Collaboration and License Agreements	12 Months Ended
Dec. 31, 2018
License Agreements [Abstract]
Collaboration and License Agreements	Collaboration and License Agreements As part of its business, the Company enters into licensing agreements with third parties that often require milestone and royalty payments based on the progress of the licensed asset through development and commercial stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency, and the Company may be required to make royalty payments based upon a percentage of net sales of the product. The expenditures required under these arrangements in any period may be material and are likely to fluctuate from period to period. These arrangements sometimes permit the Company to unilaterally terminate development of the product and thereby avoid future contingent payments; however, the Company is unlikely to cease development if the compound successfully achieves clinical testing objectives. Memorial Sloan Kettering Cancer Center On September 4, 2014, (the “MSK Effective Date”) the Company entered into a license agreement (the “Original MSK License Agreement”) with MSK under which the Company was granted an exclusive license to develop and commercialize MSK’s WT1 peptide vaccine technology. Under the terms of the Original MSK License Agreement, the Company is required to obtain certain levels of financing. If such financing is not met, MSK will have the right to terminate the Original MSK License Agreement with prior written notice, unless the Company manages to overcome the shortfall during the term of the notice period. As part of the consideration for the rights, privileges and licenses granted under the Original MSK License Agreement, the Company issued 13,199 shares to MSK representing 1.5% of the Company’s fully diluted share capital as of the MSK Effective Date, which obligation was satisfied by assignment of 6,599 shares from each of the Company’s President, Chief Executive Officer, and co-founder, Dr. Angelos M. Stergiou, and the Company’s other co-founder, Dr. Miltiadis Sougioultzoglou (M.D.), to MSK, for which they received no consideration. Additionally, the Company was obligated to pay upfront license fees in an amount equal to $1.3 million. The Company recognized this amount as research and development expense during the year ended December 31, 2014, as it had no alternative future use. The Company would further be obligated to pay minimum royalty payments in the amount of $0.1 million each year commencing in 2015 and research funding costs of $0.2 million in each year and for three years commencing in January 2015. In addition, to the extent certain development and commercial milestones are achieved, the Company will be required to pay MSK up to $17.4 million in milestone payments for each licensed product, in addition to royalties in the event of commercial sales of any licensed products. The Original MSK License Agreement, unless terminated earlier in accordance with the terms of the Original MSK License Agreement, will continue on a country-by-country and licensed product-by-licensed product basis, until the later of: (i) expiration of the last valid claim embracing such licensed product; (ii) expiration of any market exclusivity period granted by law with respect to such licensed product; or (iii) ten (10) years from the first commercial sale in such country. On October 30, 2015, the Company and MSK entered into the License Amendment, Waiver and Share Issuance Agreement (the “First MSK Amendment”). The First MSK Amendment extended the date required for the Company to obtain financing from August 1, 2015 to December 31, 2016, modified the amount of required financing and waived past non-compliance with certain related provisions of the Original MSK License Agreement. In exchange for the First MSK Amendment, the Company agreed to issue an aggregate of 10,867 shares to MSK, which represented 1% of the fully diluted share capital of the Company at such date. The First MSK Amendment added certain anti-dilution protection clauses and entitled MSK to additional shares to the extent the Company was not able to obtain the required financing. On August 10, 2016, the Company and MSK entered into the Second License Amendment, Waiver and Agreement (the “Second MSK Amendment”). The Second MSK Amendment extended further the date required for the Company to obtain financing from December 31, 2016 to June 30, 2017, amended the anti-dilution provisions of the First MSK Amendment and waived past non-compliance with certain related provisions of the First MSK Amendment. Under the Second MSK Amendment, outstanding obligations of the Company to MSK in an amount of $0.9 million were converted into 13,815 shares effective November 1, 2016 upon the Company’s re-domiciliation to Bermuda. In consideration for this amendment and pursuant to the anti-dilution provisions in the Original MSK License Agreement as amended by the First MSK Amendment and the Second MSK Amendment, the Company issued MSK 30,314 additional shares and incurred accordingly $2.0 million of research and development expense, which reflected the fair value of the Company’s shares at such date. On May 25, 2017, the Company and MSK entered into an Amended and Restated Exclusive License Agreement (the “MSK A&R License Agreement”). Under the MSK A&R License Agreement, the Company expanded its license under the original MSK License Agreement, as amended, to include a license to commercially develop certain additional WT1 peptides through a program of exploiting certain patents and other rights covering such peptides. The MSK A&R License Agreement, among other changes, added certain milestone payments for each additional patent licensed product as defined in the MSK A&R License Agreement, and amended the milestone payments