settlement. The preliminary order also approved the form and manner of the notice of the Settlement. As part of the Settlement, in July 2023 the Company paid $1.2 million to plaintiffs’ counsel for their fees and expenses. In October 2023, the court entered an order and final judgment approving the Settlement, which became effective in November 2023. The Company has implemented the corporate governance reforms in response to the provisions of the Stipulation of Settlement. VGXI Litigation In June 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. In June 2020, the Company filed a petition for preliminary injunction, which was denied. Following an appeal by the Company, in July 2020, VGXI filed 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. VGXI also 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, but VGXI later discontinued its third-party claims. The Company filed an answer to VGXI’s counterclaims, disputing the allegations and the claims raised in VGXI’s filing. In October 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 In December 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 in October 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. The Company filed preliminary objections to the complaint, which were overruled by the court. In September 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. In October 2021, GeneOne filed its answer to the Company’s counterclaims and new matter. On February 29, 2024, the Company filed a motion for summary judgment. On April 1, 2024, GeneOne filed an opposition to the Company’s motion for summary judgment. On June 28, 2024, the court denied the motion for summary judgment. 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 its 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.

Collaborative Agreements

Collaborative Agreements	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Agreements	Collaborative Agreements Advaccine Biopharmaceuticals Suzhou Co., Ltd. In December 2020, the Company entered into a Collaboration and License Agreement with Advaccine Biopharmaceuticals Suzhou Co., Ltd. (“Advaccine”), which was amended and restated in June 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. The June 2021 amendment related to a collaboration between the Company and Advaccine to jointly conduct a global Phase 3 segment of the Company’s clinical trial of INO-4800 that was planned. The parties were jointly participating in the trial and were to equally share the global development costs for the trial, including the Company’s manufacturing costs to supply INO-4800. Advaccine agreed to be fully responsible for conducting the trial in Greater China, including its costs and expenses incurred. In the fourth quarter of 2022, the Company discontinued its internally funded efforts to develop INO-4800 as a COVID-19 heterologous booster vaccine. Advaccine continues to develop INO-4800 with its own resources under the terms of the Advaccine Agreement. In connection with the June 2021 amendment, the Company determined that the global Phase 3 trial component of the agreement was a collaboration and not a contract with a customer and therefore accounted for the June 2021 amendment under ASC Topic 808. Reimbursements from Advaccine were recognized as contra-research development expense on the condensed consolidated statement of operations once earned and collectibility was assured. For the three and nine months ended September 30, 2023, the Company received funding of $1.2 million and $3.6 million, respectively, from Advaccine that was recorded as contra-research and development expense. No funding was received during the three and nine months ended September 30, 2024. ApolloBio Corporation In December 2017, the Company entered into an Amended and Restated License and Collaboration Agreement (the "ApolloBio Agreement"), with ApolloBio Corporation ("ApolloBio"), which was amended in June 2023. 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. 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. During the three and nine months ended September 30, 2024, the Company received funding of $0 and $101,000, respectively, from the ApolloBio Agreement that was recorded as revenue. During the three and nine months ended September 30, 2023, the Company received funding of $238,000 and $243,000, respectively, from the ApolloBio Agreement that was recorded as revenue. Coalition for Epidemic Preparedness Innovations The Company previously entered into agreements with CEPI, pursuant to which the Company intended to develop vaccine candidates against Lassa fever and MERS. As part of the arrangement between the parties, CEPI 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. In November 2022, the Company announced that it and CEPI would discontinue the development of these product candidates targeting Lassa fever and MERS, following the initial analysis of data from the studies conducted by the Company and funded by CEPI. For both the three and nine months ended September 30, 2024, the Company received funding of $1.6 million related to the final close-out of these grants, which was recorded as contra-research and development expense. During the three and nine months ended September 30, 2023, the Company received funding of $0 and $1.8 million, respectively, related to these 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 three and nine months ended September 30, 2023, the Company received funding of $8,000 and $196,000, respectively, from CEPI related to these grants for INO-4800 and recorded such amounts as contra-research and development expense. For both the three and nine months ended September 30, 2024, the Company received no funding from CEPI related to these grants. Bill & Melinda Gates Foundation In October 2018, 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 three and nine months ended September 30, 2024, the Company recorded $0 and $39,000, respectively, as contra-research and development expense related to the Gates dMAb grant. During the three and nine months ended September 30, 2023, the Company recorded $0 and $70,000, respectively, as contra-research and development expense related to the grant.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company uses an estimated annual effective tax rate, which is based on expected annual income, statutory tax rates and tax planning opportunities available in the various jurisdictions in which the Company operates, to determine its quarterly provision for income taxes. Certain significant or unusual items are separately recognized in the quarter in which they occur and can be a source of variability in the effective tax rates from quarter to quarter. Due to the adoption of ASU 2019-12 which removes the exception under ASC 740-20-45-7 to consider all sources of income in order to determine the tax benefit resulting from a loss from continuing operations, ASC 740-20-45-7 no longer applies.

