HIV Cure? Lung Cancer Drugs 'Shock and Kill' HIV in French Patient

In Chengdu,, China, an event organized by the local government to promote HIV/AIDS knowledge among migrant workers, on December 1, 2005. China Photos/Getty Images

Updated | For the 37 million people living with HIV, a cure could be life-changing. However, the virus's biology makes finding a real cure exceedingly difficult. Copies of HIV's genetic code can hide themselves in cells where current therapies can't reach them. But one specific drug, already hailed as a class of potentially breakthrough drugs for cancer, might be able to flush those copies of the virus out—and some people with HIV have already begun to see results.

A 51-year-old man with both HIV and lung cancer, whose HIV levels were undetectable before he began treatment, received a drug called nivolumab after the first attempt to treat his cancer didn't work.

Though the number of copies of the HIV virus found in his blood rose while he was receiving the drug, scientists believed the treatment may have helped expose the viruses' hiding places, making them vulnerable to conventional immune system attacks. At the end of the treatment, the number of copies of the virus found in his blood had fallen again. His doctors published the details of his treatment in Annals of Oncology on Thursday.

Nivolumab, also called Opdivo, is a type of drug called a checkpoint inhibitor. Checkpoint inhibitors essentially unmask some very tricky tumors that have proteins on their surface, telling the immune system not to attack them. But checkpoint inhibitors also can prevent the message from being received by the immune cells or from being sent in the first place by the tumor cells. Either way, the result is the same: The immune system can recognize cancer cells for the interlopers they are.

The immune cells that checkpoint inhibitors influence are the same ones where HIV can hide: CD4+ cells. The researchers thought the drug may have worked through what they called "shock-and-kill" mechanisms. The drugs may have spurred the HIV within the immune cells to come to life and replicate, allowing other immune cells to identify and kill the infected ones.

Despite all that promise, it's just one case, experts emphasized to Bloomberg reporters. According to the BBC, only about 50 people with both HIV and cancer had been given immunotherapy, and not everyone treated with checkpoint inhibitors saw the same effect.

"It's difficult to speculate at this stage why the second patient did not show the same response," Dr. Andrew Freedman, an infectious disease specialist at Cardiff University, told Reuters. "Differences in the size of the latent reservoir or genetic differences between individuals, affecting their ability to mount immune responses to HIV, might be important factors."

The fact that all of those patients with HIV also had cancer had to play into any consideration of using those drugs with the intention to treat HIV in the future. Immunotherapy drugs like checkpoint inhibitors are no joke: Because they work by turning the immune system against a person's own body, they have serious side effects and can cause problems in major organs, according to the American Cancer Society. Some people have even died as a result.

Other, larger, clinical trials with those drugs in HIV-infected people are ongoing. One such study being conducted by the National Cancer Institute is expected to wrap up in 2020.

Correction: A previous version of this article misstated the results of a different study testing immunotherapy drugs on patients with terminal skin cancer.