20 January 2021 - - The first patient has been dosed in a Phase 1 clinical trial evaluating FT-7051, a selective inhibitor of CBP/p300, a known co-activator of the androgen receptor in men with metastatic castration-resistant prostate cancer (mCRPC), US-based Forma Therapeutics Holdings, Inc. (NASDAQ: FMTX) said.

The Phase 1 trial is a multicenter, open-label evaluation of the safety and tolerability, preliminary anti-tumor activity (PSA and radiographic responses), and pharmacokinetics/pharmacodynamics (PK/PD) of FT-7051 in men with mCRPC who have progressed despite prior therapy and have been treated with at least one potent anti-androgen therapy.

This is an adaptive trial design, intended to accelerate the escalation to potentially therapeutic doses and yield important safety information.

FT-7051 is a selective inhibitor of CREB-binding protein/E1A binding protein p300 (CBP/p300) and a co-activator of androgen receptor. In prostate cancer cell lines in vitro, FT-7051 demonstrated inhibition of AR-dependent gene expression and reductions in androgen receptor expression.

FT-7051 also demonstrated antiproliferative activity in AR-positive prostate cancer cell lines, including resistance variant AR-v7 positive models.

Prostate cancer is the second leading cause of cancer death for men in the US, and mCRPC is the most advanced form of this disease.

Prostate cancer cell growth is driven by activity of the androgen receptor. Primary treatments of mCRPC include therapies that reduce androgen synthesis or inhibit androgen binding and activation of the AR.

Studies have shown that approximately 20% to 40% of mCRPC patients demonstrate primary resistance to enzalutamide and abiraterone acetate, two commonly used therapies, and virtually all patients who demonstrate initial clinical responses eventually acquire resistance.

There are currently no approved therapies specifically aimed at mCRPC over-expressing AR variants, including AR-v7; therefore, a novel inhibitor of AR co-activator CBP/p300 may play a role in the suppression of mCRPC driven by AR aberrations.

Forma Therapeutics is a clinical-stage biopharmaceutical company focused on the research, development and commercialization of novel therapeutics to transform the lives of patients with rare hematologic diseases and cancers.