Geneos Therapeutics, Inc.

Geneos Therapeutics, Inc.	9 Months Ended
	Sep. 30, 2024
Noncontrolling Interest [Abstract]
Geneos Therapeutics, Inc.	Geneos Therapeutics, Inc. In 2016, the Company formed Geneos Therapeutics 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. The Company's Chief Scientific Officer Dr. Laurent Humeau is on the Board of Directors of Geneos. The Company's director Dr. David B. Weiner is the Chairman of the Scientific Advisory Board of Geneos. Following a series of financing transactions through June 2020, the Company held less than a majority of the outstanding equity of Geneos on an as-converted to common stock basis, which 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 in 2020. Following the deconsolidation, 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. 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’ 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 investment at fair value. The Company determined that its investment in Geneos did not have a readily determinable fair value and 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 is marked to fair value. 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 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. Of the total amount, $819,000 was allocated to the equity method investment, reducing the balance to $0 as of March 31, 2021. The remaining $4.2 million loss was allocated to the Company’s Series A and Series A-1 preferred stock investment in Geneos, on a ratable basis, reducing the balance to $0 as of March 31, 2021. In February 2021, Geneos completed a second closing of its 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. In March 2022, Geneos completed the closing of a Series A-2 preferred stock financing. The Company invested $2.0 million in the Series A-2 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 continued to be a VIE as it did not have sufficient equity at risk to finance its activities without additional subordinated financial support. The Company continued to not be the primary beneficiary of Geneos, as it did 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 28% of the outstanding equity, on an as-converted to common stock basis. Accordingly, the Company continued 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-2 preferred stock was based on the per share price paid by third-party investors. The Company concluded that its Series A-2 preferred stock investment was a similar financial instrument as its Series A-1 preferred stock, and therefore remeasured the carrying value of the Series A-1 preferred stock investment at the Series A-2 preferred stock price, resulting in a gain on remeasurement of $165,000. The Company recorded its current and accumulated share of net losses of Geneos of $2.2 million, which was allocated to the Series A-1 and Series A-2 preferred stock investment in Geneos, thereby reducing the balance to $0 as of March 31, 2022. The Company has not made any further investment in Geneos subsequent to March 31, 2022. 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 2023, Geneos completed the closing of its Series A-3 preferred stock financing, in which the Company did not participate. Following this transaction, the Company held approximately 23% of the outstanding equity of Geneos on an as-converted to common stock basis. The Company continues to exclusively license its SynCon ®

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events From October 1, 2024 through the date these financial statements were issued, the Company sold 47,539 shares of common stock under the 2024 Sales Agreement at a weighted average price of $5.52 per share, for net proceeds of $258,000.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net loss	$ (25,165,478)	$ (32,237,098)	$ (30,469,871)	$ (33,929,864)	$ (35,534,533)	$ (40,649,317)	$ (87,872,447)	$ (110,113,714)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation, Liquid_2

