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- Pfizer Inc (NYSE:PFE) announced data from the CLOVER Phase 3 trial evaluating Clostridioides difficile vaccine candidate to prevent C. difficile infection (CDI).
- Initial analyses of two secondary endpoints indicated a highly favorable benefit in reducing CDI severity and 100% vaccine efficacy in preventing medically attended CDI.
- However, 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.
- Vaccine efficacy under the primary endpoint was 31% following the third dose and 28.6% following the second dose for the C. difficile vaccine candidate.
- For all CDI cases recorded 14 days post dose 3, vaccine efficacy 49%, 47%, and 31% up to 12 months, 24 months, and at the final analysis, respectively.
- Pfizer noted a highly favorable potential benefit in reducing the duration and severity of the disease.
- None of the participants with CDI in the vaccine group required medical attention (including hospitalization) compared to 11 in the placebo group.
- Price Action: PFE shares are down 1.36% at $46.30 during the market session on the last check Tuesday.