Earendil Labs Files for IPO Following $18.45B AI-Powered Bispecific Antibody Deal with Sanofi

On April 17, Earendil Labs (the overseas company of Helixon), a global AI-driven biopharmaceutical R&D enterprise, announced that it had reached a licensing agreement with Sanofi for two potential first-in-class bispecific antibodies.

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: The total deal 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 improve clinical efficacy, especially 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 the 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 research and development 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 streamline the drug discovery and research process, aiming to significantly accelerate drug development. Earendil Labs' proprietary integrated framework enables precise optimization of the functionality, manufacturability, and developability of protein-based biologics, demonstrating best-in-class potential.

Helixon, as an AI + high-throughput antibody optimization company, was founded in 2021 by computational biology expert Jian Peng and incubated by the Artificial Intelligence Industry Research Institute of Tsinghua University. 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 was appointed President and Co-CEO. He is responsible for the R&D of innovative drugs and pipeline advancement, strategy formulation, and operations at Helixon. Since then, Helixon has further increased its investment in the drug R&D pipeline.

Regarding this transaction, Dr. Peng Jian, CEO of Earendil Labs, stated, "We are delighted 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 candidates, 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, significantly impacting patients' quality of life. Existing drugs have limited efficacy, representing an unmet medical need. We believe Sanofi's expertise in the autoimmune field will greatly 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 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 strategy 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 targeting a previously undruggable transcription factor.

TL1A as a popular target in the autoimmune field in recent years, its advantage lies in 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. By binding to death receptor 3 (DR3) and activating downstream signaling pathways, TL1A plays a crucial role in maintaining homeostasis in both innate and adaptive immunity.

Research shows that the TL1A target has potential effects across multiple different diseases, such as inflammatory diseases, autoimmune diseases, and has a direct anti-fibrotic effect. 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, no drugs targeting TL1A have been approved for marketing globally, but several candidate drugs targeting the TL1A pathway have entered clinical trials and shown promising results. Among them, the development of TL1A monoclonal antibodies is proceeding relatively quickly, with eight TL1A monoclonal antibodies currently in clinical research. Notably, Merck's tulisokibart and Pfizer's PF-06480605 are in Phase III clinical trials. In contrast, the development of TL1A bispecific antibodies is still in its early stages, with Pfizer's PF-07261271 being the only TL1A bispecific antibody currently in clinical trials.

For Sanofi, this transaction holds multiple values. Following the failure of a Phase II clinical trial for an asthma drug acquired from Kymab in early 2025, Sanofi faced a gap in its immunology pipeline. This deal quickly fills that void by expanding Sanofi's pipeline 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 companies and China's local AI pharmaceutical enterprises, in line with Sanofi's "AI-first" strategy. It is reported that the previous cooperation between Sanofi and Formation Bio, OpenAI has preliminarily verified 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 in the autoimmune field by 2025. Its goal is to build a full pipeline matrix covering inflammatory bowel disease, lupus, and psoriasis through the combination of "bispecific antibodies + AI," challenging AbbVie and Johnson & Johnson's dominance.