I have been a bit slow on blogging recently due to moving to a new house at the start of a semester (remind me why I thought *that* would be an OK idea again?) but I did want to share this very interesting piece from the New Yorker by Christopher Glazek “Why Is No One On the First Treatment To Prevent H.I.V.?“
At Petrie-Flom we held a great panel discussion right when this PrEP (pre-exposure prohylaxis) treatment (and the OraQuick home HIV test) came out, and you can watch it here. (The event featured Robert Greenwald, Director of the Center for Health Law and Policy Innovation; Douglas A. Michels, President and CEO, OraSure Technologies, Inc; David Piontkowsky, Senior Director for Medical Affairs, HIV and HIV Global Medical Director, Gilead Sciences, Inc; Kenneth H. Mayer, Medical Research Director, Co-Chair of The Fenway Institute; Kevin Cranston, Director, Bureau of Infectious Disease, Massachusetts Department of Public Health; Mark Barnes, Partner, Ropes Gray, Lecturer in Law, Harvard Law School.)
As the New Yorker Article describes (and full disclosure, I sat on an IRB that oversaw a good chunk of this research at Fenway Health at one point in my career, so I am not a disinterested observe) the use of of the drug Truvada for PrEP has some pretty impressive figures from the clinical studies:
while adherence is a concern, as it is with condoms, Truvada offers H.I.V. protection that is more effective than any other method short of abstinence. In the N.I.H. study, for example, 5.2 per cent of the placebo group “seroconverted,” or became H.I.V. positive, compared with 2.9 per cent of the Truvada group. That’s a forty-four-per-cent added protection over-all—better than inconsistent condom use. More impressively, patients who maintained a detectable amount of the drug in their system were protected at a rate of ninety-five per cent. (A later statistical analysis estimated that the drug would need to be taken four times a week to offer protection in that range.) Grant said that people in the study who took the drug four to seven days a week “were absolutely protected. We didn’t have anyone seroconvert in our cohort in the United States.”
Taking Truvada to prevent H.I.V. comes with very few risks. In the N.I.H. study, one in two hundred people had to temporarily go off the pill owing to kidney issues, but even those people were able to resume treatment after a couple of weeks. While bone-density loss occasionally occurs in Truvada takers who are already infected with the virus, no significant bone issues have emerged in the PrEP studies. And though about one in ten PrEP takers suffer from nausea at the onset of treatment, it usually dissipates after a couple of weeks. According to the U.N. panel’s Karim, Truvada’s side-effects profile is “terrific,” and Grant said that common daily medications like aspirin and birth control, as well as drugs to control blood pressure and cholesterol, are all arguably more toxic than Truvada.
Perhaps more important, drug resistance has not been observed in people who were H.I.V.-negative when they began treatment. “We’re not seeing people getting infected who are actually taking the drug,” said Grant. “There are people who take the drug home with them and choose not to take it; they get infected, but you’re not going to get drug resistance from something that stays in a drawer.” Some patients who entered the trials turned out to already have an H.I.V. infection that was too recent to be caught by a blood test. These subjects showed a small amount of drug resistance, which is why the F.D.A. now requires doctors to conduct an H.I.V. test before putting their patients on PrEP. The larger resistance threat, though, comes from the ten million H.I.V.-positive people around the world who take antiretrovirals for treatment, including, in some cases, Truvada. “The best way to prevent drug resistance is to prevent H.I.V. infection entirely,” said Grant. “We know that when we prevent a case of H.I.V., we’re preventing a lifelong risk of drug resistance.”
But that just prompts the mystery, why aren’t more people taking the drug?