Pfizer Inc. announced results from the CLOVER trial (CLOstridium difficile Vaccine Efficacy TRial), a pivotal phase 3 study evaluating its Clostridioides difficile (C. difficile) vaccine candidate (PF-06425090) in the prevention of C. difficile infection (CDI). Initial analyses of two protocol defined secondary endpoints indicated a highly favourable benefit in reducing CDI severity and 100% vaccine efficacy in preventing medically attended CDI, although the trial did not meet its pre-specified primary endpoint of prevention of primary CDI. Safety reviews indicated that the investigational vaccine was safe and well tolerated.
