Pfizer seemed to have a good win over this past weekend because it presented positive results from its phase 3 CREST study, which used anti-PD-1 monoclonal antibody (mAb) sasanlimab in combination with current standard of care (SOC) Bacillus Calmette-Guerin (BCG) for the treatment of patients with BCG-naive, high-risk non-muscle invasive bladder cancer (NMIBC).
Such data from this phase 3 study was presented as a plenary oral presentation at the 2025 American Urological Association (AUA) Annual Meeting. The primary endpoint was the evaluation of something known as Event-Free Survival (EFS). This primary endpoint was met with statistical significance with a p-value of p=0.019.
To put it quite simply, patients who took sasanlimab in combination with BCG achieved a statistically significant improvement compared to that of BCG. The ultimate finding for this CREST trial was that there was a 32% reduction in risk of disease-related events. Such events are broken down into the components of reduced high-grade disease recurrence or progression of disease.
The premise here is not just that the data is extremely good for Pfizer in that it could eventually obtain marketing approval of sasanlimab as a subcutaneously injected anti-PD-1 mAb for the treatment of these high-risk NMIBC patients. Speaking of which, it is already one step ahead of the game here since it has already submitted results to several global health authorities around the globe.
The importance of this is generating a new SOC option that could benefit these patients in more than three decades. The nature of high-risk disease for these bladder cancer patients is recurrent disease or one that just progresses continuously. As Pfizer noted in its press release, “Up to 50% of patients with high-risk non-muscle invasive bladder cancer may experience failure of BCG intravesical immunotherapy, yet it has been the standard of care after tumor resection for decades.”
Thus, the opportunity here for Pfizer is that it could potentially establish a new treatment option for high-risk BCG-naive NMIBC patients in over three decades. The major downside though, is that an interim analysis performed with a 40.9 month average follow-up period revealed no difference between that of sasanlimab compared to BCG in terms of overall survival (OS).
Regardless, this secondary endpoint of OS is going to be followed until final analysis. What’s intriguing is that this is only the beginning of the potential of sasanlimab in the targeting of patients with bladder cancer and other solid tumors. I state this in that Pfizer is also evaluating this anti-PD-1 therapy in several ongoing clinical studies with its antibody drug conjugate (ADC) portfolio.
It remains to be seen what can be achieved with such combinations of sasanlimab with its ADC therapies, but what has transpired here is nothing short of amazing news for BCG-naive high-risk NMIBC patients who needed something new to prevent disease recurrence or progression for quite some time.
