HIV specialist ViiV Healthcare looks set to roll out a second potential blockbuster in 12 months after getting approval in the US for new triple combination therapy Triumeq.
Triumeq combines ViiV’s antiretroviral stalwarts lamivudine and abacavir with its brand new integrase inhibitor Tivicay (dolutegravir), which was approved in the US last August and in Europe in January.
It is is the first fixed-dose combination based on dolutegravir to be launched by ViiV and is the first single-tablet HIV regimen approved in the US that does not contain Gilead Science’s tenofovir/emtricitabine combination, which means it can be used more safely in people with impaired kidney function. Tenofovir is linked to kidney damage that can increase over time so patients on the drug should undergo routine monitoring.
ViiV is already riding high at the moment as it rolls out Tivicay in the US, Europe and Japan, which helped sales for the joint venture between GlaxoSmithKline, Pfizer and Shionogi climb 13 per cent in the second quarter to £352m ($583m) despite generic competition to older HIV drugs such as Combivir (lamivudine/zidovudine).
Datamonitor has previously forecast that dolutegravir will become the leading integrase inhibitor treatment for HIV by 2016 and reach annual sales in excess of $2.1bn by 2022, while other analysts have suggested combination tablets such as Triumeq could add another couple of billion dollars to the franchise’s tally.
At the moment the HIV fixed-dose combination market is led by Gilead’s Atripla (tenofovir, emtricitabine and efavirenz) with sales of $3.65bn last year. Gilead also has a strong follow-up in four-drug combination Stribild – which adds in integrase inhibitor elvitegravir to the Atripla cocktail and racked up $484m in the first six months of 2014, despite a hefty price tag of $28,000 a year.
Datamonitor picks dolutegravir to win the integrase inhibitor battle because it does not require co-dosing with a boosting agent and has a very attractive resistance profile.
Triumeq’s approval was based on the results of the phase III SINGLE study in treatment-naïve patients, which tested dolutegravir and abacavir/lamivudine administered as separate pills, as well as a bioequivalence study showing that the fixed-dose tablet performed equally effectively.
In SINGLE 80 per cent of subjects on the dolutegravir-based regimen were virologically suppressed compared to 72 per cent of participants on Atripla.
The FDA noted in a statement issued on the approval that Triumeq alone is not recommended in patients with integrase inhibitor resistance mutations, because the dose of dolutegravir in the fixed-dose combination is insufficient. It is also contraindicated in patients with moderate or severe liver damage.