due upon commencement of the Phase 3 AML and mesothelioma clinical trials from $0.3 million to $0.4 million. In consideration for the MSK A&R License Agreement, the Company issued 8,799 shares to MSK. Pursuant to a side letter to the MSK A&R License Agreement, dated May 25, 2017 (the “MSK Side Letter”), MSK converted the next milestone payment of $0.2 million, which was due June 30, 2017, into shares. Further, in consideration for the MSK Side Letter, Dr. Stergiou, the Company’s Chief Executive Officer, assigned 15,399 of his shares to MSK, for which Dr. Stergiou received no cash consideration. On October 11, 2017, the Company and MSK entered into a second Amended and Restated Exclusive License Agreement (the “Second MSK A&R License Agreement”). Under the Second MSK A&R License Agreement, the Company and MSK extended the dates for the Company to have obtained necessary financing, and certain milestone dates, in exchange for increased milestone payments, clarification regarding MSK’s anti-dilution rights, and termination of the MSK Side Letter dated May 25, 2017. In connection with the Second MSK A&R License Agreement, the Company issued 74,795 shares to MSK. Prior to the Merger, the Company issued an additional 7,700 shares to MSK in connection with their anti-dilution rights. For the year ended December 31, 2018 the Company incurred $1.0 million of expenses relating to $0.5 million of milestone payments, $0.3 million in licensing fees, $0.1 million of guaranteed minimum royalty payments and $0.1 million of research funding costs. For the year ended December 31, 2017, the Company incurred $1.0 million of expenses relating to $0.7 million of milestone payments, $0.1 million of guaranteed minimum royal payments and $0.2 million of research funding costs. Such expenses have been included in research and development costs. Further, under the Second MSK Amendment, the Company is obligated to pay MSK $0.7 million in milestone payments in two equal installments, within 60 days following the initiation of its Phase 3 AML and mesothelioma clinical studies. Merck & Co., Inc. On September 21, 2017, the Company entered into a clinical trial collaboration and supply agreement through a Merck & Co., Inc. subsidiary, Merck Sharp & Dohme B.V. (“Merck subsidiary”), whereby the Company agreed with the Merck subsidiary to collaborate in a research program to evaluate GPS as it is administered in combination with Merck’s PD1 blocker pembrolizumab in a Phase 1/2 clinical trial enrolling patients in up to five cancer indications, including both hematologic malignancies and solid tumors. The Phase 1/2 clinical trial will utilize a combination of GPS plus pembrolizumab in patients with WT1+ relapsed or refractory tumors. Specifically, the study is expected to explore the following cancer indications: AML, ovarian, triple-negative breast, small cell lung, and colorectal (arm enriched in but not exclusive to patients with microsatelite instability-low tumors). This study will assess the efficacy and safety of the combination, comparing overall response rates and immune response markers achieved with the combination compared to prespecified rates based on those seen with pembrolizumab alone in comparable patient populations. This trial was initiated in December 2018. Advaxis, Inc. On February 24, 2017, the Company and Advaxis, Inc. (“Advaxis”) entered into a research and development collaboration agreement, whereby both parties will collaborate in a research program to evaluate, through a “proof of principle” trial or trials (“PoP Clinical Trial”), a clinical candidate comprised of the combination of Advaxis’ proprietary Lm-based antigen delivery technology and the Company’s patented WT1 targeted heteroclitic peptide antigen mixture (GPS). The term of the Advaxis agreement will expire upon the earlier of: (a) completion of the PoP Clinical Trial, (b) a decision by the parties to cease further development of the clinical candidate and (c) early termination of the Advaxis agreement pursuant to the terms thereof. The Advaxis agreement provides for cost-sharing between the parties, with Advaxis being responsible for the costs of performing the research activities and filing any investigational new drug application (“IND”), cost-sharing for preparation of the IND, and the Company being responsible for the costs (exclusive of product costs) of conducting the PoP Clinical Trial. The Company also agreed to make certain non-refundable milestone payments to Advaxis having an aggregate amount of up to $108.0 million, upon meeting certain clinical, regulatory and commercial milestones. In addition, if net sales exceed certain targets, the Company agreed to make non-refundable sales milestone payments up to $250.0 million and royalty payments based on specific royalty rates, with a maximum rate capped at a percentage rate in the low double digits if net sales exceed $1.0 billion. The University of Texas M. D. Anderson Cancer Center and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. On September 11, 2006, the Company acquired rights and assumed obligations under a license agreement among Apthera and The University of Texas M. D. Anderson Cancer Center (“MDACC”) and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (“HJF”) which grants exclusive worldwide rights to a United States patent covering the nelipepimut-S peptide vaccine ("NPS") and several United States and foreign patents and patent applications covering methods of using the peptide as a vaccine. Under the terms of this license, the Company is required to pay an annual maintenance fee of $0.2 million, up to $3.8 million for clinical milestone payments, and to pay a tiered royalty in the mid-single digits based on sales of NPS or other therapeutic products developed from the licensed technologies.

