FOCUS Phase III clinical trial of Tavalisse fails to meet statistical significance in COVID-19

The trial approached but did not meet statistical significance (p=0.0603) in the primary efficacy endpoint of the number of days on oxygen through Day 29. All prespecified secondary endpoints in the study numerically favored fostamatinib over placebo, including mortality, time to sustained recovery, change in ordinal scale assessment, and number of days in the ICU.

This multi-center, double-blind, placebo-controlled Phase III study, supported by the U.S. Department of Defense, enrolled 280 patients that were randomly assigned to either fostamatinib plus standard of care (SOC) (N=141) or matched placebo plus SOC (N=139). Treatment was administered orally twice daily for 14 days with a follow-up period to Day 60. The primary endpoint of this study was the number of days patients spent on supplemental oxygen through Day 29. Secondary endpoints were designed to assess mortality risk, patient improvement from severe disease, duration of hospitalization, and number of days in the ICU, as well as safety. There were no meaningful imbalances between treatment groups at baseline.

Key findings from the Phase III clinical data readout include the following: The mean number of days on oxygen through Day 29 in the fostamatinib treatment arm was 6.9 days compared to 9.0 days in the placebo arm (p=0.0603). By Day 29, in the overall population, there were 4 deaths in the fostamatinib group compared to 8 in the placebo group. Fostamatinib numerically reduced patient all-cause mortality by 50% (p=0.4521). The mean change from baseline in clinical status score to Day 15 using the 8-point ordinal scale was -2.4 for fostamatinib and -1.9 for placebo (p=0.0428). The median number of days to first sustained hospital discharge by Day 29 was 6 days for fostamatinib and 7 days for placebo (p=0.2371). The proportion of patients alive and oxygen free on Day 29 was 85.1% for fostamatinib and 73.4% for placebo (p=0.0653). The number of days in the ICU was 2.2 for fostamatinib and 3.3 for placebo (p=0.1883). The safety profile for fostamatinib was consistent with prior clinical experience and no new safety issues were discovered. The safety profile between fostamatinib and placebo was generally comparable.