Trastunix

Generic Name : Trastuzumab

Indications

Adjuvant Breast Cancer: Trastunix is indicated for adjuvant treatment of HER2 overexpressing node-positive or node-negative ER/PR negative or with one high-risk feature breast cancer

• as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel
• as part of a treatment regimen with docetaxel and carboplatin
• as a single agent following multi-modality anthracycline-based therapy.

Metastatic Breast Cancer: Trastunix is indicated:

• In combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer
• As a single agent for treatment of HER2-overexpressing breast cancer in a patient who has received one or more chemotherapy regimens for metastatic disease. overexpressing breast cancer in patient.

Metastatic Gastric Cancer: Trastunix 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.

Pharmacology

The HER2 (or c-erbB2) proto-oncogene encodes a transmembrane receptor protein of 185 kDa, which is structurally related to the epidermal growth factor receptor. Trastuzumab has been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumor cells that overexpress HER2. Trastuzumab is a mediator of antibody-dependent cellular cytotoxicity (ADCC). In vitro, Trastuzumab-mediated ADCC has been shown to be preferentially exerted on HER2 overexpressing cancer cells compared with cancer cells that do not overexpress HER2.

Dosage

Recommended Doses and Schedules: Do not administer as an intravenous push or bolus. Do not mix Trastuzumab with other drugs.

Adjuvant Treatment, Breast Cancer: Administer according to one of the following doses and schedules for a total of 52 weeks of Trastuzumab therapy:

During and following paclitaxel, docetaxel, or docetaxel/carboplatin:

• Initial dose of 4 mg/kg as an intravenous infusion over 90 minutes then at 2 mg/kg as an intravenous infusion over 30 minutes weekly during chemotherapy for the first 12 weeks (paclitaxel or docetaxel) or 18 weeks (docetaxel/carboplatin).
• One week following the last weekly dose of Trastuzumab, administer Trastuzumab at 6 mg/kg as an intravenous infusion over 30−90 minutes every three weeks.

As a single agent within three weeks following completion of multi-modality, anthracycline-based chemotherapy regimens:

• Initial dose at 8 mg/kg as an intravenous infusion over 90 minutes
• Subsequent doses at 6 mg/kg as an intravenous infusion over 30−90 minutes every three weeks.
• Extending adjuvant treatment beyond one year is not recommended

Metastatic Treatment, Breast Cancer: Administer Trastuzumab, alone or in combination with paclitaxel, at an initial dose of 4 mg/kg as a 90 minute intravenous infusion followed by subsequent once-weekly doses of 2 mg/kg as 30-minute intravenous infusions until disease progression.

Metastatic Gastric Cancer: Administer Trastuzumab at an initial dose of 8 mg/kg as a 90-minute intravenous infusion followed by subsequent doses of 6 mg/kg as an intravenous infusion over 30–90 minutes every three weeks until disease progression. Or, as directed by the registered physician.

Administration

• Using a sterile syringe, slowly inject the 20 ml of diluent into the vial containing the lyophilized powder of Trastuzumab, which has a cake-like appearance. The stream of diluent should be directed into the cake. The reconstituted vial yields a solution for multiple-dose use, containing 21 mg/ml Trastuzumab.
• Swirl the vial gently to aid reconstitution. DO NOT SHAKE.
• Slight foaming of the product may be present upon reconstitution. Allow the vial to stand undisturbed for approximately 5 minutes.
• Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Inspect visually for particulates and discoloration. The solution should be free of visible particulates, clear to slightly opalescent and colorless to pale yellow.
• Store reconstituted Trastuzumab in the refrigerator at 2°C to 8°C, discard unused Trastuzumab after 28 days. If Trastuzumab is reconstituted with SWFI without preservative, use immediately and discard any unused portion.