Collaboration and License Agreements

As part of its business, the Company enters into licensing agreements with third parties that often require milestone and royalty payments based on the progress of the licensed asset through development and commercial stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency, and the Company may be required to make royalty payments based upon a percentage of net sales of the product. The expenditures required under these arrangements in any period may be material and are likely to fluctuate from period to period. These arrangements sometimes permit the Company to unilaterally terminate development of the product and thereby avoid future contingent payments; however, the Company is unlikely to cease development if the compound successfully achieves clinical testing objectives.

Memorial Sloan Kettering Cancer Center

On September 4, 2014, (the “MSK Effective Date”) the Company entered into a license agreement (the “Original MSK License Agreement”) with MSK under which the Company was granted an exclusive license to develop and commercialize MSK’s WT1 peptide vaccine technology. Under the terms of the Original MSK License Agreement, the Company is required to obtain certain levels of financing. If such financing is not met, MSK will have the right to terminate the Original MSK License Agreement with prior written notice, unless the Company manages to overcome the shortfall during the term of the notice period.

As part of the consideration for the rights, privileges and licenses granted under the Original MSK License Agreement, the Company issued 13,199 shares to MSK representing 1.5% of the Company’s fully diluted share capital as of the MSK Effective Date, which obligation was satisfied by assignment of 6,599 shares from each of the Company’s President, Chief Executive Officer, and co-founder, Dr. Angelos M. Stergiou, and the Company’s other co-founder, Dr. Miltiadis Sougioultzoglou (M.D.), to MSK, for which they received no consideration. Additionally, the Company was obligated to pay upfront license fees in an amount equal to $1.3 million. The Company recognized this amount as research and development expense during the year ended December 31, 2014, as it had no alternative future use. The Company would further be obligated to pay minimum royalty payments in the amount of $0.1 million each year commencing in 2015 and research funding costs of $0.2 million in each year and for three years commencing in January 2015. In addition, to the extent certain development and commercial milestones are achieved, the Company will be required to pay MSK up to $17.4 million in milestone payments for each licensed product, in addition to royalties in the event of commercial sales of any licensed products.

The Original MSK License Agreement, unless terminated earlier in accordance with the terms of the Original MSK License Agreement, will continue on a country-by-country and licensed product-by-licensed product basis, until the later of: (i) expiration of the last valid claim embracing such licensed product; (ii) expiration of any market exclusivity period granted by law with respect to such licensed product; or (iii) ten (10) years from the first commercial sale in such country.

On October 30, 2015, the Company and MSK entered into the License Amendment, Waiver and Share Issuance Agreement (the “First MSK Amendment”). The First MSK Amendment extended the date required for the Company to obtain financing from August 1, 2015 to December 31, 2016, modified the amount of required financing and waived past non-compliance with certain related provisions of the Original MSK License Agreement. In exchange for the First MSK Amendment, the Company agreed to issue an aggregate of 10,867 shares to MSK, which represented 1% of the fully diluted share capital of the Company at such date. The First MSK Amendment added certain anti-dilution protection clauses and entitled MSK to additional shares to the extent the Company was not able to obtain the required financing.

On August 10, 2016, the Company and MSK entered into the Second License Amendment, Waiver and Agreement (the “Second MSK Amendment”). The Second MSK Amendment extended further the date required for the Company to obtain financing from December 31, 2016 to June 30, 2017, amended the anti-dilution provisions of the First MSK Amendment and waived past non-compliance with certain related provisions of the First MSK Amendment. Under the Second MSK Amendment, outstanding obligations of the Company to MSK in an amount of $0.9 million were converted into 13,815 shares effective November 1, 2016 upon the Company’s re-domiciliation to Bermuda. In consideration for this amendment and pursuant to the anti-dilution provisions in the Original MSK License Agreement as amended by the First MSK Amendment and the Second MSK Amendment, the Company issued MSK 30,314 additional shares and incurred accordingly $2.0 million of research and development expense, which reflected the fair value of the Company’s shares at such date.

On May 25, 2017, the Company and MSK entered into an Amended and Restated Exclusive License Agreement (the “MSK A&R License Agreement”). Under the MSK A&R License Agreement, the Company expanded its license under the original MSK License Agreement, as amended, to include a license to commercially develop certain additional WT1 peptides through a program of exploiting certain patents and other rights covering such peptides.

The MSK A&R License Agreement, among other changes, added certain milestone payments for each additional patent licensed product as defined in the MSK A&R License Agreement, and amended the milestone payments due upon commencement of the Phase 3 AML and mesothelioma clinical trials from $0.3 million to $0.4 million. In consideration for the MSK A&R License Agreement, the Company issued 8,799 shares to MSK. Pursuant to a side letter to the MSK A&R License Agreement, dated May 25, 2017 (the “MSK Side Letter”), MSK converted the next milestone payment of $0.2 million, which was due June 30, 2017, into shares. Further, in consideration for the MSK Side Letter, Dr. Stergiou, the Company’s Chief Executive Officer, assigned 15,399 of his shares to MSK, for which Dr. Stergiou received no cash consideration.

