(Reuters) - Bristol-Myers Squibb Co said on Tuesday the U.S. Food and Drug Administration had approved a four-week dosing schedule for its cancer drug, Opdivo.

Opdivo with a two-week dosing schedule was previously approved to treat a number of cancers such as melanoma.

The drug belongs to a fast-growing class of drugs called PD-L1 or PD-1 inhibitors that help the immune system attack cancer by blocking a mechanism tumors use to evade detection.

William Blair analyst Matt Phipps in a client note said the new approval may help the drug expand into the “maintenance and adjuvant therapy settings”. Maintenance therapy immediately follows initial treatment to keep patients cancer-free if they go into remission.

The company said on Tuesday the drug was also approved for shorter 30-minute infusions, reducing previous infusion time in half.

“Cutting the number of infusions in half with the four-week dosing schedule provides meaningful benefit to patients and reduces the burden at infusion centers,” said Phipps.

The analyst added that Bristol-Myers is testing Opdivo in nine late-stage adjuvant trials and as maintenance therapy in small-cell lung cancer.

Other PD-1 inhibitors include drugs from rivals such as Merck & Co and Roche.

The FDA decision makes Opdivo the only PD-1 inhibitor to offer every four-week dosing, according to the company.