The US FDA approved Gilead Sciences’ triple-drug Biktarvy product for HIV this week, but the company’s celebrations were swiftly undermined by a legal challenge from GlaxoSmithKline.
GSK’s ViiV Healthcare unit has filed a lawsuit against Gilead claiming that its integrase inhibitor bictegravir – which is one of the active ingredients of Biktarvy along with emtricitabine and tenofovir alafenamide (TAF) – infringes its patent estate.
The lawsuit has been submitted in the US and Canada and is seeking to prove that bictegravir infringes on intellectual property held by ViiV for its rival integrase inhibitor Tivicay (dolutegravir), which was first approved in the US in 2013 and is a key component of ViiV’s latest HIV product launches including three-drug combo Triumeq and recently-approved Juluca.
ViiV says Biktarvy infringes its US and Canadian patents covering “dolutegravir and many other compounds that include dolutegravir’s unique chemical scaffold”.
GSK has indicated that it is seeking financial redress for the infringement but is not seeking to have Biktarvy barred from the market, with analysts suggesting the play is likely aimed at securing a royalty on sales of Gilead’s drug. Given that Biktarvy has been predicted to make blockbuster sales – and possibly as much as $4bn-$5bn a year at peak – that might not be an insignificant revenue stream for ViiV.
Biktarvy’s approval is a clear threat to ViiV and parent GSK, which is relying on Tivicay, Triumeq and Juluca to perform well – along with other new products such as shingles vaccine Shingrix and recently-approved triple therapy for chronic obstructive pulmonary disorder (COPD) Trelegy – as it faces the imminent threat of generic competition to its big-selling respiratory drug Advair (salmeterol and fluticasone propionate) in the US.
GSK reported its fourth-quarter results yesterday, and chief executive Emma Walmsley said the company “could see a potential generic version of Advair in the US” before the end of the year, having already lost ground to generics in most other areas of the world.
The company has posted cautious guidance for the current year as a result but ended 2017 on a high with revenues of £30.2bn, up 8% and slightly ahead of analyst forecasts. Tivicay and Triumeq posted strong growth to reach £1.4bn and £2.5bn respectively in 2017, while Juluca added another £5m after its approval late in the fourth quarter.
Shingrix was approved in the US in October and got off to a reasonable start, posting sales of £22m in the last three months, while Trelegy – which only started a detailing drive in mid-November – contributed £2m before the close of the year.