Sanofi has returned to U.S. artificial intelligence research biotech Earendil Labs for another significant autoimmune and immunology development pact.
The latest agreement sees the French pharma offer $160 million—spread between upfront and near-term milestone payments—to apply Earendil's discovery platform to multiple bispecific autoimmune and inflammatory disease programs.
Sanofi will take charge of development and worldwide commercialization of all bispecific candidates resulting from the collaboration. In return, Earendil is in line for further development and commercial milestone payments that could bring the deal’s value up to $2.56 billion.
In addition, Earendil will receive tiered royalties up to low double-digit percent on sales of any bispecific drug that makes it to market.
The latest collaboration follows a similar pact signed in April 2025, where Sanofi handed $125 million to Earendil for the exclusive worldwide rights to a pair of bispecific antibodies. One of those assets, dubbed HXN-1002, targets α4β7 and TL1A with the aim of treating ulcerative colitis and Crohn's disease, while the other, HXN-1003, targets TL1A and IL23 in order to treat colitis and skin inflammation.
Earendil touts itself as a “global leader in AI-driven research and development of next-generation biologics therapeutics.” The biotech has described itself as affiliated with Helixon Therapeutics, a company that, like Earendil, claims to harness machine learning for protein drug design.
In July, Earendil announced that it had completed dosing of a first cohort of a phase 1 study of HXN-1001, an anti-TL1A antibody the company is eyeing as a potential treatment of inflammatory bowel diseases like ulcerative colitis and Crohn's disease.
“Partnering with Sanofi allows us to apply Earendil's discovery platform to a broader set of autoimmune disease targets than ever before,” Earendil CEO Jian Peng, Ph.D., said in this morning's release.
“By combining advanced predictive protein modeling with high-throughput experimental validation, we can identify and optimize bispecific antibody candidates more efficiently and precisely,” Peng added. “This collaboration underscores our commitment to advancing next-generation therapeutics that have the potential to set new standards of care.”
Sanofi has been on a spending spree over the past year to bolster its autoimmune and immunology pipeline, including a $480 million deal with Nurix for a degrader of a once-undruggable transcription factor as well as a $1.6 billion agreement with Dren Bio for a CD20-directed antibody aimed at B-cell non-Hodgkin lymphoma.
The Paris-based pharma rounded off 2025 by expanding on its relationship with Dren Bio by fronting $100 million to discover and develop a potential next-generation B-cell depleting therapy for “various autoimmune diseases.”