Subsequent Events	3 Months Ended
Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	11. SUBSEQUENT EVENTS In May 2022, we obtained worldwide exclusive rights to Sanofi’s KY1066, now referred to as RLYB331, a preclinical potentially first-in-class antibody. RLYB331 has the potential to address a significant unmet need for patients with severe anemias with ineffective erythropoiesis and iron overload, including beta thalassemia and a subset of myelodysplastic syndromes. Currently these patients are underserved by the existing standard of care. 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. We plan to initiate IND-enabling activities for RLYB331 to support transition of the asset into clinical development. Under the terms of the agreement, we will make an upfront payment of $3.0 million for the exclusive license to KY1066. We could also be required to pay up to up to an aggregate of $43.0 million in development and regulatory milestones and up to an aggregate of $150.0 million in commercial milestones for a product in its first indication, plus tiered low-to-mid double digit percentages of such milestone amounts for up to three additional indications, and mid to high single digit royalties on net sales.

Subsequent Events

3 Months Ended

Mar. 31, 2022

11. SUBSEQUENT EVENTS

In May 2022, we obtained worldwide exclusive rights to Sanofi’s KY1066, now referred to as RLYB331, a preclinical potentially first-in-class antibody. RLYB331 has the potential to address a significant unmet need for patients with severe anemias with ineffective erythropoiesis and iron overload, including beta thalassemia and a subset of myelodysplastic syndromes. Currently these patients are underserved by the existing standard of care. 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. We plan to initiate IND-enabling activities for RLYB331 to support transition of the asset into clinical development. Under the terms of the agreement, we will make an upfront payment of $3.0 million for the exclusive license to KY1066. We could also be required to pay up to up to an aggregate of $43.0 million in development and regulatory milestones and up to an aggregate of $150.0 million in commercial milestones for a product in its first indication, plus tiered low-to-mid double digit percentages of such milestone amounts for up to three additional indications, and mid to high single digit royalties on net sales.