ViiV gets US approval for Atripla rival Triumeq

Armed with FDA approval for its triple HIV drug Triumeq, ViiV Healthcare can now start to challenge rival Gilead Sciences for a larger slice of the antiretroviral drugs market in the US.

Triumeq combines the HIV integrase inhibitor dolutegravir - recently-launched by ViiV under the Tivicay brand name - with the company's long-established lamivudine and abacavir drugs in a single, once-daily tablet.

The new product gives ViiV a weapon against the dominance of Gilead in the first-line HIV therapy market, which is led by the company's Atripla (efavirenz, emtricitabine, and tenofovir) and Truvada (emtricitabine and tenofovir) products.

The two products pulled in around $1.6bn apiece in the first six months of the year, with a four-drug combination adding in Gilead's own integrase inhibitor elvitegravir - Stribild - adding almost another $500m to the pot. At the same time, ViiV's fast-maturing portfolio has started to lose ground to generic competition.

Triumeq is the second product to emerge from the pipeline of ViiV since the company was set up as a joint venture between GlaxoSmithKline and Pfizer (latterly joined by Shionogi), and comes to market as Tivicay is just starting to build momentum as it rolls out in the US, EU and Japan.

During GSK's second-quarter results statement it was announced that Tivicay is now being used in combination with other drugs in around 11 per cent of the first-line HIV patient population, and is on course to become "one of GSK's most successful launches," according to the company.

Market research firm Datamonitor has suggested that Tivicay has advantages over other HIV integrase inhibitors such as elvitegravir, including a more attractive resistance profile, so it expects ViiV's drug to be the leading drug in the class with sales of more than $2bn at peak.

It has been suggested by other analysts that sales of the dolutegravir franchise could eventually reach more than twice that figure, despite the potential loss of patent protection for Atripla and Truvada around the end of the decade, with Triumeq accounting for the lion's share of sales.

Triumeq gives ViiV a fixed-dose combination product for HIV that contains the latest drug class and also - for the first time - does not contain Gilead's tenofovir, which has been linked to kidney damage.

Moreover, in the Phase III SINGLE trial, the three drugs used in Triumeq outperformed Atripla in terms of reducing viral loads to undetectable levels over one year's treatment, while in the SAILING study dolutegravir did better on that measure than another integrase inhibitor, Merck & Co's Isentress (raltegravir).

The new fixed-dose combination has also been recommended for approval by the Committee for Medicinal Products for Human Use (CHMP) in Europe and is under regulatory review in Canada, Australia and Brazil.

Image courtesy of Shutterstock / Sebastian Kaulitzki