On October 11, 2017, the Company and MSK entered into a second Amended and Restated Exclusive License Agreement (the “Second MSK A&R License Agreement”). Under the Second MSK A&R License Agreement, the Company and MSK extended the dates for the Company to have obtained necessary financing, and certain milestone dates, in exchange for increased milestone payments, clarification regarding MSK’s anti-dilution rights, and termination of the MSK Side Letter dated May 25, 2017. In connection with the Second MSK A&R License Agreement, the Company issued 74,795 shares to MSK. Prior to the Merger, the Company issued an additional 7,700 shares to MSK in connection with their anti-dilution rights.

For the year ended December 31, 2018 the Company incurred $1.0 million of expenses relating to $0.5 million of milestone payments, $0.3 million in licensing fees, $0.1 million of guaranteed minimum royalty payments and $0.1 million of research funding costs. For the year ended December 31, 2017, the Company incurred $1.0 million of expenses relating to $0.7 million of milestone payments, $0.1 million of guaranteed minimum royal payments and $0.2 million of research funding costs. Such expenses have been included in research and development costs. Further, under the Second MSK Amendment, the Company is obligated to pay MSK $0.7 million in milestone payments in two equal installments, within 60 days following the initiation of its Phase 3 AML and mesothelioma clinical studies.

Merck & Co., Inc.

On September 21, 2017, the Company entered into a clinical trial collaboration and supply agreement through a Merck & Co., Inc. subsidiary, Merck Sharp & Dohme B.V. (“Merck subsidiary”), whereby the Company agreed with the Merck subsidiary to collaborate in a research program to evaluate GPS as it is administered in combination with Merck’s PD1 blocker pembrolizumab in a Phase 1/2 clinical trial enrolling patients in up to five cancer indications, including both hematologic malignancies and solid tumors. The Phase 1/2 clinical trial will utilize a combination of GPS plus pembrolizumab in patients with WT1+ relapsed or refractory tumors. Specifically, the study is expected to explore the following cancer indications: AML, ovarian, triple-negative breast, small cell lung, and colorectal (arm enriched in but not exclusive to patients with microsatelite instability-low tumors). This study will assess the efficacy and safety of the combination, comparing overall response rates and immune response markers achieved with the combination compared to prespecified rates based on those seen with pembrolizumab alone in comparable patient populations. This trial was initiated in December 2018.

Advaxis, Inc.

On February 24, 2017, the Company and Advaxis, Inc. (“Advaxis”) entered into a research and development collaboration agreement, whereby both parties will collaborate in a research program to evaluate, through a “proof of principle” trial or trials (“PoP Clinical Trial”), a clinical candidate comprised of the combination of Advaxis’ proprietary Lm-based antigen delivery technology and the Company’s patented WT1 targeted heteroclitic peptide antigen mixture (GPS). The term of the Advaxis agreement will expire upon the earlier of: (a) completion of the PoP Clinical Trial, (b) a decision by the parties to cease further development of the clinical candidate and (c) early termination of the Advaxis agreement pursuant to the terms thereof.

The Advaxis agreement provides for cost-sharing between the parties, with Advaxis being responsible for the costs of performing the research activities and filing any investigational new drug application (“IND”), cost-sharing for preparation of the IND, and the Company being responsible for the costs (exclusive of product costs) of conducting the PoP Clinical Trial. The Company also agreed to make certain non-refundable milestone payments to Advaxis having an aggregate amount of up to $108.0 million, upon meeting certain clinical, regulatory and commercial milestones. In addition, if net sales exceed certain targets, the Company agreed to make non-refundable sales milestone payments up to $250.0 million and royalty payments based on specific royalty rates, with a maximum rate capped at a percentage rate in the low double digits if net sales exceed $1.0 billion.

The University of Texas M. D. Anderson Cancer Center and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc.

On September 11, 2006, the Company acquired rights and assumed obligations under a license agreement among Apthera and The University of Texas M. D. Anderson Cancer Center (“MDACC”) and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (“HJF”) which grants exclusive worldwide rights to a United States patent covering the nelipepimut-S peptide vaccine ("NPS") and several United States and foreign patents and patent applications covering methods of using the peptide as a vaccine. Under the terms of this license, the Company is required to pay an annual maintenance fee of $0.2 million, up to $3.8 million for clinical milestone payments, and to pay a tiered royalty in the mid-single digits based on sales of NPS or other therapeutic products developed from the licensed technologies.