Sanofi Pasteur, Sanofi’s vaccines global business unit, and Translate Bio, a clinical-stage messenger RNA (mRNA) therapeutics company, have formed a multi-year research and development (R&D) pact and licensing deal to develop mRNA vaccines for up to five undisclosed infectious disease pathogens in a deal worth up to $805 million.

Under the agreement, Translate Bio and Sanofi Pasteur will jointly conduct R&D activities to advance mRNA vaccines during an initial three-year research term. Sanofi Pasteur will make an upfront payment of $45 million to Translate Bio. In total, Translate Bio is eligible to receive up to $805 million in payments, which also includes certain development, regulatory, and sales-related milestones across several vaccine targets, and option exercise fees if Sanofi Pasteur exercises its option related to development of vaccines for additional pathogens. In addition, Translate Bio is also eligible to receive tiered royalty payments associated with worldwide sales of the developed vaccines. Sanofi Pasteur will pay for all costs during the research term and will receive exclusive worldwide commercialization rights. Translate Bio will be responsible for clinical manufacture and will be entitled to additional payments under a separate supply agreement to be established.

Translate Bio’s mRNA therapeutic (MRT) platform is designed to develop product candidates that deliver mRNA carrying instructions to produce intracellular, transmembrane, and secreted proteins for therapeutic benefit. The company says it believes that its MRT platform is applicable to a range of diseases caused by insufficient protein production or where production of proteins can modify disease, including diseases that affect the lung, liver, eye, central nervous system, lymphatic system, and circulatory system. The company also says its platform may be applied to produce therapeutic antibodies and vaccines in areas such as infectious disease and oncology. The company’s two lead programs are being developed as treatments for cystic fibrosis and ornithine transcarbamylase deficiency, a disorder that causes ammonia to accumulate in the blood.