The U.S. Food and Drug Administration has approved the use of a promising new drug to treat advanced lung cancer.

According to the FDA, the medication Opdivo (or the generic nivulumab) can now be used to treat patients with “advanced (metastatic) squamous non-small cell lung cancer (NSCLC) with progression on or after platinum-based chemotherapy.”

Opdivo (nivolumab), made by Bristol-Myers Squibb, is an immuno-therapy drug delivered via injection that enables the patient’s own immune system to attack cancer cells. The treatment is designed for patients who have been previously treated with chemotherapy.

In one study submitted to the FDA, 15% of patients showed either shrinkage or complete disappearance of their tumors.

The US #FDA has granted one of our therapies an approval in squamous NSCLC #LungCancer http://t.co/4cHxlKTkDm

— Bristol-Myers Squibb (@bmsnews) March 4, 2015

While surgery, radiation, and other traditional treatment options target the tumor itself, nivolumab takes a different approach. It focuses on lowering the risk of recurrent cancers by training the body’s T cells to recognize tumors. This allows the immune system to attack cancer on its own.

Lung cancer caused nearly 160,000 deaths last year.

Needless to say, the approval is a welcome development for lung cancer patients who haven’t responded to other drugs and operations. And the drug now opens the door for other next-generation immune therapies.