Switching to multi-pill generic HIV treatment could diminish effectiveness, study finds
NEW YORK — While replacing a single combination pill for HIV with generics would save the healthcare system money, it could also diminish the effectiveness of treatment, a new study suggests.
The study, led by investigators at the Massachusetts General Hospital and Weill Cornell Medical College, and published in the Jan. 15 issue of Annals of Internal Medicine, found $1 billion in potential savings, but the more complicated treatment regimen might result in more patients missing doses and a loss of drug effectiveness.
Currently, the recommended treatment for newly diagnosed patients is Gilead Sciences' and Bristol-Myers Squibb's Atripla, which combines three branded antiretrovirals — Viread (tenofovir), Emtriva (emtricitabine) and Sustiva (efavirenz) into one pill. A generic version of lamivudine, which has a similar mechanism of action to emtricitabine, became available in January 2012, and a generic version of efavirenz is expected to become available soon.
The issue, the authors wrote, is that while replacing two of the three drugs in Atripla with generics might be cheaper, it would also make treatment more complex, with patients having to take three pills instead of one, thus increasing the risk of missed doses. In addition, the authors wrote, lab studies have indicated that lamivudine may be slightly less effective and more vulnerable to drug-resistant strains of HIV than emtricitabine.
The researchers employed a widely used mathematical model of HIV progression to simulate the effects of a daily three-pill regimen of generic efavirenz and lamivudine plus Viread, compared with the current one-pill combination, adopting a worst-case scenario to project the efficacy of the generics and their effect on viral resistance. Results indicated that switching all HIV patients in the country to the three-drug generic therapy would save $42,500 per eligible patient and $1 billion nationwide, but reduce quality-adjusted life expectancy by as much as 4.5 months.
"The switch from branded to generic antiretrovirals would place us in the uncomfortable position of trading some losses of both quality and quantity of life for a large potential dollar savings," study lead author Rochelle Walensky of Massachusetts General Hospital said. "By estimating the likely magnitude of these offsetting effects now — before generic antiretrovirals actually hit the shelves — we can confront our willingness as clinicians, patients and as a society to make these difficult choices."