# Kelun-Biotech's Partner Windward Bio Announces Positive Phase 2 Results of SKB378/WIN378 in Asthma, and Initiates Phase 3 Study

- Link: https://www.thailand-business-news.com/pr-news/kelun-biotechs-partner-windward-bio-announces-positive-phase-2-results-of-skb378-win378-in-asthma-and-initiates-phase-3-study
- Published: 2026-09-08T19:02:00+07:00
- Author: PR Newswire

|   |

 ◦ _The POLARIS-1 study enrolled 147 patients with uncontrolled, moderate-to-severe
   asthma, and the interim analysis was conducted on the first 98 patients. The 
   analysis demonstrated a half-life of up to 75 days, with clinical effects consistent
   with twice-yearly dosing. _
 ◦ _SKB378/WIN378 produced significant and sustained effects on FEV___(1)__ (up 
   to 174 mL mean increase, placebo-adjusted mean increases up to +256 mL, p=0.033),
   FeNO and blood eosinophils, key biomarkers that correlate with asthma exacerbations.
   These effects were rapid and sustained through Week 24 after a single dose of
   SKB378/WIN378._
 ◦ _SKB378/WIN378 was well tolerated with favorable safety results — there were 
   no treatment-related serious adverse events, withdrawals or discontinuations;
   adverse events were balanced between active arms and placebo, with low rates 
   of injection site reactions and anti-drug antibodies. _
 ◦ _The first Phase 3 study of SKB378/WIN378 has been initiated evaluating two twice-
   yearly doses. A second Phase 3 trial is planned to begin in the first half of
   2027._

CHENGDU, China, Sept. 8, 2026 /PRNewswire/ — Sichuan Kelun-Biotech Biopharmaceutical
Co., Ltd. ("Kelun-Biotech" or the "Company") today announced that its partner, Windward
Bio, has reported positive interim results from the Phase 2 portion of the POLARIS-
1 clinical trial, which evaluates twice-yearly dosing of SKB378/WIN378 in asthma.

SKB378/WIN378 is a novel fully human, ultra-long-acting monoclonal antibody with
a unique binding mode to inhibit thymic stromal lymphopoietin (TSLP). It was engineered
for improved potency, extended half-life and silenced effector function. It is the
only known investigational drug that blocks TSLP signaling by binding to two different
sites on TSLP, interfering with binding of TSLP to both of its co-receptors on the
cell surface of epithelial cells. 

POLARIS-1 is an operationally seamless, global Phase 2/3 study. The Phase 2 portion
of the study is a 48-week, randomized, double-blind study evaluating three dose 
levels of SKB378/WIN378 against placebo. It is designed to evaluate the pharmacokinetics,
safety, immunogenicity, and pharmacodynamic activity of SKB378/WIN378 in patients
with uncontrolled moderate-to-severe asthma. The study also evaluates the effects
of SKB378/WIN378 on lung function and biomarkers of airway inflammation and informed
dose selection for Phase 3 development. The Phase 2 portion of the study enrolled
a total of 147 patients, exceeding the initial enrollment target of 120 patients,
with the interim analysis conducted on the first 98 patients.

The interim analysis demonstrated the following at Week 24 after a single dose of
SKB378/WIN378:

 ◦ Dose-dependent mean increases in FEV_(1) of up to 174 mL (placebo-adjusted mean
   increase up to 256 mL, p=0.033).
 ◦ Dose-dependent mean reductions in FeNO of up to 24 ppb (or -43% change, p=0.006).
 ◦ Reductions in mean blood eosinophil count (EOS) of up to 200 cells/µL (or -51%
   change, p<0.0001).
 ◦ Near maximal effects seen as early as Week 2 and sustained through Week 24.

SKB378/WIN378 was well tolerated with favorable safety results, and there were no
treatment-related serious adverse events, withdrawals or discontinuations observed
as of the cut-off date. Adverse events were balanced between active arms and placebo.
Less than 1% of participants experienced injection site reactions, and 2% developed
anti-drug antibodies (ADAs), a measure of immunogenicity. ADAs had no impact on 
the pharmacology of SKB378/WIN378. The results of the interim analysis and population
pharmacokinetic modeling support the potential of twice-yearly dosing of SKB378/
WIN378.

Dr. Michael Ge, Chief Executive Officer of Kelun-Biotech, stated: "We are delighted
to see that the Phase 2 portion of POLARIS‑1 for SKB378/WIN378 has achieved positive
results, driven by the active efforts of our partner. As a differentiated, ultra-
long-acting anti-TSLP antibody, SKB378/WIN378 balances efficacy, safety, and patient
compliance, and holds the potential to address the unmet clinical needs in moderate-
to-severe asthma."

