RAS signaling in ALK fusion lung cancer.

The success of ALK targeted therapy is blunted by resistance. To identify rational polytherapy strategies to improve clinical outcomes, we studied the molecular basis of ALK oncogene dependence in ALK gene rearrangement positive (ALK+) lung adenocarcinoma. We discovered that RAS-RAF-MEK-ERK signaling is the crucial downstream pathway that is required for ALK+ tumor cell survival. Upfront co-inhibition of ALK and MEK improved response and blocked resistance in preclinical ALK+ lung cancer models, providing rationale for a new treatment paradigm for ALK+ patients.