FLICKR, ONCOPEDIAThis week (May 18), the US Food and Drug Administration approved an immunotherapy developed by Roche for the treatment of advanced cases of a bladder cancer called urothelial carcinoma. The therapy, called Tecentriq (atezolizumab), works by preventing a protein called PD-L1 from binding to the PD-1 protein on T cells and inhibiting the body’s immune response. In a clinical study, 14.8 percent of patients had their tumors shrink significantly following treatment; in 5.5 percent, the cancer disappeared completely.

Tecentriq is the fourth so-called checkpoint inhibitor to be approved, The New York Times reported. Other checkpoint inhibitors, such as Keytruda and Opdivo, inhibit the same immune interaction, but do so by binding to PD-1, whereas Tecentriq binds to PD-L1.

The treatment will cost about $12,500 a month, according to The Wall Street Journal.

The agency also approved an accompanying diagnostic that measures PD-L1 levels to assess a patient’s likelihood...