Let003 demonstrates superior pharmacokinetics compared with competing antibodies, and when paired with semaglutide, it enhances fat loss while preserving lean mass.

HBM HOLDINGS-B disclosed preclinical data on LET003, a next‑generation monoclonal antibody targeting ACVR2A/2B, developed with the Hu-mAtrIx AI platform for obesity research.

In preclinical models, LET003 showed significantly slower blood clearance in human FcRn transgenic mice and cynomolgus monkeys, suggesting the potential for longer dosing intervals or lower doses.

Harbour BioMed is HKEX-listed and leverages Harbour Mice, HCAb Plus, HBICE, and the Hu-mAtrIx AI platform to accelerate discovery and development in immunology and oncology.

The company, listed as HKEX: 02142, focuses on antibody therapeutics in immunology and oncology, utilizing Harbour Mice, HCAb, HBICE, and AI-driven platforms.

The company attributes LET003’s favorable pharmacokinetics and efficacy to the Hu-mAtrIx AI platform and Harbour Mice technology, with the aim of speeding clinical development.

Context: ACVR2A/2B signaling governs fat and muscle balance, and prior data with bimagrumab informs ongoing AI‑driven optimization via Hu-mAtrIx.

An additional normal-diet mouse study showed LET003 increased lean mass by 18.3% versus vehicle and 13.5% against a comparator, with overall body weight rising 11.1% versus vehicle and 9.3% versus comparator.

In a normal-diet FcRn mouse study, LET003 raised lean mass by 18.3% and overall body weight by 11.1% versus vehicle, outperforming a comparator molecule.