Earendil Labs
Data verified as of Sep 18, 2026
Summary
Earendil Labs is an AI-driven biologics company designing antibodies, bispecifics, T-cell engagers and antibody-drug conjugates for autoimmune disease and cancer. Computational biologist Jian Peng founded the group in 2021 as Helixon Therapeutics in Beijing, incubated at Tsinghua's Institute for AI Industry Research; Earendil Labs is the Delaware-incorporated overseas entity, with Peng as CEO and antibody veteran Zhenping Zhu as president and co-CEO. Its protein-AI stack, which includes OmegaFold, a 2022 single-sequence structure predictor from Peng's Helixon team, feeds a pipeline the company says has produced more than 40 programs, 19 of them listed on its website. Lead internal asset HXN-1001, a half-life extended anti-TL1A monoclonal antibody for inflammatory bowel disease, completed Australian Phase 1 healthy-volunteer enrollment and dosed its first ulcerative colitis patient in a randomized, placebo-controlled Phase IIa trial on April 2, 2026, with an about 8-week half-life at projected therapeutic doses. A second internal asset, biparatopic TSLP antibody HXN-1011, completed first-cohort Phase 1 dosing on May 18, 2026. Sanofi licensed bispecifics HXN-1002 (TL1A/α4β7) and HXN-1003 (TL1A/IL-23p19) in April 2025 for $125 million upfront plus up to $1.72 billion in milestones, then signed a broader discovery collaboration in January 2026 worth up to $2.56 billion including $160 million in upfront and near-term payments. In March 2026 Earendil raised $787 million from Dimension Capital, DST Global, INCE Capital, Luminous Ventures, Miracle Capital, Sanofi and the Hillhouse/Pfizer Biotech Development Fund. Bloomberg reported in March 2026 that it was working with CICC and Morgan Stanley on a Hong Kong IPO that might raise as much as $500 million; the Wall Street Journal wrote on August 5, 2026 that Chinese regulators had raised concerns over its red-chip holding structure on a raise of close to $400 million at about a $5 billion valuation. No approved drugs, and no Phase IIa efficacy data, have been disclosed as of September 18, 2026.
Company OverviewRead the long-form profile of Earendil LabsMain Products
Earendil's foundational protein-AI stack for antibody sequence design, structure and epitope prediction, biophysical-property scoring and closed-loop optimization, paired with high-throughput wet-lab validation. The public scientific ancestor is OmegaFold, Helixon's 2022 single-sequence structure predictor.
In production use across the internal pipeline and the Sanofi discovery collaboration. Company says the engine has produced more than 40 programs. In March 2026 Peng said the firm had integrated NVIDIA context parallelism to handle complexes up to 24,000 tokens; that claim is from a LinkedIn post, not a peer-reviewed methods paper.
A half-life extended anti-TL1A monoclonal antibody for inflammatory bowel disease, including ulcerative colitis and Crohn's disease, formulated at high protein concentration for subcutaneous injection.
Phase IIa ulcerative colitis, randomized and placebo-controlled, first patient dosed April 2, 2026. Australian Phase 1 healthy-volunteer study completed enrollment. Company-reported Phase 1: well tolerated at single doses up to 1,200 mg and multiple doses of 450 mg, about 8-week half-life, low anti-drug-antibody rate. No efficacy data disclosed. Crohn's studies have been discussed as a future use, not as an active trial.
Two bispecific antibodies licensed exclusively to Sanofi for autoimmune and inflammatory bowel disease. HXN-1002 targets α4β7 and TL1A for moderate-to-severe ulcerative colitis and Crohn's disease. HXN-1003 targets TL1A and IL-23 and has shown synergistic activity in preclinical colitis and skin-inflammation models.
Out-licensed to Sanofi in April 2025. Sanofi holds exclusive worldwide rights and is responsible for development. No Sanofi-run clinical start has been announced as of September 18, 2026. Still listed on Earendil's IBD pipeline table.
A recombinant humanized biparatopic antibody against two epitopes on TSLP that is designed to block both units of the heterodimeric TSLP receptor (TSLPR/CRLF2 and IL-7Rα). High-concentration subcutaneous formulation. Aimed at asthma, COPD and other TSLP-driven inflammatory diseases.
