There was a time, not long ago, that talk of a cure for HIV was so unrealistic that the topic was all but taboo.
More recently talk of an HIV cure is the topic of headlines. First came Timothy Brown, “the Berlin Patient,” free of replicable HIV for more than half a dozen years, since a bone marrow transplant from a donor whose immune system was genetically resistant to HIV. And then, lately and in quick succession, of the “Mississippi Baby,” apparently infected, treated 30 hours after birth, now apparently HIV-free after 18 months out of treatment, and “The Visconti cohort,” 14 patients in France, treated early, and for years, and now, apparently, controlling the virus on their own.
What happened in each case was not “transferable,” Dr. Steven Deeks emphasized today, in a discussion organized by AVAC. Those cures, he said, “are not going to be applicable to most people.”
Still, he said, “They inspire people.” And to Deeks, a physician researcher, that is a good thing. All of the cases raised both questions and possibilities. They came with a caveat, as well: “We have to make sure we don’t oversell our findings, and that the optimism is contained.”
While recent cases raised hopes, obstacles to curing HIV on a mass scale remain. A primary barrier to a cure: treatment can keep the virus from replicating, but reservoirs remain out of reach, retaining the potential to replicate in the future. The details behind the recent headlines, however, have indicated that the mechanism that allows the virus to hide and remain viable can be surmounted.
Deeks reviewed the recent developments, and their ramifications, as well as the cases revealed at last summer’s International AIDS Conference of two Boston patients who remained on HIV treatment following bone marrow transplants, and in whom the virus over the eight months that followed became undetectable. “Word on the street,” Deeks said, is that the patients may soon undergo a carefully monitored interruption of their antiretroviral treatment to determine if they have been cured.
The Mississippi baby, born to an HIV-infected mother who had received no prenatal care or antiretroviral treatment, tested positive for the virus immediately after birth. Since details of her case, which have not been published, were presented at the March Conference on Retroviruses and Opportunistic Infections the possibility that the baby was never herself infected with HIV, but instead showed signs of her mother’s infection, has been raised by clinicians, researchers, and others writing about the case. Deeks says the evidence does not bear out that theory.
“The data strongly argue that the baby was infected,” he said. “That there was indeed an established infection.”
What exactly did happen, though, he says, remains unknown. Among the possibilities, he said, is that treatment addressed the virus before it found its hiding place.
News of the Visconti cohort — the 14 HIV patients in France whose viruses are not replicating, even though they are no longer on treatment also has been greeted with skepticism. That includes the question of whether they all are “elite controllers” — the very rare individuals whose immune systems control the virus without treatment. Deeks doesn’t think so, saying that testing has not indicated the characteristics shared by elite controllers.
Among promising paths of HIV cure research now, Deeks says, is a search for ways to “shock and kill” the virus — shock it out of its hiding place, and then kill it. The answer, eventually, will come from a combination of approaches, he said, including improvements in antiretroviral drugs, and a vaccination to prevent reinfection. The quest is gathering speed, but the answers are years away, he said. In the meantime, the need for a cure that can restore health and end a lifelong need for treatment, will continue.
“We are in it,” he said, “for the long run.”
For information on cure research resources, as well as the slides from today’s discussion, visit: www.avac.org/cure