Sino Biopharmaceutical Limited (SBP GROUP) has announced that its subsidiary, Chia Tai Tianqing Pharmaceutical Group, presented detailed results from a Phase II clinical study for its proprietary, novel ST2-targeting monoclonal antibody, TQC2938, at the 2026 European Academy of Allergy and Clinical Immunology (EAACI) Annual Congress.
The investigational drug, TQC2938, is the first ST2 antibody globally to report positive clinical data for treating Seasonal Allergic Rhinitis (SAR), offering a potential new therapeutic or preventive strategy for patients with moderate-to-severe SAR who respond inadequately to existing treatments.
The study was a randomized, double-blind, placebo-controlled, parallel-group Phase II trial involving 136 adult participants with at least a two-year history of moderate-to-severe SAR and an inadequate response to intranasal corticosteroids combined with antihistamines.
Participants were randomly assigned in a 1:1:1:1 ratio to receive a single subcutaneous injection of either TQC2938 at doses of 210 mg, 420 mg, or 630 mg, or a placebo, with balanced baseline characteristics across all groups.
The primary endpoint was the mean change from baseline in the daily reflective Total Nasal Symptom Score (rTNSS) over a two-week treatment period. Key secondary endpoints included the rTNSS over four weeks, daily reflective Total Ocular Symptom Score (rTOSS) over two and four weeks, and changes in the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score from baseline at weeks two and four. Safety was also evaluated.
Results indicated that among the three TQC2938 dose groups, the 420 mg dose demonstrated the most pronounced overall efficacy in improving nasal symptoms.
During the initial two-week period, the change in rTNSS for the 420 mg group compared to placebo was -0.97 (95% CI: -2.177 to 0.244, p=0.1166). Over the extended four-week period, this change improved to -1.37 (95% CI: -2.638 to -0.103, p=0.0342), showing a statistically significant and clinically meaningful improvement.
Furthermore, compared to placebo, the 420 mg dose group showed statistically significant improvements across all key secondary endpoints, including rTNSS at four weeks, rTOSS at two and four weeks, and RQLQ scores at two and four weeks.
Subgroup analyses revealed that the 420 mg dose provided consistent and stable clinical benefits across all evaluated subgroups. Notably, in the subgroup with a baseline blood eosinophil count (EOS) of less than 0.3×10^9/L, the 420 mg group (n=24) showed a more pronounced improvement trend versus the placebo group (n=26), with an rTNSS change of -1.46 (95% CI: -2.865 to -0.057, p=0.0416) during the two-week period.
Regarding safety, the 420 mg dose group exhibited a favorable profile. The incidence of drug-related Treatment-Emergent Adverse Events (TEAEs) was 17.65%, comparable to the placebo group's rate of 18.18%. No serious adverse events, Grade 3 or higher TEAEs, deaths, or study discontinuations due to TEAEs were reported in this dose group.
TQC2938 is a humanized IgG2 monoclonal antibody developed by Chia Tai Tianqing that specifically binds to the human ST2 protein, blocking its interaction with the ligand IL-33. This mechanism simultaneously inhibits both Type 2 and non-Type 2 inflammatory pathways involved in the disease.
Currently, there are no approved biologics in China specifically for SAR patients with an EOS count below 0.3×10^9/L. Research indicates this subgroup represents a larger portion of the general population, approximately 60%, highlighting a significant and unmet clinical need in this area.
The positive Phase II results for TQC2938 in SAR patients suggest it could offer an improved treatment option for this population. Globally, no ST2-targeting biologic has yet received market approval.
TQC2938 is the first ST2 monoclonal antibody to establish a differentiated position and achieve positive clinical outcomes in the SAR treatment field. The presentation of these Phase II results provides a solid foundation for advancing the program into Phase III clinical trials.