Pfizer is removing half of patients from its Lyme disease vaccine trial after a third-party clinical trial site operator was found to be violating quality standards.
Around 3,500 patients will be pulled from the Phase III study due to violations of Good Clinical Practice (GCP) rules, which refer to ethical and scientific standards for clinical trials.
It is not clear exactly which elements of GCP had been breached, but Pfizer said it was not due to any safety concerns and was not prompted by an adverse event.
The trial was looking to see how effective and safe the Lyme disease vaccine is, as well as how able it is to produce an immune response in humans.
It is not the first time Pfizer clinical trials have come under scrutiny. A BMJ investigation found that just one in 20 trial sites for its widely adopted Covid vaccine
had proper FDA oversight.