Amlitelimab

A collaboration that has already delivered the blockbuster drug Dupixent (dupilumab) is being expanded, with Sanofi agreeing to pay Regeneron Pharmaceuticals $1 billion upfront as the companies look to develop four new long-acting immunology antibodies. The deal announced Thursday also includes up to $7 billion in future milestone payments.Leonard Schleifer, Regeneron's CEO, called the alliance between the parties — which began in 2003 — "one of the most productive in biopharma history." He said the expanded agreement will position "promising new long-acting antibodies for the kind of rapid, global impact that our shared work on Dupixent has already achieved."In the most recent quarter, Dupixent, which inhibits signalling of the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathways, brought in sales of €5.2 billion ($5.9 billion), crossing the €5 billion ($5.6 billion) mark for the first time.Under the new deal, the companies will co-develop and co-commercialise four new long-acting, Regeneron-invented antibodies targeting IL-13, IL-4, the IL-4 receptor alpha and an IL-4xIL-13 bispecific. The IL-13 antibody REGN20423 is currently in a Phase I testing for atopic dermatitis, while the other three antibodies are expected to enter clinical studies in 2027. The companies said that Regeneron will lead R&D activities, and Sanofi will lead global commercial efforts. Meanwhile, the parties will share development and commercialisation costs for the new programmes, with profits split 50:50 on a global basis. As part of the agreed terms, Regeneron will also have the option to include Sanofi's lunsekimig, an investigational bispecific targeting TSLP and IL-13, in the collaboration following the completion of Phase III trials for chronic obstructive pulmonary disease."This is a deliberate first step in igniting Sanofi's innovation engine," remarked Belén Garijo, the French drugmaker's new CEO, who has been brought in to boost R&D productivity. "By deepening our collaboration, we will make rapid progress in creating the next generation of meaningful therapies for patients with immune-mediated diseases, while contributing to Sanofi's long-term future."One of Garijo's first decisions at Sanofi was to end further development of amlitelimab for moderate-to-severe atopic dermatitis, with the OX40-ligand monoclonal antibody at one time seen as a successor to Dupixent. For more, see — Spotlight On: In scrapping 'could have been' Dupixent successor, Garijo signals another break from the past at Sanofi.

iStock, Afry Harvy Sanofi and Regeneron have had a long and “sometimes contentious” partnership, BMO Capital Markets noted, as the companies contend with the looming loss of exclusivity of their blockbuster drug Dupixent. As key patent expiries loom over immunology juggernaut Dupixent, Sanofi and Regeneron have renewed their long-term partnership, with the French pharma fronting $1 billion to advance four long-acting, next-generation antibodies for immune-mediated conditions. Sanofi is offering Regeneron up to $7 billion more in development, regulatory and commercial milestones, according to a Thursday morning announcement . The French pharma will co-develop and co-commercialize four Regeneron-discovered antibodies. “Today’s agreement extends a productive (but at some points contentious) partnership,” BMO Capital Markets wrote on Thursday morning. Just last year, Regeneron sued Sanofi , alleging that the French pharma didn’t provide “full access to material information” about Dupixent’s sales. Sanofi has also resisted efforts by Regeneron to audit records related to the blockbuster drug. The companies have settled this dispute, according to their Thursday announcement. The slate of experimental therapies in the renewed partnership is led by the IL-13-targeting REGN20423, which is currently in Phase 1 development for atopic dermatitis. The three other assets are preclinical and include an IL-4xIL-13 bispecific, an anti-IL-4 therapy and a molecule designed to target IL-4R-alpha. All three are expected to enter human studies next year, according to the companies. Legal Regeneron Sues Sanofi, Alleging Stonewalling in Dupixent Pact According to the lawsuit, Sanofi has failed to provide partner Regeneron adequate information regarding the sales of Dupixent—including agreements with payers and pharmacy benefit managers that determine pricing and rebates for the drug. February 7, 2025 · 2 min read · Tristan Manalac Read more The deal could expand beyond these four therapies, as well. Regeneron has the option to include Sanofi’s TSLPxIL-13 bispecific lunsekimig into the alliance—a right that Regeneron can choose to exercise once the molecule clears Phase 3 testing for chronic obstructive pulmonary disease (COPD). Profits for these assets, if they reach the market, will be split 50-50. Lunsekimig is in a pair of Phase 3 trials for COPD, both of which are expected to have initial readouts in 2029. Sanofi is also developing lunsekimig for asthma and chronic rhinosinusitis with nasal polyps, for which it cleared respective mid-stage studies in April. Lunsekimig was also being studied in atopic dermatitis but missed the primary endpoint of improving disease severity in the exploratory Phase 2b VELVET trial. The renewed deal positions “both companies for continued leadership in the development of the next generation of therapeutics for type 2 inflammation-driven disease,” BMO added. Sanofi and Regeneron are expanding their decades-long alliance amid exclusivity concerns for Dupixent. The drug surged 26% last year to bring in $17.8 billion worldwide. But a key U.S. patent is set to expire in 2031 , which could open the blockbuster up to biosimilar challenge and, in turn, erode revenue. Sanofi general counsel Roy Papatheodorou explained during the company’s first quarter call in April that Dupixent has a web of patents extending as far as 2045. Still, the pharma has been working diligently to find a successor. Earnings Sanofi defends Dupixent patents, but execs insist it has nothing to do with CEO change Sanofi’s interim leadership sought on a Thursday earnings call to quell concerns that its sudden defense of Dupixent’s patents had anything to do with the departure of CEO Paul Hudson. April 23, 2026 · 3 min read · Annalee Armstrong Read more Sanofi had pinned a lot of hopes on the autoimmune asset amlitelimab, which came from the $1.4 billion acquisition of Kymab and had been under development for atopic dermatitis and celiac disease. Sanofi in July ended the asset’s development in atopic dermatitis , noting that “the totality of efficacy and safety evidence generated to date does not support further development” in this indication. Similarly being set up as a potential heir to Dupixent was the investigational IL-33 inhibitor itepekimab. Sanofi decided to axe the asset in July following mixed data in a late-stage study for COPD. Amlitelimab and itepekimab no longer appear on the pharma’s pipeline page . Sanofi and Regeneron split Dupixent’s U.S. earnings 50-50, while international profits are divvied up based on a pre-determined sliding scale that gives a slight edge to Sanofi, according to a 2007 agreement between the companies. Thursday’s agreement will not affect the current profit-sharing arrangement for Dupixent, the partners said.