Merck’s Immune System-Based Cancer Drug Works in 1 in 4

Merck & Co.’s experimental cancer drug that uses the immune system to target tumors triggered a response in about a quarter of lung cancer patients, according to preliminary results of an early study.

In a trial of 38 patients with non-small cell lung cancer, 24 percent had an immune-system response to the drug, called MK-3475 and previously known as lambrolizumab, Merck said today in a statement. Using a measure of whether their tumors shrank, 21 percent responded, the Whitehouse Station, New Jersey-based company said.

Merck, the second-biggest U.S. drugmaker, today announced it would fire 8,500 workers and revise its drug development effort to focus on research programs such as MK-3475. The therapy, among a new generation of cancer medicines seeking to harness the body’s immune system, is being studied in seven different clinical trials including 3,000 patients with a variety of tumor types. It has been given a breakthrough designation by U.S. regulators, which means its approval could be sped up as it moves into late-stage trials.

“These early data in lung cancer patients were the basis for Merck’s decision to rapidly advance MK-3475 into a Phase II/III clinical trial,” Eric Rubin, vice president of oncology at Merck, said in a statement.

Lung cancer kills more people in the U.S. than any other cancer, according to the American Cancer Society.

Competing Drugs

Merck is competing to get the treatment to market as rivals also push ahead with immune system-based therapies. Bristol-Myers Squibb Co.’s nivolumab is in final stages of testing, and Roche Holding AG, the world’s biggest maker of cancer treatments, is also developing a immune-system drug.

Merck shares rose 2.4 percent to $48.74 at 4 p.m. New York time.

The most-common side effects in the 38-person study were fatigue, rash and itching in 16 percent of patients, and diarrhea in 13 percent, Merck said in the statement. One person developed a pulmonary edema, or too much fluid in the lungs, the company said.

MK-3475 belongs to a class of therapies called anti-PD-1 drugs. The medicines turn back on the body’s ability to recognize cancer cells as a threat, taking the brakes off the immune system and spurring T-cells kill the cancer.

Before it's here, it's on the Bloomberg Terminal.