US-based biopharmaceutical firm Gilead Sciences has reported positive results from four Phase III clinical trials investigating the combination of bictegravir (BIC), emtricitabine (FTC) and tenofovir alafenamide (TAF) to treat patients with HIV-1.
Bictegravir is currently being developed as an investigational inhibitor of integrase strand transfer.
The results showed that 50mg of BIC combined with 200mg of FTC and 25mg of TAF met the primary objective of non-inferiority.
The double-blind Phase III 1489 and 1490 trials assessed the efficacy and safety of the combination therapy in treatment-naïve patients, while the 1844 trial evaluated it in virologically suppressed patients who switched from an existing anti-retroviral regimen.
All three trials compared BIC/FTC/TAF to 50mg dolutegravir regimens.
The fourth 1878 trial compared BIC/FTC/TAF to a regimen of two nucleoside / nucleotide reverse transcriptase inhibitors, ABC/3TC or emtricitabine (200mg) / tenofovir disoproxil fumarate (300mg), combined with a boosted protease inhibitor of darunavir (800mg) / atazanavir (300mg), in virologically suppressed patients.
Gilead Sciences research and development executive vice-president and chief scientific officer Norbert Bischofberger said: “Based on the results from these Phase III studies, the combination of bictegravir and FTC / TAF could represent an important advance in triple-therapy treatment for a broad range of HIV patients, and we look forward to submitting regulatory applications in the US and EU this year.”
The primary endpoint of the 1489 and 1490 trials is the proportion of patients with HIV-1 RNA levels less than 50 copies per millilitre (mL) at week 48, while the main endpoint of the 1844 and 1878 trials is the proportion of patients with HIV RNA greater than or equal to 50 copies/mL at week 48.