Sanofi partners with Alloy Therapeutics for CNS antisense drugs

Sanofi has embarked on a strategic collaboration with Alloy Therapeutics to advance an antisense oligonucleotide (ASO) therapy aimed at treating a specific central nervous system (CNS) disorder, although the exact condition remains undisclosed. This collaboration combines Sanofi’s neuroscience acumen with Alloy's innovative AntiClastic Antisense platform, which is designed to tackle RNA-level intracellular disease mechanisms and overcome limitations of existing antisense technologies. The platform purports to enhance a drug's therapeutic potential and enable the delivery of treatments to targets that were previously difficult to access.

Sanofi will initially commit up to $27.5 million in upfront payments and preclinical milestone payments to Alloy, with the possibility of more than $400 million in additional payments contingent on achieving various discovery, development, and commercialization milestones. Alloy also stands to gain tiered royalties from the sales of any products that emerge from this collaboration.

The partnership underscores a rising interest in nucleic acid-based therapies, especially for CNS disorders, which present both high potential and significant developmental challenges. An example of a successful ASO therapy in the CNS domain is Biogen’s Spinraza (nusinersen), which has been approved for treating spinal muscular atrophy and reported $1.7 billion in sales last year according to Biogen’s financial data.

This initiative is part of Sanofi’s broader investment strategy in ASO research, following its prior investment in October 2024 with Resalis Therapeutics for an ASO therapy aimed at obesity pathways. Historically, Sanofi has explored ASO therapeutics, including its collaboration with Ionis Pharmaceuticals on Kynamro (mipomersen). However, Kynamro faced commercial difficulties and was withdrawn from the market in 2019.

Alloy Therapeutics, having launched its AntiClastic Antisense platform in 2023 through licensed intellectual property from Arnay Sciences, is not new to partnerships with large pharmaceutical companies. In November 2024, Alloy collaborated with Takeda to advance Takeda’s proprietary induced pluripotent stem cell (iPSC)-derived chimeric antigen receptor (CAR)-T cell platforms. Earlier, in May 2024, Alloy also licensed its ATX-Gx and ATX-CLC murine platforms to Eli Lilly. These platforms are intended to facilitate fully human antibody discovery, simplifying and accelerating therapeutic development. This cooperation also involves integrating Alloy’s technology with Lilly’s Catalyze360 program, which aids biotech startups by providing access to drug discovery tools, laboratory facilities, and research and development expertise.

The collaboration between Sanofi and Alloy Therapeutics highlights the ongoing and growing interest in advancing CNS disorder therapies through cutting-edge antisense technologies. By leveraging Alloy's platform and Sanofi's expertise, both companies aim to make significant strides in developing effective treatments that can overcome the challenges of delivering therapeutics across the blood-brain barrier, a critical hurdle in CNS drug development. Through this partnership, Sanofi continues to demonstrate its commitment to exploring innovative therapeutic approaches to address unmet medical needs in the CNS domain.