Basis of Presentation, Liquidity and Risks and Uncertainties (Policies)	6 Months Ended
Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	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 June 30, 2023, 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 six months ended June 30, 2023 and 2022 and the condensed consolidated statements of cash flows for the six months ended June 30, 2023 and 2022 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 six months ended June 30, 2023 shown herein are not necessarily indicative of the results that may be expected for the year ending December 31, 2023, 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, 2022, included in the Company's Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on March 1, 2023. The balance sheet at December 31, 2022 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 June 30, 2023 and December 31, 2022, 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 attributable to common stockholders of $35.5 million and $76.2 million for the three and six months ended June 30, 2023, respectively. The Company had working capital of $151.4 million and an accumulated deficit of $1.6 billion as of June 30, 2023. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $194.9 million as of June 30, 2023 are sufficient to support the Company's planned operations for a period of at least 12 months from the date of issuance of these financial statements. In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings including At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds of $2.9 million and $83.0 million under a Sales Agreement during the six months ended June 30, 2023 and year ended December 31, 2022, 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. These condensed consolidated financial statements do not include any adjustments to the specific amounts and classifications of assets and liabilities, which might be necessary should Inovio be unable to continue as a going concern. The Company's condensed consolidated financial statements as of and for the three and six months ended June 30, 2023 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business for the foreseeable future. The Company has evaluated subsequent events after the balance sheet date through the date it issued these 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.
Collaboration Agreements and Revenue Recognition	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”). The Company enters into collaborative arrangements with partners that typically include payment of one or more of the following: (i) license fees; (ii) product supply services; (iii) milestone payments related to the achievement of developmental, regulatory, or commercial goals; and (iv) royalties on net sales of licensed products. Where a portion of non-refundable, upfront fees or other payments received are allocated to continuing performance obligations under the terms of a collaborative arrangement, they are recorded as deferred revenue and recognized as revenue when (or as) the underlying performance obligation is satisfied. As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment of management to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligation. The standalone selling price may include items such as forecasted revenues, development timelines, discount rates and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. For collaboration arrangements that include license fees, the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. For collaboration arrangements that include milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. This assessment is based on the Company’s past experience with its collaboration partner, market insight and partner communication. Milestone payments that are not within the Company’s or the collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each subsequent reporting period, the Company re-evaluates the probability of achieving such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration or other revenues and earnings in the period of adjustment and could be material. For collaboration arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue in the period the underlying sales occur. To date, the Company has not recognized any royalty revenue resulting from any of its collaborative arrangements.
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 smart 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.

Basis of Presentation, Liquidity and Risks and Uncertainties (Policies)

6 Months Ended

Jun. 30, 2023

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 June 30, 2023, 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 six months ended June 30, 2023 and 2022 and the condensed consolidated statements of cash flows for the six months ended June 30, 2023 and 2022 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 six months ended June 30, 2023 shown herein are not necessarily indicative of the results that may be expected for the year ending December 31, 2023, 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, 2022, included in the Company's Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on March 1, 2023. The balance sheet at December 31, 2022 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 June 30, 2023 and December 31, 2022, 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 attributable to common stockholders of $35.5 million and $76.2 million for the three and six months ended June 30, 2023, respectively. The Company had working capital of $151.4 million and an accumulated deficit of $1.6 billion as of June 30, 2023. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $194.9 million as of June 30, 2023 are sufficient to support the Company's planned operations for a period of at least 12 months from the date of issuance of these financial statements.

In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings including At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds of $2.9 million and $83.0 million under a Sales Agreement during the six months ended June 30, 2023 and year ended December 31, 2022, 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. These condensed consolidated financial statements do not include any adjustments to the specific amounts and classifications of assets and liabilities, which might be necessary should Inovio be unable to continue as a going concern. The Company's condensed consolidated financial statements as of and for the three and six months ended June 30, 2023 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business for the foreseeable future. The Company has evaluated subsequent events after the balance sheet date through the date it issued these 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.

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”).

The Company enters into collaborative arrangements with partners that typically include payment of one or more of the following: (i) license fees; (ii) product supply services; (iii) milestone payments related to the achievement of developmental, regulatory, or commercial goals; and (iv) royalties on net sales of licensed products. Where a portion of non-refundable, upfront fees or other payments received are allocated to continuing performance obligations under the terms of a collaborative arrangement, they are recorded as deferred revenue and recognized as revenue when (or as) the underlying performance obligation is satisfied.

As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment of management to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligation. The standalone selling price may include items such as forecasted revenues, development timelines, discount rates and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price.

For collaboration arrangements that include license fees, the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

For collaboration arrangements that include milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. This assessment is based on the Company’s past experience with its collaboration partner, market insight and partner communication. Milestone payments that are not within the Company’s or the collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each subsequent reporting period, the Company re-evaluates the probability of achieving such milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration or other revenues and earnings in the period of adjustment and could be material.

For collaboration arrangements that include sales-based royalties, including milestone payments based on the level of sales, and for which the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue in the period the underlying sales occur. To date, the Company has not recognized any royalty revenue resulting from any of its collaborative arrangements.

Research and Development Expenses - Clinical Trial Accruals

The Company's activities have largely consisted of research and development efforts related to developing its proprietary smart 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.