Sierra Oncology encouraged by early progress on SRA737 clinical trials

Sierra Oncology Inc (NASDAQ:SRRA) has reported encouraging initial progress in its clinical trials of SRA737 cancer treatment candidate.

Sierra Oncology holds exclusive and worldwide rights for the Chk1 inhibitor, SRA737, which it licensed from the CRT Pioneer Fund, a partner of London-listed drug discoverer and developer Sareum Holdings Plc (LON:SAR), in September 2016.

The checkpoint kinase 1 (Chkt1) tumor inhibitor is currently undergoing two Phase 1 clinical trials, and Dr Barbara Klencke, chief development officer of Sierra, said the team has not yet observed any dose limiting toxicity.

Dr Klencke said several cohorts (test groups) have surpassed the minimum efficacious plasma concentration for SRA737 based on pre-clinical modeling.

“This has enabled the commencement of the parallel cohort expansion phase of the study,” Dr Klencke told attendees of the 2017 American Society of Clinical Oncology (ASCO).

“This innovative clinical trial design will enroll prospectively-selected genetically-defined patients into five indication-specific cohort expansions at potentially active dose levels,” she revealed.

The Phase 1 chemotherapy combination study, which is evaluating SRA737 in combination with gemcitabine and cisplatin, has concluded enrollment and moved on to Stage 2.

“In addition to advancing our novel synthetic lethality-oriented monotherapy study, we are also excited by the potential for SRA737 to combine synergistically with other agents. Gemcitabine is a potent inducer of replication stress and DNA damage via multiple mechanisms, and represents a rational drug combination for SRA737, given Chk1′s fundamental biological role in responding to such stressors,” said Dr Nick Glover, president and chief executive officer of Sierra.

“Our pre-clinical modeling demonstrates robust synergistic anti-tumor activity of SRA737 in combination with low-dose gemcitabine,” added Dr Glover.

“We expect to accrue a solid understanding of dose, schedule, pharmacodynamic and pharmacokinetic parameters for SRA737 from these two studies, and the data observed to date are encouraging and consistent with our pre-clinical research. Our SRA737 development program remains on track and we expect to provide an update from these studies, including potential preliminary activity data, in early 2018,” he concluded.

Story by ProactiveInvestors