Regulatory Decision Summary for Descovy

Health Canada considers the changes proposed in this Supplemental New Drug Submission (SNDS) to be acceptable with respect to safety and efficacy data submitted. The clinical data provided to support the proposed changes in the Descovy Product Monograph is from the clinical trials with Genvoya, a fixed-dose combination of elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide. This data is relevant to Descovy, which was originally approved based on two bioequivalence studies that pharmacologically bridged emtricitabine and tenofovir alafenamide exposure from Descovy tablets to their exposure from Genvoya tablets.

Descovy was initially approved for use in pediatric patients weighing at least 35 kg. In this SNDS, the indication for Descovy was expanded to include pediatric patients weighing at least 25 kg. This change is supported by Week 24 data from study GS-US-292- 0106. In this single arm, open label trial, 23 virologically suppressed human immunodeficiency virus (HIV)-infected children aged 6-12 years and weighing at least 25 kg and less than 35 kg were treated with Genvoya once daily. At Week 24, all patients remained virologically suppressed (defined as HIV-1 RNA <50 copies/mL using the US FDA snapshot algorithm). The pharmacokinetic analysis demonstrated that exposures to emtricitabine and tenofovir alafenamide (the components of Descovy) in pediatric patients were within previously established margin of safety and efficacy. Genvoya was generally well-tolerated as evidenced by the absence of serious adverse events (SAEs) and AEs leading to discontinuation of study drug. There were no clinically relevant effects on bone mineral density and renal parameters, the safety endpoints of interest for tenofovir alafenamide.

The initial approval of Descovy was supported by Week 48 safety and efficacy data from Phase 3 studies GS-US-292-0104 and GS-US-292-0111 in HIV-1-infected treatment-naïve adult patients. In both trials, patients were randomized in a 1:1 ratio to receive either Genvoya or the comparator antiretroviral regimen. In this SNDS, the Descovy Product Monograph was updated with Week 144 data from these trials. In the pooled analysis at Week 144, 84.2% of patients treated with Genvoya remained virologically suppressed (HIV-1 RNA <50 copies/mL) compared to 80% of patients in the control group. Genvoya was generally well-tolerated and there were no new safety issues at Week 144 compared to Week 48.

Based on the data submitted, the overall benefit-harm-uncertainty profile of Descovy is considered to remain favorable under the conditions of use described in the Descovy Product Monograph at this time.