ENOXAJECT

What it is

Enoxaject is a biosimilar medicine to Clexane. It contains enoxaparin sodium and is available as ready-to-use, prefilled syringes in strengths of 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg and 150 mg. The evidence for comparability supports the use of Enoxaject for the listed indications.

Approved indications

— Prevention of thrombo-embolic disorders of venous origin in patients undergoing orthopaedic and general surgery. — Prophylaxis of venous thromboembolism in medical patients bedridden due to acute illness. — Prevention of thrombosis in extra-corporeal circulation during haemodialysis. — Treatment of established deep vein thrombosis. — Treatment of unstable angina and non-Q-wave myocardial infarction, administered concurrently with aspirin. — Treatment of acute ST-segment Elevation Myocardial Infarction (STEMI) as an adjunctive to thrombolytic treatment, including patients to be managed medically or with subsequent Percutaneous Coronary Intervention (PCI).

Dosing overview

Prophylaxis against thromboembolism should be tailored according to the patient's risk. In patients with high risk of thromboembolism, a dose of 40 mg should be administered subcutaneously once daily. In patients with moderate risk of thromboembolism, the recommended dose is 20 mg subcutaneously once daily. Prophylaxis should be continued for 7 to 10 days or until the risk of thromboembolism has diminished. For prophylaxis of venous thromboembolism in medical patients, the recommended dose is 40 mg once daily by subcutaneous injection for a minimum of 6 days, continuing for a maximum of 14 days or less if the patient returns to full ambulation earlier than 14 days. For treatment of established deep vein thrombosis, the recommended dosage is 1.5 mg/kg body weight once daily (150 IU anti-Xa activity/kg bodyweight) or 1 mg/kg body weight (100 IU anti-Xa activity/kg bodyweight) twice daily subcutaneously. For treatment of unstable angina and non-Q-wave myocardial infarction, the recommended dose is 1 mg/kg (100 IU anti-Xa activity/kg) every 12 hours by subcutaneous injection, administered concurrently with oral aspirin. Treatment should be prescribed for a minimum of 2 days and a maximum of 8 days. For treatment of acute ST-segment elevation myocardial infarction in patients receiving fibrinolytic therapy, the recommended dose is a single IV bolus of 30 mg plus a 1 mg/kg SC dose, followed by 1 mg/kg administered SC every 12 hours (maximum 100 mg for each of the first two SC doses only, followed by 1 mg/kg dosing for the remaining doses).

Key safety warnings

Enoxaject should be used with extreme caution in conditions with increased risk of haemorrhage. Major haemorrhages including retroperitoneal and intracranial bleeding have been reported, and some of these cases have been fatal. Bleeding can occur at any site during therapy. Rare cases of neuraxial haematomas have been reported with concurrent use of Enoxaject and spinal/epidural anaesthesia resulting in long-term or permanent paralysis. These events are rare with dosage regimens of 40 mg once daily or lower, but the risk is greater with higher dosage regimens and use of post-operative indwelling catheters or concomitant use of additional drugs affecting haemostasis. Thrombocytopenia can occur with administration of Enoxaject. Moderate thrombocytopenia occurred at a rate of 1.3% in patients given Enoxaject and platelet counts less than 50,000/mm³ occurred at a rate of 0.1%. Thrombocytopenia of any degree should be monitored closely, and if the platelet count falls below 100,000/mm³, Enoxaject should be discontinued. There have been no adequate studies to assess the safe and effective use of Enoxaject in preventing thromboembolism in patients with prosthetic heart valves. Cases of prosthetic heart valve thrombosis have been reported in patients who have received enoxaparin for thromboprophylaxis.

Contraindications

Enoxaject is contraindicated in allergy to Enoxaject, heparin or its derivatives including other low molecular weight heparins; acute bacterial endocarditis; conditions with a high risk of uncontrolled haemorrhage including major bleeding disorders, focal lesions, haemorrhagic stroke, and active ulcerative conditions showing a tendency to haemorrhage such as peptic ulcer and ulcerative colitis; thrombocytopenia associated with a positive in vitro test for anti-platelet antibody in the presence of enoxaparin sodium; and history of immune mediated heparin-induced thrombocytopenia (HIT) within the past 100 days or in the presence of circulating antibodies.

PBS listing

In July 2025, Enoxaject was recommended by the PBAC for prevention of venous thromboembolism, treatment of venous thrombosis, prevention of extracorporeal thrombosis during haemodialysis, treatment of acute ST-segment elevation myocardial infarction (STEMI), non-STEMI and unstable angina. It was recommended for listing as a biosimilar on a cost-minimisation basis under the same conditions as existing PBS-listed biosimilar brands.

Regulatory history

Enoxaject was first listed on the ARTG on 17 February 2025 across seven registered product strengths (20 mg to 150 mg). An AusPAR was issued on 31 January 2025. The TGA approved the registration of Enoxaject as a new biosimilar medicine to Clexane. The approval was based on demonstrated comparability in quality, nonclinical, and clinical bioequivalence studies, supporting the same strengths, indications, doses, and routes of administration as the reference product. In July 2025, the PBAC recommended Enoxaject for listing.