FDA Approves GlaxoSmithKline AIDS Drug Tivicay

On August 12, the U.S. Food and Drug Administration approved GlaxoSmithKline Plc's drug Tivicay to treat the most common strain of HIV. The once-daily drug, known generically as dolutegravir, belongs to a novel class known as integrase inhibitors that block the virus from entering cells.

"HIV-infected individuals require treatment regimens personalized to fit their condition and their needs," said Edward Cox, M.D., M.P.H., director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research. "The approval of new drugs like Tivicay that add to the existing options remains a priority for the FDA."

Tivicay is the second approved antiretroviral in the integrase strand transfer class, after Isentress (raltegravir). The FDA declined to approve a third drug, elvitegravir, as an individual in that class, although it has been approved as a component of the "Quad" pill Stribild.

Tivicay is owned by ViiV Healthcare, an HIV joint venture between GSK, Pfizer Inc. and Shionogi & Co Ltd., in which GSK is the largest shareholder, with a 76.5 percent stake. Analysts on average expect sales of the drug to reach about $900 million by 2017, according to six analysts polled by Thomson Reuters.

The 50-mg tablets are for use in combination with other antiretroviral agents. Tivicay can be used to treat infected adults who have been treated with other drugs or are new to treatment. The FDA also approved the drug for use in children aged 12 years and over, who weigh at least 40 kg (88 lbs.) and who have not received treatment with a drug that has the same mechanism of action.

Tivicay's safety and efficacy in adults was evaluated in 2,539 participants enrolled in four clinical trials. Depending on the trial, participants were randomly assigned to receive Tivicay or Isentress (raltegravir), each in combination with other antiretroviral drugs, or Atripla, a fixed-dose combination of three HIV drugs made by Gilead Sciences Inc. (efavirenz, emtricitabine and tenofovir. Results showed Tivicay-containing regimens were effective in reducing viral loads.

"In many regimens, the differentiating component is the third agent. Tivicay provides a new opportunity for healthcare professionals to choose the right regimen for their patients, providing a focal point around which to individualise therapy," said ViiV Healthcare's Chief Medical Officer Dr. John Pottage. "HIV treatment should not be a 'one-size fits all' paradigm."

A fifth trial established the pharmacokinetics, safety and activity of Tivicay as part of treatment regimens for HIV-infected children ages 12 years and older weighing at least 40 kg who have not previously taken integrase strand transfer inhibitors.

Common side effects of Tivicay in clinical trials included insomnia and headache. Serious side effects included hypersensitivity reactions and abnormal liver function in participants co-infected with hepatitis B and/or C.

About 50,000 people in the United States are infected with HIV each year and about 15,500 died in 2010, according to the Centers for Disease Control and Prevention.

"Today is a very important milestone for patients and the scientists and teams who developed Tivicay and brought it to this point of FDA approval," said ViiV Healthcare Chief Executive Officer Dr. Dominique Limet. "I am very proud that we are serving people living with HIV with a much-needed new treatment option."