Rallybio In-Licenses Preclinical Antibody Candidate from Sanofi Targeting Rare Blood Disorders

Rare hematological disease focused biotech Rallybio obtained worldwide exclusive rights to Sanofi’s KY1066 (renamed RLYB331), a preclinical potentially first-in-class antibody that has the potential to address a significant unmet need for patients with severe anemia with ineffective erythropoiesis and iron overload, such as beta thalassemia and a subset of myelodysplastic syndromes, among others.

Photo: Martin Mackay, CEO of Rallybio

The transaction expands Rallybio’s pipeline and aligns with its mission to accelerate the development of life-transforming therapies for patients with severe and rare disorders.

“We believe RLYB331 is differentiated from all programs in clinical development based on its mechanism of action, with the potential to be first-in-class,” said Martin Mackay, CEO of Rallybio. “We expect that RLYB331 may address a significant unmet need by correcting ineffective erythropoiesis, improving hemoglobin, reducing red blood cell transfusions and reducing iron overload in multiple hematological disorders such as beta thalassemia and myelodysplastic syndromes.”

RLYB331 is a monoclonal antibody that inhibits Matriptase-2 (MTP-2). The inhibition of MTP-2 significantly increases levels of hepcidin, decreases iron load and treats ineffective erythropoiesis. The standard of care for many such hematological disorders leaves a significant unmet need in iron overload associated anemias with patients experiencing significant morbidity and consequent mortality.

Rallybio plans to prosecute preclinical activities for RLYB331 including CMC, and dose-range finding and toxicity studies, which will then support transition of the asset into clinical development.

Under the terms of the license agreement, Rallybio will make an upfront cash payment of $3 million to Sanofi, in addition to development and commercial milestones, and mid to high single digit royalties on net sales.

Author: Rare Daily Staff