Opening new battlefront with Gilead, GSK touts new Dovato non-inferiority data months after first approval
GlaxoSmithKline is giving its best shot at rivaling Gilead on its home turf with Dovato, a 2-drug HIV regimen approved in Europe just days ago following a recent FDA OK. And it’s strengthening its case with a fresh slate of Phase III data that shows the drug is just as good as triple therapies for patients already on treatment.
The takeaway from the topline results announced today is simple: When patients switch from a TAF-containing, 3-drug regimen to Dovato after at least six months, they maintain similar rates of viral suppression to others who continue the original treatment.
That was the key hypothesis they wanted to test in the TANGO study, said Kim Smith, head of global research & medical strategy at GSK’s HIV-minded subsidiary ViiV Healthcare. GSK had shown in other Phase III trials that Dovato worked as well as other standard 3-drug therapies in treatment-naive patients — the indication it was approved for. And now the Week 48 results show patients who are already virally suppressed can indeed safely reduce the number of medicines in their regimen.
But will that matter?
Credit Suisse analyst Evan Seigerman is skeptical. Drawing from a survey of 30 US-based physicians, he found a high preference for Gilead’s single-tablet regimens, even if they comprise one more drug than Dovato.
Enthusiasm for two-drug (2DR) single-tablet regiments (STRs) is modest; Gilead likely to remain the market leader: While Dovato (dolutegravir + lamivudine) has comparable efficacy and safety in a clinical trial setting, physicians generally preferred a three-drug STR like Biktarvy, as respondents demonstrated concern over disease resistance in 2DRs. Overall, we view the competitive threat from 2DRs and generics as limited, since neither address treatment selection priorities as comprehensively as Biktarvy.
Biktarvy, which racked up $1.184 billion in sales in its first 11 months, consists of bictegravir, emtricitabine, and tenofovir alafenamide. The former is an integrase inhibitor, which works against HIV’s integrase protein, blocking its ability to integrate its genetic code into human cells. The latter two are nucleoside analog reverse transcriptase inhibitors, or nukes, which thwart the viruses’ efforts to replicate themselves in cells.
GSK has historically had issues with its nukes, Umer Raffat of Evercore ISI noted. Specifically, abacavir has been linked to CV and hypersensitivity issues, dragging down demand for another combo containing both dolutegravir and abacavir.
With Dovato and its other 2-drug regimen, Juluca, GSK is looking to shake off that issue by combining the integrase inhibitor dolutegravir with new nukes — lamivudine and rilpivirine — all under the premise that 2, rather than 3 or more, is the magic number in keeping HIV in check.