An investigational triple combination therapy including 2 immune checkpoint inhibitors and chemotherapy demonstrated positive results for the treatment of relapsed or refractory acute myeloid leukemia (AML), according to a phase 2 study at The University of Texas MD Anderson Cancer Center.
The therapy, which combines nivolumab and ipilimumab plus chemotherapy azacitidine (AZA), was evaluated in 20 patients compared with 70 patients who received AZA plus nivolumab.
Overall, patients treated with the triple combination showed a complete response rate of 43% and a projected 1-year overall survival of 58%. According to the data, the AZA plus nivolumab arm reported a complete response rate of 22% with a projected 1-year overall survival rate of 40%. In both groups, the best responses were within 3 months of therapy initiation.
“The response rate and survival in patients with relapsed AML treated with azacitidine with both nivolumab and ipilimumab, appears encouraging and potentially superior to azacitidine with nivolumab in a small cohort of patients,” lead study author Naval Daver, MD, associate professor of leukemia, said in a press release. “However, we need to study more patients with longer follow-up to make firm conclusions.”
According to Dr Daver, the triply therapy also comes with the risk of more common and more severe immune related toxicities, which indicates providers should be vigilant in monitoring the effects and treating any toxicities.
In the trial, 11% of patients in the AZA plus nivolumab group reported adverse effects, with the most common being pneumonitis and colitis. Thirty-five percent of patients in the triple therapy group reported grade 3 or 4 immune adverse effects, including pneumonitis, skin rash, pituitary hormone and liver enzyme irregularities, and colitis.
The AZA plus nivolumab cohort is now closed and the triple therapy cohort will continue to enroll up to 30 patients. Dr Daver noted that another trial will open to evaluate a higher dose of ipilimumab and a lower dose of nivolumab to determine the appropriate dosing for a larger multi-center study.
The study findings are being presented at the 60th American Society of Hematology Annual Meeting and Exposition in San Diego, California.
Immunotherapy combination and chemotherapy show encouraging results in Phase II acute myeloid leukemia study [news release]. MD Anderson Cancer Center’s website. https://www.mdanderson.org/newsroom/2018/11/immunotherapy-combination-and-chemotherapy-show-encouraging-results-in-phase-2-acute-myeloid-leukemia-study.html. Accessed November 13, 2018.