Earendil Labs Secures $1.845 Billion Deal with Sanofi for AI-Discovered Bispecific Antibodies, Files IPO Prospectus

According to the agreement, Sanofi will obtain the global exclusive license for two bispecific antibodies, HXN-1002 and HXN-1003, independently developed by Earendil Labs. Both antibodies are developed based on Earendil Labs' proprietary artificial intelligence and high-throughput discovery and research platform, aiming to provide treatment options for autoimmune diseases such as colitis and skin inflammation.

In return, Earendil Labs will receive an upfront payment of $125 million and is eligible for development and commercial milestone payments totaling up to $1.72 billion, including a near-term payment of $50 million. Additionally, Earendil Labs is eligible for tiered royalties ranging from high single digits to low double digits on product sales. (Note: Total transaction value is $1.845 billion, approximately RMB 13.4 billion.)

HXN-1002 is a bispecific antibody targeting α4β7 and TL1A. By simultaneously inhibiting two clinically validated targets, HXN-1002 is expected to significantly enhance clinical efficacy, particularly for refractory patients. HXN-1002 aims to provide a treatment option for patients with moderate to severe ulcerative colitis (UC) and Crohn's disease (CD).

HXN-1003 is a bispecific antibody targeting TL1A and IL23. These two targets are core drivers of inflammatory responses in multiple human autoimmune diseases. By simultaneously blocking these two pathways, the drug has demonstrated synergistic effects in preclinical models of colitis and skin inflammation, offering potential to address unmet therapeutic needs.

Both of these bispecific antibodies were developed based on Earendil Labs' artificial intelligence and high-throughput discovery and research platform. Behind Earendil Labs is a Chinese AI + drug discovery company: Helixon.

According to public information, Earendil Labs is an affiliate of Helixon, with its headquarters located in the United States. By integrating advanced machine learning, generative protein engineering, and high-throughput experimental technologies, Earendil Labs and Helixon have streamlined the drug discovery and research process, aiming to significantly accelerate drug development. Earendil Labs' proprietary integrated framework can precisely optimize the functionality, manufacturability, and developability of protein-based biologics, demonstrating best-in-class potential.

Helixon, as an AI + high-throughput antibody optimization company focused on this field, was incubated by the Artificial Intelligence Industry Research Institute of Tsinghua University and founded in 2021 by computational biology expert Peng Jian. Since its establishment, the company has developed various innovative algorithms for protein drug design and modeling. Its AI antibody design platform, Helixon Design, can simulate molecular interactions on a large scale, efficiently design multi-target antibodies, and significantly shorten the R&D cycle.

In February 2023, Dr. Zhu Zhenping, a senior scientist in new drug research and development, joined Helixon as a co-founder and assumed the roles of President and Co-CEO. He is responsible for the research and development of innovative drugs, advancement of the product pipeline, strategy formulation, and operations at Helixon. Following this, Helixon further increased its investment in the drug research and development pipeline.

Regarding this transaction, Dr. Peng Jian, CEO of Earendil Labs, stated, "We are very pleased to collaborate with Sanofi, a global leader in immunology, to advance the development of HXN-1002 and HXN-1003. Our platform revolutionizes the discovery and development of bispecific antibodies through advanced predictive protein models and high-throughput biology. This collaboration highlights Earendil's ability to develop potential first-in-class candidate products, aiming to transform patient care."

Dr. Zhenping Zhu, President and Co-CEO of Earendil Labs, stated that autoimmune diseases are characterized by chronic disease progression and high recurrence rates, severely impacting patients' quality of life. Current medications have limited efficacy, reflecting unmet medical needs. We believe Sanofi's expertise in the autoimmune field will significantly accelerate the development of HXN-1002 and HXN-1003, ultimately bringing these potentially life-changing treatments to patients worldwide as soon as possible.

The autoimmune field is an important strategic focus for Sanofi. In January 2025, Dr. Houman Ashrafian, Sanofi's R&D head, reiterated on the pharmaceutical industry's annual earnings call that the company’s goal is to become "the leading immunology powerhouse."

In March 2025, Sanofi signed a $1.6 billion agreement with Dren Bio to develop a CD20-targeted antibody for B-cell non-Hodgkin lymphoma. In April, Sanofi reached a $480 million autoimmune deal with Nurix, which includes a degrader of a previously undruggable transcription factor.

TL1A, as a popular target in the autoimmune field in recent years, has the advantage of simultaneously regulating inflammatory and fibrotic pathways, with significant potential for indication expansion. TL1A (TNF-like ligand 1A), an important member of the tumor necrosis factor family, is a type 2 transmembrane protein expressed in various immune and non-immune cells. TL1A plays a crucial role in maintaining innate and adaptive immune homeostasis by binding to death receptor 3 (DR3) and activating downstream signaling pathways.

Studies have shown that the TL1A target has potential effects across multiple different diseases, such as inflammatory diseases, autoimmune diseases, and possesses direct anti-fibrotic action. It is associated with the occurrence and pathogenesis of various autoimmune diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), atopic dermatitis, systemic lupus erythematosus, asthma, and psoriasis.

Currently, there are no drugs targeting TL1A approved for marketing globally, but several candidate drugs targeting the TL1A have entered clinical trials and shown positive results. Among them, the development of TL1A monoclonal antibodies is proceeding relatively quickly, with eight TL1A monoclonal antibodies currently in clinical research, including Merck's tulisokibart and Pfizer's PF-06480605 in Phase III clinical trials. TL1A bispecific antibodies are still in the early stages of development, with Pfizer's PF-07261271 being the only TL1A bispecific antibody currently in the clinical stage.

For Sanofi, this transaction holds multiple values. Following the failure of the Phase II clinical trial of an asthma drug acquired from Kymab in early 2025, Sanofi faced a gap in its immunology pipeline. This deal quickly fills Sanofi’s pipeline layout in niche markets such as moderate to severe IBD, potentially providing new momentum for future revenue growth.

This transaction is also a typical case of cooperation between multinational pharmaceutical enterprises and China-based AI pharmaceutical companies, aligning with Sanofi's "AI-first" strategy. It is reported that Sanofi's previous collaborations with Formation Bio and OpenAI have preliminarily validated the value of AI in molecular optimization.

As of now, with the addition of DR-0201, the myeloid cell bispecific antibody from Dren Bio acquired in March this year, Sanofi has invested nearly $4 billion by 2025 to establish a presence in the autoimmune field. Its goal is to use the "bispecific antibody + AI" combination to build a full pipeline matrix covering inflammatory bowel disease, lupus, and psoriasis, challenging AbbVie and Johnson & Johnson's dominance.