After more than a decade’s worth of work, GlaxoSmithKline $GSK researchers today are unveiling pooled data from their two late-stage trials of a two-drug regimen for keeping HIV in check. Facing off against some deep-seated skepticism and a powerhouse rival at Gilead $GILD, the pharma giant’s majority owned subsidiary ViiV says the combo performed just as well as a triplet in their big faceoff involving treatment-naive patients, making it a likely new entry in the global fight against the virus that spurs AIDS.
“Therapy has gotten better, people are living longer,” says ViiV CSO John Pottage. “Then you have to think about treating people for their lifetime, decades of therapy.”
The simpler, the better.
The two drugs ViiV put together in its big Gemini Phase III program are dolutegravir and lamivudine (3TC). The pooled data demonstrated a 91% control rate, with the bulk of the patients under the rate of HIV-1 RNA<50 copies/mL compared with 93% in a three-drug arm featuring dolutegravir and two nucleoside reverse transcriptase inhibitors: tenofovir disoproxil fumarate/emtricitabine.
Pottage also says that the data hold up when you pull out the patients with high viral loads.
This is one-year data, meaning that researchers will continue to watch on durability, a key feature for any new treatment in this field, where patients are monitored to see if their treatment regimen is losing effect and requires a shift to keep the virus at bay.
“It used to be month-to-month,” Pottage says to me about the drug changeover rate. “Here they last for years.”
In that scenario, the fewer drugs you use, the less likely you’ll run into problems, including fewer drug-drug interactions as these patients get older and face multiple co-morbidities. It’s an edge, and an edge can amount to a major market niche in HIV.
If the data hold up under regulatory scrutiny at the FDA, the EMA and indeed around the world, GSK will quite likely have a new product in this blockbuster arena. Regulators and physicians love alternative drug options to put on their list of go-to therapies for chronic diseases. But just getting an OK likely won’t dampen the skepticism some analysts have offered about GSK as the UK pharma giant battles a dominant Gilead on what amounts to be their home turf.
One of the most skeptical watching the battle of the HIV giants is Leerink’s Geoffrey Porges, who recently ticked off a lineup of hurdles GSK will likely find difficulty clearing. GSK already fell behind Gilead’s latest 3-drug combination Biktarvy with their other two-drug combo Juluca, using dolutegravir and rilpivirine. That, he said, was clearly inferior.
Gilead looks to remain the dominant player, he adds, noting:
Though we believe physicians will be more willing to prescribe a two-drug HIV regimen that includes 3TC instead of rilpivirine, all of the HIV prescription trends and our proprietary survey work suggest that GSK’s two-drug regimens will not undermine Gilead’s increasing HIV market share trend over the next 3 years, and we do not anticipate any value erosion in Gilead’s stock from these disclosures or even the approval of this second 2 drug combination from ViiV.
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