RIXIMYO

What it is

RIXIMYO is a medicine biosimilar to MABTHERA (rituximab). Rituximab is a genetically engineered chimeric murine/human monoclonal antibody directed against the CD20 antigen found on the surface of normal and malignant B lymphocytes. RIXIMYO is supplied at a concentration of 10 mg/mL in either 100 mg (10 mL) or 500 mg (50 mL) single-use vials. It is a concentrated solution for injection.

Approved indications —

CD20 positive, previously untreated, Stage III/IV follicular B-cell non-Hodgkin's lymphoma — CD20 positive, relapsed or refractory low-grade or follicular B-cell non-Hodgkin's lymphoma — CD20 positive diffuse large B-cell non-Hodgkin's lymphoma, in combination with chemotherapy — CD20 positive chronic lymphocytic leukaemia in combination with chemotherapy — Severe, active rheumatoid arthritis in adult patients who have had an inadequate response or intolerance to at least one tumour necrosis factor (TNF) inhibitor therapy, in combination with methotrexate — Severely active Granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis) and Microscopic polyangiitis (MPA), in combination with glucocorticoids, for the induction of remission

Dosing overview

For relapsed or refractory low-grade or follicular non-Hodgkin's lymphoma as monotherapy, the recommended dose is 375 mg/m² administered as an intravenous infusion once weekly for four weeks. When used in combination with CHOP chemotherapy, the dose is 375 mg/m² administered on day 1 of each chemotherapy cycle for 6 cycles. Maintenance treatment consists of 375 mg/m² once every 3 months until disease progression or for a maximum period of two years. For previously untreated Stage III/IV follicular non-Hodgkin's lymphoma in combination with chemotherapy, 375 mg/m² is administered on day 1 of each chemotherapy cycle for up to 8 cycles as induction therapy, prior to the administration of chemotherapy. Maintenance treatment for these patients consists of 375 mg/m² once every 2 months until disease progression or for a maximum period of two years. For diffuse large B-cell non-Hodgkin's lymphoma in combination with CHOP chemotherapy, the recommended dose is 375 mg/m² administered on day 1 of each chemotherapy cycle for up to 8 cycles. For chronic lymphocytic leukaemia in combination with chemotherapy, 375 mg/m² is administered on day 1 of the first treatment cycle followed by 500 mg/m² on day 1 of each subsequent cycle, for a total of 6 cycles. For rheumatoid arthritis, a course consists of two 1000 mg IV infusions, with the recommended dosage of 1000 mg by IV infusion followed by a second 1000 mg IV infusion two weeks later. For Granulomatosis with polyangiitis and Microscopic polyangiitis, the recommended dosage is 375 mg/m² body surface area, administered as an IV infusion once weekly for 4 weeks.

Key safety warnings

Use of RIXIMYO may be associated with an increased risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that usually leads to death or severe disability. Patients must be monitored for any new or worsening neurological symptoms or signs suggestive of PML. If such symptoms occur, further administration of RIXIMYO should be immediately suspended until a diagnosis of PML has been excluded. Rituximab is associated with infusion-related reactions, which may be related to release of cytokines and/or other chemical mediators. Severe infusion-related reactions with fatal outcome have been reported during post-marketing use. Severe reactions usually manifested within 30 minutes to 2 hours after starting the first rituximab infusion, were characterised by pulmonary events and included, in some cases, rapid tumour lysis and features of tumour lysis syndrome in addition to fever, chills, rigors, hypotension, urticaria, angioedema and other symptoms. Cases of Hepatitis B virus (HBV) reactivation, occasionally with fulminant hepatitis, hepatic failure, and death have been reported in some patients with haematologic malignancies treated with rituximab. The majority of patients received rituximab in combination with chemotherapy. HBV screening should be performed in all patients before initiation of treatment with rituximab. At a minimum this should include HBsAg-status and HBcAb-status. Patients have an increased risk of infection following rituximab therapy. Serious infections, including fatalities, can occur during therapy with rituximab.

Contraindications

RIXIMYO is contraindicated in patients with known hypersensitivity to rituximab, to any of its excipients or to murine proteins. RIXIMYO is contraindicated in patients with active, severe infections. RIXIMYO is contraindicated in patients in a severely immunocompromised state. RIXIMYO is contraindicated in patients with severe heart failure (New York Heart Association Class IV) or severe, uncontrolled cardiac disease for use in rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis and pemphigus vulgaris only.

PBS listing

RIXIMYO 100 mg in 10 mL solution for intravenous infusion is listed on the PBS with 2 items. The listing is unrestricted with an ex-manufacturer price of A$86.48.

Regulatory history

RIXIMYO was first listed on the ARTG on 30 November 2017 for both the 100 mg/10 mL and 500 mg/50 mL concentrated injection vial strengths. In November 2014, rituximab received PBAC recommendations for amendments to the PBS listing for chronic lymphocytic leukaemia and follicular lymphoma for patients who had failed prior treatment. In March 2017, rituximab received a PBAC recommendation for a new streamlined authority required listing for chronic lymphocytic leukaemia. In November 2017, PBAC recommended a new biosimilar brand listing for RIXIMYO for treatment of non-Hodgkin lymphoma, chronic lymphocytic leukaemia, rheumatoid arthritis, Granulomatosis with polyangiitis and Microscopic polyangiitis, with price reductions. In September 2021, PBAC recommended changes to multiple indications to unrestricted benefit listings.