The independent Data Safety Monitoring Board flagged an overall-survival imbalance after cancer patients received an aggressive hyper-dosing regimen of up to 15 IV mRNA doses.
BioNTech has abruptly terminated a Phase 2 trial of its experimental personalized mRNA cancer “vaccine” after an independent safety board identified an alarming imbalance in overall survival between the treatment groups.
The trial, known as BNT122-01 (NCT04486378), enrolled approximately 327 patients with surgically resected high-risk Stage II or Stage III colorectal cancer who remained positive for circulating tumor DNA. Participants were randomized to receive BioNTech’s individualized mRNA cancer immunotherapy, autogene cevumeran (BNT122/RO7198457), or watchful waiting.
Patients in the mRNA arm underwent an aggressive hyper-dosing regimen of up to 15 intravenous infusions over roughly one year—six weekly doses across the first six treatment weeks, two more at two-week intervals over the following month, followed by seven additional doses every six weeks for the remainder of the year.
The independent Data Safety Monitoring Board has now reported a “numerical imbalance in overall survival between treatment arms” and concluded that continuing the study was unlikely to change its efficacy outcome. It recommended that treatment be stopped and the entire clinical trial terminated. BioNTech surprisingly accepted the recommendation.
In lay terms, overall survival measures how long patients remain alive after entering the trial. An imbalance therefore represents a mortality signal between the groups. BioNTech has not yet disclosed the number of deaths in each arm, the mortality rates, hazard ratio, causes of death, or which treatment group experienced poorer survival.