Commitments and Contingencies	9 Months Ended
Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	4. Commitments and Contingencies License Agreements Exclusive License Agreement with Precigen On April 3, 2023, the Company entered into the Amended and Restated Exclusive License Agreement with Precigen, or the A&R License Agreement, which restated and amended the parties' previous license agreement in full. Under the A&R License Agreement, the Company still had exclusive, worldwide rights to research, develop and commercialize TCR products designed for neoantigens or driver mutations for the treatment of cancer and non-exclusive rights to use non-driver mutation TCRs. On October 4, 2024, pursuant to Section 10.2 of the License Agreement, the Company duly notified Precigen of its full termination of all rights under the License Agreement. The decision to terminate the A&R License Agreement was made after a thorough review of our strategic priorities and business objectives, including recognizing that the non-viral Sleeping Beauty gene transfer platform patent will expire in 2026. The Company continues to prosecute certain of the intellectual property underlying the TCRs targeting driver mutations such as KRAS, TP53 and EGFR, and the hunTR TCR discovery platform used in the discovery of our proprietary TCR library. The Company continues to explore strategic alternatives, including, but not limited to, an acquisition, merger, reverse merger, sale of assets, strategic partnerships, capital raises or other transactions. License Agreement and Research and Development Agreement —The University of Texas MD Anderson Cancer Center In 2015, the Company, together with Precigen, entered into a license agreement, or the MD Anderson License with MD Anderson (which Precigen subsequently assigned to PGEN). Pursuant to the MD Anderson License, the Company, together with Precigen, holds an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell therapies, non-viral gene transfer systems, genetic modification and/or propagation of immune cells and other cellular therapy approaches, Natural Killer, or NK Cells, and TCRs. In 2015, the Company, Precigen and MD Anderson entered into the 2015 R&D Agreement to formalize the scope and process for the transfer by MD Anderson, pursuant to the terms of the MD Anderson License, of certain existing research programs and related technology rights, as well as the terms and conditions for future collaborative research and development of new and ongoing research programs. As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the 2015 R&D Agreement. At various times, the Company amended the 2015 R&D Agreement to extend the term until December 31, 2026 and in 2019 entered into the 2019 R&D Agreement, pursuant to which the Company agreed to collaborate with respect to the TCR program. The Company incur $0 and $28 thousand clinical costs from MD Anderson related to the these agreements for the three and nine months ended September 30, 2025. The 2019 R&D Agreement will terminate on December 31, 2026 and either party may terminate the 2019 R&D Agreement following written notice of a material breach. The 2019 R&D Agreement also contains customary provisions related to indemnification obligations, confidentiality and other matters. During the reporting period, the Company continued to engage with The University of Texas M.D. Anderson Cancer Center (“MD Anderson”) to wind down the TCR trials. The parties completed the final reconciliation of amounts due under the related R&D agreements, and the Company received the final invoice during the second quarter of 2025. Amounts due to MD Anderson and recorded in accounts payable were $257 thousand, $262 thousand, $285 thousand, and $285 thousand as of December 31, 2024, March 31, 2025, June 30, 2025, and September 30, 2025, respectively. On November 4, 2025, the Office of the Attorney General of Texas, on behalf of MD Anderson, issued a demand asserting that $192 thousand is owed under an R&D agreement and requested payment within 30 days. As of September 30, 2025, the Company included the asserted amount within accounts payable. The Company is in discussions to pay the amounts due on an agreed upon payment schedule over six months. Patent and Technology License Agreement—The University of Texas MD Anderson Cancer Center and the Texas A&M University System In August 2004, the Company entered into a patent and technology license agreement with MD Anderson and the Texas A&M University System, which the Company refers to, collectively, as the Licensors. Under this agreement, the Company was granted an exclusive, worldwide license to rights (including rights to U.S. and foreign patent and patent applications and related improvements and know-how) for the manufacture and commercialization of two classes of organic arsenicals (water- and lipid-based) for human and animal use. The class of water-based organic arsenicals includes darinaparsin. Under the terms of the agreement, the Company may be required to make payments to the Licensors upon achievement of certain milestones in varying amounts which, on a cumulative basis could total up to an additional $4.5 million. In addition, the Licensors are