Senhwa Biosciences Receives US FDA 'Study May Proceed' Letter to Treat BRCA2+ or PALB2+ Solid Tumors With CX-5461

Senhwa Biosciences, Inc., a clinical-stage biopharmaceutical company focused on next-generation DNA Damage Response (DDR) therapeutics for the treatment of cancer, announced that it has received a "Study May Proceed" letter from the US Food and Drug Administration (FDA) to begin a Phase Ib study evaluating CX-5461, a first-in-class G-quadruplex stabilizer, to treat solid tumors with BRCA2 or PALB2 mutations.

"The FDA's approval of our Phase Ib clinical trial application for testing CX-5461 in patients with BRCA2 or PALB2 mutations is an important milestone and marks a new paradigm in the treatment of cancers with specific pathogenic mutations," stated Dr. John Soong, the Chief Medical Officer of Senhwa Biosciences.

In 2016, Canadian Cancer Trial Group (CCTG), a recipient of the Stand Up to Cancer's Dream Team Grant selected CX-5461 to study in their Phase I trial. In the CCTG Trial, CX-5461 demonstrated clinically significant and lasting benefits in patients with specific tumor biomarkers that were resistant to platinum and other chemotherapeutics. This new Phase Ib trial will occur in both the US and Canada, and study endpoints include a re-confirmation of the efficacy signal. This trial is currently under review with Health Canada.

CX-5461 was recently named as a PCF (Prostate Cancer Foundation)-Pfizer Global Challenge Award recipient. Specifically, it will be used together with Pfizer's PARP inhibitor (PARPi), Talazoparib, to evaluate the combined therapeutic potential in treating prostate cancer. For American men, prostate cancer is the second-leading cause of cancer death. Due to a DNA repair defect, BRCA1/2 deficient tumor cells are more sensitive to PARPi through the mechanism of synthetic lethality; however, PARPi resistance is commonly seen in clinical use. More than 40% of BRCA1/2-deficient patients fail to respond to PARPi.

"CX-5461 has proven human efficacy across certain tumor types by accelerating dsDNA breaks. We believe CX-5461 has great potential as a therapeutic for patients who have developed resistance to PAPRi or other chemotherapies. Addressing treatment for resistant tumors continues to be an unmet medical need in cancer treatment," said Dr. Tai-Sen Soong, CEO of Senhwa Biosciences.

About CX-5461

Specific mutations within the Homologous Recombination (HR) pathway may be exploited by CX-5461 through a synthetic lethality approach by targeting the DNA repair defects in Homologous Recombination Deficiency (HRD) tumors. Specifically, CX-5461 is designed to stabilize DNA G-quadruplexes of cancer cells which leads to disruption of the cell's replication fork. While acting in concert with HR pathway deficiencies, such as BRCA1/2 mutations, replication forks stall and cause DNA breaks, ultimately resulting in cancer cell death.

About Senhwa Bioscience

Senhwa Biosciences, Inc. is a leading clinical-stage company focusing on developing first-in-class, next-generation DDR therapeutics for patients with unmet medical needs in oncology. Headquartered in Taiwan, China, with an operational base in San Diego, California, Senhwa is well-positioned to oversee the development of its compounds.

Development is currently focused on two lead products Silmitasertib (CX-4945) and Pidnarulex (CX-5461) with novel mechanisms of action and for multiple indications. Clinical trials are currently ongoing in Australia, Canada, United States, Korea, and Taiwan, China Region of China.