Collaborative Agreements	12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Agreements	Collaborative Agreements ApolloBio Corporation On December 29, 2017, the Company entered into an Amended and Restated License and Collaboration Agreement (the "ApolloBio Agreement"), with ApolloBio Corporation ("ApolloBio"), with an effective date of March 20, 2018. Under the terms of the ApolloBio Agreement, the Company granted to ApolloBio the exclusive right to develop and commercialize VGX-3100, its DNA immunotherapy product designed to treat pre-cancers caused by HPV, within the territories of China, Hong Kong, Macao, Taiwan, and may include Korea in the event that no patent covering VGX-3100 is issued in China within the three years following the effective date of the ApolloBio Agreement. Under the ApolloBio Agreement, the Company received proceeds of $19.4 million in March 2018, which comprised the upfront payment of $23.0 million less $2.2 million in foreign income taxes and $1.4 million in certain foreign non-income taxes. The foreign income taxes were recorded as a provision for income taxes and the foreign non-income taxes were recorded as a general and administrative expense, on the condensed consolidated statement of operations during the quarter ended March 31, 2018. The Company also incurred advisory fees of $960,000 in connection with receiving the upfront payment from ApolloBio. These fees were determined to be incremental costs of obtaining the contract. The Company applied the practical expedient that permits a company to expense incremental costs to obtain a contract when the expected amortization period is one year or less and recorded the fees in general and administrative expense during the quarter ended March 31, 2018. No additional advisory fees are due related to the ApolloBio Agreement. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of $20.0 million, less required income, withholding or other taxes, upon the achievement of specified milestones related to the regulatory approval of VGX-3100 in the United States, China and Korea. In the event that VGX-3100 is approved for marketing, the Company will be entitled to receive royalty payments based on a tiered percentage of annual net sales, with such percentage being in the low- to mid-teens, subject to reduction in the event of generic competition in a particular territory. ApolloBio’s obligation to pay royalties will continue for 10 years after the first commercial sale in a particular territory or, if later, until the expiration of the last-to-expire patent covering the licensed products in the specified territory. The Company evaluated the terms of the ApolloBio Agreement under Topic 606, and the license to VGX-3100 in the territories was identified as the only distinct performance obligation on a standalone basis as of the inception of the agreement. The Company concluded that the license was distinct from potential future manufacturing and supply obligations. The Company further determined that the transaction price under the agreement consisted of the $23.0 million upfront payment. The future potential milestone amounts were not included in the transaction price, as they were all determined to be fully constrained. As part of the evaluation of the development and regulatory milestones constraint, the Company determined that the achievement of such milestones is contingent upon success in future clinical trials and regulatory approvals, each of which is uncertain at this time. Future potential milestone amounts may be recognized as revenue under the ApolloBio Agreement, as well as under other collaborative research and development arrangements, if unconstrained. Reimbursable program costs will be recognized proportionately with the performance of the underlying services or delivery of drug supply and are excluded from the transaction price. The ApolloBio Agreement will continue in force until ApolloBio has no remaining royalty obligations. Either party may terminate the ApolloBio Agreement in the event the other party shall materially breach or default in the performance of its material obligations thereunder and such default continues for a specified period after written notice thereof. In addition, ApolloBio may terminate the ApolloBio Agreement at any time beginning one year after the effective date for any reason upon 90 days written notice to the Company. Under Topic 606, the entire transaction price of $23.0 million was allocated to the license performance obligation. The Company determined that during the quarter ended June 30, 2018, the transfer of technology occurred and accordingly, the performance obligation was fully satisfied. The Company has recorded the gross upfront payment received from ApolloBio of $23.0 million as revenue under collaborative research and development arrangements on the consolidated statement of operations during the year ended December 31, 2018. AstraZeneca On August 7, 2015, the Company entered into a license and collaboration agreement with MedImmune, the global biologics research and development arm of AstraZeneca ("AstraZeneca"). Under the agreement, AstraZeneca acquired exclusive rights to the Company's INO-3112 immunotherapy, renamed as MEDI0457, which targets cancers caused by human papillomavirus (HPV) types 16 and 18, with the ability to sublicense those license rights. AstraZeneca made an upfront payment of $27.5 million to the Company in September 2015 and agreed to make potential future development and regulatory event-based payments totaling up to $355 million and potential future commercial event-based payments totaling up to $345 million, in each case upon the achievement of specified milestones set forth in the license and collaboration agreement. AstraZeneca will fund all development costs associated with MEDI0457 immunotherapy. The Company is entitled to receive up to mid-single to double-digit tiered royalties on MEDI0457 product sales. Within the broader collaboration, at AstraZeneca’s discretion, AstraZeneca and the Company will develop up to two additional