Disclosure of molecular targets in CT-01 project

Current Report No. 11/2022

Date of preparation: 11 April 2022

Subject: Disclosure of molecular targets in CT-01 project

Legal basis: Art. 17(1) of MAR – inside information

The Management Board of Captor Therapeutics S.A., with its registered office in Wroclaw (the "Company"), hereby discloses  the degradation profile of the CT-01 lead compounds. As we informed in current report no. RB ESPI 3/2022, CT-01 compounds induce tumor regression in a Hep 3B2.1-7 mouse model of hepatocellular carcinoma.

With recent scientific results, increasing confidence in the strong scientific and competitive value of the project, as well as an elaborated IP strategy, the Company has decided to disclose the molecular targets in the CT-01 project. CT-01 compounds present a unique degradation profile:they induce the potent degradation of the GSPT1 and SALL4 protein and another undisclosed neosubstrate with essential function in tumorigenesis.

GSPT1 (Eukaryotic peptide chain release factor GTP-binding subunit ERF3A) is a protein involved in the termination of translation (a process in which ribosomes synthesize proteins after the process of transcription of DNA to RNA). Because of the demonstrated link between GSPT1 degradation and antitumor activity, selective GSPT1 degraders are being developed, including a clinical-stage compound CC-90009. SALL4 (Sal-like protein 4) is a transcription factor expressed in the human fetal liver and silenced in adults but often reexpressed in hepatocellular carcinoma patients, which correlates with a poor prognosis. An additional protein degraded by CT-01 compounds remains undisclosed for IP reasons, and contributes to cancer development. Its targeted elimination constitutes a strong  added value in the treatment of several malignancies including liver and lung cancers. The combined and unique degradation profile of the compounds supports our confidence in the strong competitive potential of this program.

The Company will inform about further progress in CT-01 project in accordance with legal requirements.