Bemarituzumab is an advancement in targeted cancer therapy, offering a new treatment approach for specific types of gastric cancer. This therapy addresses an unmet medical need for patients with advanced forms of this aggressive disease. The United States Food and Drug Administration (FDA) has granted it a designation to expedite its development and review process.
Understanding Bemarituzumab
Bemarituzumab is a humanized monoclonal antibody designed to target Fibroblast Growth Factor Receptor 2b (FGFR2b). This protein is found on certain cancer cells and plays a role in their growth and survival. By binding to FGFR2b, bemarituzumab blocks signals that promote tumor growth and enhances the body’s immune response against cancer cells.
The drug works through a dual mechanism. It inhibits FGFR2b signaling by preventing fibroblast growth factors (FGFs) from binding to the receptor, disrupting pathways that drive tumor proliferation. It also enhances antibody-dependent cell-mediated cytotoxicity (ADCC), recruiting immune cells to destroy FGFR2b-overexpressing tumor cells. This approach attacks cancer cells while minimizing harm to healthy cells.
Details of FDA Approval
The FDA granted bemarituzumab Breakthrough Therapy Designation for the first-line treatment of patients with HER2-negative, FGFR2b-overexpressing metastatic and locally advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. This designation, granted in April 2021, is for therapies showing substantial improvement over available treatments for serious conditions. Approval is contingent on an FDA-approved companion diagnostic assay confirming at least 10% of tumor cells overexpress FGFR2b.
The basis for this designation comes from positive results observed in the Phase 2 FIGHT trial (NCT03694522). In this study, bemarituzumab was evaluated in combination with modified FOLFOX6 chemotherapy (a regimen of fluoropyrimidine, leucovorin, and oxaliplatin) compared to chemotherapy alone. The trial demonstrated improvements in progression-free survival and overall survival in the patient population with FGFR2b overexpression.
Implications for Gastric Cancer Treatment
The introduction of bemarituzumab represents a significant step forward for patients battling advanced gastric or GEJ adenocarcinoma, particularly those with FGFR2b overexpression. This targeted therapy addresses a specific molecular alteration, offering a new avenue for treatment where options have historically been limited. Approximately 30-38% of patients with advanced gastric and GEJ cancers exhibit FGFR2b overexpression.
This new treatment has the potential to become the first targeted therapy specifically for FGFR2b-overexpressing gastric cancer. By focusing on a distinct subset of patients, bemarituzumab aligns with the growing field of precision medicine, tailoring treatments to the unique molecular profile of a patient’s tumor. This approach can lead to more effective outcomes and potentially improved quality of life for patients.