entitled to receive low single digit royalties on net sales from a licensed product and will also be entitled to receive a portion of any fees that the Company may receive from a possible sublicense under certain circumstances. During three and nine months ended September 30, 2025 and 2024, the Company did not incur any milestone expenses or royalty expenses under this agreement. Collaboration Agreement with Solasia Pharma K.K. In 2011, the Company entered into a License and Collaboration Agreement with Solasia Pharma K. K., or Solasia, which was amended in 2014 to include an exclusive worldwide license and further amended in 2021 to revise certain payment schedule details, or, as so amended, the Solasia License and Collaboration Agreement. Pursuant to the Solasia License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both intravenous and oral forms and related organic arsenic molecules, in all indications for human use. As consideration for the license, the Company is eligible to receive from Solasia development- and sales-based milestones, a royalty on net sales of darinaparsin, once commercialized, and a percentage of any sublicense revenue generated by Solasia. During the nine months ended September 30, 2025, the Company earned royalty revenue totaling $2 thousand under this agreement, all of which was earned during the three months ended March 31, 2025. During the three and nine months ended September 30, 2024, the Company earned $0 thousand and $6 thousand, respectively, in royalty revenues on net sales under this agreement. Insurance Contract During the nine months ended September 30, 2025 , the Company entered into an insurance arrangement for certain risks which were previously paid in full began to be in force for a period of six years. Accordingly, the Company began amortizing the prepaid expense related to the contract. The Company has classified the prepaid contract between its current portion and long term-portion. As of September 30, 2025, $747 thousand is included in prepaid expenses and other current assets and $942 thousand is included in prepaid expense and other non-current assets in the accompanying condensed consolidated balance sheet. Director Resignation On April 15, 2025, Dr. Robert Hofmeister, Ph.D. resigned as a member of the Board of Directors of the Company with immediate effect. Dr. Robert Hofmeister's, Ph.D. resignation was not the result of any disagreement on any matter relating to the Company’s operations, policies or practices. Changes in Corporate Governance On July 1, 2025, Dale Curtis Hogue, Jr. resigned from his positions as Chief Executive Officer and a member of the Board of Directors of the Company, effective immediately. His resignation was not due to any disagreement with the Company. In connection with his departure, the Company entered into a Consulting Agreement with Mr. Hogue, effective July 1, 2025, under which he will provide strategic and advisory services to the Company at a rate of $250 per hour. The agreement remains in effect until terminated by either party. On July 2, 2025, the Board appointed Holger Weis as Chief Executive Officer, effective immediately. Mr. Weis will continue to serve as Chair of the Board of Directors, but has relinquished his roles on the Audit and Compensation Committees, pursuant to applicable Nasdaq Listing Rules. In connection with his appointment, the Company entered into an Employment Agreement with Mr. Weis, providing for an annual base salary of $275 thousand and a stock option to purchase 130,000 shares of common stock at an exercise price of $5.06 per share. One-quarter of the option vested immediately, with the remainder vesting in equal quarterly installments over three years. On July 15, 2025, the Board of Directors of the Company appointed Mr. Michael A. Jerman as an independent director of the Company, effective immediately, to fill the vacancy on the Board of Directors created by the resignation of Mr. Hogue and the vacancies on the audit and compensation committees from Mr. Weis’s appointment as CEO. In connection with his appointment, Mr. Jerman was also named to the Audit Committee and the Compensation Committee of the Board, and will serve as the Chair of the Audit Committee. Upon his appointment, Mr. Jerman was awarded options to purchase Common Stock pursuant to the Company's Non-employee Director Compensation Policy. On July 16, 2025, Melinda Lackey notified the Company of her decision to terminate the Consulting Agreement dated November 14, 2023 (the “Agreement”) pursuant to terms of the agreement, with such termination to be effective 30 days from the date of notice, or August 15, 2025. In connection with the termination of the Agreement, Ms. Lackey resigned from her roles as Legal and Administrative Officer and Corporate Secretary of the Company as of the effective Date. Ms. Lackey’s departure is not the result of any disagreement with the Company on any matter relating to the Company’s operations, policies, or practices. On August 14, 2025, the Board of Directors of the Company appointed Mr. Ferdinand Groenewald as Corporate Secretary effective upon the resignation of Ms. Lackey.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

