Eli Lilly and Company and Boehringer Ingelheim (BI) have formed a clinical-trial collaboration for a Phase Ib study on a combination breast cancer drug. The drug is a combination of Lilly's abemaciclib, an inhibitor of cyclin-dependent kinase (CDK)-4 and CDK-6, and BI's compound, designated as BI 836845, an insulin-like growth factor (IGF)-1/IGF-2 ligand-neutralizing antibody. The drug is being developed to treat patients diagnosed with hormone-receptor-positive (HR+), human-epidermal-receptor-2 (HER2)-metastic breast cancer (mBC).

In 2015, the US Food and Drug Administration granted abemaciclib breakthrough therapy designation. Enrollment in the Phase Ib clinical trial will begin in late 2016.

The two compounds have a complementary mode of action. Lilly's abemaciclib blocks the growth of cancer cells by specifically inhibiting CDK-4 and CDK-6. BI 836845 binds to both IGF-1 and IGF-2, preventing activation of the respective receptor which decreases growth-promoting signaling in tumor cells, potentially decreasing tumor growth. In combination, the two agents offer pathway interference and could potentially prolong cell cycle arrest. This could reverse the resistance to hormone therapy that can develop in HR+, HER2- mBC patients, according to company.

Source: Eli Lilly and Company