Johnson & Johnson and partner Gilead Sciences won approval yesterday in the USA for Complera, a once-daily HIV drug that combines triple therapy in a single tablet.

Complera contains J&J's Edurant (rilpivirine) - the newest antiretroviral agent approved by the FDA - with Gilead Sciences' Truvada (tenofovir and emtricitabine), the most-prescribed HIV product in the USA. It has been approved for patients starting antiretroviral therapy for the first time.

The new product is only the second all-in-one fixed-dose combination tablet to be approved for HIV after Gilead and Bristol-Myers Squibb's Atripla (efavirenz/tenofovir/emtricitabine, which debuted in 2006.

Atripla achieved sales of $1.57 billion in the first six months of this year, and analysts have estimated Complera could rake in $500 million plus within a couple of years of launch.

"The concept of a single-tablet regimen has become a goal in HIV drug development, and the standard of care in medical practice in the US," commented Tony Mills, one of the principal investigators in the Complera trials.

Edurant was approved as a single-agent tablet in May on the back of two Phase III trials (ECHO and THRIVE), carried out by J&J subsidiary Tibotec, which compared rilpivirine with efavirenz on top of background therapy with Truvada and other drugs. Both regimens were comparable in terms of efficacy, although fewer patients in the rilpivirine group experiencing side effects, notably the central nervous system reactions associated with efavirenz.

Gilead then conducted a bioequivalence study to show that the co-formulated tablet generated the same blood levels of the three drugs as separate dosing.

The company says a number of factors should be considered before starting patients on rilpivirine-based therapy. For example, in the Phase III trials patients with higher viral load (more than 100,000 copies/ml or more) were more likely to experience treatment failure with rilpivirine than efavirenz.

When treatment fails, patients taking rilpivirine were also more likely to develop resistance to the drugs in their regimen than those on efavirenz.

"No one therapy is appropriate for all patients," said Mills. "The availability of Complera represents an exciting milestone in addressing the individual needs of patients new to HIV therapy."

A marketing application for Complera has also been submitted for approval in the EU.