Senhwa Biosciences, Inc. announced that the US Food and Drug Administration (FDA) has granted Fast Track Designation (FTD) for Pidnarulex, a first-in-class G-quadruplex stabilizer, for the treatment of patients with breast and ovarian cancers BRCA1/2, PALB2, or other HRD mutations. Currently, Pidnarulex is tested in a Phase 1b Open-label, Multi-center Expansion Study (in both US and Canada) to determine a tolerable dose in patients with selected solid tumors (such as Breast Cancer, Ovarian Cancer, Pancreatic Cancer and Prostate Cancer) with BRCA2 and PALB2, and Ovarian Cancer with BRCA1 and other HR gene mutations. This dose will be used in future Phase II trials.

In a previous Phase 1 trial, Pidnarulex demonstrated clinically significant and lasting benefits in patients with BRCA1/2, and PALB2 mutations and that were also resistant to platinum and other chemotherapeutics. 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 not uncommon in clinical use.

According to an article published on Molecular Cancer in 2020, more than 40% of BRCA1/2 deficient patients fail to respond to PARPi alone. Addressing treatment resistant tumors continues to be an unmet medical need in cancer treatment. Pidnarulex has proven human efficacy across certain tumor types by accelerating dsDNA breaks.

By targeting the G-quadruplex DNA structure instead, Senhwa's Pidnarulex has great potential as an alternative treatment for patients who have developed resistance to PAPRi or other chemotherapies.