Commitment and Contingencies, including License Agreements	9 Months Ended
Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies, including License Agreements	Commitments and Contingencies, including License Agreements Operating Lease In March 2024, the Company amended its lease for corporate office space in Philadelphia, Pennsylvania that it initially entered into in March 2023, in order to extend the expiration date to November 30, 2024. In July 2024, the Company further amended the lease, which is now set to expire on November 30, 2026, thus making the arrangement no longer qualify for the short-term lease exception under ASC 842. The Company also retains the right to renew the lease for up to two consecutive 12-month terms upon at least nine months advance notice to the landlord before any such successive renewal. These renewal options were not contemplated in the Company's calculation of its right of use asset and lease liability. As of September 30, 2025, the operating lease right-of-use asset and the operating lease liabilities were each $0.1 million, which were estimated using a discount rate of 11%. As of September 30, 2025, the remaining term of the Company’s noncancellable operating lease was 1.17 years. Future minimum lease payments under the sublease are $0.1 million at September 30, 2025. The Company recognizes rent expense on a straight-line basis over the lease period and accrues for rent expense incurred but not yet paid. Rent expense related to the Company’s operating lease was approximately $32,000 and $31,000 for the three months ended September 30, 2025 and 2024, respectively. Rent expense related to the Company’s operating lease was approximately $95,000 and $93,000 for the nine months ended September 30, 2025 and 2024, respectively. Employee Benefit Plans The Company established a defined contribution 401(k) plan in which employees may contribute up to 100% of their salary and bonus, subject to statutory maximum contribution amounts. The Company contributes a safe harbor minimum contribution equivalent to 3% of employees’ compensation. The Company generally assumes all administrative costs of the plan. For the three months ended September 30, 2025 and 2024, the Company provided contributions of approximately $19,000 and $9,000, respectively. For the nine months ended September 30, 2025 and 2024, the Company provided contributions of approximately $88,000 and $50,000, respectively. Collaboration Agreement with Tyligand Bioscience In March 2020, the Company entered into a process development agreement (the “Tyligand Process Development Agreement”) with Tyligand Bioscience (Shanghai) Limited (“Tyligand”) for the development, manufacturing, registration and future commercialization of onapristone extended release. In August 2024, the Company and Tyligand mutually agreed to terminate the license agreement previously entered into between the parties in August 2021, and further agreed to terminate any ongoing payment obligations the Company may have had to Tyligand under the Tyligand Process Development Agreement. Collaboration and Licensing Agreement with Integral Molecular In April 2021, the Company entered into a collaboration and licensing agreement with Integral Molecular, Inc. (“Integral”) (the “Integral License Agreement”) for the development of a CLDN6 bsAb for cancer therapy. Under the terms of the Integral License Agreement, Integral and the Company developed a CLDN6 bsAb that is intended to trigger the activation of T cells and eliminate cancer cells displaying CLDN6. The Company will conduct preclinical and all clinical development, as well as regulatory and commercial activities through exclusive worldwide rights to develop and commercialize the novel CLDN6 candidates. The payment for the initial upfront license fee as well as subsequent payments for milestones achieved were expensed to acquired IPR&D. As a part of the Integral License Agreement, Integral was eligible to receive remaining development and regulatory milestone payments totaling approximately $55.0 million, sales milestone payments totaling up to $130.0 million, and tiered royalties of up to 12% of net sales of certain products developed under the Integral License Agreement. On March 20, 2023, the Company amended the Integral License Agreement (the “First Amendment”) to remove the previously agreed to second milestone payment and to change the amount of the third milestone payment to increase such payment by the amount of the prior second milestone payment and to add payment for third-party research funding obtained and used by Integral in connection with the development of CTIM-76. On February 29, 2024, the Company further amended the Integral License Agreement (the “Second Amendment”) to reflect updated financial terms. Integral’s right to receive certain future payments was reduced as follows: aggregate development and regulatory milestone payments were reduced from $55 million to $15 million, aggregate sales milestone payments were reduced from $130 million to $12.5 million, and a tiered royalty of 8-12% that commenced at first commercial sale was reduced to a flat royalty rate of 6% on net sales beginning no sooner than February 1, 