Senhwa Biosciences, Inc. announced that their first patient has been successfully dosed, in a phase I clinical study evaluating the combined treatment with Senhwa's Pidnarulex, the 2019 PCF-Pfizer Global Challenge Awards winner and Pfizer's PARP inhibitor, Talazoparib (Talzenna), in patients with metastatic castration-resistant prostate cancer(mCRPC). The study will be conducted by Peter MacCallum Cancer Centre (PMCC), Senhwa's clinical partner in Melbourne, Australia. This Phase I trial of Pidnarulex and Talazoparib will be mainly funded by the US Prostate Cancer Foundation (PCF) and Pfizer.

Senhwa will provide supplies of their study drug, Pidnarulex, in addition to specific funding for the study. In 2020, US FDA granted approval of the use of PARP inhibitors (PARPi), such as olaparib (Lynparza) and rucaparib (Rubraca), to treat prostate cancer patients, whose tumors have specific genetic alterations. The most common gene alterations in this population were BCRA1/2. While BRCA1/2 deficient tumor cells are responsive to PARPi treatments, the development of PARPi resistance is common.

In a previous Phase I trial, Pidnarulex demonstrated clinically significant and lasting benefits in patients with specific tumor biomarkers, such as BRCA1/2 and PALB2 mutations and that were also resistant to PARP inhibitors, platinum-based drugs and other chemotherapeutics. Prostate Cancer is the second most lethal cancer for men in the United States. Although nearly 70% of patients can be cured with surgery, once the cancer has metastasized, almost all patients develop into castration-resistance (a form of advanced prostate cancer in which the cancer no longer completely responds to treatments that lower testosterone), with a median survival time of less than two years.