Moderna, Inc. announced on April 20, 2026, that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its mRNA-4359 program. This investigational messenger RNA cancer vaccine is being developed for the treatment of patients with unresectable or metastatic cutaneous melanoma, specifically when used in combination with the immune checkpoint inhibitor pembrolizumab. The designation is intended to facilitate the development and expedite the review of drugs that treat serious conditions and address unmet medical needs.
The FDA decision is based on clinical data from the ongoing Phase 1/2 Intervallum study. This clinical trial evaluates the safety, tolerability, and initial efficacy of mRNA-4359 both as a monotherapy and in combination with pembrolizumab. Preliminary data shared by the company indicated that the combination therapy demonstrated signs of immune activation and clinical benefit in patients who had previously undergone standard treatments. mRNA-4359 is an off-the-shelf vaccine designed to stimulate the immune system to target and eliminate cancer cells by focusing on specific proteins, such as indoleamine 2,3-dioxygenase (IDO) and programmed death-ligand 1 (PD-L1), which tumors often use to suppress immune responses.
In an official statement, Moderna noted that the Fast Track status provides the company with opportunities for more frequent meetings with the FDA to discuss the drug development plan and ensure the collection of appropriate data. The designation also makes the program eligible for Rolling Review, allowing the company to submit completed sections of its Biologics License Application for agency review as they become available, rather than waiting for the entire application to be finalized.
Dr. Stephen Hoge, President of Moderna, stated that the designation highlights the potential of the company’s mRNA platform to address high-risk oncology indications. He emphasized that the company is focused on advancing its cancer vaccine candidates to provide new therapeutic options for patients with advanced solid tumors. The mRNA-4359 program is a central component of Moderna’s oncology pipeline, which includes multiple candidates targeting various types of cancer.
Cutaneous melanoma is a highly aggressive form of skin cancer, and while existing immunotherapies have improved survival rates, many patients with advanced disease still face limited options. Moderna’s strategy involves using mRNA technology to enhance the body’s natural immune response against the tumor microenvironment. The company confirmed it will continue the Intervallum study and expects to provide additional data regarding future late-stage trial protocols later this year.