Taiwan-based biopharmaceutical company Senhwa Biosciences Inc (TPEx:6492) announced on Tuesday that it has completed enrolment in a Phase 1b expansion trial evaluating pidnarulex (CX-5461) monotherapy in patients with advanced solid tumours harbouring BRCA1/2, PALB2, or other homologous recombination deficiency (HRD)-associated alterations.

Next, the study will proceed to data review and reconciliation, database lock, and comprehensive statistical analysis. The Clinical Study Report is expected in the first quarter of 2027.

The final analysis is expected to inform decisions on indication prioritisation, biomarker-based patient selection, potential combination strategies, and the next stage of CX-5461's clinical development. The findings may also support Senhwa's global licensing and strategic partnering efforts.

Patients who continue to derive clinical benefit at the end of the main treatment period, as determined by investigators, may enter the protocol-defined extension phase and continue receiving CX-5461. Ongoing treatment and follow-up will provide additional data on the durability of disease control, longer-term safety, and overall clinical benefit.

The Phase 1b trial evaluates CX-5461 monotherapy in heavily pretreated patients with advanced DNA repair-deficient solid tumours. Enrolled tumour types include pancreatic, breast, and ovarian cancers. Patients had received a median of six prior lines of therapy (range, 1-14), and most had received multiple standard-of-care treatments, including PARP inhibitors. This population has limited treatment options and substantial unmet medical need.

CX-5461 is a first-in-class G-quadruplex stabiliser designed to exploit vulnerabilities in DNA repair-deficient tumours through a mechanism distinct from PARP inhibition. Preliminary data presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting showed that, in an exploratory advanced ovarian cancer cohort, CX-5461 achieved a disease control rate of nearly 60% among 16 patients with BRCA mutations, all of whom had previously received PARP inhibitor therapy.