Sino Biopharmaceutical Limited (SBP Group) reported positive Phase II data for TQC2938, the world’s first ST2-targeting monoclonal antibody to reach this stage in seasonal allergic rhinitis (SAR). Findings were delivered at the 2026 European Academy of Allergy and Clinical Immunology (EAACI) Congress.

The multicentre, randomised, double-blind, placebo-controlled study enrolled 136 adults with ≥2-year histories of moderate-to-severe SAR who had shown inadequate response to intranasal corticosteroid-antihistamine therapy. Participants were randomised 1:1:1:1 to receive a single subcutaneous dose of TQC2938 (210 mg, 420 mg or 630 mg) or placebo. Primary evaluation focused on the change from baseline in daily reflective Total Nasal Symptom Score (rTNSS) over two weeks; secondary measures included rTNSS at week 4, reflective Total Ocular Symptom Score (rTOSS) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at weeks 2 and 4, alongside safety metrics.

Key efficacy results: • The 420 mg cohort delivered the most pronounced benefit. rTNSS improvement versus placebo was –0.97 (95% CI: –2.18 to 0.24, p=0.1166) at two weeks and –1.37 (95% CI: –2.64 to –0.10, p=0.0342) at four weeks, meeting statistical significance at the latter timepoint. • All key secondary endpoints showed significant gains for the 420 mg group, including rTOSS and RQLQ at both assessment points. • Sub-analysis in patients with baseline eosinophil counts below 0.3 × 10⁹/L (approximately 60 % prevalence in the general population) revealed a –1.46 rTNSS change versus placebo at two weeks (95% CI: –2.87 to –0.06, p=0.0416).

Safety profile: • Treatment-emergent adverse events related to study drug occurred in 17.65 % of patients receiving 420 mg, comparable with 18.18 % for placebo. • No serious adverse events, Grade ≥3 events, deaths or discontinuations due to adverse events were observed in the 420 mg arm.

TQC2938 is a humanised IgG2 antibody that blocks the interaction between ST2 and IL-33, targeting both type 2 and non-type 2 inflammatory pathways. No ST2-directed biologics are currently approved worldwide, and no biologic therapy is available in China for SAR patients with eosinophil counts below 0.3 × 10⁹/L. The favourable safety and efficacy profile positions TQC2938 as a differentiated candidate and supports advancement into Phase III development.