Canadian-based drug development firm Sierra Oncology has received clearance from the UK regulatory authorities to amend two of its ongoing Phase I clinical trials of SRA737 within the country.
SRA737 is a potent, orally bio-available, highly selective, small molecule checkpoint kinase 1 (Chk1) inhibitor.
The amended Phase I trial of SRA737 as a monotherapy will assess the product's preliminary efficacy in addition to the originally planned evaluation of the safety and tolerability.
The trial will now include a cohort expansion phase simultaneously with a dose expansion phase.
While the dose expansion phase will examine increasing doses of SRA737, the cohort expansion phase will recruit patients with genetically defined tumours that have genomic alterations.
The cohort expansion phase will involve patients with colorectal cancer, ovarian cancer, castration-resistant prostate cancer, non-small-cell lung cancer, and head and neck squamous cell carcinoma.
Sierra Oncology president and CEO Dr Nick Glover said: "Collaborating closely with our investigators and The Institute of Cancer Research, London, and The Royal Marsden in the UK, we have designed significant enhancements to our ongoing clinical trials for SRA737, which can now be implemented immediately and that are intended to enrich these studies with patients we believe are promising candidates for treatment with our drug."
Alongside the determination of safety profile, maximum tolerated dose (MTD) and recommended dose, the other Phase I trial of SRA737 in combination with gemcitabine will also evaluate the preliminary efficacy.
A stage 2 dose escalation phase and a cohort expansion phase is now being added to the trial, which also includes a stage 1 dose escalation phase.
The trial is being carried out for the treatment of patients with bladder cancer and pancreatic cancer.