Harbour BioMed Reports Positive Phase I Results for HBM9378 Antibody

The TSLP-targeting antibody demonstrated a favorable safety profile and extended half-life in healthy subjects, supporting further clinical development.

Mar. 23, 2026 at 5:04am

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Harbour BioMed, a global biopharmaceutical company, announced the online publication of positive results from the first-in-human Phase I trial of its novel antibody HBM9378 (also known as SKB378 or WIN378). The study in 50 healthy adult subjects showed the antibody had a favorable safety profile and extended half-life, supporting further exploration in patients with severe immunological disorders.

Why it matters

HBM9378 is a potentially best-in-class, long-acting monoclonal antibody targeting thymic stromal lymphopoietin (TSLP), a key cytokine involved in the development and progression of various immunological diseases like asthma and chronic obstructive pulmonary disease (COPD). The positive Phase I results reinforce the promise of HBM9378 to address unmet medical needs in these conditions.

The details

The randomized, double-blind, placebo-controlled, single-ascending-dose study enrolled 50 healthy adults, with 8 receiving HBM9378 and 2 receiving placebo across 5 dose cohorts (20 mg, 60 mg, 200 mg, 600 mg, and 900 mg). The data showed the incidence of treatment-emergent adverse events was comparable between HBM9378 and placebo, with no trend for increasing safety risks with dose escalation. The median time to maximum concentration ranged from 4.05 to 14.1 days, and the mean half-life ranged from 55.0 to 65.8 days. HBM9378 exposure increased in a dose-proportional manner.

  • The Phase I trial was conducted under an Investigational New Drug (IND) application in China.
  • Harbour BioMed has completed the Phase I trial and is now planning further clinical development of HBM9378.

The players

Harbour BioMed

A global biopharmaceutical company committed to developing novel antibody therapeutics, including HBM9378.

Dr. Jingsong Wang

Founder, Chairman, and CEO of Harbour BioMed.

Dr. Min Xu

Physician in Respiratory Medicine at Chengdu Fifth People's Hospital and Principal Investigator of the HBM9378 Phase I study.

Kelun-Biotech

A holding subsidiary of Kelun Pharmaceutical that co-developed HBM9378 with Harbour BioMed.

Windward Bio

A clinical-stage biotechnology company that licensed global rights to HBM9378 (also known as WIN378) from Harbour BioMed and Kelun-Biotech.

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What they’re saying

“The positive Phase I results for HBM9378 mark a significant milestone in our mission to develop innovative therapies for immunological diseases.”

— Dr. Jingsong Wang, Founder, Chairman, and CEO of Harbour BioMed

“This Phase I clinical trial demonstrates that HBM9378 is well-tolerated and exhibits a favorable pharmacokinetic profile in healthy subjects. The extended half-life of HBM9378 may reduce dosing frequency in clinical practice, potentially enhancing patient adherence and improving outcomes.”

— Dr. Min Xu, Physician in Respiratory Medicine, Chengdu Fifth People's Hospital and Principal Investigator

What’s next

A global Phase II POLARIS trial for the treatment of moderate-to-severe asthma was initiated by Windward Bio in July 2025. Additionally, the National Medical Products Administration (NMPA) of China has approved the IND application of HBM9378 for the treatment of COPD.

The takeaway

The positive Phase I results for Harbour BioMed's HBM9378 antibody, which targets the key immunological cytokine TSLP, demonstrate its potential to address unmet needs in severe asthma, COPD, and other immunological disorders. The extended half-life and favorable safety profile support further clinical development of this promising therapeutic.