Basis of Presentation, Liquidity and Risks and Uncertainties (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation and Liquidity	Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Inovio have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) as contained in the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") for interim financial information and with instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The condensed consolidated balance sheet as of September 30, 2024, the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive loss and the condensed consolidated statements of stockholders' equity for the three and nine months ended September 30, 2024 and 2023 and the condensed consolidated statements of cash flows for the nine months ended September 30, 2024 and 2023 are unaudited, but include all adjustments (consisting of normal recurring adjustments) that the Company considers necessary for a fair presentation of the financial position, results of operations, cash flows and changes in stockholders' equity for the periods presented. The results of operations for the three and nine months ended September 30, 2024 shown herein are not necessarily indicative of the results that may be expected for the year ending December 31, 2024, or for any other period. These unaudited financial statements, and notes thereto, should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2023, included in the Company's Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on March 6, 2024. The balance sheet at December 31, 2023 has been derived from the audited financial statements at that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These unaudited condensed consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiary. As of September 30, 2024 and December 31, 2023, the Company consolidated its wholly-owned subsidiary Inovio Asia LLC. All intercompany accounts and transactions were eliminated upon consolidation. Liquidity The Company incurred a net loss of $25.2 million and $87.9 million for the three and nine months ended September 30, 2024, respectively. The Company had working capital of $67.8 million and an accumulated deficit of $1.7 billion as of September 30, 2024. 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. On April 18, 2024, the Company closed an underwritten registered direct offering (the “Offering”) relating to the issuance and sale of 2,536,258 shares (the “Shares”) of its common stock, par value $0.001 per share, at a price of $7.693 per share and pre-funded warrants to purchase up to 2,135,477 shares of common stock (the “Pre-Funded Warrants”) at a price of $7.692 per Pre-Funded Warrant, which represents the per share price for the Shares less the $0.001 per share exercise price for each Pre-Funded Warrant. The net proceeds from the Offering were $33.2 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company. Going Concern The Company’s cash, cash equivalents and short-term investments of $84.8 million as of September 30, 2024 are expected to be sufficient to support the Company's planned operations into the third quarter of 2025. The Company's current financial resources may not be sufficient to support its planned operations beyond this date without securing additional financing. 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 Offering described above, and the receipt of net proceeds of $667,000 and $5.5 million under Sales Agreements during the nine months ended September 30, 2024 and year ended December 31, 2023, respectively. 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. In light of these factors, management believes that there is substantial doubt about the Company's ability to continue as a going concern beyond the third quarter of 2025. The Company's condensed consolidated financial statements as of and for the three and nine months ended September 30, 2024 do not include any adjustments that might result from the outcome of this uncertainty. The Company has evaluated subsequent events after the balance sheet date through the date it issued these condensed consolidated financial statements.
Collaboration Agreements and Revenue Recognition	Collaboration Agreements and Revenue Recognition
Research and Development Expenses - Clinical Trial Accruals	Research and Development Expenses - Clinical Trial Accruals The Company's activities have largely consisted of research and development efforts related to developing its proprietary device technology and DNA medicine candidates. For clinical trial expenses, judgements used in estimating accruals rely 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.
Net Loss Per Share	Basic net loss per share is computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding during the period. The outstanding Pre-Funded Warrants (see Note 7) are included in the weighted-average common shares outstanding in the basic net loss per share calculation for the three and nine months ended September 30, 2024 given their nominal exercise price. Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding stock options and RSUs and refle cts the potential dilution that would occur if securities or other con tracts to issue common stock were exercised or converted to common stock. The dilutive impact of the Notes previously issued by the Company (discussed in Note 6) was 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 the 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 three and nine months ended September 30, 2024 and 2023, basic and diluted net loss per share were the same, as the assumed exercise or settlement of stock options, service-based RSUs, performance-and market-based RSUs and the potentially dilutive shares issuable upon conversion of the Notes prior to their repayment on March 1, 2024 would have been anti-dilutive.
Stock-Based Compensation	The Company incurs stock-based compensation expense related to service-based RSUs, performance-based 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 Capital 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.

Short-term Investments and Fa_2

Short-term Investments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Summary of Investments	The following is a summary of available-for-sale securities as of September 30, 2024 and December 31, 2023: As of September 30, 2024 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 36,127,635 $ — $ (1,712,020) $ 34,415,615 U.S. treasury securities Less than 1 24,812,301 16,999 — 24,829,300 Certificates of deposit Less than 1 2,979,932 10,242 (285) 2,989,889 U.S. agency mortgage-backed securities * 1,270,330 — (387,846) 882,484 $ 65,190,198 $ 27,241 $ (2,100,151) $ 63,117,288 As of December 31, 2023 Contractual Cost Gross Unrealized Gross Unrealized Fair Market Value Mutual funds --- $ 55,389,289 $ — $ (3,522,888) $ 51,866,401 U.S. treasury securities Less than 1 75,164,782 24,938 — 75,189,720 Certificates of deposit Less than 1 2,978,917 11,709 (300) 2,990,326 U.S. agency mortgage-backed securities * 1,340,439 — (403,973) 936,466 $ 134,873,427 $ 36,647 $ (3,927,161) $ 130,982,913 *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 September 30, 2024: Fair Value Measurements at September 30, 2024 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 34,415,615 $ 34,415,615 $ — $ — U.S. treasury securities 24,829,300 24,829,300 — — Certificates of deposit 2,989,889 — 2,989,889 — U.S. agency mortgage-backed securities 882,484 — 882,484 — Total short-term investments 63,117,288 59,244,915 3,872,373 — Investment in affiliated entity 2,644,226 2,644,226 — — Total assets measured at fair value $ 65,761,514 $ 61,889,141 $ 3,872,373 $ — 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, 2023: Fair Value Measurements at December 31, 2023 Total Quoted Prices Significant Significant Short-term investments Mutual funds $ 51,866,401 $ 51,866,401 $ — $ — U.S. treasury securities 75,189,720 75,189,720 — — Certificates of deposit 2,990,326 — 2,990,326 — U.S. agency mortgage-backed securities 936,466 — 936,466 — Total short-term investments 130,982,913 127,056,121 3,926,792 — Investment in affiliated entity 2,780,287 2,780,287 — — Total assets measured at fair value $ 133,763,200 $ 129,836,408 $ 3,926,792 $ —

