Eli Lilly will continue its MONARCH 2 Phase 3 clinical trial of abemaciclib for advanced breast cancer into the first half of 2017, including a final analysis of patients’ progression-free survival rate, overall survival rate and safety data.
The company made the decision after an independent data monitoring committee (DMC) recommended the study be continued without modifications although the interim efficacy criteria were not met.
The trial is evaluating the progression-free survival of women with hormone receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer receiving the Lilly drug candidate abemaciclib plus the chemotherapy drug Faslodex (fulvestrant), or Faslodex with a placebo.
The Phase 3 trial was conducted across 142 global sites and enrolled 669 patients who were randomized to receive either abemaciclib or a placebo orally every 12 hours on a continuous dosing schedule in combination with Faslodex over nine months or until the disease progressed.
According to Eli Lilly, abemaciclib is designed to block the growth of cancer cells by specifically inhibiting cyclin-dependent kinases (CDKs) CDK 4 and CDK 6.
CDKs can be considered check-point officers of the cells that police the regulation of cells as they go through each phase making sure nothing abnormal happens to cellular growth. But as with any policing strategy that is deemed insufficient, problems occur, and this is what happens when CDKs begin to over-police their checkpoints by sending too many cell cycle signals that can lead to abnormal cellular growth, resulting in cancer.
Abemaciclib has been shown to efficiently block both CDK 4 and CDK 6 in laboratory assays, as well as exhibiting positive safety outcomes in a Phase 1 trial — leading to a Breakthrough Therapy designation by the U.S. FDA in 2015.
“We had stringent criteria set for this interim analysis and we look forward to receiving the final MONARCH 2 results in the first half of 2017,” Dr. Richard Gaynor, MD, senior vice president of product development and medical affairs for Lilly Oncology, said in a press release.
“We remain optimistic that treatment with abemaciclib, in combination with fulvestrant, could offer improved outcomes for patients,” he said.