By Fineline Cube China’s National Medical Products Administration (NMPA) has granted approval for anbenitamab, a HER2 bispecific antibody developed through collaboration between Alphamab Oncology (HKG: 9966) and CSPC Pharmaceutical Group (HKG: 1093), for the treatment of adult patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma who have previously received at least one trastuzumab-containing regimen. The approval, supported by the pivotal Phase II/III KC-WISE study, demonstrated unprecedented efficacy with a 75% reduction in disease progression or death risk and 71% reduction in mortality risk compared to standard chemotherapy.
Regulatory Approval Details
| Item | Detail |
|---|---|
| Agency | NMPA (China) |
| Companies | Alphamab Oncology (9966.HK) and CSPC Pharmaceutical Group (HKG: 1093) |
| Product | Anbenitamab – HER2 bispecific antibody |
| Indication | Previously treated HER2-positive gastric/gastroesophageal junction adenocarcinoma |
| Regimen | Anbenitamab + chemotherapy |
| Approval Basis | Phase II/III KC-WISE study |
| Approval Date | Late May 2026 |
Clinical Trial Results
| Endpoint | Result (Anbenitamab + Chemo) | Comparator (Chemo alone) | Benefit |
|---|---|---|---|
| Progression-Free Survival (PFS) | 7.1 months | 2.7 months | 75% risk reduction (HR: 0.25; p<0.0001) |
| Overall Survival (OS) | 19.6 months | 11.5 months | 71% risk reduction (HR: 0.29; p<0.0001) |
| Patient Population | HER2-positive gastric/GEJ adenocarcinoma, ≥1 prior line including trastuzumab | Same population | Heavily pre-treated cohort |
| Additional Endpoints | Favorable ORR and DOR trends | Standard outcomes | Consistent benefit across all subgroups |
Drug Profile & Mechanism of Action
- Molecule: Anbenitamab – innovative HER2 bispecific antibody
- Target: Dual targeting of HER2 receptor with enhanced tumor cell killing
- Development Partnership: Joint development between Alphamab’s bispecific platform and CSPC’s commercial infrastructure
- Patient Population: Addresses critical unmet need in refractory HER2-positive gastric cancer
- Safety Profile: Demonstrated favorable tolerability consistent with known antibody safety profiles
Strategic Market Implications
The approval positions anbenitamab as a practice-changing therapy in China’s gastric cancer landscape:
- Market Opportunity: China accounts for approximately 40% of global gastric cancer cases, with HER2-positive rate of 15–20%
- Addressable Population: Estimated 25,000–30,000 eligible patients annually in China
- Clinical Impact: Median OS improvement from 11.5 to 19.6 months represents transformative benefit in refractory setting
- Competitive Positioning: First bispecific antibody approved for gastric cancer in China; no direct competitors in this specific indication
“This NMPA approval represents a landmark achievement for patients with HER2-positive gastric cancer who have exhausted standard treatment options,” said Dr. Tao Xu, Chief Executive Officer of Alphamab Oncology. “The unprecedented survival benefit demonstrated in the KC-WISE study establishes anbenitamab as a new standard of care for this difficult-to-treat population.”
Commercial Outlook & Partnership Dynamics
The Alphamab-CSPC collaboration leverages complementary strengths:
- Alphamab: Proprietary bispecific antibody technology and clinical development expertise
- CSPC: Extensive oncology commercial infrastructure and hospital relationships across China
- Pricing Strategy: Premium positioning reflecting magnitude of clinical benefit
- Market Access: Immediate inclusion in major cancer center formularies and provincial reimbursement negotiations
Industry analysts estimate peak annual sales potential of ¥2–3 billion ($280–420 million) in the Chinese market alone, with potential for international expansion leveraging the compelling clinical data package.
Forward‑Looking Statements
This brief contains forward-looking statements regarding regulatory approvals, commercial launches, and market opportunities for anbenitamab. Actual results may differ due to market adoption patterns, pricing negotiations, and competitive developments.-Fineline Info & Tech