March 1 Quick Takes: Setbacks in C. diff for Pfizer, Finch

Pfizer Inc. (NYSE:PFE) said it was evaluating next steps in coordination with regulatory agencies after its Clostridioides difficile vaccine, PF-06425090, met the secondary endpoint of efficacy, but not the primary endpoint of preventing primary C. difficile infection. The Phase III CLOVER trial randomized participants to receive three doses of PF-06425090 (n=8,766) or placebo (n=8,769) at 0, 1 and 6 months. Results showed 100% vaccine efficacy for medically attended C. diff infection, a pre-specified secondary endpoint, with zero out of 17 infected people in the vaccinated group requiring medical attention compared with 11 out of 25 in the placebo group. For all C. diff infections recorded 14 days post-dose three, vaccine efficacy was 49%, 47% and 31% up to 12 months, 24 months and at final analysis, respectively. The median duration of infection was reduced by 75% in vaccinated people. 

According to BioCentury’s BCIQ database, there are at least three other vaccines in development to prevent C. diff infections: GSK2904545A from GlaxoSmithKline plc (LSE:GSK; NYSE:GSK), an unnamed candidate from Affinivax Inc., and SporeVax from SporeGen Ltd. Valneva SE (Euronext:VLA; NASDAQ:VALN) said its candidate, VLA84, is on hold after completing a Phase II trial, but could reactivate the program if it found a suitable partner...