US-based Tolero Pharmaceuticals Inc, a clinical-stage biopharmaceutical company focused on developing treatments for hematologic and oncologic diseases, has signed a clinical research collaboration with AbbVie, a research-based global biopharmaceutical company, it was reported on Friday.

The collaboration is aimed at exploring the potential of combination therapy with AbbVie's venetoclax and Tolero's investigational agent, alvocidib intended for the treatment of relapsed/refractory acute myeloid leukaemia.

The product is a small molecule inhibitor of cyclin-dependent kinase 9 (CDK9), which controls the expression of a survival factor, MCL-1. Venetoclax is a small molecule inhibitor of B-cell lymphoma-2 (BCL-2). Both MCL-1 and BCL-2 are key proteins used by certain cancer cells to avoid apoptosis, and non-clinical studies have indicated that cancer cells can resist inhibition of BCL-2 by using MCL-1 to avoid cell death.

Alvocidib is presently in Phase II development for the treatment of MCL-1-dependent acute myeloid leukaemia.