Disitamab vedotin is a targeted antibody-drug conjugate (ADC) indicated for the treatment of HER2-expressing locally advanced or metastatic solid tumors such as gastric cancer and urothelial carcinoma. It must be administered strictly under medical prescription, with key focus on its indications, dosage, adverse reactions, and contraindications.
I. Indications and Pre-Administration Evaluation
Eligible Patients: Patients with specific solid tumors confirmed to have positive HER2 expression in tumor tissue or blood (e.g., immunohistochemistry result ≥1+ or positive ISH).
Contraindications:
Patients with hypersensitivity to any ingredient of the drug;
Pregnant women (may cause fetal harm);
Patients with uncontrolled severe hepatic or renal impairment.
Baseline Tests: Before treatment, HER2 testing, complete blood count (CBC), hepatic and renal function tests, and electrocardiogram (ECG, for cardiac function assessment) are required.
II. Dosage and Administration
Route of Administration
Intravenous infusion, to be performed only in hospitals or professional medical institutions. Do not adjust the dose or infusion rate without medical advice.
Standard Dose
Generally 2.5 mg/kg once every 2 weeks, adjusted individually based on body weight, tumor type, and treatment tolerance.
Infusion Management:
The first infusion should last at least 90 minutes;
Subsequent infusions may be shortened to 30 minutes if well-tolerated;
Monitor for hypersensitivity reactions during infusion.
III. Precautions and Adverse Reactions
Hypersensitivity Reactions
May manifest as rash, dyspnea, etc. Discontinue the drug immediately and initiate emergency treatment in severe cases.
Prophylactic anti-allergic medications may be used as directed by a physician before infusion.
Hematologic Toxicity
Common events include leukopenia and anemia. Regular CBC monitoring is required, and white blood cell-boosting agents may be administered if necessary.
Cardiac Toxicity
A small number of patients may develop decreased left ventricular ejection fraction (LVEF). ECG and echocardiography should be performed regularly during treatment.
Other Common Reactions
Fatigue, nausea, alopecia, decreased appetite, etc. Symptomatic management can be given for mild symptoms.
IV. Special Populations and Drug Interactions
Pregnancy/Lactation: Strict contraception is required during treatment and for 7 months after the last dose. Lactation must be suspended during treatment.
Concomitant Medications
Caution is advised when co-administered with hepatotoxic drugs (e.g., anti-tuberculosis agents) or cardiotoxic drugs. Inform the physician of all current medications.
V. Storage and Follow-Up
Storage Conditions: Unopened vials must be refrigerated at 2–8°C; avoid freezing or shaking. Prepared infusion solution should be used immediately.
Regular Follow-Up:
CBC and hepatic/renal function tests every 2–3 weeks during treatment;
Tumor progression assessment every 3 months.
Note: Disitamab vedotin is a prescription drug. The specific regimen shall be formulated by an oncologist based on individual conditions. Seek immediate medical attention if severe adverse reactions occur (e.g., persistent high fever, chest pain, dyspnea).
