Maintenance sunitinib for extensive-stage small cell lung cancer: a new standard, an option or a step in the right direction?

Systemic treatment for extensive-stage small-cell lung cancer (ES-SCLC) has been stagnant for several decades. Sunitinib is a small molecule that inhibits a variety of receptor tyrosine kinases relevant in tumor biology. CALGB (Alliance) 30504 is a phase II study that investigated the use of maintenance sunitinib vs. placebo in patients with ES-SCLC after treatment with induction platinum/etoposide chemotherapy. The trial met its primary endpoint with an improvement in median progression free survival (PFS) of 1.6 months over placebo. Toxicity included grade 3 fatigue in 19% of patients. Although PFS may be a meaningful endpoint in this patient population, the modest improvement in PFS identified with maintenance sunitinib combined with the toxicity profile would not change the current standard of care. Changes in future trial design may enhance the ability to identify agents that will preserve patient functionality and prolong survival.