Instructions for Trastuzumab

1. Generic name: Trastuzumab

Product name:Herceptin

All names: Trastuzumab,Trastuzumab, Herceptin, Herceptin

2. Indications:

1. Auxiliary breast cancer:

Trastuzumab (Trastuzumab)Applicable topositive or negative lymph nodes with overexpression of HER2 (ER/P R-negative or with a high-risk feature) breast cancer, either as part of a regimen consisting of doxorubicin, cyclophosphamide, and paclitaxel or docetaxel, or as part of a regimen of docetaxel and carboplatin, as a single agent after multimodal anthracycline therapy.

2. Metastatic breast cancer:

Trastuzumab is indicated in combination with paclitaxel for the first-line treatment of HER2-overexpressing metastatic breast cancer and as a single agent for the treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease.

3. Metastatic gastric cancer:

Trastuzumab is indicated in combination with cisplatin and capecitabine or 5-fluorouracil for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease.

3. Usage and dosage:

1. Recommended dosage: Trastuzumab should not be administered as an intravenous push or bolus injection, and it cannot be mixed with other drugs. Trastuzumab is not a substitute for ado-trastuzumab emtansine.

(1)Adjuvant breast cancer:

Approximately total requiredFor 52 weeks of trastuzumab treatment, if administered in combination with paclitaxel, docetaxel, or docetaxel/carboplatin, during the first 12 weeks (paclitaxel or docetaxel) or 18 weeks (docetaxel/carboplatin) of chemotherapy, the initial dose is 4 mg/kg IV over 90 minutes, followed by 2 mg/kg IV over 30 minutes weekly. One week after the last weekly dose of trastuzumab, 6 mg/kg of trastuzumab is administered as an intravenous infusion over 30 to 90 minutes every three weeks. If used as a single agent within three weeks of completing a multimodal anthracycline-based chemotherapy regimen, trastuzumab is administered at an initial dose of 8 mg/kg as an intravenous infusion over 90 minutes, followed by doses of 6 mg/kg as an intravenous infusion over 30 to 90 minutes every three weeks. Extending adjuvant therapy beyond one year is not recommended.

(2)Metastatic breast cancer: Use trastuzumab alone or in combination with paclitaxel at an initial dose of 4 mg/kg as an intravenous infusion over 90 minutes, followed by 2 mg/kg as an intravenous infusion over 30 minutes once weekly until disease progression.

(3) Metastatic gastric cancer : The initial dose of trastuzumab is 8 mg/kg intravenously over 90 minutes, followed by 6 mg/kg intravenously over 30-90 minutes every three weeks until disease progression.

2. Repeated administration:

If the patient has not taken trastuzumab in one week or less, the usual maintenance dose (weekly schedule: 2 mg/kg; three-week schedule: 6 mg/kg) should be administered as soon as possible without waiting until the next scheduled cycle. Subsequent trastuzumab maintenance doses should be administered after 7 or 21 days according to a weekly or every three-week schedule, respectively. If a patient misses a dose of trastuzumab for more than a week, a new dose of trastuzumab (once weekly: 4 mg/kg; three-week schedule: 8 mg/kg) should be taken as soon as possible, within approximately 90 minutes. Subsequent maintenance doses of trastuzumab (weekly regimen: 2 mg/kg; three-week regimen: 6 mg/kg) should be administered after 7 or 21 days according to the weekly or three-week regimen, respectively.

4. Adverse reactions:

The most common adverse reactions in patients with metastatic breast cancer receiving adjuvant trastuzumab are pyrexia, nausea, vomiting, infusion reactions, diarrhea, infection, worsening cough, headache, fatigue, dyspnea, rash, neutropenia, anemia, and myalgia.

In the setting of metastatic gastric cancer, the most common adverse reactions that were increased (≥10%) with trastuzumab compared with chemotherapy alone were neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infection, pyrexia, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia.

5. Storage:

Trastuzumab is supplied as a lyophilized sterile powder under vacuum in single-dose vials and typically stored in a refrigerator at 2°C to 8°C (36°F to 46°F) until To reconstitute, if not for immediate use, store the reconstituted trastuzumab solution at 2°C to 8°C (36°F to 46°F) for 24 hours. Discard any unused trastuzumab after 24 hours. Do not freeze.

6. Special groups:

Trastuzumab can cause harm to the fetus when administered to pregnant women, and in postmarketing reports, trastuzumab use during pregnancy resulted in a series of cases of oligohydramnios and oligohydramnios, manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. If trastuzumab is used in a pregnant woman, or if the patient becomes pregnant within 7 months of the last dose of trastuzumab, there are clinical considerations and women of childbearing potential should use effective contraception during treatment with trastuzumab and for 7 months after the last dose of trastuzumab.

7. Mechanism of action:

The HER2 ( or c-erbB2) proto-oncogene encodes a 185kDa transmembrane receptor protein that is structurally related to the epidermal growth factor receptor. In both in vitro and animal experiments, trastuzumab has been shown to inhibit the proliferation of human tumor cells that overexpress HER2. Trastuzumabis a mediator of antibody-dependent cellular cytotoxicity (ADCC). In vitro, trastuzumabmediated ADCC was shown to preferentially act on cancer cells that overexpress HER2 compared with cancer cells that do not overexpress HER2.

Trastuzumab is sold under the brand name Herceptin in China and has entered the scope of Class B medical insurance, but it may be limited to patients who meet the indications for this drug, such as patients with HER2-positive metastatic breast cancer and its adjuvant and neoadjuvant treatment or HER2-positive metastatic gastric cancer. The price is around 6,000 yuan. The original trastuzumab drug has also been launched overseas. The ingredients of domestic and foreign original drugs are basically the same. For specific prices and drug details, you can consult a medical consultant. Currently, there are no generic trastuzumab drugs on the market.