A new collaboration on a phase 1b study will evaluate the safety and tolerability of BI 836845, Boehringer Ingelheim’s insulin-like growth factor (IGF)-1/IGF-2 ligand neutralising antibody, in combination with abemaciclib (LY2835219), Eli Lilly’s cyclin-dependent kinase (CDK) 4 and 6 inhibitor, in patients diagnosed with HR+/HER2- mBC. The combination of the two agents could offer a more complete pathway interference and could potentially prolong cell cycle arrest. For HR+/HER2- mBC patients, this could translate to a reversal of resistance to hormone therapy.