License Agreements

Exclusive License Agreement with Precigen

On April 3, 2023, the Company entered into the Amended and Restated Exclusive License Agreement with Precigen, or the A&R License Agreement, which restated and amended the parties' previous license agreement in full. Under the A&R License Agreement, the Company still had exclusive, worldwide rights to research, develop and commercialize TCR products designed for neoantigens or driver mutations for the treatment of cancer and non-exclusive rights to use non-driver mutation TCRs. On October 4, 2024, pursuant to Section 10.2 of the License Agreement, the Company duly notified Precigen of its full termination of all rights under the License Agreement.

The decision to terminate the A&R License Agreement was made after a thorough review of our strategic priorities and business objectives, including recognizing that the non-viral Sleeping Beauty gene transfer platform patent will expire in 2026. The Company continues to prosecute certain of the intellectual property underlying the TCRs targeting driver mutations such as KRAS, TP53 and EGFR, and the hunTR TCR discovery platform used in the discovery of our proprietary TCR library. The Company continues to explore strategic alternatives, including, but not limited to, an acquisition, merger, reverse merger, sale of assets, strategic partnerships, capital raises or other transactions.

License Agreement and Research and Development Agreement —The University of Texas MD Anderson Cancer Center

In 2015, the Company, together with Precigen, entered into a license agreement, or the MD Anderson License with MD Anderson (which Precigen subsequently assigned to PGEN). Pursuant to the MD Anderson License, the Company, together with Precigen, holds an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell therapies, non-viral gene transfer systems, genetic modification and/or propagation of immune cells and other cellular therapy approaches, Natural Killer, or NK Cells, and TCRs.

In 2015, the Company, Precigen and MD Anderson entered into the 2015 R&D Agreement to formalize the scope and process for the transfer by MD Anderson, pursuant to the terms of the MD Anderson License, of certain existing research programs and related technology rights, as well as the terms and conditions for future collaborative research and development of new and ongoing research programs.

As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the 2015 R&D Agreement. At various times, the Company amended the 2015 R&D Agreement to extend the term until December 31, 2026 and in 2019 entered into the 2019 R&D Agreement, pursuant to which the Company agreed to collaborate with respect to the TCR program. The Company incur $0 and $28 thousand clinical costs from MD Anderson related to the these agreements for the three and nine months ended September 30, 2025.

The 2019 R&D Agreement will terminate on December 31, 2026 and either party may terminate the 2019 R&D Agreement following written notice of a material breach. The 2019 R&D Agreement also contains customary provisions related to indemnification obligations, confidentiality and other matters.

During the reporting period, the Company continued to engage with The University of Texas M.D. Anderson Cancer Center (“MD Anderson”) to wind down the TCR trials. The parties completed the final reconciliation of amounts due under the related R&D agreements, and the Company received the final invoice during the second quarter of 2025. Amounts due to MD Anderson and recorded in accounts payable were $257 thousand, $262 thousand, $285 thousand, and $285 thousand as of December 31, 2024, March 31, 2025, June 30, 2025, and September 30, 2025, respectively. On November 4, 2025, the Office of the Attorney General of Texas, on behalf of MD Anderson, issued a demand asserting that $192 thousand is owed under an R&D agreement and requested payment within 30 days. As of September 30, 2025, the Company included the asserted amount within accounts payable. The Company is in discussions to pay the amounts due on an agreed upon payment schedule over six months.

Patent and Technology License Agreement—The University of Texas MD Anderson Cancer Center and the Texas A&M University System

In August 2004, the Company entered into a patent and technology license agreement with MD Anderson and the Texas A&M University System, which the Company refers to, collectively, as the Licensors. Under this agreement, the Company was granted an exclusive, worldwide license to rights (including rights to U.S. and foreign patent and patent applications and related improvements and know-how) for the manufacture and commercialization of two classes of organic arsenicals (water- and lipid-based) for human and animal use. The class of water-based organic arsenicals includes darinaparsin.

Under the terms of the agreement, the Company may be required to make payments to the Licensors upon achievement of certain milestones in varying amounts which, on a cumulative basis could total up to an additional $4.5 million. In addition, the Licensors are entitled to receive low single digit royalties on net sales from a licensed product and will also be entitled to receive a portion of any fees that the Company may receive from a possible sublicense under certain circumstances. During three and nine months ended September 30, 2025 and 2024, the Company did not incur any milestone expenses or royalty expenses under this agreement.

