Advances In HIV Treatment
October 2006, article submitted by David Hillman
On July 12, the US Food & Drug Administration approved Atripla a new fixed-dose combination of 3 widely used HIV meds to be taken as a single tablet once a day. This is the first time 3 drugs from 2 different classes have been combined into a single pill. The combination consists of efavirenz (Sustiva), tenoforir (Viread) and emtricitabine because the individual components have been on the market for some time and this particular combination was already the preferred "first choice" for people starting therapy. Since the side effects of the components are well known, Atripla would not be recommended for pregnant women, people with underlying kidney disease and/or a history of clinical depression. Canadian approval is expected later this year or early 2007.
On August 10th, Health Canada approved Duranavir (formerly known as TMC-114), a powerful new protease inhibitor (PI) for people with significant resistance to currently approved drugs in this class. The drug will be marketed under the trade name Prezista. In clinical trials, nearly 4 times as many HIV+ Volunteers with extensive previous treatment failure were able to achieve an undetectable viral load after 24 weeks compared to those treated with other protease inhibitors. In addition, Prezista is dosed as 2 tablets twice daily and taken with food to enhance absorption. The most common side effects reported by participants in the trials were diarrhea (20%) and nausea (18%).
Integrase inhibitors represent an entirely new class of HIV meds. In order to replicate itself HIV needs to integrate material into the DNA of an infected CD4 cell. These drugs block this process. At the recent International AIDS Conference in Toronto, HIV+ volunteers took one of 3 doses of the experimental drug MK-0518 in combination with the approved drugs lamivudine/3TC (Epivir) and tenofovir (Viread). A "control" group took a standard-of-care combination of LOaminvudine + tenofovir + Efavirenz (Sustiva). All participants were starting HIV treatment for the first time. After 24 weeks, 90% of those using the experimental combination had an undetectable viral load, with the greatest reduction occurring in the first 4 to 8 weeks. No serious drug-related side effects were reported. The company plans to recruit 700 HIV+ volunteers for larger, international Phase III trials in the very near future. Several sites in Canada will be participating.
On September 12, Abbott Canada announced that it received marketing approval from Health Canada for a new formulation of its boosted protease inhibitor lopinavir/ritonavir, sold under the trade name Kaletra. A pale yellow tablet will replace the bright orange capsule and will not require refrigeration like the original. The dosage will be 2 tablets twice daily wiith or without food. The current formulation requires 3 capsules twice daily with food. Anyone combining Kaletra with either Viramune (nevirapine) or Sustiva (efavirenz) may need a dosage adjustment. The tablets are expeted to be available in B.C. in early 2007.