DNA-based cancer vaccine products not included in the Company's current product pipeline, which AstraZeneca will have the exclusive rights to develop and commercialize. These additional development services would be provided by the Company at an industry standard full-time-equivalent rate. Under the agreement, AstraZeneca can also request the Company to provide certain clinical manufacturing at an agreed upon price. The Company determined these options did not represent material rights at the inception of the agreement. As of December 31, 2017, the Company had recognized all of the $27.5 million upfront payment as revenue, as all identified material performance obligations had been met with respect to that payment. In December 2017 and December 2018, the Company recognized as revenue $7.0 million and $2.0 million, respectively, in milestone payments from AstraZeneca triggered by AstraZeneca’s initiation of the Phase 2 portion of ongoing clinical trials in the first and second major indication, respectively, under the agreement. During the year ended December 31, 2018, the Company recognized total revenues of $6.9 million from AstraZeneca primarily for manufacturing services and the milestone achieved as discussed above. As of December 31, 2018 and 2017, the Company has a deferred revenue balance of $288,000 and $1.1 million, respectively, related to AstraZeneca. The deferred revenue relates to advanced payments made by the Company to a third-party biologics manufacturer for which AstraZeneca is obligated to reimburse. As of December 31, 2018 and 2017, the Company had an accounts receivable balance of $3.2 million and $1.7 million, respectively, related to the collaboration agreement with AstraZeneca. Prior to January 1, 2018 the Company accounted for the arrangement under Topic 605, which resulted in revenue of $22.3 million from AstraZeneca for the year ended December 31, 2017. Roche In September 2013, the Company entered into a Collaborative, License, and Option Agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. (together, “Roche”) and received an upfront payment of $10.0 million. The parties agreed to co-develop multi-antigen DNA immunotherapies targeting prostate cancer and hepatitis B. On November 14, 2014, Roche provided notice to the Company that it would be partially terminating the agreement with respect to the development of the Company’s DNA immunotherapy targeting prostate cancer. The termination was effective in February 2015. All of Roche’s rights to the Company’s DNA immunotherapy targeting prostate cancer, including the right to license the product to other parties, have been returned to the Company. On July 28, 2016, Roche provided notice to the Company that it would be discontinuing the agreement and its development of INO-1800, the Company’s DNA immunotherapy against the hepatitis B virus. The termination was effective in October 2016. All of Roche’s rights to INO-1800, including the right to license the product to other parties, have been returned to the Company. In February 2017, the Company received full payment of $8.5 million from Roche for its past and future obligations which were completed during the quarter ended June 30, 2017, associated with the termination of the agreement. During the year ended December 31, 2018, the Company recognized no revenues from Roche. During the year ended December 31, 2017, the Company recognized revenues of $6.1 million from Roche. Coalition for Epidemic Preparedness Innovations On April 11, 2018, the Company entered into agreements with the Coalition for Epidemic Preparedness Innovations ("CEPI"), pursuant to which the Company intends to develop vaccine candidates against Lassa fever and MERS. The goal of the collaboration between the Company and CEPI is to conduct research and development so that investigational stockpiles will be ready for clinical efficacy trial testing during potential disease outbreaks. The agreements with CEPI contemplate preclinical studies, as well as Phase 1 and Phase 2 clinical trials, occurring over the next few years. As part of the arrangement between the parties, CEPI has agreed to fund up to an aggregate of $56 million of costs over a five-year period for preclinical studies, as well as planned Phase 1 and Phase 2 clinical trials, to be conducted by the Company and collaborators, with funding from CEPI based on the achievement of identified milestones. During the year ended December 31, 2018, the Company received upfront funding of $6.5 million related to the CEPI grant, and recorded $4.3 million as contra-research and development expense. As of December 31, 2018, the Company had a deferred grant funding balance related to the CEPI grant of $2.1 million recorded as deferred grant funding on the consolidated balance sheet. DARPA- Ebola In April 2015, the Company received a grant from the Defense Advanced Research Projects Agency ("DARPA") to lead a collaborative team to develop multiple treatment and prevention approaches against Ebola. The consortium, led by the Company, is taking a multi-faceted approach to develop products to prevent and treat Ebola infection. The award covers pre-clinical development costs as well as good manufacturing practice, manufacturing costs and the Phase 1 clinical study costs. The initial funding period covers a base award of $19.6 million and an option award of $24.6 million, which was exercised in September 2015. During the year ended December 31, 2018, the Company received funding of $1.1 million related to the DARPA Ebola grant and recorded it as contra-research and development expense. During the year ended December 31, 2017, the Company recognized revenues of $9.8 million related to the DARPA Ebola grant. As of December 31, 2018 the Company had a deferred grant funding balance of $74,000, and as of December 31, 2017 the Company had a deferred revenue balance of $149,000, related to the DARPA grant. As of December 31, 2018 and 2017, the Company had an accounts receivable balance of $82,000 and $4.1 million, respectively, related to the DARPA grant.

