Single HIV Pill Not Always Best (CME/CE)
HIV patients taking single pills containing three drugs are thought to be less likely to stop taking their medications than those on more complicated regimens, but that may not be completely accurate, researchers said here.
In a retrospective, observational study, people taking the most widely used single pill were just as likely to switch therapies as were those on multipill regimens, according to Benoit Trottier, MD, of Clinique Medicale L'Actuel in Montreal, and colleagues at the AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention.
On the other hand, it was true that taking the single pill containing efavirenz, tenofovir, and emtricitabine (Atripla) was more likely to result in sustained control of HIV than multipill regimens, he reported.
But even there, one multipill regimen did just as well, Trottier reported.
There are currently three such single-pill regimens on the market: Atripla (Complera): A combination of efavirenz, tenofovir, and emtricitabineStribild: A combination of elvitegravir, cobicistat, tenofovir, and emtricitabine
Trottier and colleagues used their clinic records to see what happened to new HIV patients who started on Atripla, or one of three other recommended first-line regimens that have a higher number of pills.
The primary endpoint of the study was the time to stopping the first regimen, while a secondary endpoint was the loss of virological control.
Of the 575 patients who started therapy at the clinic from 2007 through March 2012, 32% stopped their initial regimen -- 35% of the 187 who started on Atripla and 31% of the 388 who started on another regimen.
That difference wasn't significant, but when the researchers compared Atripla with individual multipill regimens, they found that one -- based on the integrase inhibitor raltegravir (Isentress) -- was actually significantly less likely to lead to switching treatment.
The main reasons for switching treatment were side effects and toxicities, Trottier noted.
The single-pill regimen was significantly better in maintaining viral control as patients on multipill regimens were overall 85% more likely to have a virological failure.
But again, the raltegravir-based regimen did as well as Atripla, he reported, while the other multipill regimens were significantly worse.
The main problem with the study is that it doesn't distinguish between the effects of a single tablet regimen as such and the effects of the component drugs, commented Joel Gallant, MD, of Johns Hopkins University School of Medicine, who was not part of the study but who moderated the session at which it was presented.
"You couldn't necessarily extrapolate these findings to other (single tablet regimens)," he told MedPage Today
, noting that efavirenz is known to have distressing central nervous system adverse effects not shared by most other HIV drugs.
But he added that the analyses that have suggested such regimens have more durable and effective results may suffer themselves from selection biases -- physicians tend to put highly motivated patients on Atripla knowing they are unlikely to miss doses.
If adherence is likely to be an issue, he added, doctors might choose regimens that are more forgiving.
Trottier agreed that the lack of data on other single-pill combinations is "a limit of our study."
But, he told MedPage Today
, that's because other single tablet regimens have only recently reached the market so he and colleagues have limited numbers of patients on which to base an analysis.
Trottier said the study and the researchers had no external support from industry.
Gallant has disclosed commercial relationships with Bristol-Myers Squibb, Gilead Sciences, Janssen Therapeutics, Merck, RAPID Pharmaceuticals, and Sangamo Biosciences.
Primary source: International AIDS Society
Source reference:
Trottier B, et al "Single tablet regimens do not necessarily translate into more durable HIV treatments" IAS
2013; Abstract TUPDB0106. North American Correspondent for MedPage Today, is a three-time winner of the Science and Society Journalism Award of the Canadian Science Writers' Association. After working for newspapers in several parts of Canada, he was the science writer for the Toronto Star before becoming a freelancer in 1994. His byline has appeared in New Scientist, Science, the Globe and Mail, United Press International, Toronto Life, Canadian Business, the Toronto Star, Marketing Computers, and many others. He is based in Toronto, and when not transforming dense science into compelling prose he can usually be found sailing.
