Pfizer's sasanlimab enhances event-free survival in phase 3 bladder cancer study

Pfizer has unveiled promising results from a phase 3 clinical study focusing on sasanlimab, an investigational anti-PD-1 monoclonal antibody, in treating a particular group of bladder cancer patients. This pivotal study, known as the CREST trial, primarily evaluated the efficacy of sasanlimab combined with Bacillus Calmette-Guérin (BCG) compared to BCG treatment alone. The study targeted patients with high-risk non-muscle invasive bladder cancer (NMIBC) who had not previously received BCG treatment.

Key findings from the CREST trial revealed that the sasanlimab and BCG combination reduced the risk of disease-related events by 32%. These events include high-grade disease recurrence or progression. Furthermore, the likelihood of remaining event-free at 36 months was significantly higher for patients receiving the sasanlimab combination, with a probability of 82.1% compared to 74.8% for those treated with BCG alone. However, it was also noted that using sasanlimab with BCG only during the induction phase did not enhance event-free survival when compared to BCG used in both induction and maintenance phases. This outcome highlights the importance of BCG maintenance in treatment regimens for high-risk NMIBC.

Bladder cancer ranks as the ninth most prevalent cancer worldwide, with NMIBC accounting for approximately 75% of cases. In NMIBC, cancerous cells are restricted to the bladder's inner lining. Despite BCG being a standard treatment, up to 50% of patients with high-risk NMIBC experience a recurrence, often necessitating a radical cystectomy, a procedure fraught with significant risks.

Megan O’Meara, interim chief development officer at Pfizer Oncology, emphasized the significance of the CREST trial results, describing them as a "therapeutic breakthrough." She underscored that sasanlimab represents the first immunotherapy combined with BCG to notably improve patient outcomes for those with BCG-naïve, high-risk NMIBC in over thirty years. The findings have been presented to global health authorities to support potential regulatory filings.

O'Meara expressed excitement about the possibility of collaborating with global regulatory bodies to introduce sasanlimab as a vital new treatment option for high-risk NMIBC patients. This development is particularly noteworthy following Pfizer's recent approval by the UK Medicines and Healthcare products Regulatory Agency (MHRA) for Hympavzi (marstacimab), a treatment for haemophilia A or B in both adult and pediatric patients.

In conclusion, the CREST trial's positive results mark a promising advancement in bladder cancer treatment, highlighting sasanlimab's potential to significantly improve outcomes for patients facing high-risk NMIBC. As Pfizer continues discussions with regulatory authorities, there is hope that sasanlimab will soon become an integral part of bladder cancer therapy, offering new hope to patients worldwide.