Boehringer Ingelheim and Lilly are teaming up again, this time to test the potent of a novel combination of two medicines for the treatment of breast cancer.

The firms will collaborate on a Phase Ib study evaluating the safety and tolerability of Lilly's abemaciclib in combination with Boehringer's BI 836845 in patients diagnosed with HR+, HER2- forms of the condition.

Abemaciclib is designed to block the growth of cancer cells by specifically inhibiting CDK 4 and CDK 6, known to play a role in uncontrolled cell growth.

BI 836845 is an IGF ligand-neutralisng antibody that binds to both IGF-1 and IGF-2, to prevent activation of the respective receptor resulting in decreased growth-promoting signalling, which may decrease tumour growth.

The companies are hoping that combining the two agents could offer a more complete pathway interference and potentially prolong cell cycle arrest which, for HR+, HER2- mBC patients, could translate to a reversal of resistance to hormone therapy.

"For patients living with metastatic breast cancer, the limited treatment options available make this an important area of focus for our efforts to advance the most innovative treatments," said Richard Gaynor, senior vice president of product development and medical affairs, Lilly Oncology.

Enrolment in the trial is scheduled to begin in late 2016, and Boehringer will be the sponsor of the study programme.