Collaborative Agreements

ApolloBio Corporation

On December 29, 2017, the Company entered into an Amended and Restated License and Collaboration Agreement (the "ApolloBio Agreement"), with ApolloBio Corporation ("ApolloBio"), with an effective date of March 20, 2018. Under the terms of the ApolloBio Agreement, the Company granted to ApolloBio the exclusive right to develop and commercialize VGX-3100, its DNA immunotherapy product designed to treat pre-cancers caused by HPV, within the territories of China, Hong Kong, Macao, Taiwan, and may include Korea in the event that no patent covering VGX-3100 is issued in China within the three years following the effective date of the ApolloBio Agreement.

Under the ApolloBio Agreement, the Company received proceeds of $19.4 million in March 2018, which comprised the upfront payment of $23.0 million less $2.2 million in foreign income taxes and $1.4 million in certain foreign non-income taxes. The foreign income taxes were recorded as a provision for income taxes and the foreign non-income taxes were recorded as a general and administrative expense, on the condensed consolidated statement of operations during the quarter ended March 31, 2018. The Company also incurred advisory fees of $960,000 in connection with receiving the upfront payment from ApolloBio. These fees were determined to be incremental costs of obtaining the contract. The Company applied the practical expedient that permits a company to expense incremental costs to obtain a contract when the expected amortization period is one year or less and recorded the fees in general and administrative expense during the quarter ended March 31, 2018. No additional advisory fees are due related to the ApolloBio Agreement.

In addition to the upfront payment, the Company is entitled to receive up to an aggregate of $20.0 million, less required income, withholding or other taxes, upon the achievement of specified milestones related to the regulatory approval of VGX-3100 in the United States, China and Korea. In the event that VGX-3100 is approved for marketing, the Company will be entitled to receive royalty payments based on a tiered percentage of annual net sales, with such percentage being in the low- to mid-teens, subject to reduction in the event of generic competition in a particular territory. ApolloBio’s obligation to pay royalties will continue for 10 years after the first commercial sale in a particular territory or, if later, until the expiration of the last-to-expire patent covering the licensed products in the specified territory.