Phase 1. First cohort dosed May 18, 2026. Company says preclinical assays showed more potent and longer-lasting pharmacodynamic effects than unnamed clinical-stage TSLP benchmarks. No human PK or safety table has been published beyond the first-cohort announcement.
A preclinical oncology set listed on Earendil's pipeline page: CDH17 dual-payload ADC (HXN-2001), CEACAM5/CDH17 TCE and ADC, GUCY2C TCE, DLL3 TCE and dual-payload ADC, B7-H3 ADC, TROP2/PD-L1 and EGFR/PD-L1 bispecific ADCs, and a PD-1/IL-15 fusion protein. February 2026 WuXiTecan-2 license is meant to supply payload-linkers for a subset of these ADCs.
Preclinical / IND-enabling. Company has said multiple INDs are planned in 2026 and 2027 without naming which oncology assets file first. No oncology program has been reported in the clinic.
What's Next
HXN-1001 Phase IIa ulcerative colitis readout
The randomized, placebo-controlled Phase IIa study that dosed its first patient on April 2, 2026 is the first test of whether HXN-1001 does anything in patients, not just healthy volunteers. No completion date, trial ID or primary-endpoint window has been disclosed. Watch for an efficacy and safety table, a Crohn's protocol, and whether the 8-week half-life holds in diseased patients.
Advance HXN-1011 Phase 1 and file additional 2026-2027 INDs
HXN-1011 completed first-cohort Phase 1 dosing on May 18, 2026; remaining cohorts, PK and a patient-study decision are the next disclosed work. The March 2026 raise promised multiple IND submissions in 2026 and 2027. None of those additional INDs has been announced as accepted.
Sanofi to start human studies of HXN-1002 and HXN-1003
The April 2025 license put two bispecifics in Sanofi's hands. As of September 18, 2026 Sanofi has not announced a first-in-human study for either asset. A posted trial, an IND, or a Sanofi pipeline listing is the next hard signal that the first deal is more than an upfront payment.
Resolve the Hong Kong IPO / CSRC red-chip review
Bloomberg reported a CICC and Morgan Stanley-advised Hong Kong listing of up to $500 million in March 2026. The Wall Street Journal reported on August 5, 2026 that Chinese regulators had objected to the red-chip holding structure on a close-to-$400 million raise at about a $5 billion valuation. Watch for a refiled application, a restructuring, a prospectus, or a decision to stay private on the $787 million.
Track Record
2 of 2 announced dates hit
Advance a second internal program into the clinic in 2026
Target 2026 · Resolved May 18, 2026
The March 2026 financing release promised multiple IND submissions in 2026 and 2027. On May 18, 2026 Earendil completed first-cohort Phase 1 dosing of HXN-1011, a biparatopic TSLP antibody, putting a second wholly owned program into human studies.
Operations & Revenue
Two wholly owned programs are in the clinic (HXN-1001 Phase IIa ulcerative colitis; HXN-1011 Phase 1). Two bispecifics are licensed to Sanofi and have not been reported as clinical. No approved products. A Hong Kong IPO at a reported ~$5B valuation remains blocked at the Chinese regulatory step as of the August 5, 2026 WSJ report. CMC for complex antibodies and ADCs is contracted to WuXi Biologics and WuXi XDC. Helixon Beijing corporate filings still list the China affiliate at under 50 people; ZoomInfo puts the US Earendil entity in the 11-50 band.
Revenue Streams
Sanofi HXN-1002 / HXN-1003 license
Worldwide exclusive license of two IBD/autoimmune bispecifics. $125M upfront, up to $1.72B in milestones including a $50M near-term payment, plus high-single to low-double-digit royalties if the drugs are sold.
Sanofi discovery collaboration
Multi-program bispecific discovery for autoimmune and inflammatory disease. Up to $160M in upfront and near-term payments, total potential value up to $2.56B, plus royalties up to low double-digit percent. Sanofi owns development and worldwide commercialization of resulting candidates.
Key Metrics
- Employees
- 11-50 (US entity; Helixon Beijing affiliate also listed under 50)
- Est. Annual Revenue
- No product sales. Near-term cash is partnership economics: $125M upfront plus a $50M near-term milestone on the April 2025 Sanofi license, and up to $160M in upfront and near-term payments on the January 2026 Sanofi discovery collaboration. Remaining biobucks on both deals are contingent. The $787M March 2026 round is equity, not revenue.
