Immunotherapy for Cancer Safe in HIV Patients on Antiretroviral Therapy

Aurelien Gobert, MD

New data from a small study suggests immunotherapy is safe in patients with HIV infection who are taking antiretroviral therapy.

The results were presented at the European Society for Medical Oncology’s ESMO 18 Congress in Munich. Though the results would need to be confirmed in larger studies, they are a promising sign that game-changing breakthroughs in both cancer therapy and HIV treatment can be effective in the same patients at the same time.

"The point of this study was to look at an HIV-positive patient cohort treated with immunotherapy in conjunction with a close monitoring of their viral load and CD4 lymphocyte count," said study author Aurelien Gobert, MD, of Paris’ Groupe Hospitalier Pitie Salpetrire, in a press release.

Gobert noted that people with AIDS already face a higher risk of certain types of cancers, known as AIDS-defining cancers. For some of those patients, immunotherapy could be a life-saving or life-extending option.

Gobert and colleagues evaluated the question by monitoring 20 patients with HIV who were prescribed the PD-1 immune checkpoint inhibitor nivolumab. Of those patients, most of whom were men around 60 years of age, 1 had metastatic melanoma, and the rest had metastatic non-small-cell lung cancer. At diagnosis, 17 of those patients had undetectable HIV viral loads, 2 had what were described as “low” viral loads, and the remaining patient’s viral load status was unknown.

Those study participants’ viral loads, CD4 lymphocyte counts, and tolerance of nivolumab were assessed throughout the study, as was the drug’s efficacy.

After a median follow-up time of 11 months, the data showed nivolumab appeared to be safe.

“We didn't see any toxic deaths or immune-related adverse events,” Gobert said. “One patient did experience a rising HIV viral load and decreasing CD4 lymphocyte count, indicating a reactivation of the virus, but this occurred following the interruption of his antiretroviral therapy.”

The patients in the study received a median of 6 nivolumab infusions, though the range of infusions was between 3 and 53 over the course of the study.

Though the therapy was safe, nivolumab only had a positive effect on a handful of patients in the study. Four patients’ cancers responded to the drug; 2 patients’ cancers remained stable during the study period; the remaining patients’ disease progressed in spite of the therapy.

Gobert said those findings are consistent with findings in other cancer populations.

“We know that few patients respond to immunotherapy, but those who do respond for long periods of time and thus have significantly improved survival,” Gobert said. “This seems to have been the case for the melanoma patient in our cohort, but the study is too recent for us to quantify survival rates at this time.”

Indeed, Gobert said the study is too small and its follow-up time frame too short to draw any firm conclusions about the efficacy of nivolumab in patients taking ART.

“Our key insight then, is that the treatment appears to be well tolerated by HIV-positive cancer patients—so long as antiretroviral therapy is continued in parallel," Gobert concluded.

The study abstract, “Tolerance and efficacy of immune-checkpoint inhibitors for cancer in people living with HIV (PWHIV),” can be read on ESMO’s website.