Collaboration Agreement with Solasia Pharma K.K.

In 2011, the Company entered into a License and Collaboration Agreement with Solasia Pharma K. K., or Solasia, which was amended in 2014 to include an exclusive worldwide license and further amended in 2021 to revise certain payment schedule details, or, as so amended, the Solasia License and Collaboration Agreement. Pursuant to the Solasia License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both intravenous and oral forms and related organic arsenic molecules, in all indications for human use.

As consideration for the license, the Company is eligible to receive from Solasia development- and sales-based milestones, a royalty on net sales of darinaparsin, once commercialized, and a percentage of any sublicense revenue generated by Solasia.

During the nine months ended September 30, 2025, the Company earned royalty revenue totaling $2 thousand under this agreement, all of which was earned during the three months ended March 31, 2025. During the three and nine months ended September 30, 2024, the Company earned $0 thousand and $6 thousand, respectively, in royalty revenues on net sales under this agreement.

Insurance Contract

During the nine months ended September 30, 2025 , the Company entered into an insurance arrangement for certain risks which were previously paid in full began to be in force for a period of six years. Accordingly, the Company began amortizing the prepaid expense related to the contract. The Company has classified the prepaid contract between its current portion and long term-portion. As of September 30, 2025, $747 thousand is included in prepaid expenses and other current assets and $942 thousand is included in prepaid expense and other non-current assets in the accompanying condensed consolidated balance sheet.

Director Resignation

On April 15, 2025, Dr. Robert Hofmeister, Ph.D. resigned as a member of the Board of Directors of the Company with immediate effect. Dr. Robert Hofmeister's, Ph.D. resignation was not the result of any disagreement on any matter relating to the Company’s operations, policies or practices.

Changes in Corporate Governance

On July 1, 2025, Dale Curtis Hogue, Jr. resigned from his positions as Chief Executive Officer and a member of the Board of Directors of the Company, effective immediately. His resignation was not due to any disagreement with the Company. In connection with his departure, the Company entered into a Consulting Agreement with Mr. Hogue, effective July 1, 2025, under which he will provide strategic and advisory services to the Company at a rate of $250 per hour. The agreement remains in effect until terminated by either party.

On July 2, 2025, the Board appointed Holger Weis as Chief Executive Officer, effective immediately. Mr. Weis will continue to serve as Chair of the Board of Directors, but has relinquished his roles on the Audit and Compensation Committees, pursuant to applicable Nasdaq Listing Rules. In connection with his appointment, the Company entered into an Employment Agreement with Mr. Weis, providing for an annual base salary of $275 thousand and a stock option to purchase 130,000 shares of common stock at an exercise price of $5.06 per share. One-quarter of the option vested immediately, with the remainder vesting in equal quarterly installments over three years.

On July 15, 2025, the Board of Directors of the Company appointed Mr. Michael A. Jerman as an independent director of the Company, effective immediately, to fill the vacancy on the Board of Directors created by the resignation of Mr. Hogue and the vacancies on the audit and compensation committees from Mr. Weis’s appointment as CEO. In connection with his appointment, Mr. Jerman was also named to the Audit Committee and the Compensation Committee of the Board, and will serve as the Chair of the Audit Committee. Upon his appointment, Mr. Jerman was awarded options to purchase Common Stock pursuant to the Company's Non-employee Director Compensation Policy.

On July 16, 2025, Melinda Lackey notified the Company of her decision to terminate the Consulting Agreement dated November 14, 2023 (the “Agreement”) pursuant to terms of the agreement, with such termination to be effective 30 days from the date of notice, or August 15, 2025. In connection with the termination of the Agreement, Ms. Lackey resigned from her roles as Legal and Administrative Officer and Corporate Secretary of the Company as of the effective Date. Ms. Lackey’s departure is not the result of any disagreement with the Company on any matter relating to the Company’s operations, policies, or practices.

On August 14, 2025, the Board of Directors of the Company appointed Mr. Ferdinand Groenewald as Corporate Secretary effective upon the resignation of Ms. Lackey.