Patients with human immunodeficiency virus (HIV) may safely receive immune checkpoint inhibitors as a cancer treatment, as long as they continue taking antiretroviral therapies, a retrospective study shows.
Findings from the study were revealed recently at the European Society for Medical Oncology 2018 Congress in Munich. The poster, “Tolerance and efficacy of immune-checkpoint inhibitors for cancer in people living with HIV (PWHIV),” was presented by Aurélien Gobert, MD, an assistant professor at the Groupe Hospitalier Pitié Salpêtrière in Paris.
Immunotherapy, a kind of cancer treatment that boosts the body’s own immune system to fight cancer, has brought new hope to cancer patients. Many of these treatments — including vaccines, immune checkpoint inhibitors, and CAR T-cell therapies — are now approved for multiple tumor types.
However, clinical trials testing these treatments select candidates with the lowest chances of experiencing complications, a practice that leaves out HIV patients. These patients have a higher risk of a number of cancers, but it is still not known if immunotherapies are a feasible approach for treating them once cancer develops.
To address this, researchers in France examined the outcomes of HIV-positive patients who received the immune checkpoint inhibitor Opdivo (nivolumab) — which targets the same cells affected by the HIV virus.
Their study included 20 patients — one with metastatic melanoma and 19 with metastatic non small-cell lung cancer — whose cases had been presented during multidisciplinary meetings of Cancer VIH, a nationwide network in France that organizes regular meetings to discuss issues related to HIV patients who have cancer.
To assess if Opdivo was safe in these patients, investigators studied if the treatment had an impact on patients’ viral load and on the amount of CD4 T-cells. Responses to treatment were used to determine effectiveness
“Viral load is the quantity of virus found in the bloodstream, and CD4 lymphocytes are the cells of the immune system that HIV targets,” Gobert said in a press release. “Both measures are indicators of the extent to which a person is affected by the virus: patients treated properly with antiretroviral therapy typically have a lymphocyte count of 350-500/mm3 and a viral load that is undetectable.”
At diagnosis, the median amount of CD4 T-cells was within the normal range. Viral load was undetectable in 17 patients, low in two, and unknown in one patient. At the time of the analysis, patients had been followed for a median of 11 months, and had received a median of six Opdivo doses (ranging from three to 53).
At this point, no patient had experienced immune-related adverse events or died due to toxicity. One patient did experience a rise in viral load and a decrease in CD4 T-cells, but researchers point out that this was only observed after his retroviral treatment was discontinued.
Responses were studied in 17 patients, four of whom had a partial response. In addition, one patient had their disease stabilized after Opdivo treatment.
“Although the response data is fairly consistent with results obtained with the same drug among other cancer patients, the size of our sample and the length of follow-up do not allow us to draw any conclusions regarding efficacy,” Gobert cautioned.
Nonetheless, the findings suggest that Opdivo treatment — and possibly other PD-1/PD-L1 inhibitors — are “well tolerated by HIV-positive cancer patients — so long as antiretroviral therapy is continued in parallel,” Gobert concluded.
According to John Haanen, MD, PhD, a professor from the Netherlands Cancer Institute in Amsterdam, the findings confirm the results of other small studies in HIV patients, but advises that “these promising results need to be confirmed in larger studies — ideally, in a prospective clinical trial.”