Health Watch: Advanced Melanoma trial when Keytruda alone is not enough

LOS ANGELES -- Patients with metastatic melanoma have faced grim prospects: the American cancer society says the five-year survival rate is only 15 percent. That started changing when the FDA approved Keytruda in 2014. Despite the drug's success, 60 percent of patients didn't respond. Now researchers at UCLA hope that adding a second drug could cut that number in half.

When John Gilligan was diagnosed with metastatic melanoma, he, his wife Carol Baker, and his doctors chose the SD 101 clinical trial as a first line treatment.

"The numbers for survival for metastatic melanoma have not been very good, so trying something experimental seemed like a good idea," Gilligan said.

The trial combines the immunotherapy drug Keytruda with injections of SD 101 into tumors. SD 101 is a bacteria-like agent that changes the microenvironment so the immune system kills cancer cells more effectively. Oncologist Deborah Wong, MD, PhD, Assistant Clinical Professor of Medicine at UCLA School of Medicine says it's like a flare to get the process going.

"Not only does this combination work to shrink the tumor that we're injecting, but on scans, the tumors apart, far away from the ones we're injecting, also shrank," said Dr. Wong.

Nine study participants got immunotherapy for the first time. Seven of them had good responses, including two whose tumors disappeared. That's a 78 percent response rate, nearly twice as good as Keytruda alone. The other 13 had had immunotherapy before and had modest or no response. After six months, Gilligan's tumors disappeared. He now gets just Keytruda, with few side effects.

"I've managed to keep working and keep working out and being active and, you know, all of those things that help keep you optimistic," said Gilligan.

Optimistic enough to start planning a family trip to Paris when he retires next year.

The combination therapy does have some side effects including flu-like symptoms, injection site irritation, and the possibility of toxic immune responses. John says most of his side effects went away when he switched to just Keytruda. This trial was small, just 22 participants so far. UCLA's Jonsson Comprehensive Cancer Center is now part of a 45-center trial testing SD 101 and Keytruda in patients with melanoma and neck cancer. For information, go to https://www.clinicaltrials.gov/ and search SD 101