Sasanlimab is an investigational therapeutic developed by Pfizer. It is currently under evaluation for treating various forms of cancer. Its purpose is to address specific biological pathways that contribute to cancer progression, offering a targeted strategy for intervention.
What Sasanlimab Is
Sasanlimab is classified as a humanized immunoglobulin G4 (IgG4) monoclonal antibody. As a biologic, it is engineered to target a particular molecule in the body. It functions as an anti-programmed cell death protein 1 (PD-1) antibody, placing it within the category of immunotherapies known as checkpoint inhibitors. Sasanlimab is administered through a subcutaneous injection, typically once every four weeks.
Conditions Treated by Sasanlimab
Sasanlimab is being investigated for several cancer types, with a particular focus on urothelial carcinoma, including non-muscle invasive bladder cancer (NMIBC). High-risk NMIBC, especially in patients who have not previously received Bacillus Calmette-Guérin (BCG) therapy, represents an area of significant unmet medical need. The drug is also undergoing evaluation for other solid tumors, such as sarcoma, metastatic melanoma, head and neck squamous cell carcinoma, non-small cell lung cancer (NSCLC), and ovarian cancer.
How Sasanlimab Functions
Sasanlimab’s mechanism of action involves targeting the PD-1 pathway, a key immune checkpoint. The PD-1 protein is found on the surface of various immune cells, including T cells. When PD-1 binds to its ligands, PD-L1 and PD-L2, it delivers an inhibitory signal that can suppress T-cell activation and effector functions, allowing cancer cells to evade immune surveillance.
By binding to PD-1, Sasanlimab blocks this interaction with PD-L1 and PD-L2. This blockade is intended to release the “brakes” on the immune system, thereby promoting the activation of T cells. Activated T cells can then more effectively recognize and eliminate cancer cells.
Sasanlimab’s Journey Through Clinical Trials
Sasanlimab is currently undergoing various stages of clinical development. It is in Phase 3 clinical trials for non-muscle invasive bladder cancer (NMIBC), specifically in combination with Bacillus Calmette-Guérin (BCG) for patients with high-risk, BCG-naïve disease. This late-stage trial, known as CREST, is a multinational, randomized study evaluating the drug’s efficacy and safety.
Beyond NMIBC, Sasanlimab is also in earlier phases of development for other conditions. It is in Phase 1 combination studies for advanced solid tumors and Phase 1b/2 combination studies for non-small cell lung cancer. Pfizer is leading the development of Sasanlimab, exploring its potential as a standalone treatment and in combination with other anti-cancer therapies, including Pfizer’s antibody-drug conjugate (ADC) portfolio.
Trial Outcomes and Safety Information
Recent clinical trial results for Sasanlimab have shown promising outcomes, particularly in the pivotal Phase 3 CREST trial for high-risk, BCG-naïve non-muscle invasive bladder cancer. This trial met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in event-free survival (EFS) when Sasanlimab was combined with BCG. The combination regimen resulted in a 32% reduction in the risk of disease-related events, such as high-grade disease recurrence or progression, compared to BCG alone. At 36 months, the probability of being event-free was 82.1% with the Sasanlimab combination, versus 74.8% with BCG alone.
While specific detailed safety profiles from all trials are still emerging, early-stage clinical studies have indicated that Sasanlimab, administered at 300 mg subcutaneously every four weeks, showed clinical efficacy in advanced solid tumors and advanced urothelial cancer. The balance between the benefits of improved event-free survival and potential risks is continuously evaluated throughout the clinical development process. The subcutaneous administration method is being explored to potentially reduce treatment burden for patients and healthcare systems.