Merck scored yet another FDA approval for its blockbuster drug Keytruda (pembrolizumab), for treating patients with metastatic small cell lung cancer (SCLC).

The accelerated approval is for treatment of SCLC patients who show disease progression on or after platinum-based chemo and at least one other prior line of therapy.

The approval was supported by positive results from two trials. Ninety-four percent of the responding patients showed a duration of response of six months or longer, 63 percent of 12 months or longer, and 56 percent of 18 months or longer.