Table 2.
SARS-CoV-2 infection by study period
| CAS + IMD 1200 mg (n=841) | Placebo (n=842) | ||
|---|---|---|---|
| Symptomatic SARS-CoV-2 infections (COVID-19) | |||
| Month 1 (28-day EAP) | .. | .. | |
| Participants | 13 (1·5%) | 70 (8·3%) | |
| Relative risk reduction | 81·4% | .. | |
| Odds ratio (95% CI)* | 0·17 (0·09–0·31) | .. | |
| Nominal p value* | <0·0001 | .. | |
| Follow-up (months 2 to 5)† | .. | .. | |
| Participants | 0 | 32 (3·8%) | |
| Relative risk reduction | 100% | .. | |
| Odds ratio (95% CI) | 0·00 (0·00–0·09)‡ | .. | |
| Nominal p value | <0·0001‡ | .. | |
| Follow-up (months 6 to 8)† | .. | .. | |
| Participants | 8 (1·0%) | 10 (1·2%) | |
| Relative risk reduction | 19·9% | .. | |
| Odds ratio (95% CI)* | 0·80 (0·31–2·04) | .. | |
| Nominal p value* | 0·64 | .. | |
| Follow-up (months 2 to 8) | .. | .. | |
| Participants | 8 (1·0%) | 42 (5·0%) | |
| Relative risk reduction | 80·9% | .. | |
| Odds ratio (95% CI)* | 0·18 (0·09–0·39) | .. | |
| Nominal p value* | <0·0001 | .. | |
| Entire study (months 1 to 8) | .. | .. | |
| Participants | 21 (2·5%) | 112 (13·3%) | |
| Relative risk reduction | 81·2% | .. | |
| Odds ratio (95% CI)* | 0·17 (0·10–0·27) | .. | |
| Nominal p value* | <0·0001 | .. | |
| RT-PCR-confirmed SARS-CoV-2 infections (symptomatic or asymptomatic) | |||
| Month 1 (28-day EAP) | .. | .. | |
| Participants | 42 (5·0%) | 122 (14·5%) | |
| Relative risk reduction | 65·5% | .. | |
| Odds ratio (95% CI)* | 0·31 (0·22–0·45) | .. | |
| Nominal p value* | <0·0001 | .. | |
| Follow-up (months 2 to 5)† | .. | .. | |
| Participants | 4 (0·5%) | 38 (4·5%) | |
| Relative risk reduction | 89·5% | .. | |
| Odds ratio (95% CI)* | 0·10 (0·04–0·29) | .. | |
| Nominal p value* | <0·0001 | .. | |
| Follow-up (months 6 to 8)† | .. | .. | |
| Participants | 9 (1·1%) | 13 (1·5%) | |
| Relative risk reduction | 30·7% | .. | |
| Odds ratio (95% CI)* | 0·69 (0·29–1·63) | .. | |
| Nominal p value* | 0·40 | .. | |
| Follow-up (months 2 to 8) | .. | .. | |
| Participants | 13 (1·5%) | 51 (6·1%) | |
| Relative risk reduction | 74·5% | .. | |
| Odds ratio (95% CI)* | 0·24 (0·13–0·45) | .. | |
| Nominal p value* | <0·0001 | .. | |
| Entire study (months 1 to 8) | .. | .. | |
| Participants | 55 (6·5%) | 173 (20·5%) | |
| Relative risk reduction | 68·2% | .. | |
| Odds ratio (95% CI)* | 0·27 (0·20–0·37) | .. | |
| Nominal p value* | <0·0001 | .. | |
Data are n (%) unless otherwise specified. Population includes participants who were seronegative and RT-PCR-negative for SARS-CoV-2 at baseline, excluding participants from the initial descriptive assessment. SARS-CoV-2 infection was confirmed by central or local SARS-CoV-2 RT-PCR. CAS + IMD=casirivimab and imdevimab. EAP=efficacy assessment period.
*
Based on a logistic regression model adjusted by region (USA vs not USA) and age group (12 to <50 years vs ≥50 years).
†
Post-hoc analysis.
‡
Unadjusted odds ratio and the exact 95% CI are reported due to sparse events; p value is based on the Fisher's exact test.