Cancer Immunotherapy Possible for HIV-Positive Patients

The results from a phase 1 clinical trial suggest that checkpoint inhibitors may be effective in HIV-positive patients with advanced cancer, a population previously excluded from immunotherapy research, according to a study presented at the Society for Immunotherapy of Cancer annual meeting.

Cancer is a leading cause of death for patients with HIV. Since data are limited regarding the use of immunotherapy in these patients, checkpoint inhibitors are not commonly used.

“During the development of these drugs, people with HIV were routinely excluded from studies due to concerns that they would not tolerate these medications or perhaps not benefit from them because of their underlying HIV and associated immune dysfunction,” said researcher Thomas Uldrick, MD. “The most important first step was to show that this class of drug would be safe in certain cancer patients with HIV.”

In the study, 17 patients with various drug-resistant cancers who were treated with antiretroviral therapy (ART) for HIV received pembrolizumab (Keytruda). The preliminary results demonstrate that pembrolizumab immunotherapy was beneficial, according to the study.

Pembrolizumab has shown efficacy in treating numerous types of cancers and has been approved to treat melanoma, lung cancer, kidney cancer, head and neck cancer, Hodgkin’s lymphoma, and bladder cancer.

“These drugs are the backbone of cancer immunotherapy at present and have been shown to be effective in subsets of virtually every different kind of cancer,” said senior author Martin Cheever, MD. “For patients with HIV who are using effective antiretroviral therapy and have cancers for which these drugs are approved, there’s no reason not to consider these drugs as standard therapy.”

Although ART has dropped the prevalence of AIDS-related deaths, the link between HIV and cancer remains, according to the authors.

“Globally, more than 35 million people are infected with HIV, and cancer is the number one reason they are dying,” Dr Uldrick said. “Establishing proven effective regimens to manage cancer in people with HIV is critically important.”

The ongoing clinical trial will enroll up to 36 more HIV-positive patients, including those with Kaposia sarcoma. This cancer is a common cause of death in sub-Saharan Africa, where HIV rates are high, according to the study.

The authors note that immunotherapy has not been extensively studied in Kaposi sarcoma, which is caused by the Kaposi sarcoma herpes virus (KSHV). One HIV-positive patient with Kaposi sarcoma in the trial died. There were 6 other patients with Kaposi sarcoma or primary effusion lymphoma caused by KSHV who were treated with immunotherapy and did not experience similar results, according to the study.

While the authors are continuing to determine the cause of death, they have revised the study to exclude patients with symptomatic KSHV, according to the authors.

“We do not believe that this takes away from the safety message in patients with HIV and other, better studied cancers,” Dr Uldrick said. “However, more experience is clearly needed in treating KSHV-associated diseases with checkpoint inhibitors.”

The authors note that the National Cancer Institute recommends including HIV-positive patients in clinical trials of immunotherapy, but there has been a slow uptake likely due to a perception that patients die of opportunistic infections.

The investigators hope that these preliminary results increase immunotherapy studies involving patients with HIV, especially in cancers that are common in this population, according to the study.

Overall, the authors suggest that HIV-positive individuals should be candidates for immunotherapy treatment, according to the study.

“We’d recommend that patients with HIV and malignancy be considered for this therapy if it’s approved for their particular cancer,” Dr Uldrick concluded.