The Food and Drug Administration has given approval to Opdivo, a form of immunotherapy  for the treatment of kidney cancer and also expanded its use in fighting melanoma.

The FDA's approval of the drug for kidney cancer came on Monday. In addition, Bristol-Myers Squibb, the drug’s maker, announced today that the regulators had expanded Opdivo's use as the single treatment for melanoma that has spread.

Previously Opdivo had been approved for melanoma in combination with other drugs. The expanded approval means it can be used as a single, frontline agent.

In both cases, the FDA's action came after studies showed that Opdivo extended the lives of patients over treatment with chemotherapy.

Opdivo (nivolumab) is an immunological drug, which is a new type of cancer treatment that works by blocking a protein that prevents the body's immune system from attacking cancer cells.

Similar drugs include Yervoy (ipilimumab), also from Bristol-Myers and Merck's Keytruda (pembrolizumab) the drug currently being used by former President Jimmy Carter, who is battling melanoma that spread to his brain.

Unlike chemotherapy, which kills both cancer and healthy cells, immunologic drugs do not attack the cancer directly, but instead bolster the patient’s immune system to fight it.

Although these drugs have side effects, they are generally fewer than those produced by chemotherapy. This is because chemotherapy kills both cancer and healthy cells, while immunologic drugs do not attack the cancer directly.

The FDA has been issuing approvals for Opdivo under its expedited drug review program.  Since its first approval last Dec. 22 for melanoma, Opdivo has been approved to treat lung and now kidney cancer.