Certain Balance Sheet Items (Ta

Certain Balance Sheet Items (Tables)	9 Months Ended
	Sep. 30, 2024
Certain Balance Sheet Items [Abstract]
Schedule Of Prepaid Expenses And Other Current Assets	Prepaid and other current assets consisted of the following: September 30, 2024 December 31, 2023 Prepaid clinical expenses (a) $ 2,264,051 $ 3,410,442 Other prepaid expenses 2,353,065 1,983,223 $ 4,617,116 $ 5,393,665
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable and accrued expenses consisted of the following: September 30, 2024 December 31, 2023 Trade accounts payable $ 3,551,234 $ 3,577,826 Accrued compensation 9,918,354 9,837,104 Other accrued expenses (b) 1,273,603 6,432,814 $ 14,743,191 $ 19,847,744 (a) As of September 30, 2024 and December 31, 2023, balance included $95,000 and $1.5 million, respectively, of prepaid manufacturing expenses. (b) As of September 30, 2024 and December 31, 2023, balance included $0 and $4.3 million, respectively, of liability for unused grant funding.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Schedule of Summary of Common and Preferred Stock Authorized, Issued and Outstanding	The following is a summary of the Company's authorized and issued common and preferred stock as of September 30, 2024 and December 31, 2023: Outstanding as of Authorized Issued September 30, 2024 December 31, 2023 Common Stock, par value $0.001 per share 600,000,000 26,052,452 26,052,452 22,793,075 Series C Preferred Stock, par value $0.001 per share 1,091 1,091 9 9

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	Basic and diluted net loss per share for the three and nine months ended September 30, 2024 and 2023 are calculated as follows: Three Months Ended September 30, 2024 2023 Numerator: Net loss $ (25,165,478) $ (33,929,864) Denominator: Shares used to compute net loss per share, basic and diluted Weighted-average common shares outstanding 26,005,020 22,385,229 Weighted-average pre-funded warrants 2,135,477 — Weighted-average common shares outstanding used to compute basic and diluted net loss per share 28,140,497 22,385,229 Net loss per share Basic and diluted $ (0.89) $ (1.52) Nine Months Ended September 30, 2024 2023 Numerator: Net loss $ (87,872,447) $ (110,113,714) Denominator: Shares used to compute net loss per share, basic and diluted Weighted-average common shares outstanding 24,923,227 21,986,840 Weighted-average pre-funded warrants 1,293,756 — Weighted-average common shares outstanding used to compute basic and diluted net loss per share 26,216,983 21,986,840 Net loss per share Basic and diluted $ (3.35) $ (5.01)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table summarizes potential shares of common stock that were excluded from the diluted net loss per share calculation because of their anti-dilutive effect: Three and Nine Months Ended September 30 2024 2023 Options to purchase common stock 1,319,769 1,209,989 Service-based restricted stock units 326,108 277,440 Performance-and market-based restricted stock units 83,800 — Convertible preferred stock 275 275 Convertible notes — 254,165 Total 1,729,952 1,741,869

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Weighted Average Assumptions	The weighted average assumptions used in the Black-Scholes model for option grants to employees and directors are presented below: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Risk-free interest rate 3.86% 4.11% 4.21% 4.05% Expected volatility 106% 101% 105% 100% Expected life in years 5.6 5.6 5.5 5.5 Dividend yield — — — —
Schedule of Significant Assumption Used in Monte Carlo Simulation Method	The significant assumptions used in the Monte Carlo simulation method were as follows: Risk-free interest rate 4.60% Expected volatility 90% Expected life in years 3.61 Dividend yield —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	As of September 30, 2024, the maturities of the Company's operating lease liabilities were as follows: Remainder of 2024 $ 873,000 2025 3,483,000 2026 3,555,000 2027 2,955,000 2028 2,310,000 Thereafter 2,132,000 Total remaining lease payments 15,308,000 Less: present value adjustment (2,863,000) Total operating lease liabilities 12,445,000 Less: current portion (2,425,000) Long-term operating lease liabilities $ 10,020,000 Weighted-average remaining lease term 4.6 years Weighted-average discount rate 9.0%

Basis of Presentation, Liquid_3

Basis of Presentation, Liquidity and Risks and Uncertainties (Details)			1 Months Ended	3 Months Ended						9 Months Ended		12 Months Ended
	Apr. 18, 2024 USD ($) $ / shares shares	Jan. 24, 2024	Jan. 31, 2024	Sep. 30, 2024 USD ($) $ / shares	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) $ / shares
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net loss				$ 25,165,478	$ 32,237,098	$ 30,469,871	$ 33,929,864	$ 35,534,533	$ 40,649,317	$ 87,872,447	$ 110,113,714
Working capital				67,800,000						67,800,000
Accumulated deficit				$ 1,710,837,583						$ 1,710,837,583		$ 1,622,965,136
Common stock, par value (in dollars per share) | $ / shares				$ 0.001						$ 0.001		$ 0.001
Cash, cash equivalents, and short-term investments				$ 84,800,000						$ 84,800,000
Proceeds from issuance of stock										22,951,867	$ 3,623,462
Stock split, conversion ratio		0.083333	0.083333
Underwritten Registered Direct Offering
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Proceeds from sale of stock	$ 33,200,000
Underwritten Registered Direct Offering | Common stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of shares issued in transaction (in shares) | shares	2,536,258
Common stock, par value (in dollars per share) | $ / shares	$ 0.001
Sale of stock, price per share (in dollars per share) | $ / shares	$ 7.693
Underwritten Registered Direct Offering | Warrant
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of shares issued in transaction (in shares) | shares	2,135,477
Sale of stock, price per share (in dollars per share) | $ / shares	$ 7.692
Warrant exercise price (in dollars per share) | $ / shares	$ 0.001
2024 Sales Agreement | Common stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Proceeds from issuance of stock										$ 667,000		$ 5,500,000

