Oncternal Therapeutics, Inc. (NASDAQ:ONCT), a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies, today announced that the first patient has been dosed in the fourth cohort of its Phase 1/2 study of ONCT-534 for the treatment of patients with advanced prostate cancer who are relapsed or refractory to approved androgen receptor pathway inhibitors (ARPI). Patients in the fourth dosing cohort will receive ONCT-534, the company's dual-action androgen receptor inhibitor (DAARI), at a dose of 300 mg taken orally each day. The decision to proceed to this higher dose level was made by the study's Safety Review Committee (SRC) after reviewing data from the patients treated to date, including the third dose level of 160 mg ONCT-534 daily.
"Reaching the 300 mg dose level represents a significant milestone for our ONCT-534 program. The drug has been well tolerated so far, and based on preclinical analyses, we are optimistic that study participants are receiving doses of ONCT-534 that may be within the active dose range for antitumor activity," said Salim Yazji M.D., Chief Medical Officer at Oncternal Therapeutics. "We continue to see strong demand from investigators and patients to participate in the study and expect to continue enrolling at a brisk pace. We look forward to announcing initial efficacy and safety data from the study, which we expect will be at the end of this quarter."
About Study ONCT-534-101
Study ONCT-534-101 is a Phase 1/2, single-arm, open-label, multi-center study to evaluate the safety and tolerability, pharmacokinetics, and preliminary anti-tumor activity of ONCT-534 in patients with mCRPC who have relapsed or are refractory to approved ARPIs including enzalutamide, abiraterone, apalutamide, and darolutamide. After the safety and tolerability and preliminary antitumor activity of ONCT-534 have been assessed in Phase 1, Phase 2 will commence to further evaluate the safety and preliminary antitumor activity of ONCT-534 to support selecting an optimal dose.