OMJJARA

What it is

OMJJARA is a film-coated tablet containing 100 mg, 150 mg or 200 mg of momelotinib as momelotinib dihydrochloride monohydrate. Momelotinib and its major circulating metabolite (M21) are inhibitors of wild type Janus Kinase 1 and 2 (JAK1/JAK2) and mutant JAK2 V617F. Momelotinib and its major human circulating metabolite, M21, additionally inhibit ACVR1 which subsequently down regulates liver hepcidin expression resulting in increased iron availability and red blood cell production. OMJJARA is subject to additional monitoring in Australia to allow quick identification of new safety information.

Approved indications —

Disease-related splenomegaly or symptoms in adult patients with moderate to severe anaemia who have primary myelofibrosis, post polycythaemia vera myelofibrosis or post essential thrombocythaemia myelofibrosis and who are Janus Kinase (JAK) inhibitor naïve or have been treated with ruxolitinib.

Dosing overview

The recommended dosage of OMJJARA is 200 mg taken orally once daily. OMJJARA may be taken with or without food. Complete blood cell count and liver function tests must be performed before initiating treatment with OMJJARA, periodically during treatment, and as clinically indicated. Dose modifications should be considered for haematologic and nonhaematologic toxicities, including thrombocytopenia, neutropenia, hepatotoxicity, and Grade 2 or higher bleeding. The recommended starting dose of OMJJARA is 150 mg once daily in patients with severe hepatic impairment (Child-Pugh Class C).

Key safety warnings

Infections, including serious and sometimes fatal bacterial and viral infections (including COVID-19), have occurred in patients treated with OMJJARA. OMJJARA should not be initiated in patients with active infections. Physicians should monitor patients receiving OMJJARA for signs and symptoms of infection and initiate appropriate treatment promptly. Hepatitis B viral load (HBV-DNA titre) increases, with or without associated elevations in alanine transaminase (ALT) or aspartate transaminase (AST), have been reported in patients with chronic hepatitis B virus (HBV) infection taking JAK inhibitors, including OMJJARA. The effect of OMJJARA on viral replication in patients with chronic HBV infection is unknown. Patients with chronic HBV infection who receive OMJJARA should have their chronic HBV infection treated and monitored according to clinical HBV guidelines. New onset of severe (Grade ≥3) thrombocytopenia and neutropenia was observed in patients treated with OMJJARA. A complete blood count, including platelet count, should be obtained before initiating treatment with OMJJARA, periodically during treatment, and as clinically indicated. Dose interruption or reduction may be required. Events of Major Adverse Cardiovascular Events (MACE) have been reported in patients receiving OMJJARA, however, a causal relationship has not been established. Prior to initiating or continuing therapy with OMJJARA, the benefits and risks for the individual patient should be considered particularly in patients 65 years of age and older, patients who are current or past long-time smokers, and patients with history of atherosclerotic cardiovascular disease or other cardiovascular risk factors. Events of DVT and PE have been reported in patients receiving OMJJARA. However, a causal association has not been established. In patients with myelofibrosis treated with OMJJARA in clinical trials, the rates of thromboembolic events were similar in OMJJARA and control-treated patients. Prior to initiating or continuing therapy with OMJJARA, the benefits and risks for the individual patient should be considered particularly in patients with cardiovascular risk factors. Given uncertainties about whether OMJJARA may reduce the effectiveness of hormonal contraceptives, women using systemically acting hormonal contraceptives should add a barrier method during OMJJARA treatment and for at least 1 week after the last dose.

Contraindications

OMJJARA should not be used during pregnancy and breast feeding. OMJJARA is contraindicated in patients with hypersensitivity to the active substance or to any of the excipients.

PBS listing

In November 2024, PBAC recommended OMJJARA for listing on the PBS for myelofibrosis (intermediate or high-risk primary, post-polycythaemia vera, or post-essential thrombocythaemia) in patients with moderate to severe anaemia and who are JAK inhibitor naïve or have been treated with ruxolitinib. The recommendation was for listing cost-minimised against ruxolitinib, with non-inferior effectiveness and safety.

Regulatory history

OMJJARA received initial approval in Australia on 18 December 2024. Three strengths (100 mg, 150 mg and 200 mg film-coated tablets) were registered on the ARTG on 18 December 2024. In November 2024, the PBAC recommended OMJJARA for listing on the Pharmaceutical Benefits Scheme for myelofibrosis in eligible patients, finding it non-inferior to ruxolitinib in effectiveness and safety.