'Pembrolizumab' Immunotherapy Offers New Hope To Melanoma Patients

NEW YORK (CBSNewYork) -- It's been called the most helpful development for melanoma patients in decades.

In the past, when melanoma spread to other organs and reached stage 4, the average survival time was only 6 to 10 months.

As CBS2's Dr. Max Gomez reported, new drugs have completely changed that bleak outlook.

When Tom Stutz was diagnosed with melanoma about 5 years ago, it had already spread to several of his organs.

"I was whipped to be honest with you, and I thought that was pretty much the end of the line for me," he said.

Stutz enrolled in a clinical trial and received a new type of immunotherapy called pembrolizumab, an antibody that takes the brakes off the body's immune system.

"With pembrolizumab what we're trying to do is redirect that immune response to fight the cancer. Pembrolizumab binds to PD-1 and then the immune system cells attack the cancer," Dr. Antoni Ribas, University of California-Los Angeles said.

Researchers tested the drug on more than 650 patients around the world. Early in the study, several patients showed enough of a response that the FDA later gave pembrolizumab 'break through' therapy status.

"When we compared the baseline tumors to the tumors after dosing, the metastases or the lesions around the body were smaller in one third of the patients," Dr. Ribas said.

The study appeared in JAMA, Journal of the American Medical Association.

"The patients who responded, the great majority, continued to respond at one or two years, 75 percent of them maintained the response," Dr. Ribas said.

The drug was well tolerated in the majority of patients.

"We're now having a sizable number of patients who have a response to the therapy and are going on to live normal lives, three or four years later," Dr. Ribas said.

That's exactly what happened with Stutz who has continued to receive the therapy.

"I've been to family events, I've gone on vacations with my kids. I'm feeling great, so what can I say? No complaints," Stutz said.

Pembrolizumab, brand name Keytruda, is the drug that has made the melanoma that spread to former President Jimmy Carter's brain apparently disappear.

Some patients have had very long lasting remissions, and some have had their cancer come back, but other immune therapy drugs may still help them.