Short-term Investments and Fa_3

Short-term Investments and Fair Value Measurements - Summary of Available-for-sale Securities (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Abstract]
Cost	$ 65,190,198	$ 134,873,427
Gross Unrealized Gains	27,241	36,647
Gross Unrealized Losses	(2,100,151)	(3,927,161)
Fair Market Value	63,117,288	130,982,913
Mutual funds
Debt Securities, Available-for-sale [Abstract]
Cost	36,127,635	55,389,289
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,712,020)	(3,522,888)
Fair Market Value	$ 34,415,615	$ 51,866,401
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity (in years)	1 year	1 year
Debt Securities, Available-for-sale [Abstract]
Cost	$ 24,812,301	$ 75,164,782
Gross Unrealized Gains	16,999	24,938
Gross Unrealized Losses	0	0
Fair Market Value	$ 24,829,300	$ 75,189,720
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Contractual Maturity (in years)	1 year	1 year
Debt Securities, Available-for-sale [Abstract]
Cost	$ 2,979,932	$ 2,978,917
Gross Unrealized Gains	10,242	11,709
Gross Unrealized Losses	(285)	(300)
Fair Market Value	2,989,889	2,990,326
U.S. agency mortgage-backed securities
Debt Securities, Available-for-sale [Abstract]
Cost	1,270,330	1,340,439
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(387,846)	(403,973)
Fair Market Value	$ 882,484	$ 936,466

Short-term Investments and Fa_4

Short-term Investments and Fair Value Measurements - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) position shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) position shares	Sep. 30, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Realized gain on investments	$ 200	$ 300	$ 700	$ 800
Realized loss on investments	587,000	500	1,300,000	3,900,000
Net unrealized gain (loss) on available-for-sale equity securities	$ 1,330,811	$ (219,337)	$ 1,810,868	$ 3,921,819
Number of securities in a gross unrealized loss position | position	19		19
Unrealized loss			$ 2,100,000
Level 1
Debt Securities, Available-for-sale [Line Items]
Investment owned (in shares) | shares	597,808		597,808

Short-term Investments and Fa_5

Short-term Investments and Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	$ 63,117,288	$ 130,982,913
Mutual funds
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	34,415,615	51,866,401
Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	2,989,889	2,990,326
U.S. agency mortgage-backed securities
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	882,484	936,466
Fair Value, Measurements, Recurring
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	63,117,288	130,982,913
Investment in affiliated entity	2,644,226	2,780,287
Total assets measured at fair value	65,761,514	133,763,200
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	59,244,915	127,056,121
Investment in affiliated entity	2,644,226	2,780,287
Total assets measured at fair value	61,889,141	129,836,408
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	3,872,373	3,926,792
Investment in affiliated entity	0	0
Total assets measured at fair value	3,872,373	3,926,792
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
Investment 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	34,415,615	51,866,401
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	34,415,615	51,866,401
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
Short-term investments	24,829,300	75,189,720
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
Short-term investments	24,829,300	75,189,720
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
Short-term investments	0	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
Short-term investments	0	0
Fair Value, Measurements, Recurring | Certificates of deposit
Financial assets and liabilities that are measured at fair value on recurring basis
Short-term investments	2,989,889	2,990,326
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	2,989,889	2,990,326
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	882,484	936,466
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	882,484	936,466
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

Certain Balance Sheet Items - P

Certain Balance Sheet Items - Prepaid and Other Current Assets (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Certain Balance Sheet Items [Abstract]
Prepaid clinical expenses	$ 2,264,051	$ 3,410,442
Other prepaid expenses	2,353,065	1,983,223
Prepaid expense and other assets, current	$ 4,617,116	$ 5,393,665

Certain Balance Sheet Items - A

Certain Balance Sheet Items - Accounts Payable and Accrued Expenses (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Accounts Payable and Accrued Expenses [Line Items]
Prepaid manufacturing expenses	$ 95,000	$ 1,500,000
Grant liability	0	4,300,000
Nonrelated Party
Accounts Payable and Accrued Expenses [Line Items]
Trade accounts payable	3,551,234	3,577,826
Accrued compensation	9,918,354	9,837,104
Other accrued expenses	1,273,603	6,432,814
Total	$ 14,743,191	$ 19,847,744

Convertible Debt (Details)

