AstraZeneca announces results from POTOMAC Phase III trial

Positive results from the POTOMAC Phase III trial showed adding one year of treatment with AstraZeneca’s (AZN) IMFINZI to BCG induction and maintenance therapy demonstrated a statistically significant and clinically meaningful improvement in disease-free survival for patients with BCG-naive, high-risk non-muscle-invasive bladder cancer BC) compared to BCG treatment alone. The results of this final analysis will be presented today during a late-breaking Proffered Paper session at the European Society for Medical Oncology Congress 2025 in Berlin, Germany and simultaneously published in The Lancet. With a median follow-up of more than five years, the IMFINZI regimen showed a 32% reduction in the risk of high-risk disease recurrence or death versus the comparator arm. Estimated median DFS was not yet reached for either arm. An estimated 87% of patients treated with the IMFINZI regimen remained alive and disease-free at two years compared to 82% in the comparator arm. The trial was not statistically powered to formally test overall survival; however, after a median follow-up of more than five years, a descriptive analysis showed an OS HR of 0.80, demonstrating that there was no detriment to OS.