Table 2.
Primary efficacy endpoints and supportive analyses, and secondary efficacy endpoints
| Population | Tixagevimab–cilgavimab | Placebo | RR reduction (95% CI) | p value | |
|---|---|---|---|---|---|
| Primary efficacy endpoints and supportive estimands | |||||
| Primary endpoint: severe COVID-19 or death from any cause through to day 29 | Modified full analysis set* | 18/407 (4%) | 37/415 (9%) | 50·5% (14·6–71·3) | 0·0096 |
| First supportive estimand: severe COVID-19 or death from any cause through to day 29 | Non-hospitalised participants who received study drug ≤5 days from symptom onset (early intervention analysis set) | 9/253 (4%) | 27/251 (11%) | 66·9% (31·1–84·1) | 0·0017 |
| Second supportive estimand: severe COVID-19 or death from any cause from day 4 through to day 29 | Modified full analysis set* | 12/407 (3%) | 33/415 (8%) | 63·0% (29·4–80·6) | 0·0015 |
| Third supportive estimand: severe COVID-19 or death from any cause through to day 29 | Full analysis set† | 24/446 (5%) | 41/444 (9%) | 41·6% (5·0–64·1) | 0·028 |
| Fourth supportive estimand: severe COVID-19 or death from any cause through to day 29 | Non-hospitalised participants, who were seronegative at baseline and received study drug ≤7 days from symptom onset (seronegative analysis set) | 14/347 (4%) | 36/345 (10%) | 61·3% (29·7–78·7) | 0·0011 |
| Secondary and exploratory endpoints | |||||
| Secondary endpoint: prevention of respiratory failure | Modified full analysis set | 3/405 (1%) | 11/412 (3%) | 71·9% (0·3–92·1) | 0·036 |
| Exploratory: hospitalisation for COVID-19 including complications through to day 29 | Modified full analysis set | 17/413 (4%) | 40/421 (10%) | .. | .. |
Data are n/N (%). RR=relative risk. Results from a Cochran-Mantel-Haenszel test stratified by time from symptom onset (≤5 days vs >5 days) and risk of progression to severe COVID-19 (high risk vs low risk). RR reduction represents the percentage reduction in incidence of severe COVID-19 or death from any cause in the tixagevimab–cilgavimab group relative to the placebo group. A RR reduction >0 represents favourable efficacy in the tixagevimab–cilgavimab group. For the primary outcome and supportive estimands, p<0·05 indicates a statistically significant result; missing response data were not imputed. For the secondary outcome, p<0·05 indicates a nominally statistically significant result, as this analysis was not included in the multiple testing hierarchy.
Six patients from each group had missing data and were not included in this analysis.
Six patients in the tixagevimab–cilgavimab group and seven patients in the placebo group had missing data and were not included in this analysis.