Immunotherapy Combination Offers Hope to Patients with Relapsed/Refractory AML

Patients with acute myeloid leukemia (AML) who have relapsed or whose disease has become resistant to treatment may have new hope in a combination therapy, according to the findings of a phase 1b/2 clinical trial.

Researchers examined how well combining chemotherapy with immunotherapy works in these patients. One group of the trial included 70 patients with relapsed/refractory AML who were able to perform ambulatory and selfcare functions and had adequate organ function.

They were treated with Vidaza (azacitidine), a type of chemotherapy, and Opvido (nivolumab), an immunotherapy. The researchers saw an overall response rate of about 35% and 11% of patients had stable disease for more than six months.

“We think 40% to 45% of patients had a clinical benefit beyond what we would see in general AML therapies,” Dr. Naval G. Daver, an associate professor in the Department of Leukemia at The University of Texas MD Anderson Cancer Center in Houston, said in an interview with OncLive®, a sister publication of CURE®.

Although 11% of patients did not achieve remission, they experienced an improvement in transfusion and improved quality of life, Daver explained. “Of course, this is very well known to be occurring with immune-checkpoint therapy in solid tumors,” he said.

An additional analysis explored the use of Vidaza alone in patients with AML. And the researchers learned that the Vidaza/Opdivo combination was better. In fact, the response rates were approximately doubled with the combination compared with Vidaza alone, Daver explained.

“What was very interesting is that there were patients who were (in first relapse) seemed to have the best survival improvement,” he said. “The median survival in these patients, the majority being above 70 years of age, was 10.5 months, which is almost double of what we have seen with azacitidine alone.”

Daver believes a greater depletion of T cells in patients who received several prior lines of therapy may be the reason why patients who had initial relapse fared better.

A second group in the trial included 31 patients with relapsed/refractory AML who were a median age of 71, and were treated with Vidaza, Opdivo and Yervoy (ipilimumab). Among those treated with all three therapies, nine patients (36%) had a complete response and four (16%) had stable disease. The median overall survival — defined by the start of treatment until the time of patient death – was greater than 10 months.

Roughly more than 60,000 cases of leukemia will be diagnosed this year in the United States, and of those, nearly 20,000 will be new cases of AML, according to the American Cancer Society. The disease typically affects older adults; the average age of when a first diagnosis occurs is 68 years old. AML is also slightly more common in men.