Datopotamab (Datroway) is a Trop-2-targeted antibody-drug conjugate (ADC). It was first approved in the United States in 2025 for the treatment of adult patients with unresectable or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer who have previously received endocrine therapy and chemotherapy.

Precautions for Administration of Datopotamab (Datroway)

Dosage Regimen

(1) The standard recommended dosage of Datroway is 6 mg/kg (with a maximum dosage of 540 mg for patients with a body weight ≥ 90 kg).

(2) Intravenous infusion is administered once every 3 weeks (a 21-day treatment cycle).

(3) Administration continues until disease progression or the occurrence of intolerable toxicity.

Operational Specifications

(1) Route of Administration: For intravenous infusion only; intravenous push or rapid injection is prohibited.

(2) Solvent Selection: Must be diluted with 5% dextrose injection; sodium chloride injection is strictly prohibited.

(3) Infusion Equipment: Infusion sets made of polyvinyl chloride (PVC), polybutadiene, or low-density polyethylene (LDPE) must be used, together with a 0.2-micron filter made of polytetrafluoroethylene (PTFE), polyethersulfone (PES), or nylon 66.

(4) Administration Time: The first infusion should last 90 minutes. If well tolerated, the second and subsequent infusions can be shortened to 30 minutes.

(5) Pretreatment Medication: 30-60 minutes before each administration, prophylactic use of antihistamines (e.g., diphenhydramine 25-50 mg), antipyretics (e.g., paracetamol 650-1000 mg), and antiemetics (5-HT3 receptor antagonists) is required.

Interstitial Lung Disease (ILD)/Pneumonitis

(1) Datroway may cause severe, life-threatening, or even fatal interstitial lung disease (ILD)/pneumonitis.

(2) During medication use, close monitoring of new or worsening respiratory symptoms (such as dyspnea, cough, fever, etc.) is necessary.

(3) Once ILD/pneumonitis is suspected, administration should be immediately suspended and corticosteroid therapy (e.g., prednisone ≥ 1 mg/kg per day) initiated.

(4) For confirmed ILD/pneumonitis of grade ≥ 2, permanent discontinuation of the drug is required.

Ocular Adverse Reactions

(1) Approximately 51% of patients will experience ocular adverse reactions, including dry eye (27%), keratitis (24%), blepharitis (8%), increased tear secretion (8%), and meibomian gland dysfunction (7%).

(2) All patients should undergo an ophthalmic examination (including visual acuity, slit-lamp examination, intraocular pressure measurement, and fundus examination) before the start of treatment, with annual re-examinations during treatment and another assessment at the end of treatment.

(3) Patients are advised to use preservative-free artificial tears multiple times a day and avoid wearing contact lenses during treatment (unless recommended by an ophthalmologist).

Stomatitis

(1) Approximately 59% of patients will develop stomatitis, of which 7% are grade 3-4.

(2) Preventive measures include: using steroid-containing mouthwash (e.g., dexamethasone oral solution 0.1 mg/mL) four times a day, and holding ice chips or ice water in the mouth during Datroway infusion.

(3) When stomatitis occurs, the frequency of mouth rinsing should be increased; suspension, dosage reduction, or permanent discontinuation of the drug should be considered based on the severity.

Embryo-Fetal Toxicity

(1) DXd, the topoisomerase inhibitor component in Datroway, has genotoxicity and cytotoxicity and may cause harm to the fetus.

(2) Women of childbearing age should take effective contraceptive measures during treatment and for 7 months after the last dose.

(3) Male patients with partners of childbearing age should take effective contraceptive measures during treatment and for 4 months after the last dose.

Medication Monitoring for Datopotamab (Datroway)

Pre-Treatment Assessment

(1) Baseline Examination: Includes laboratory tests such as complete blood count, liver function, renal function, and electrolytes.

(2) Respiratory Function Assessment: Conduct a detailed inquiry about the history of lung diseases; if there is a history of ILD/pneumonitis, a careful assessment is required.

(3) Ophthalmic Examination: Includes visual acuity, slit-lamp examination (fluorescein staining), intraocular pressure measurement, and fundus examination.

(4) Pregnancy Testing: Women of childbearing age must confirm they are not pregnant.

(5) Tumor Assessment: Clarify the disease status through imaging examinations, which serve as the baseline for subsequent efficacy evaluation.

Routine Monitoring

(1) Hematological Monitoring: Complete blood count is checked before each treatment cycle. Common abnormalities include leukopenia (41%), lymphopenia (36%), hemoglobin reduction (35%), and neutropenia (30%).

(2) Biochemical Monitoring: Regularly check liver function (elevated ALT/AST is seen in 24%/23% of patients respectively), blood calcium (reduced in 39% of patients), and alkaline phosphatase (elevated in 23% of patients).

(3) Infusion Reaction Monitoring: Observe for at least 1 hour after the first infusion; observation for 1 hour is required in the first 2 cycles; for subsequent cycles, if well tolerated, the observation time can be shortened to 30 minutes.