Interim results of REGEN-COV prophylaxis showing 100% prevention of symptomatic infection (8/223 placebo vs. 0/186 REGEN-COV), and approximately 50% lower overall rates of infection (symptomatic and asymptomatic) (23/223 placebo vs. 10/186 REGEN-COV).
Regeneron et al., 1/26/2021, Randomized Controlled Trial, USA, North America, preprint, 1 author.
risk of symptomatic case, 93.6% lower, RR 0.06, p = 0.009, treatment 0 of 186 (0.0%), control 8 of 223 (3.6%), continuity correction due to zero event (with reciprocal of the contrasting arm).
risk of COVID-19 case, 47.9% lower, RR 0.52, p = 0.07, treatment 10 of 186 (5.4%), control 23 of 223 (10.3%).
Effect extraction follows pre-specified rules
prioritizing more serious outcomes. For an individual study the most serious
outcome may have a smaller number of events and lower statistical signficance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.