ILiAD says homer hit in whooping cough vaccine challenge trial, in per-protocol population

ILiAD Biotechnologies says it hit a homer in a whooping cough vaccine challenge trial. The biotech linked its nasal vaccine to protection against colonization by the pathogen, causing the phase 2b study to meet its primary endpoint in the per-protocol population.  

Florida-based ILiAD worked with universities in the U.K. to assess the effect of exposing recipients of its live attenuated intranasal vaccine candidate, BPZE1, to the Bordetella pertussis bacterium that causes whooping cough. Investigators gave 53 healthy adults BPZE1 or placebo. Two to four months later, 46 of the participants were inoculated with B. pertussis.

ILiAD linked vaccination to protection from colonization by the bacterium in the per-protocol adequate challenge inoculum group. The biotech focused on the per-protocol group, rather than the more robust intention-to-treat analysis, because of an inoculation problem that affected some people.  

“Early in study enrollment a small group of participants were identified to have received a lower dose of wild-type B. pertussis challenge than was originally specified in the protocol,” ILiAD wrote in a statement. The researchers then changed the preparation method to ensure adequate inoculum. In the entire study population, “the primary endpoint showed a comparable trend of BPZE1 prevention of colonization.”

ILiAD is yet to share numbers from the trial beyond the 0.03 p-value for the per-protocol analysis, limiting the conclusions that the public can draw from the study before more data are shared at the World Vaccine Congress next month. The exclusion of patients from the analysis that achieved statistical significance leaves questions hanging over the results, but ILiAD now has its eyes on a planned phase 3 trial.

“These results represent a major milestone in global public health efforts to control Bordetella pertussis, a pathogen that harms tens of millions of people each year,” ILiAD CEO Keith Rubin, M.D., said in a statement. “We still have a lot of work to do, but this is far and away the best evidence to date that we can fulfill our mission to eradicate all disease due to B. pertussis.” 

Children are vaccinated against whooping cough through multi-pathogen shots, but pertussis continues to cause thousands of cases a year. The number of U.S. cases hit 18,617 in 2019 before dropping as people interacted less face to face in the pandemic, and waning vaccine immunity is a concern. While breakthrough cases in vaccinated people are milder, ILiAD sees a need for more effective protection.