Mifamurtide for the treatment of osteosarcoma

Mifamurtide (Mepact, Takeda) is an immune macrophage stimulant. It has a marketing authorisation for use in 'children, adolescents and young adults for the treatment of high-grade resectable non-metastatic osteosarcoma after macroscopically complete surgical resection'. The marketing authorisation further states that mifamurtide is used in combination with postoperative multi-agent chemotherapy, and that safety and efficacy have been assessed in studies of patients 2 to 30 years of age at initial diagnosis. It is not recommended for use in children below the age of 2 years.

The summary of product characteristics lists the following adverse events that may be associated with mifamurtide treatment: respiratory distress, neutropenia, pronounced inflammatory response, cardiovascular disorders, allergic reactions and gastrointestinal toxicity. The results of a clinical study also suggested that mifamurtide significantly increased the incidence of objective and subjective hearing loss. For full details of side effects and contraindications, see the summary of product characteristics.

Mifamurtide is available as a powder for suspension for intravenous infusion, with each vial containing 4 mg of mifamurtide. The recommended dose of mifamurtide for all patients is 2 mg/m² body surface area. Mifamurtide should be administered as adjuvant therapy after macroscopically complete resection: twice weekly at least 3 days apart for 12 weeks, followed by once-weekly treatments for an additional 24 weeks for a total of 48 doses in 36 weeks. For full details of dosage and administration, see the summary of product characteristics.

The acquisition cost of mifamurtide is £2,375 for a 4-mg vial (excluding VAT, BNF, edition 61). The manufacturer's submission states that the cost of a full treatment course of 48 doses of mifamurtide is £114,000.

The manufacturer of mifamurtide has agreed a revised patient access scheme with the Department of Health (which replaces an earlier patient access scheme, referred to as the 'original' patient access scheme in this document), in which mifamurtide for the treatment of osteosarcoma will be available at a reduced cost to the NHS. The nature of this cost reduction is confidential. The Department of Health considered that this patient access scheme does not constitute an excessive administrative burden on the NHS.