Study of CX-5461 in Patients With Solid Tumours and BRCA1/2, PALB2 or Homologous Recombination Deficiency (HRD) Mutation

Official Title

Phase Ib Expansion Study of CX-5461 in Patients With Solid Tumours and BRCA2 and/or PALB2 Mutation


This is an open-label, multi-centre, phase 1b study designed to determine a tolerable dose of CX-5461 administered by IV infusion on Day 1 and Day 8 of a 28-day cycle in patients with selected solid tumours and associated mutations for future Phase II trials. The safety and tolerability of CX-5461, preliminary evidence of antitumour effect and the effect of CX-5461 on the Health-Related Quality of Life (HRQoL) will also be evaluated. The study will also evaluate the predictive value of mutational signatures and explore the significance of dynamic changes in ctDNA levels and plasma DNA methylome profiling in this study's exploratory cohort.

Trial Description

Primary Outcome:

  • Determination of Recommended Phase 2 Dose (RP2D)
Secondary Outcome:
  • Adverse Event (AE)
  • Objective Response
  • Patient-Reported Outcomes (PRO)
CX-5461 (Pidnarulex), a synthetically-derived small molecule that selectively kills HR-deficient cancer cells through the binding and stabilization of G4 DNA structure. Early phase 1 studies suggest CX-5461 has activity and warrants further investigation in HR-deficient tumours. This study aims to determine the tolerable dose of CX-5461 for phase II studies, amongst an expansion cohorts of BRCA1/2, PALB2 or HRD mutant tumours.

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Canadian Cancer Society

These resources are provided in partnership with the Canadian Cancer Society