The Company evaluated the terms of the ApolloBio Agreement under Topic 606, and the license to VGX-3100 in the territories was identified as the only distinct performance obligation on a standalone basis as of the inception of the agreement. The Company concluded that the license was distinct from potential future manufacturing and supply obligations. The Company further determined that the transaction price under the agreement consisted of the $23.0 million upfront payment. The future potential milestone amounts were not included in the transaction price, as they were all determined to be fully constrained. As part of the evaluation of the development and regulatory milestones constraint, the Company determined that the achievement of such milestones is contingent upon success in future clinical trials and regulatory approvals, each of which is uncertain at this time. Future potential milestone amounts may be recognized as revenue under the ApolloBio Agreement, as well as under other collaborative research and development arrangements, if unconstrained. Reimbursable program costs will be recognized proportionately with the performance of the underlying services or delivery of drug supply and are excluded from the transaction price.

The ApolloBio Agreement will continue in force until ApolloBio has no remaining royalty obligations. Either party may terminate the ApolloBio Agreement in the event the other party shall materially breach or default in the performance of its material obligations thereunder and such default continues for a specified period after written notice thereof. In addition, ApolloBio may terminate the ApolloBio Agreement at any time beginning one year after the effective date for any reason upon 90 days written notice to the Company.

Under Topic 606, the entire transaction price of $23.0 million was allocated to the license performance obligation. The Company determined that during the quarter ended June 30, 2018, the transfer of technology occurred and accordingly, the performance obligation was fully satisfied. The Company has recorded the gross upfront payment received from ApolloBio of $23.0 million as revenue under collaborative research and development arrangements on the consolidated statement of operations during the year ended December 31, 2018.

AstraZeneca

On August 7, 2015, the Company entered into a license and collaboration agreement with MedImmune, the global biologics research and development arm of AstraZeneca ("AstraZeneca"). Under the agreement, AstraZeneca acquired exclusive rights to the Company's INO-3112 immunotherapy, renamed as MEDI0457, which targets cancers caused by human papillomavirus (HPV) types 16 and 18, with the ability to sublicense those license rights. AstraZeneca made an upfront payment of $27.5 million to the Company in September 2015 and agreed to make potential future development and regulatory event-based payments totaling up to $355 million and potential future commercial event-based payments totaling up to $345 million, in each case upon the achievement of specified milestones set forth in the license and collaboration agreement. AstraZeneca will fund all development costs associated with MEDI0457 immunotherapy. The Company is entitled to receive up to mid-single to double-digit tiered royalties on MEDI0457 product sales. Within the broader collaboration, at AstraZeneca’s discretion, AstraZeneca and the Company will develop up to two additional DNA-based cancer vaccine products not included in the Company's current product pipeline, which AstraZeneca will have the exclusive rights to develop and commercialize. These additional development services would be provided by the Company at an industry standard full-time-equivalent rate. Under the agreement, AstraZeneca can also request the Company to provide certain clinical manufacturing at an agreed upon price. The Company determined these options did not represent material rights at the inception of the agreement.

As of December 31, 2017, the Company had recognized all of the $27.5 million upfront payment as revenue, as all identified material performance obligations had been met with respect to that payment. In December 2017 and December 2018, the Company recognized as revenue $7.0 million and $2.0 million, respectively, in milestone payments from AstraZeneca triggered by AstraZeneca’s initiation of the Phase 2 portion of ongoing clinical trials in the first and second major indication, respectively, under the agreement. During the year ended December 31, 2018, the Company recognized total revenues of $6.9 million from AstraZeneca primarily for manufacturing services and the milestone achieved as discussed above. As of December 31, 2018 and 2017, the Company has a deferred revenue balance of $288,000 and $1.1 million, respectively, related to AstraZeneca. The deferred revenue relates to advanced payments made by the Company to a third-party biologics manufacturer for which AstraZeneca is obligated to reimburse. As of December 31, 2018 and 2017, the Company had an accounts receivable balance of $3.2 million and $1.7 million, respectively, related to the collaboration agreement with AstraZeneca.

