(Amgen ( AMGN ) correction to pricing estimate in paragraph 4)

May 16 (Reuters) - The U.S. Food and Drug Administration

on Thursday granted accelerated approval to Amgen's ( AMGN )

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 ( AMGN ) 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 ( AMGN ) 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 ( AMGN ) 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 ( AMGN ) 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 ( AMGN ), which fell by less than 1% to close at

$314.72 on Nasdaq, were unchanged after hours.