Ennituo Anbenitamab Injection

1. Indications and Usage
Anbenitamab Injection (KN026; brand name: Enyituo®/恩尼妥®) is indicated in combination with chemotherapy for the treatment of adult patients with locally advanced or metastatic HER2-positive gastric cancer or gastroesophageal junction adenocarcinoma who have previously received at least one trastuzumab-containing regimen.
2. Dosage and Administration
Recommended Dose: 30 mg/kg administered by intravenous infusion once every 3 weeks.
Administration: Administer as an IV infusion in combination with chemotherapy (paclitaxel, docetaxel, or irinotecan) as determined by the treating physician.
Dose Modifications: Withhold or reduce dose in the event of infusion-related reactions or other clinically significant toxicities.
Premedication: Consider premedication per institutional protocol to reduce infusion-related reactions.
3. Mechanism of Action
Anbenitamab is a humanized biparatopic bispecific IgG1κ monoclonal antibody that simultaneously binds two non-overlapping epitopes on HER2 (domains II and IV). This dual binding blocks HER2 signaling, promotes receptor clustering, internalization and degradation, and enhances antibody-dependent cellular cytotoxicity (ADCC), thereby inhibiting tumor cell proliferation and inducing apoptosis.
4. Safety and Warnings
Infusion-Related Reactions: Monitor patients during and after infusion; interrupt or discontinue for severe reactions.
Cardiotoxicity: HER2-targeted therapies may cause left ventricular dysfunction. Assess cardiac function prior to and during treatment.
Embryo-Fetal Toxicity: May cause fetal harm. Advise patients of reproductive potential to use effective contraception during treatment and for a period after the last dose.
Hepatotoxicity and Interstitial Lung Disease: Monitor liver function and pulmonary symptoms; discontinue if severe toxicity occurs.
Immunogenicity: Clinical data indicate low immunogenicity.
5. Adverse Reactions and Clinical Research
Common Adverse Reactions: Infusion-related reactions, neutropenia, anemia, thrombocytopenia, fatigue, nausea, diarrhea, elevated liver enzymes, and decreased appetite.
Clinical Research: The pivotal Phase II/III KC-WISE trial (NCT05427383) demonstrated that anbenitamab plus chemotherapy significantly improved progression-free survival and overall survival compared with chemotherapy alone in HER2-positive GC/GEJ cancer previously treated with trastuzumab, with median OS of 20.9 months versus approximately 11 months with standard chemotherapy. No new safety signals were identified.
6. Drug Interactions
No formal drug interaction studies have been published. Concomitant use with other HER2-targeted agents (e.g., trastuzumab, pertuzumab) outside of clinical trials is not recommended due to overlapping mechanisms and potential additive cardiotoxicity.
7. Pharmaceutical Information
Active Ingredient: Anbenitamab (KN026).
Drug Class: Bispecific monoclonal antibody (HER2 biparatopic IgG1κ).
Strength: 360 mg/14.4 mL (25 mg/mL) single-dose vial.
Description: Sterile solution for intravenous infusion.
Storage: Store refrigerated at 2°C–8°C; protect from light. Do not freeze or shake.
Developer: Alphamab Oncology / CSPC Pharmaceutical Group (JMT-Bio).