Prevention of COVID-19 Following a Single Intramuscular Administration of Adintrevimab: Results From a Phase 2/3 Randomized, Double-Blind, Placebo-Controlled Trial (EVADE)

Abstract Background The prevention of COVID-19 in vulnerable populations is a global health priority. EVADE was phase 2/3 multicenter, double-blind, randomized, placebo-controlled trial adintrevimab, an extended–half-life monoclonal antibody, for post-exposure (PEP) and pre-exposure prophylaxis (PrEP) symptomatic COVID-19. Methods Eligible participants (vaccine-naïve, aged ≥12 years) were randomized 1:1 to receive single 300-mg intramuscular injection adintrevimab or placebo. Primary efficacy endpoints reverse-transcription polymerase chain reaction (RT-PCR)-confirmed through day 28 the PEP cohort (RT-PCR-negative at baseline) month 3 PrEP seronegative among before emergence SARS-CoV-2 Omicron variant (30 November 2021). Safety assessed 6 months. Results Between 27 April 2021, 11 January 2022, 2582 randomized. In primary analysis, RT-PCR-confirmed occurred 3/175 (1.7%) vs 12/176 (6.8%) adintrevimab- placebo-treated participants, respectively (74.9% relative risk reduction [RRR]; standardized difference –5.0%; 95% CI, –8.87 –1.08; P=.0123), 12/752 (1.6%) 40/728 (5.5%) (71.0% RRR; –3.9%; –5.75 –‍2.01; P<.0001). prespecified exploratory analysis 428 after Omicron, reduced by 40.6% (standardized −8.4%; −15.35 −1.46; nominal P=.0177) Adintrevimab well tolerated with no serious drug-related adverse events reported. Conclusions A provided prophylactic against due susceptible variants without safety concerns.