Bambusa Reports Positive Phase 1 Data for Dual-Targeting Bispecific Antibody BBT002 in Type 2 Inflammatory Diseases

Bambusa Therapeutics has reported positive preliminary results from the multiple ascending dose (MAD) portion of a phase 1 study evaluating BBT002, a next-generation bispecific antibody designed to target both IL-4 receptor alpha (IL-4Rα) and interleukin-5 (IL-5). The findings, presented at the European Academy of Allergy and Clinical Immunology Annual Congress 2026, demonstrated sustained pharmacodynamic activity, favorable tolerability, and pharmacokinetic characteristics that may support extended dosing intervals.¹

BBT002 is being developed for Type 2 inflammatory diseases, including chronic obstructive pulmonary disease (COPD) and chronic rhinosinusitis with nasal polyps (CRSwNP). The investigational therapy combines inhibition of the IL-4/IL-13 pathway through IL-4Rα with blockade of the IL-5 eosinophil pathway, two mechanisms implicated in Type 2 inflammation.¹

“We are highly encouraged by the preliminary Phase 1 multiple ascending dose data of BBT002,” said Thang Ho, PhD, chief development officer of Bambusa Therapeutics. “BBT002 continues to demonstrate rapid, deep, and sustained biologic activity across multiple clinically relevant biomarkers, including eosinophils, TARC, and pSTAT6, while also supporting the potential for extended dosing intervals through prolonged half-life.”¹

Could dual IL-4Rα and IL-5 inhibition improve treatment of type 2 inflammatory diseases?

The study evaluated safety, tolerability, pharmacokinetics, immunogenicity, and pharmacodynamic effects in healthy volunteers. Investigators reported rapid and sustained reductions in multiple biomarkers associated with Type 2 inflammation.

Eosinophil levels, a marker linked to IL-5 signaling and airway inflammation, remained suppressed for more than eight weeks following multiple doses. Researchers also observed dose-dependent reductions in thymus and activation-regulated chemokine (TARC), a biomarker associated with Th2-driven immune responses. In addition, BBT002 produced rapid and sustained inhibition of phosphorylated STAT6 (pSTAT6), a downstream mediator of IL-4Rα signaling.¹

The combined biomarker findings suggest that BBT002 may simultaneously modulate complementary inflammatory pathways that contribute to respiratory and eosinophilic diseases. Current biologic therapies often target a single cytokine pathway, while bispecific approaches aim to address multiple disease drivers within one treatment.²

Extended half-life supports infrequent dosing

Pharmacokinetic analyses showed that BBT002 achieved a half-life of approximately 29.4 days, consistent with findings from previously reported single ascending dose cohorts. According to the company, the prolonged exposure profile supports the possibility of extended maintenance dosing intervals.¹

The therapy was generally well tolerated across both single and multiple ascending dose cohorts, with no apparent impact of anti-drug antibodies on safety or pharmacokinetics.¹

The results arrive as competition continues to intensify in the immunology and inflammation sector, particularly among therapies targeting Type 2 inflammatory pathways. Existing biologics directed against IL-4Rα or IL-5 have demonstrated clinical benefit in diseases such as atopic dermatitis, asthma, and CRSwNP, validating both targets as important therapeutic mechanisms.³

Bambusa is currently evaluating BBT002 in proof-of-concept studies in patients with COPD and CRSwNP. The company expects topline COPD data by the end of 2026 and CRSwNP results during the first half of 2027.¹

If future studies confirm that simultaneous inhibition of IL-4Rα and IL-5 translates into improved clinical outcomes, BBT002 could offer a differentiated treatment approach for patients with Type 2 inflammatory diseases.

References

1. Bambusa Therapeutics Presents Positive Preliminary Multiple Ascending Dose Phase 1 Data for BBT002 at the European Academy of Allergy & Clinical Immunology Annual Congress 2026. (2026 Jun 15). PR Newswire. https://www.prnewswire.com/news-releases/bambusa-therapeutics-presents-positive-preliminary-multiple-ascending-dose-phase-1-data-for-bbt002-at-the-european-academy-of-allergy--clinical-immunology-eaaci-annual-congress-2026-302799221.html
2. Zhao Q. (2020 Apr). Bispecific Antibodies for Autoimmune and Inflammatory Diseases: Clinical Progress to Date. BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy. https://doi.org/10.1007/s40259-019-00400-2
3. Bachert C., Zhang N., Cavaliere C., et al. (2020 Mar). Biologics for chronic rhinosinusitis with nasal polyps. J Allergy Clin Immunol. https://www.sciencedirect.com/science/article/abs/pii/S0091674920301093