Convertible Debt (Details) - USD ($)			3 Months Ended	9 Months Ended
	Mar. 01, 2024	Mar. 01, 2019	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Feb. 19, 2019
Debt Instrument [Line Items]
Repayment of convertible senior notes				$ 16,415,000	$ 0
Convertible senior notes | Convertible Debt
Debt Instrument [Line Items]
Debt instrument, face amount		$ 78,500,000				$ 78,500,000
Debt interest based on the fixed rate (in percent)		6.50%				6.50%
Proceeds from issuance of debt		$ 75,700,000
Repayment of convertible senior notes	$ 16,900,000
Non-cash interest expense			$ 313,000	$ 178,000	940,000
Interest expense, contractual interest			$ 267,000		$ 800,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Authorized and Issued Common and Preferred Stock (Details) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Summary of common and preferred stock authorized, issued and outstanding
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares, authorized (in shares)	600,000,000
Common stock, shares, issued (in shares)	26,052,452
Common stock, shares, outstanding (in shares)	26,052,452	22,793,075
Series C Preferred Stock
Summary of common and preferred stock authorized, issued and outstanding
Preferred stock, par value (in dollars per share)	$ 0.001	$ 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 ($) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended	12 Months Ended
	Aug. 13, 2024	Nov. 09, 2021	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2024	Dec. 31, 2023	Apr. 18, 2024	May 16, 2023	Mar. 31, 2023	Jun. 24, 2022
2023 Incentive Plan
Class of Stock [Line Items]
Number of shares authorized (in shares)								1,166,666
Number of shares available for grant (in shares)			873,434		873,434
Number of shares of unvested restricted stock units and options outstanding (in shares)			176,279		176,279
Common stock, other shares, outstanding (in shares)			265,191		265,191
Award vesting period (in years)					3 years
Maximum contractual term (in years)					10 years
2016 Incentive Plan
Class of Stock [Line Items]
Number of shares of unvested restricted stock units and options outstanding (in shares)			129,000		129,000
Common stock, other shares, outstanding (in shares)			905,952		905,952
Award vesting period (in years)					3 years
Maximum contractual term (in years)					10 years
2022 Inducement Plan
Class of Stock [Line Items]
Number of shares authorized (in shares)										166,666
Number of shares available for grant (in shares)			85,994		85,994
Number of shares of unvested restricted stock units and options outstanding (in shares)			20,829		20,829
Common stock, other shares, outstanding (in shares)			52,018		52,018
2007 Incentive Plan
Class of Stock [Line Items]
Common stock, other shares, outstanding (in shares)			96,608		96,608
Maximum contractual term (in years)					10 years
McDermid v. Inovio Pharmaceuticals, Inc. and J. Joseph Kim
Class of Stock [Line Items]
Shares issued in settlement (in shares)									760,083
Underwritten Registered Direct Offering
Class of Stock [Line Items]
Class of warrant or right, common stock ownership (in percent)							19.99%
2024 Sales Agreement | Common stock
Class of Stock [Line Items]
Maximum authorized amount	$ 60,000
Sale of stock, sales proceeds of any common stock, percentage (in percent)	3%
Aggregate number of shares issued (in shares)			86,361
Stock sale agreement weighted average price (in dollars per share)			$ 7.84
Aggregate proceeds			$ 667
Stock sale agreement, remaining capacity, amount			$ 59,300		$ 59,300
2021 Sales Agreement | Common stock
Class of Stock [Line Items]
Maximum authorized amount		$ 300,000
Sale of stock, sales proceeds of any common stock, percentage (in percent)		3%
Aggregate number of shares issued (in shares)				543,620		875,305
Stock sale agreement weighted average price (in dollars per share)				$ 9.76		$ 6.33
Aggregate proceeds				$ 5,200		$ 5,500
Warrant | Underwritten Registered Direct Offering
Class of Stock [Line Items]
Warrant exercise price (in dollars per share)							$ 0.001
Common stock | Underwritten Registered Direct Offering
Class of Stock [Line Items]
Class of warrant or right, common stock ownership (in percent)							9.99%

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($)		3 Months Ended						9 Months Ended
		Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss		$ (25,165,478)	$ (32,237,098)	$ (30,469,871)	$ (33,929,864)	$ (35,534,533)	$ (40,649,317)	$ (87,872,447)	$ (110,113,714)
Denominator:
Weighted-average common shares outstanding (in shares)		26,005,020			22,385,229			24,923,227	21,986,840
Weighted-average pre-funded warrants (in shares)		2,135,477			0			1,293,756	0
Weighted-average common shares outstanding used to compute basic and diluted net loss per share, basic (in shares)	[1]	28,140,497			22,385,229			26,216,983	21,986,840
Weighted-average common shares outstanding used to compute basic and diluted net loss per share, diluted (in shares)	[1]	28,140,497			22,385,229			26,216,983	21,986,840
Net loss per share
Basic (in dollars per share)	[1]	$ (0.89)			$ (1.52)			$ (3.35)	$ (5.01)
Diluted (in dollars per share)	[1]	$ (0.89)			$ (1.52)			$ (3.35)	$ (5.01)
[1]Share and per share amounts have been restated to reflect the 1-for-12 reverse stock split effected in January 2024 on a retroactive basis for all periods presented.

