By Katie Campbell
A team of researchers in France report that when treating a HIV-positive patient with the cancer drug nivolumab, there was also a significant decrease in cells found in the immune system, brain, bone marrow, and genital tract where the HIV virus can hide. These hidden, HIV-infected cells are not impacted by anti-retroviral therapy. This means that if treatment is stopped, these “reservoirs” of virus can replicate and begin to infect more cells.
A specific type of immune cell, the CD4 T cell, can become infected latently with HIV in the early stages of the disease. This means that the cell is infected with HIV, but not actively producing the virus; so that if the cell becomes activated it will produce HIV. Researchers are looking to tackle this problem by inhibiting a cell-replication checkpoint that can cause cell death. Drugs that inhibit this checkpoint (such as nivolumab) are frequently used in cancer treatment to intensify a patient’s immune response against the cancerous cells.
This case is the first in which a cell death inhibitor impacted a human’s latent HIV infection. The researchers described that at the start of treatment, his HIV was “undetectable” but it slowly increased and then declined. This follows the pattern of increased T cell activity which can attack and destroy the HIV cells.
Unfortunately, this team has also seen a case with no change in HIV infection after treatment with a similar drug. They are pursuing a clinical trial to evaluate toxicity, as well as identification of biomarkers that could personalize treatment. Additionally, they remain excited by these results as they suggest that we might be one step closer to controlling both HIV and cancer.
European Society for Medical Oncology. (2017, November 30). Cancer drug leads to 'drastic decrease' in HIV infection in lung cancer patient. ScienceDaily. Retrieved December 3, 2017 from www.sciencedaily.com/releases/2017/11/171130214929.htm