An experimental breast cancer combination being developed by Eli Lilly has hit its key goal of extending progression-free survival (PFS) in certain patients with advanced disease.

The Phase III MONARCH 2 trial assessed abemaciclib (LY2835219), a cyclin-dependent kinase (CDK) 4 and CDK 6 inhibitor, in combination with fulvestrant (AstraZeneca's Faslodex) in women with hormone-receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), advanced breast cancer who have relapsed or progressed after endocrine therapy.

The results showed that adding abemaciclib to fulvestrant resulted in a statistically significant improvement in PFS, when compared to the control arm of placebo plus fulvestrant.

Safety-wise, the most common adverse events observed were diarrhoea, neutropenia, nausea and fatigue, and these were consistent with the previous studies of Lilly’s drug, it noted.

The firm and its investors will be particularly pleased with the data given that, back in August, the drug failed to hit interim efficacy targets in the trial.

Lilly is also currently assessing its drug as a single agent in patients with refractory metastatic breast cancer, whose disease had progressed following multiple prior treatments, including chemotherapy.

The firm said it will submit a new drug application for single-agent abemaciclib in the second quarter of 2017, based on the MONARCH 1 study, for the treatment of refractory metastatic breast cancer patients whose disease had progressed following multiple prior treatments, while an additional application for MONARCH 2 will be filed in the third quarter.