Net Loss Per Share - Anti-dilut

Net Loss Per Share - Anti-dilutive (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	1,729,952	1,741,869	1,729,952	1,741,869
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	1,319,769	1,209,989	1,319,769	1,209,989
Service-based restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	326,108	277,440	326,108	277,440
Performance-and market-based restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	83,800	0	83,800	0
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	275	275	275	275
Convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded (in shares)	0	254,165	0	254,165

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted Average Assumptions (Details) - Stock Options - Employees and Directors	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	3.86%	4.11%	4.21%	4.05%
Expected volatility	106%	101%	105%	100%
Expected life in years	5 years 7 months 6 days	5 years 7 months 6 days	5 years 6 months	5 years 6 months
Dividend yield	0%	0%	0%	0%

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation			$ 5,279,344	$ 8,806,188
Total unrecognized compensation cost related to unvested stock options	$ 2,800,000		$ 2,800,000
Period over which total unrecognized compensation cost related to unvested stock options will be recognized (in years)			1 year 6 months
Weighted average grant date fair value (in dollars per share)	$ 7.96	$ 5.04	$ 7.01	$ 11.28
Threshold, percentage			150%
Service-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to unvested stock options	$ 2,600,000		$ 2,600,000
Period over which total unrecognized compensation cost related to unvested stock options will be recognized (in years)			1 year 8 months 12 days
Weighted average grant date fair value, restricted stock units (in dollars per share)	$ 9.97	$ 6.36	$ 8.68	$ 10.32
Performance-and market-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding (in shares)	83,800		83,800
Threshold, percentage			100%
Milestone-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation	$ 0		$ 0
Weighted average grant date fair value, restricted stock units (in dollars per share)			$ 10.96
Vesting percentage			70%
Grant date fair value			$ 629,000
Market-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation	18,000		$ 26,000
Weighted average grant date fair value, restricted stock units (in dollars per share)			$ 10.69
Vesting percentage			30%
Award vesting period (in years)			3 years
Grant date fair value			$ 269,000
Market-Based RSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			0%
Market-Based RSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			150%
Total Stockholders Return
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Threshold, percentage			50%
Employees and Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation	1,200,000	$ 1,900,000	$ 5,100,000	$ 8,300,000
Employees and Directors | Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	581,000	846,000	2,200,000	3,500,000
Employees and Directors | General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	619,000	1,100,000	2,900,000	4,800,000
Non Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation	$ 40,000	$ 153,000	$ 186,000	$ 519,000

Stock-Based Compensation - Sign

Stock-Based Compensation - Significant Assumption Used in Monte Carlo Simulation Method (Details) - Market-Based RSUs	9 Months Ended
	Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	4.60%
Expected volatility	90%
Expected life in years	3 years 7 months 9 days
Dividend yield	0%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2024	Dec. 31, 2022	Mar. 31, 2016	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2023
Related Party Transaction [Line Items]
Research and development expenses				$ 18,733,584	$ 15,503,032	$ 62,734,891	$ 69,423,513
Accounts receivable				1,862,739		1,862,739				$ 2,405,228
The Wistar Institute
Related Party Transaction [Line Items]
Collaborative agreement, amended amount								$ 13,600,000
Affiliated Entity
Related Party Transaction [Line Items]
Expenses to reimburse			$ 3,100,000
Collaborative arrangement, term (in years)			5 years
Contra-research and development expense				153,000	316,000	302,000	705,000
Affiliated Entity | The Wistar Institute
Related Party Transaction [Line Items]
Awarded amount		$ 1,200,000				2,400,000			$ 10,700,000
Collaborative agreement, amended amount	$ 12,500,000
Awarded option amount						4,200,000
Research and development expenses				296,000	$ 407,000	1,300,000	$ 1,300,000
Accounts receivable				1,900,000		1,900,000				2,400,000
Accounts payable and accrued liabilities, current				1,800,000		1,800,000				1,100,000
Deferred grant funding, from affiliate				$ 0		$ 0				$ 22,000
Plumbline Life Sciences
Related Party Transaction [Line Items]
Investment owned (in shares)				597,808		597,808
Non-controlling interest (in percent)				17.80%		17.80%