2034. The Second Amendment also narrowed the license grant from Integral to the Company to only cover CTIM-76, removed any further obligation to reimburse Integral for any independently obtained research funding Integral applied against CTIM-76 research, and included mutual releases by the parties. Asset Purchase Agreement On July 9, 2024, the Company entered into an asset purchase agreement (the “Asset Purchase Agreement”) pursuant to which the Company acquired CT-95 (formerly known as LNK-101), an MSLN x CD3 TCE engaging bsAb, from Link (assignment for the benefit of creditors), LLC (“Link”), which succeeded to the assets of Link Immunotherapeutics Inc. Pursuant to the Asset Purchase Agreement, the Company purchased all of the assets from Link associated with CT-95, including patent rights, know-how, regulatory filings, and inventory of drug substance and drug product (the “Transferred Assets”), on an “as is” and “where is” basis. CT-95 patents are currently being prosecuted and/or maintained in the United States, Europe, Canada, Australia, Taiwan and Japan. The Company also assumed certain liabilities relating to the Transferred Assets. In consideration of the purchase of the Transferred Assets, the Company made a one-time payment to Link of $3.75 million and is not obligated to make any other payments. This transaction qualified as an asset purchase as prescribed by ASC 805-50 and the assets purchased were determined to have no alternative future use under the accounting definition, and therefore the Company expensed the one-time payment as a component of research and development expense in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024. Collaboration and Licensing Agreement with BioAtla On September 23, 2024, the Company entered into a license agreement (the “BioAtla License Agreement”) with BioAtla, Inc. ("BioAtla"), pursuant to which the Company obtained an exclusive, worldwide license to develop, manufacture and commercialize two licensed antibodies (the “BioAtla Assets”), including BA3362 (renamed by the Company as CT-202), BioAtla’s Nectin-4 x CD3 T cell engaging bispecific antibody. As partial consideration for the exclusive license under the BioAtla License Agreement, the Company made an upfront payment of $11.0 million for the IPR&D asset, which was determined to have no alternative future use under the accounting definition. Therefore, the upfront payment was expensed as a component of research and development expense in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024. The Company may be obligated to pay up to $122.5 million in additional milestone payments based upon the achievement of specified pre-clinical, clinical, development and commercial milestones, as well as tiered mid-single digit to low double-digit royalties on future net sales for products containing the BioAtla Assets, subject to standard reductions. See Note 9 for further discussion. The BioAtla License Agreement will continue on a country-by-country, product-by-product basis until the expiration of the royalty term as defined in the BioAtla License Agreement, unless earlier terminated. CTIM-76 Lonza License Agreement On November 7, 2022, the Company entered into a License Agreement (the “CTIM-76 Lonza License Agreement”) with Lonza Sales AG ("Lonza") in connection with Lonza’s development and manufacturing services with respect to CTIM-76. Under the terms of the CTIM-76 Lonza License Agreement, to the extent Lonza's technology is incorporated into CTIM-76, Lonza granted the Company a non-exclusive license to use certain proprietary Lonza intellectual property and systems for the Company to develop, manufacture and commercially exploit CTIM-76. The Company shall pay certain royalties and annual payments in respect of the manufacturing and sale of CTIM-76, which amounts shall be determined by the party manufacturing CTIM-76 and ranges from a potential annual payment of up to less than $500,000 and a royalty on net sales from 0% up to a low single digit percentage. The royalty payments and annual payments would be reduced in certain circumstances, including should the valid claims for any such patent rights not exist in the country in which CTIM-76 is being sold, and the royalty payments would expire upon the later of the expiration of the licensed patents in the country in which CTIM-76 is being sold, the expiration of the licensed patents in the country in which CTIM-76 is being manufactured, and ten years from the first commercial sales of CTIM-76 in such country of sale. Research and Development Arrangements In the course of normal business operations, the Company enters into agreements with investigative sites and contract research organizations to assist in the performance of research and development activities and contract manufacturers to assist with chemistry, manufacturing, and controls-related expenses. Expenditures to contract research organizations represent a significant cost in clinical development for the Company. The Company could also enter into additional collaborative research, contract research, manufacturing, and supplier agreements in the future, which may require upfront payments and long-term commitments of cash.

