Senhwa Biosciences to Present Pidnarulex Data at 2024 ESMO Congress

Senhwa Biosciences, Inc., a company focused on developing breakthrough therapeutics for cancer, rare diseases, and infectious diseases, has announced promising findings for its investigational drug Pidnarulex (CX-5461). These results were showcased at the 2024 European Society for Medical Oncology (ESMO) Congress and mark a significant achievement for the company and its clinical collaborators in Canada and the USA.

Pidnarulex has demonstrated efficacy in treating advanced-stage solid tumors with BRCA1/2 or PALB2 gene defects. This development is particularly important for end-stage oncology patients who have exhausted other treatment options. The findings stem from a Phase Ib study involving patients who had previously undergone several lines of treatment, including platinum-based chemotherapy and PARP inhibitors, without success.

In this study, Pidnarulex showed acceptable clinical tolerability and early signs of effectiveness. Among the 15 patients evaluated for drug response, 40% experienced clinical benefit, with stable disease being the best therapeutic outcome observed. Specifically, five ovarian cancer patients, all of whom had failed previous treatments with platinum chemotherapy and PARP inhibitors, maintained stable disease during the trial, including two who sustained this condition for at least six months.

The trial comprised two cohorts: the Main Study Cohort and the Exploratory Cohort, targeting patients with BRCA2 and/or PALB2 gene deficiencies from various cancer types such as pancreatic, ovarian, prostate, and breast cancers. Additionally, it included ovarian cancer patients with BRCA1 deficiencies or other HRD-related homologous recombination defects. The primary goal was to determine the recommended Phase II trial dose for these specific genetic deficiencies. Secondary objectives included evaluating the safety, tolerability, and antitumor activity of Pidnarulex.

Out of the first 28 enrolled patients, 22 completed at least one treatment cycle and were evaluated for dose-limiting toxicity. These patients had previously undergone a median of six lines of therapy. Notably, 77% had received platinum-based chemotherapy, 41% had been treated with bevacizumab, and 86% had undergone unsuccessful PARP inhibitor treatments. Despite their advanced disease stages and lack of other treatment options, the median number of Pidnarulex treatments among these patients was four doses.

The trial concluded that Pidnarulex exhibited manageable photosensitivity through preventive measures. Given the limited effectiveness of current PARP inhibitors, particularly for patients with BRCA1/2 and PALB2 gene deficiencies, Pidnarulex presents a potential rescue treatment. Preclinical studies have also shown that Pidnarulex can modulate the tumor microenvironment, enhancing the sensitivity and efficacy of immunotherapy agents like anti-PD-1 and anti-PD-L1.

Senhwa Biosciences envisions combining Pidnarulex with immunotherapy drugs such as Keytruda, which is approved for over 30 cancer types and achieved global sales of over $25 billion in 2023. While immunotherapy significantly benefits only about 20% of patients, the potential of Pidnarulex to enhance these effects could introduce new options for future cancer treatment plans.

In summary, the Phase Ib study of Pidnarulex shows promising potential as a treatment for patients with specific genetic deficiencies who have not responded to conventional therapies. Senhwa Biosciences looks forward to further exploring its efficacy and safety in subsequent clinical trials, potentially offering new hope for patients with challenging cancer diagnoses.