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Thousands	1 Months Ended			3 Months Ended				9 Months Ended
	Nov. 30, 2023 ft²	Jul. 31, 2023 USD ($)	Apr. 30, 2020 director	Sep. 30, 2024 USD ($)	Dec. 31, 2023 ft²	Sep. 30, 2023 USD ($) ft²	Dec. 31, 2019 ft² agreement	Sep. 30, 2024 USD ($) ft²	Sep. 30, 2023 USD ($)	Mar. 31, 2023 shares	Jan. 31, 2023 USD ($)
Lessee, Lease, Description [Line Items]
Lease cost				$ 662		$ 851		$ 2,000	$ 2,500
Number of agreements | agreement							2
McDermid v. Inovio Pharmaceuticals, Inc. and J. Joseph Kim
Lessee, Lease, Description [Line Items]
Estimate of cash settlement											$ 30,000
Estimate of shares settlement											$ 14,000
Shares issued in settlement (in shares) | shares										760,083
Behesti v. Kim, et al.
Lessee, Lease, Description [Line Items]
Number of defendants | director			8
Damages paid		$ 1,200
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease term (in years)				2 years 8 months 12 days				2 years 8 months 12 days
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease term (in years)				5 years 3 months 18 days				5 years 3 months 18 days
San Diego, California
Lessee, Lease, Description [Line Items]
Area leased (in square feet) | ft²								56,600
Plymouth Meeting, Pennsylvania
Lessee, Lease, Description [Line Items]
Area leased (in square feet) | ft²					7,000	4,400	13,500	57,400
San Diego, California
Lessee, Lease, Description [Line Items]
Area leased (in square feet) | ft²	5,600
Lessee, operating lease, term of contract (in years)	4 years 3 months 18 days
Lessee, operating lease, base rate percentage (in percent)	3%

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2024	$ 873,000
2025	3,483,000
2026	3,555,000
2027	2,955,000
2028	2,310,000
Thereafter	2,132,000
Total remaining lease payments	15,308,000
Less: present value adjustment	(2,863,000)
Total operating lease liabilities	12,445,000
Less: current portion	(2,425,112)	$ (2,406,522)
Long-term operating lease liabilities	$ 10,020,227	$ 11,032,066
Weighted-average remaining lease term	4 years 7 months 6 days
Weighted-average discount rate	9%

Collaborative Agreements (Detai

Collaborative Agreements (Details) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Aug. 31, 2019	Oct. 31, 2018	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from related parties					$ 0	$ 388,446	$ 100,762	$ 729,359
Advaccine | Collaborative Arrangement, Product
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment received					0	1,200,000	0	3,600,000
ApolloBio | Collaborative Arrangement, Product
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional revenue to be achieved							$ 20,000,000
Royalty period (in years)							10 years
Revenue from related parties					0	238,000	$ 101,000	243,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement, Product
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received	$ 6,900,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement, Product | Lassa Fever and MERS Vaccine
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received							$ 56,000,000
Collaborative agreement, period to receive funding for research and development (in years)							5 years
Collaborative agreement, funding received					1,600,000	0	$ 1,600,000	1,800,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement, Product | INO-4800
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received	1,300,000	$ 9,000,000
Collaborative agreement, funding received					0	8,000	0	196,000
Coalition for Epidemic Preparedness Innovations | Collaborative Arrangement, Product | CELLECTRA 3PSP Proprietary Smart Device
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding to be received	$ 5,000,000
Bill and Melinda Gates Foundation | Collaborative Arrangement, Product | DNA-Encoded Monoclonal Antibody Technology
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, funding received			$ 1,100,000	$ 2,200,000	$ 0	$ 0	$ 39,000	$ 70,000

Geneos Therapeutics, Inc. (Deta

Geneos Therapeutics, Inc. (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2023	Feb. 28, 2021
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by parent (in percent)	28%		23%	35%
Series A-2 One Preferred Stock
Noncontrolling Interest [Line Items]
Share of net loss in Geneos	$ 2,200
Investment in Geneos	0
Resulting in again on remeasurement	165
Geneos Therapeutics, Inc.
Noncontrolling Interest [Line Items]
Loss from equity method investment, recorded and allocated to investment		$ 1,500
Share of net loss in Geneos		434
Investment in Geneos		0
Geneos Therapeutics, Inc. | Series A One Preferred Stock
Noncontrolling Interest [Line Items]
Share of net loss in Geneos		819
Geneos Therapeutics, Inc. | Common stock
Noncontrolling Interest [Line Items]
Investment in Geneos		0
Geneos Therapeutics, Inc. | Preferred stock
Noncontrolling Interest [Line Items]
Share of net loss in Geneos		4,200
Investment in Geneos		$ 0
Payments to acquire additional interest in subsidiaries	$ 2,000

Subsequent Events (Details)

Subsequent Events (Details) - 2024 Sales Agreement - Common stock - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Nov. 14, 2024	Sep. 30, 2024
Subsequent Event [Line Items]
Aggregate number of shares issued (in shares)		86,361
Stock sale agreement weighted average price (in dollars per share)		$ 7.84
Aggregate proceeds		$ 667
Subsequent Event
Subsequent Event [Line Items]
Aggregate number of shares issued (in shares)	47,539
Stock sale agreement weighted average price (in dollars per share)	$ 5.52
Aggregate proceeds	$ 258