In March 2024, the Company amended its lease for corporate office space in Philadelphia, Pennsylvania that it initially entered into in March 2023, in order to extend the expiration date to November 30, 2024. In July 2024, the Company further amended the lease, which is now set to expire on November 30, 2026, thus making the arrangement no longer qualify for the short-term lease exception under ASC 842. The Company also retains the right to renew the lease for up to two consecutive 12-month terms upon at least nine months advance notice to the landlord before any such successive renewal. These renewal options were not contemplated in the Company's calculation of its right of use asset and lease liability.

As of September 30, 2025, the operating lease right-of-use asset and the operating lease liabilities were each $0.1 million, which were estimated using a discount rate of 11%. As of September 30, 2025, the remaining term of the Company’s noncancellable operating lease was 1.17 years. Future minimum lease payments under the sublease are $0.1 million at September 30, 2025.

The Company recognizes rent expense on a straight-line basis over the lease period and accrues for rent expense incurred but not yet paid. Rent expense related to the Company’s operating lease was approximately $32,000 and $31,000 for the three months ended September 30, 2025 and 2024, respectively. Rent expense related to the Company’s operating lease was approximately $95,000 and $93,000 for the nine months ended September 30, 2025 and 2024, respectively.

The Company established a defined contribution 401(k) plan in which employees may contribute up to 100% of their salary and bonus, subject to statutory maximum contribution amounts. The Company contributes a safe harbor minimum contribution equivalent to 3% of employees’ compensation. The Company generally assumes all administrative costs of the plan. For the three months ended September 30, 2025 and 2024, the Company provided contributions of approximately $19,000 and $9,000, respectively. For the nine months ended September 30, 2025 and 2024, the Company provided contributions of approximately $88,000 and $50,000, respectively.

In March 2020, the Company entered into a process development agreement (the “Tyligand Process Development Agreement”) with Tyligand Bioscience (Shanghai) Limited (“Tyligand”) for the development, manufacturing, registration and future commercialization of onapristone extended release. In August 2024, the Company and Tyligand mutually agreed to terminate the license agreement previously entered into between the parties in August 2021, and further agreed to terminate any ongoing payment obligations the Company may have had to Tyligand under the Tyligand Process Development Agreement.

In April 2021, the Company entered into a collaboration and licensing agreement with Integral Molecular, Inc. (“Integral”) (the “Integral License Agreement”) for the development of a CLDN6 bsAb for cancer therapy. Under the terms of the Integral License Agreement, Integral and the Company developed a CLDN6 bsAb that is intended to trigger the activation of T cells and eliminate cancer cells displaying CLDN6. The Company will conduct preclinical and all clinical development, as well as regulatory and commercial activities through exclusive worldwide rights to develop and commercialize the novel CLDN6 candidates. The payment for the initial upfront license fee as well as subsequent payments for milestones achieved were expensed to acquired IPR&D. As a part of the Integral License Agreement, Integral was eligible to receive remaining development and regulatory milestone payments totaling approximately $55.0 million, sales milestone payments totaling up to $130.0 million, and tiered royalties of up to 12% of net sales of certain products developed under the Integral License Agreement.

On March 20, 2023, the Company amended the Integral License Agreement (the “First Amendment”) to remove the previously agreed to second milestone payment and to change the amount of the third milestone payment to increase such payment by the amount of the prior second milestone payment and to add payment for third-party research funding obtained and used by Integral in connection with the development of CTIM-76.

On February 29, 2024, the Company further amended the Integral License Agreement (the “Second Amendment”) to reflect updated financial terms. Integral’s right to receive certain future payments was reduced as follows: aggregate development and regulatory milestone payments were reduced from $55 million to $15 million, aggregate sales milestone payments were reduced from $130 million to $12.5 million, and a tiered royalty of 8-12% that commenced at first commercial sale was reduced to a flat royalty rate of 6% on net sales beginning no sooner than February 1, 2034. The Second Amendment also narrowed the license grant from Integral to the Company to only cover CTIM-76, removed any further obligation to reimburse Integral for any independently obtained research funding Integral applied against CTIM-76 research, and included mutual releases by the parties.

