“A clinical trial conducted at the University of North Carolina Lineberger Comprehensive Cancer Center and Johns Hopkins Sidney Kimmel Comprehensive Cancer Center found that high-dose cytarabine followed by subsequent immunotherapy treatment with pembrolizumab (Keytruda) benefited patients with resistant or relapsed AML.”

37 patients under the age of 70 received high doses of cytarabine. Two weeks later, they received pembrolizumab. By the end of this treatment plan, 38% of the patients had complete remission of their cancer. It is well established that AML is a highly aggressive cancer, so these findings offer a promising option for those with relapsed or refractory (not responding to treatment) AML.

“Patients with AML carry innate and adaptive immune aberrations at diagnosis that lead to immunity suppression, exhaustion and senescence (a tumor-suppressive process).” Thus, the results of this new clinical trial are favorable. They compare with the outcomes of cytarabine and other chemotherapy drugs. “Patients who had not benefited from standard therapy and received high-dose cytarabine followed by pembrolizumab in their second overall treatment phase, 46% of trial enrollees achieved the complete remission with the one-two punch, suggesting this treatment might be best early in the course of their disease. Serious side-effects were rare and limited.”

Trial participants generally lived for one year after their treatment. This compares to the average of a six to seven month survival rate from chemotherapy alone. The AML five-year survival rate has risen just slightly to 30%. Thus, this clinical trial provides another treatment option that has shown to extend life expectancy. 

In addition to the chemotherapy/immunotherapy combination success, researchers also found that T cells were prevalent prior to the start of any treatment. It’s possible that the pembrolizumab reinvigorated these T cells, which benefited the patient’s overall response to this trial process. Other gene pathways were also discovered in the leukemia cells of those patients who responded well to pembrolizumab. This gene discovery could serve as future potential biomarkers to help predict a patient’s response to this treatment.

Currently, the majority of patients with relapsed or refractory AML do not have many options for treatment, but trials like this are providing hope for new treatment breakthroughs. In most cases, cytarabine chemotherapy is the only medication used in treatment which has shown to not extend life much. The addition of pembrolizumab now shows a greater response.