Pfizer’s Sasanlimab Shows Promise in Bladder Cancer

The CREST trial is a Phase III multinational, randomized, open-label, three parallel-arm study of sasanlimab, an anti-PD-1 mAb, in combination with BCG (BCG induction with or without BCG maintenance) versus BCG (induction and maintenance) in participants with BCG-naïve, high-risk NMIBC. Patients were randomized to receive sasanlimab 300 mg by subcutaneous (SC) injection every four weeks up to cycle 25 (cycle = four weeks), in combination with BCG once weekly for six consecutive weeks (induction period) followed (Arm A) or not (Arm B) by maintenance with BCG, or BCG induction and maintenance up to cycle 25 (Arm C). The primary endpoint is EFS as assessed by the investigator, between Arm A and C, defined as the time from randomization to the earliest of recurrence of high-grade disease, progression of disease, persistence of CIS, or death. Key secondary endpoints include EFS as assessed by the investigator between Arm B and Arm C.

The study met its primary endpoint of event-free survival (EFS) by investigator assessment, demonstrating a clinically meaningful and statistically significant improvement with sasanlimab in combination with BCG (induction and maintenance) as compared to BCG alone (induction and maintenance). The overall safety profile of sasanlimab in combination with BCG was generally consistent with the known profile of BCG and data reported from clinical trials with sasanlimab. The profile of sasanlimab was also generally consistent with the reported safety profile of PD-1 inhibitors.

Results will be submitted for presentation at an upcoming medical congress. Pfizer plans to discuss these data with global health authorities to support potential regulatory filings. Sasanlimab also continues to be investigated in combination with Pfizer’s antibody drug conjugate (ADC) portfolio in advanced solid tumors.

Sasanlimab is a humanized immunoglobulin G4 mAb that binds to human programmed death-1 (PD-1) to block its interaction with PD-1 and PD-L1/PD-L2. PD-1 is a protein expressed on T cells, dendritic cells, natural killer cells, macrophages, and B cells, that functions as an immune checkpoint that negatively regulates T-cell activation and effector function when activated by its ligands and may play an important role in tumor evasion from host immunity. It can be administered once every four weeks by subcutaneous injection by prefilled syringe (2mL).

"Patients with BCG-naïve high-risk non-muscle invasive bladder cancer have high rates of recurrence and progression,” said Dr. Neal Shore, Medical Director for the Carolina Urologic Research Center, and lead investigator for the CREST trial. “These study results demonstrate the potential for sasanlimab in combination with BCG to redefine the treatment paradigm for patients living with BCG-naïve, high-risk non-muscle invasive bladder cancer, including patients with carcinoma in-situ (CIS), providing prolonged event-free survival which may delay or reduce the need for more aggressive treatment options. Administered subcutaneously every four weeks, sasanlimab, if approved, could also help lower the treatment burden on both patients and healthcare systems.”

“The initial therapy of high-risk, non-muscle invasive bladder cancer with BCG has not advanced in decades. The pivotal Phase III CREST results are potentially practice-changing, representing the first advance in therapy for BCG-naïve, high-risk, non-muscle invasive cancer in over 30 years,” said Dr. Roger Dansey, Chief Oncology Officer, Pfizer. “These results reinforce Pfizer’s leadership in genitourinary cancer research and development, demonstrating our ongoing commitment to deliver new treatment options for patients with bladder cancer.”