Rallybio wades into Sanofi storeroom for $3M rare disease deal

Rallybio is making room for a rare disease candidate from Sanofi’s stockroom with a small $3 million upfront cash payment.

The biotech will take over development of KY1066, which will be renamed RLYB331, for severe anemia and iron overload in patients who have diseases such as beta thalassemia and a certain type of myelodysplastic syndrome.

RLYB331 will fit right into Rallybio’s pipeline, which has a focus on hematology and rare diseases. The biotech’s lead asset is in a phase 1/2 study for a rare fetal bleeding disorder.

This is the first licensing deal for Rallybio. The company plans to conduct preclinical studies for toxicity and to assess the appropriate dose range.

Sanofi has not said much about the drug formerly known as KY1066, but the “KY” part of the name refers to Kymab, which was bought by the French pharma in 2021. More interesting for Sanofi in that $1.1 billion deal was the monoclonal antibody KY1005, under development for immune-mediated diseases and inflammatory disorders.

Besides the small upfront fee, Sanofi will be entitled to development and commercial milestones and royalties; however, further financial details were not disclosed.

Rallybio went public in July 2021 with an $81 million IPO to fuel its rare disease pipeline. The Fierce 15-winning biotech's leadership team is stacked with executives formerly from Alexion Pharmaceuticals, which AstraZeneca bought in December 2020.