Loxo buys BTK inhibitor

Loxo Oncology will pay Redx Pharma $40 million for the full rights to an inhibitor of BTK, an enzyme involved in B-cell development. Imbruvica, a B-cell cancer treatment marketed by AbbVie, and other BTK inhibitors in clinical studies all covalently bind to the enzyme, a mechanism Loxo argues drives resistance to those molecules through a specific mutation. By reversibly binding to BTK, Redx’s lead molecule, RXC005, could help people with cancer who no longer respond to the covalent inhibitors. Now known as LOXO-305, the compound is expected to begin human trials next year.