Pfizer Releases Positive Top Line Results from C. Difficile Trial

On Jan. 26, 2017, Pfizer released the results from Phase II clinical trials with its Clostridium difficile (C. difficile) vaccine candidate, PF-06425090. Based on the results from the Phase II trial, the company said PF-06425090 will be advancing to Phase III trials in the first half of 2017. The vaccine was granted FDA Fast Track designation in August 2014.

The randomized Phase II study examined the safety, tolerability, and immunogenicity of the vaccine in more than 850 healthy adults 65–85 years of age. The vaccine is designed to help prevent C. difficile infection by inducing a functional antibody response capable to neutralizing the two main disease-causing toxins produced by the infection. The Phase II study, evaluated the safety, tolerability, and immunogenicity of two dose levels (100 µg and 200 µg) of the C. difficile vaccine candidate on two different three-dose vaccination schedules.

“Despite improved infection control measures, C. difficile disease continues to rise, further augmenting an already urgent public health threat with particular negative impact on older adults,” said Kathrin Jansen, PhD, senior vice-president and head of Vaccine Research and Development for Pfizer in a statement. “We are very encouraged by these interim immunogenicity and safety results demonstrating robust increases in vaccine-elicited neutralizing antibodies to both toxins, that we believe could provide protection against C. difficile disease.”