ANZATAX

What it is

Anzatax is paclitaxel, an anticancer agent from the taxane class of drugs. Anzatax Injection Concentrate is a sterile solution containing 6 mg/mL paclitaxel. Paclitaxel is formulated in PEG-35 castor oil and ethanol because it is extremely hydrophobic. It is a concentrate for solution for injection.

Approved indications

— Primary treatment of ovarian cancer in combination with a platinum agent. — Treatment of metastatic ovarian cancer and metastatic breast cancer, after failure of standard therapy. — Treatment of non-small cell lung cancer (NSCLC). — Adjuvant treatment of node positive breast cancer administered sequentially to doxorubicin and cyclophosphamide. — Treatment of metastatic cancer of the breast, in combination with trastuzumab (Herceptin), in patients who have tumours that over-express HER-2 and who have not received previous chemotherapy for their metastatic disease.

Dosing overview

All patients should be premedicated before paclitaxel is administered. Premedication should include dexamethasone 20 mg orally 12 hours and 6 hours prior to starting the paclitaxel infusion, promethazine 25 mg to 50 mg intravenously or other suitable H1-antagonist 30 minutes prior to starting the infusion, and ranitidine 50 mg by intravenous infusion over 15 minutes, starting 30 minutes prior to the paclitaxel infusion.

Key safety warnings

In order to minimise hypersensitivity reactions due to histamine release, patients should be premedicated before every treatment cycle of paclitaxel with corticosteroids, antihistamines and an H2-receptor antagonist. The characteristic symptoms of hypersensitivity reactions are dyspnoea and hypotension both requiring treatment, angioedema and widespread urticaria. In clinical trials, 2% of patients treated with paclitaxel experienced severe hypersensitivity, and one of these reactions was fatal in a patient treated without premedication. As the dose limiting toxicity of paclitaxel is dose related bone marrow suppression (primarily neutropenia), paclitaxel should not be administered to patients with a pre-treatment neutrophil count of less than 1.5 × 10⁹ cells/L or platelet count of less than 100 × 10⁹ cells/L. Blood counts should be frequently monitored during treatment. Repetition of a course of paclitaxel is not recommended until the patient's neutrophil count is at least 1.5 × 10⁹ cells/L and the platelet count is at least 100 × 10⁹ cells/L. Peripheral neuropathy is frequently reported in patients receiving paclitaxel and the severity is dose dependent. Patients with pre-existing neuropathy should be carefully monitored, and a 20% reduction in paclitaxel dose for all subsequent courses is recommended for patients who develop severe peripheral neuropathy during therapy. Hypotension, hypertension and bradycardia have been observed during paclitaxel administration, but generally do not require treatment. Frequent monitoring of vital signs, particular during the first hours of paclitaxel infusion is recommended.

Contraindications

Anzatax must not be used in patients who have exhibited hypersensitivity reactions to paclitaxel or other taxanes. Anzatax must not be used in patients who have a history of hypersensitivity reactions to PEG-35 castor oil or drugs formulated in PEG-35 castor oil or any of the other excipients. Anzatax should not be administered in patients who have a baseline neutrophil counts of less than 1.5 × 10⁹ cells/L.

Regulatory history

Anzatax 30 mg/5 mL injection vial was first listed on the ARTG on 12 January 1995. Anzatax 150 mg/25 mL injection vial was first listed on the ARTG on 12 January 1995. Anzatax 300 mg/50 mL injection vial was first listed on the ARTG on 7 January 2003. Anzatax 100 mg/16.7 mL injection vial was first listed on the ARTG on 24 February 2005.