ViiV Healthcare now has approval on both sides of the Atlantic for two-drug HIV therapy Dovato after a green light from the EMA.
Dovato – a fixed-dose combination of ViiV’s blockbuster integrase inhibitor Tivicay (dolutegravir) and the nucleoside reverse transcriptase inhibitor lamivudine – is integral to the company’s attempt to muscle out arch-rival Gilead Sciences in the market for previously-untreated HIV.
Dovato was approved in the US in April as a single-tablet, once-daily regimen for treatment-naïve HIV patients, setting up a market tussle with Gilead’s three-drug Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) product.
Biktarvy has grown quickly since its launch in the US and Europe last year, already hitting a $1bn-plus annual sales rate, and has been predicted by some analysts to be heading for peak sales of almost $4bn. Its approval has already sparked a lawsuit between the two rivals.
ViiV – a joint venture majority owned by GlaxoSmithKline with Pfizer and Shionogi as shareholders – is relying on two-drug regimens to build market share in HIV, working on the premise that two drugs are better than three. It claims the two-drug regimens can reduce drug exposure and side effects, as well as improve adherence to therapy while maintaining the same level of efficacy.
Dovato is the second two-drug combination to be introduced by the company after Juluca (dolutegravir/rilpivirine), which is approved for use in patients a second-line option for patients who have been virally suppressed on their current regimen for at least six months.
Deborah Waterhouse
“With the authorisation of Dovato, people living with HIV can for the first time start treatment on a once-daily, single-pill, two-drug regimen with the knowledge that efficacy is non-inferior to a three-drug regimen whilst containing fewer antiretrovirals,” said ViiV’s chief executive Deborah Waterhouse.
The challenge for ViiV is to convince patients and prescribers of that benefit. Juluca struggled to make much headway with sales running at around $88 million in the first quarter of this year, although it is pitching only at second-line treatment. Some analysts put the comparatively slow take-up down to lingering concerns that having only two drugs in the regimen may increase the risk of resistance.
ViiV hasn’t seen any evidence of this in 48-week trials, but GlobalData thinks adoption could start to accelerate once there is more experience with its use and real-world data on resistance and treatment failures in the longer term.
Meanwhile ViiV thinks the treatment-naïve population will be a key battleground, and with Dovato approved it now has an option to offer the approximately 25,000 new HIV patients diagnosed in Europe every year.
Having lamivudine in the formulation – a generic drug – has allowed ViiV to price Dovato at a 25% discount to Biktarvy in the US, although it’s not clear what the differential is after discounts and rebates offered to formularies.
EvaluatePharma has suggested that GSK’s two-drug regimens will eventually come to lead the market with sales of more than $5bn in 2024.