- Disclosed equity raised
- About $870M across Helixon/Earendil rounds ($10M 2021, ~$75M 2022 Series A, $787M March 2026)
- Named pipeline programs
- 19 listed on the company pipeline page; company says the platform has produced 40+ programs overall
- Programs in the clinic
- 2 internal: HXN-1001 (Phase IIa ulcerative colitis, first patient April 2, 2026) and HXN-1011 (Phase 1, first cohort May 18, 2026)
- HXN-1001 half-life
- About 8 weeks at projected therapeutic doses (Phase 1 healthy volunteers, company-reported)
Timeline
On January 5, 2026 Earendil and Sanofi expand the relationship into a multi-program discovery collaboration. Earendil applies its platform to multiple autoimmune and inflammatory bispecific programs; Sanofi leads development and worldwide commercialization. Economics: up to $160 million in upfront and near-term payments, total potential value up to $2.56 billion, plus tiered royalties up to low double-digit percent.
On February 27, 2026 WuXi XDC grants Earendil an exclusive global license to its WuXiTecan-2 payload-linker for multiple specific targets, and will support CMC and manufacturing of the resulting ADC components. Potential deal value is about $885 million in upfront, development, regulatory and sales milestones, plus tiered royalties. Earendil leads later-stage development, filings and commercialization.
On March 12, 2026 Earendil and WuXi Biologics sign a strategic collaboration for end-to-end development and GMP manufacturing of multiple bispecific, multispecific and ADC candidates in Earendil's autoimmune and oncology pipeline, including cell-line, process, formulation and drug-product work.
On March 20, 2026 Earendil announces $787 million in financing from Dimension Capital, DST Global, INCE Capital, Luminous Ventures, Miracle Capital, Sanofi and the Biotech Development Fund created by Hillhouse and Pfizer. Bloomberg had reported a week earlier that Earendil was working with CICC and Morgan Stanley on a Hong Kong IPO that might raise as much as $500 million.
On April 2, 2026 Earendil doses the first ulcerative colitis patient in a randomized, placebo-controlled Phase IIa study of HXN-1001 and completes Phase 1 healthy-volunteer enrollment in Australia. Zhu reports an about 8-week half-life at projected therapeutic doses, single doses up to 1,200 mg and multiple doses of 450 mg well tolerated, with low anti-drug-antibody incidence.
On May 18, 2026 Earendil completes cohort 1 dosing in a Phase 1 study of HXN-1011, a biparatopic TSLP antibody designed to block both TSLPR/CRLF2 and IL-7Rα, formulated for subcutaneous injection and aimed at asthma, atopic dermatitis, eosinophilic esophagitis, chronic rhinosinusitis with nasal polyps and COPD.
On August 5, 2026 the Wall Street Journal reports that Earendil is planning to raise close to $400 million in a Hong Kong IPO at about a $5 billion valuation, and that Chinese regulators have raised concerns over its red-chip holding structure after the company submitted its application. No prospectus or listing date has been published as of September 18, 2026.
On April 17, 2025 Earendil and Sanofi announce a worldwide exclusive license to two bispecific antibodies for autoimmune and inflammatory bowel disease: HXN-1002 (α4β7 and TL1A) and HXN-1003 (TL1A and IL-23). Earendil receives $125 million upfront, is eligible for up to $1.72 billion in development and commercial milestones including a $50 million near-term payment, and tiered royalties from the high-single to low-double digits.
On July 21, 2022 Helixon posts OmegaFold, a single-sequence protein structure predictor, on bioRxiv and later open-sources the code. In June 2022 it closes a Series A of nearly CNY 500 million (about $75 million) led by 5Y Capital, with Gaorong Capital, Neumann Capital, Xianghe Capital, Hillhouse Ventures and Qingzhi Capital participating.
Jian Peng founds Helixon Therapeutics (华深智药) in June 2021, incubated at Tsinghua University's Institute for AI Industry Research, to build an AI scientific-computing platform for protein therapeutics. Dealroom records an about $10 million early round in October 2021 from Hillhouse, Xianghe Capital and Qingzhi Capital.
Funding
Cumulative disclosed raise · dated rounds
