(Reuters) -The U.S. Food and Drug Administration has approved AbbVie's drug to treat adults with a type of lung cancer who have received previous treatment, the drugmaker said on Wednesday.

The treatment, branded as Emrelis, belongs to a class of drugs known as antibody-drug conjugates, which act as "guided-missiles" that target only cancer cells while sparing healthy cells, unlike conventional chemotherapy.

Emrelis was approved for a type of non-squamous non-small cell lung cancer (NSCLC), for which patients were previously treated with other drugs but the disease still spread to other parts of the body.

These patients also showed an excess of c-Met protein, which is known to trigger tumor development and resistance to certain therapies.

According to the National Institutes of Health, about 25%-37% of patients with this type of lung cancer exhibit high c-Met protein overexpression.

NSCLC is the most common type of lung cancer in the United States, accounting for roughly 197,000 new NSCLC cases in a year, according to the American Cancer Society.

The FDA's accelerated approval of Emrelis was based on a mid-stage trial of 84 patients, where the drug showed an overall response rate of 35%. It is currently being evaluated in a late-stage trial.

Other treatment options for NSCLC include Merck's blockbuster Keytruda and AstraZeneca's Tagrisso, which belong to different classes of drugs.