On July 9, 2024, the Company entered into an asset purchase agreement (the “Asset Purchase Agreement”) pursuant to which the Company acquired CT-95 (formerly known as LNK-101), an MSLN x CD3 TCE engaging bsAb, from Link (assignment for the benefit of creditors), LLC (“Link”), which succeeded to the assets of Link Immunotherapeutics Inc.

Pursuant to the Asset Purchase Agreement, the Company purchased all of the assets from Link associated with CT-95, including patent rights, know-how, regulatory filings, and inventory of drug substance and drug product (the “Transferred Assets”), on an “as is” and “where is” basis. CT-95 patents are currently being prosecuted and/or maintained in the United States, Europe, Canada, Australia, Taiwan and Japan. The Company also assumed certain liabilities relating to the Transferred Assets. In consideration of the purchase of the Transferred Assets, the Company made a one-time payment to Link of $3.75 million and is not obligated to make any other payments. This transaction qualified as an asset purchase as prescribed by ASC 805-50 and the assets purchased were determined to have no alternative future use under the accounting definition, and therefore the Company expensed the one-time payment as a component of research and development expense in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024.

On September 23, 2024, the Company entered into a license agreement (the “BioAtla License Agreement”) with BioAtla, Inc. ("BioAtla"), pursuant to which the Company obtained an exclusive, worldwide license to develop, manufacture and commercialize two licensed antibodies (the “BioAtla Assets”), including BA3362 (renamed by the Company as CT-202), BioAtla’s Nectin-4 x CD3 T cell engaging bispecific antibody.

As partial consideration for the exclusive license under the BioAtla License Agreement, the Company made an upfront payment of $11.0 million for the IPR&D asset, which was determined to have no alternative future use under the accounting definition. Therefore, the upfront payment was expensed as a component of research and development expense in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024. The Company may be obligated to pay up to $122.5 million in additional milestone payments based upon the achievement of specified pre-clinical, clinical, development and commercial milestones, as well as tiered mid-single digit to low double-digit royalties on future net sales for products containing the BioAtla Assets, subject to standard reductions. See Note 9 for further discussion. The BioAtla License Agreement will continue on a country-by-country, product-by-product basis until the expiration of the royalty term as defined in the BioAtla License Agreement, unless earlier terminated.

On November 7, 2022, the Company entered into a License Agreement (the “CTIM-76 Lonza License Agreement”) with Lonza Sales AG ("Lonza") in connection with Lonza’s development and manufacturing services with respect to CTIM-76. Under the terms of the CTIM-76 Lonza License Agreement, to the extent Lonza's technology is incorporated into CTIM-76, Lonza granted the Company a non-exclusive license to use certain proprietary Lonza intellectual property and systems for the Company to develop, manufacture and commercially exploit CTIM-76.

The Company shall pay certain royalties and annual payments in respect of the manufacturing and sale of CTIM-76, which amounts shall be determined by the party manufacturing CTIM-76 and ranges from a potential annual payment of up to less than $500,000 and a royalty on net sales from 0% up to a low single digit percentage. The royalty payments and annual payments would be reduced in certain circumstances, including should the valid claims for any such patent rights not exist in

the country in which CTIM-76 is being sold, and the royalty payments would expire upon the later of the expiration of the licensed patents in the country in which CTIM-76 is being sold, the expiration of the licensed patents in the country in which CTIM-76 is being manufactured, and ten years from the first commercial sales of CTIM-76 in such country of sale.

In the course of normal business operations, the Company enters into agreements with investigative sites and contract research organizations to assist in the performance of research and development activities and contract manufacturers to assist with chemistry, manufacturing, and controls-related expenses. Expenditures to contract research organizations represent a significant cost in clinical development for the Company. The Company could also enter into additional collaborative research, contract research, manufacturing, and supplier agreements in the future, which may require upfront payments and long-term commitments of cash.