US FDA approves Amgen drug for small cell lung cancer

FILE PHOTO: An Amgen sign is seen at the company's headquarters in Thousand Oaks

(This May 16 story has been officially corrected to change the pricing estimate in paragraph 4)

(Reuters) - The U.S. Food and Drug Administration on Thursday granted accelerated approval to Amgen's tarlatamab, a targeted immunotherapy for adults in the advanced stages of hard-to-treat small cell lung cancer that has worsened despite chemotherapy.

The drug, marketed under the name Imdelltra, is part of Amgen's pipeline of bispecific antibodies designed to attach to a cancer cell and an immune cell, bringing them together so that the body's immune system can kill the cancer.

Results from a mid-stage trial published last year in the New England Journal of Medicine showed that tumors shrank in 40% of patients receiving 10 mg of tarlatamab by intravenous infusion every two weeks.

Amgen said the U.S. price for Imdelltra is $31,500 for the first cycle, and $30,000 for subsequent cycles. The company said trial patients were on the treatment for a median of over five months, which would equate to a commercial price of about $166,500.

Patients in the study lived for a median of 14.3 months, compared with a typical survival rate of about five months.

Most lung cancer cases are non-small cell, while up to 15%, according to the American Cancer Society, are the more aggressive small cell variety targeted by Imdelltra.

The disease, which is diagnosed in about 35,000 U.S. patients annually, is "one of most rapidly proliferating and most aggressive cancers there is," Jay Bradner, Amgen's chief scientific officer, said in an interview ahead of the decision.

In clinical trials, the most common side effect of the treatment was cytokine release syndrome, a potentially dangerous condition that occurs when the body's immune system responds over aggressively to infection or immunotherapy drugs.

Amgen said it will need to complete its larger, pivotal trial in advanced small cell lung cancer to receive full FDA approval of the drug.

The company is also testing tarlatamab for treating patients with earlier-stage small cell lung cancer.

If those studies prove successful, Wall Street analysts have said tarlatamab could represent an annual sales opportunity for the company of more than $2 billion.

Shares of Amgen, which fell by less than 1% to close at $314.72 on Nasdaq, were unchanged after hours.

(Reporting By Deena Beasley and Sneha S K; Editing by Bill Berkrot, Shailesh Kuber and Jamie Freed)