Prior to January 1, 2018 the Company accounted for the arrangement under Topic 605, which resulted in revenue of $22.3 million from AstraZeneca for the year ended December 31, 2017.

Roche

In September 2013, the Company entered into a Collaborative, License, and Option Agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. (together, “Roche”) and received an upfront payment of $10.0 million. The parties agreed to co-develop multi-antigen DNA immunotherapies targeting prostate cancer and hepatitis B.

On November 14, 2014, Roche provided notice to the Company that it would be partially terminating the agreement with respect to the development of the Company’s DNA immunotherapy targeting prostate cancer. The termination was effective in February 2015. All of Roche’s rights to the Company’s DNA immunotherapy targeting prostate cancer, including the right to license the product to other parties, have been returned to the Company.

On July 28, 2016, Roche provided notice to the Company that it would be discontinuing the agreement and its development of INO-1800, the Company’s DNA immunotherapy against the hepatitis B virus. The termination was effective in October 2016. All of Roche’s rights to INO-1800, including the right to license the product to other parties, have been returned to the Company. In February 2017, the Company received full payment of $8.5 million from Roche for its past and future obligations which were completed during the quarter ended June 30, 2017, associated with the termination of the agreement. During the year ended December 31, 2018, the Company recognized no revenues from Roche. During the year ended December 31, 2017, the Company recognized revenues of $6.1 million from Roche.

Coalition for Epidemic Preparedness Innovations

On April 11, 2018, the Company entered into agreements with the Coalition for Epidemic Preparedness Innovations ("CEPI"), pursuant to which the Company intends to develop vaccine candidates against Lassa fever and MERS. The goal of the collaboration between the Company and CEPI is to conduct research and development so that investigational stockpiles will be ready for clinical efficacy trial testing during potential disease outbreaks. The agreements with CEPI contemplate preclinical studies, as well as Phase 1 and Phase 2 clinical trials, occurring over the next few years. As part of the arrangement between the parties, CEPI has agreed to fund up to an aggregate of $56 million of costs over a five-year period for preclinical studies, as well as planned Phase 1 and Phase 2 clinical trials, to be conducted by the Company and collaborators, with funding from CEPI based on the achievement of identified milestones. During the year ended December 31, 2018, the Company received upfront funding of $6.5 million related to the CEPI grant, and recorded $4.3 million as contra-research and development expense. As of December 31, 2018, the Company had a deferred grant funding balance related to the CEPI grant of $2.1 million recorded as deferred grant funding on the consolidated balance sheet.

DARPA- Ebola

In April 2015, the Company received a grant from the Defense Advanced Research Projects Agency ("DARPA") to lead a collaborative team to develop multiple treatment and prevention approaches against Ebola. The consortium, led by the Company, is taking a multi-faceted approach to develop products to prevent and treat Ebola infection. The award covers pre-clinical development costs as well as good manufacturing practice, manufacturing costs and the Phase 1 clinical study costs. The initial funding period covers a base award of $19.6 million and an option award of $24.6 million, which was exercised in September 2015. During the year ended December 31, 2018, the Company received funding of $1.1 million related to the DARPA Ebola grant and recorded it as contra-research and development expense. During the year ended December 31, 2017, the Company recognized revenues of $9.8 million related to the DARPA Ebola grant. As of December 31, 2018 the Company had a deferred grant funding balance of $74,000, and as of December 31, 2017 the Company had a deferred revenue balance of $149,000, related to the DARPA grant. As of December 31, 2018 and 2017, the Company had an accounts receivable balance of $82,000 and $4.1 million, respectively, related to the DARPA grant.