Clash of the Titans: ViiV/GSK shares data from head-to-head trial of every-2-month injectable vs Gilead’s once-daily oral for PLWHIV
On Wednesday Feb 22, ViiV/GSK presented the first dataset from its Phase 3b SOLAR trial, an open-label non-inferiority study which compared the virologic outcomes of PLWHIV who switched from Gilead’s Biktarvy (oral once-daily) to Cabenuva (ViiV/GSK’s every-two-month injectable). At 12-months follow-up, Cabenuva demonstrated noninferior efficacy, with 90% of PLWHIV maintaining virological suppression following the switch, compared to 93% of patients who remained on Biktarvy.
With this data, ViiV/GSK has increased its body of evidence that Cabenuva is a suitable complete drug regimen for the treatment of HIV, and provides patients with a more convenient regimen, due to its less frequent dosing interval compared to oral alternatives. The keen-eyed amongst us may however note that in SOLAR, two patients had confirmed virologic failures with Cabenuva compared to zero in the Biktarvy arm. Whilst SOLAR may sway some individuals to Cabenuva due to the benefits of a wider dosing interval, the incidence of virologic failures may dissuade others, especially considering Gilead has recently shared 5y long term follow up data for Biktarvy from its own pivotal trials and reports Biktarvy to provide robust efficacy having seen zero cases of resistance to Biktarvy in its original trial cohort.
Admittedly, ViiV/GSK has acknowledged it expects approximately 70% of PLWHIV in the US to remain on their once-daily oral regimen, because so many patients are satisfied with their oral medication. Patient preference will likely boil down to compliance for once-daily orals or acceptability for intramuscular injectable therapies. Once-weekly orals are in development by companies including Merck, Gilead, and ViiV/GSK and may provide patients with a happy medium or reduced pill burden and non-invasive long-acting treatments option.