Background Rituximab is an anti-CD20 monoclonal antibody. Its off-label use has increased in the management of a variety of neurologic diseases.

Purpose To describe rituximab prescriptions in the Neurology Department, and evaluate the scientific evidence in off-label indications to rationalise its use.

Material and methods Retrospective observational study including all neurology patients under rituximab treatment between January 2012 and September 2017.

After analysing clinical histories, dispensations and Neurologic Day Hospital administrations the following data were collected: demographic (sex and age), clinical (indication), therapy-related (dose, posology, previous treatments and adverse events) and economic (annual cost). ‘The Oxford 2011 Levels of Evidence (LE)’ was used to categorise evidence.

Results Thirty-nine patients (61.5% females, average age 45.5±12 years) were included, being 100% off-label use.

Indication and LE, describing benefit/no benefit/harm: Relapsing-Remitting Multiple Sclerosis (RRMS), LE:2, no benefit, (19 patients; 48.7%); Primary/Secondary Progressive Multiple Sclerosis (PMS), LE:2, no benefit, (six patients, 15.4%); Optic Neuromyelitis (ONM), LE:4, benefit, (seven patients; 17.9%); Optic Neuritis (ON) (two patients; 5.1%); Isolated Central Nervous System Vasculitis, (two patients; 5.1%); and Clippers Syndrome, Chronic Progressive Dorsal Myelopathy and Pseudotumoral Inflammatory Demyelinating Disease (one patient; 2.5% each three last diseases). Literature review found no good quality evidence in the last five diseases.

Rituximab was first-line treatment in four ONM patients and in one with ON. Sixteen patients (41%) with RRMS and PMS received it as, at least, third-line therapy. Dosage regimen was: 500–1000 mg on first month (days 1 and 15, repeated 6 months’ later) and a maintaining dose of 500–1000 mg each 6–12 months.

Four patients (10.2%) suffered infusion-related reactions: 14 infections (21.4% respiratory, 21.4% urinary, 7.1% dermic and 7.1% viral) and one case of breast cancer were reported.

The average cost per patient is €6366 during the first year, and €2546 each following year. Thirty-nine per cent of this cost was spent in treating pathologies in which rituximab has shown poor evidence.

Conclusion Off-label rituximab is extensively used in neurological pathologies with no strong evidence. As many adverse events have been observed, close monitoring of patients is suggested. The high economic impact makes it necessary to rationalise rituximab prescription and optimise the efficiency of sanitary resources.

No conflict of interest