By Jessica Sier

Merck KGaA said late Tuesday that the U.S. Food and Drug Administration has fully approved the supplemental Biologics License Application for Bavencio, a treatment for patients with bladder cancer.

The German pharmaceutical and chemicals company said the approval comes after an accelerated approval program in 2017 for the treatment of those with bladder cancer that has progressed during or following platinum-containing chemotherapy.

The FDA has now converted the accelerated approval to full approval, the company said.

Merck demonstrated the clinical benefit of Bavencio in its Javelin Bladder 100 phase 3 study, which showed a 7.1-month improvement in median overall survival.

Write to Jessica Sier at jessica.sier@wsj.com