Two twice-yearly doses have been selected for the Phase 3 portion of POLARIS-1, 
which is designed to evaluate the effect of SKB378/WIN378 on annualized asthma exacerbation
rate and other key efficacy measures in patients with severe asthma. The Phase 3
portion of the study has been initiated by Windward Bio who plans to begin a second
Phase 3 study, POLARIS-2, in the first half of 2027. Data from the Phase 2 portion
of POLARIS-1 will be presented at an upcoming medical congress.

SKB378/WIN378 started as a co-development project jointly conducted by Kelun-Biotech
and Harbour BioMed, with both parties equally sharing global rights.

Notes: FEV_(1) (forced expiratory volume in one second) is a key measure of lung
function. FeNO (fractional exhaled nitric oxide) and EOS are key markers of inflammation
that correlate with exacerbations.

**About POLARIS-1 Study**

POLARIS-1 (NCT07120503) is an operationally seamless, global Phase 2/3 study of 
SKB378/WIN378 in adults with uncontrolled asthma conducted by Windward Bio. The 
Phase 2 portion is a randomized, double-blind study evaluating three dose levels
of SKB378/WIN378 administered subcutaneously against placebo, with primary objectives
of characterizing pharmacokinetics, safety, immunogenicity and pharmacodynamic activity,
as well as informing dose selection for Phase 3. The Phase 3 portion is evaluating
two twice-yearly doses of SKB378/WIN378 against placebo, with a primary endpoint
of annualized asthma exacerbation rate in patients with severe asthma.

**About SKB378/WIN378**

SKB378/WIN378 is a novel fully human, ultra-long-acting monoclonal antibody with
a unique binding mode to inhibit thymic stromal lymphopoietin (TSLP). This clinically
validated target plays a key role in the development and progression of a wide array
of immunological diseases, including asthma, chronic obstructive pulmonary disease(
COPD), chronic rhinosinusitis with nasal polyps, and eosinophilic esophagitis. SKB378/
WIN378 was engineered for improved potency, extended half-life and silenced effector
function. It is the only known investigational drug that blocks TSLP signaling by
binding to two different sites on TSLP, interfering with binding of TSLP to both
of its co-receptors on the cell surface of epithelial cells. Phase 2 interim results
support the potential of twice-yearly dosing. SKB378/WIN378 produced significant,
sustained and dose-dependent increases in FEV_(1), a measure of lung function, together
with significant and sustained reductions in FeNO and blood eosinophils — key markers
that correlate with asthma exacerbations. SKB378/WIN378 is being evaluated in the
global Phase 2/3 POLARIS-1 study in asthma and the Phase 2 SIRIUS study in COPD,
with a second pivotal Phase 3 asthma trial, POLARIS-2, planned to begin in the first
half of 2027. Windward Bio licensed the global rights (excluding Greater China and
several Southeast and West Asian countries) for this molecule from Kelun-Biotech(
also known as SKB378) and Harbour BioMed (also known as HBM9378).

**About Kelun-Biotech**

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses
on the R&D, manufacturing, commercialization and global collaboration of innovative
biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease
areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing
a globalized drug development and industrialization platform to address the unmet
medical needs in China and the rest of world. Kelun-Biotech is committed to becoming
a leading global enterprise in the field of innovative drugs. At present, Kelun-
Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects
with 8 indications have been approved for marketing, 2 projects with 3 indications
are in the NDA stage and more than 10 projects are in the clinical stage. Kelun-
Biotech has established one of the world’s leading proprietary ADC and novel DC 
platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing,
and multiple ADC and novel DC assets in clinical or preclinical research stage. 
For more information, please visit: [https://en.kelun-biotech.com/](https://en.kelun-biotech.com/).

**About Windward Bio **

Windward Bio is a clinical-stage biotechnology company with deep discovery, development
and commercial expertise, developing ultra-long-acting antibodies for patients with
serious respiratory and dermatologic diseases, including asthma, COPD, and atopic
dermatitis. The Company is advancing a pipeline of potentially differentiated biologics
targeting clinically validated molecular pathways, with the goal of improving clinical
outcomes while reducing treatment burden through less frequent dosing. Windward 
Bio’s lead program is WIN378, a novel fully human monoclonal antibody engineered
for improved potency, extended half-life and silenced effector function, targeting
TSLP. WIN378 is in clinical development for asthma and COPD. The Company’s second
program is WIN027, an ultra-long-acting, humanized bispecific antibody targeting
TSLP and IL-13 in development for respiratory and dermatologic diseases. Windward
Bio was founded in 2024 and is headquartered in Basel, Switzerland, with operations
in the United States. For more information, please visit: [https://windwardbio.com/](https://windwardbio.com/).

---

  |  This article was produced by Cision PR Newswire, our trusted news partner. The views expressed and the content presented here are solely those of the author and may not fully reflect the opinions of Thailand Business News. |

---

 
**Read the original article :** [Kelun-Biotech's Partner Windward Bio Announces Positive Phase 2 Results of SKB378/WIN378 in Asthma, and Initiates Phase 3 Study ](http://www.prnasia.com/story/archive/5042289_AE42289_0?rand=184833)