Background Natalizumab is a monoclonal antibody authorised as second-line treatment after failure with interferon beta or in rapidly evolving severe relapsing-remitting multiple sclerosis (RRMS). Due to its high cost and safety profile, the appropriate selection of patients who will benefit most is of paramount importance.

Purpose To evaluate the adequacy of criteria for starting treatment with natalizumab in patients with multiple sclerosis (MS) based on the protocol approved in a tertiary hospital.

Materials and Methods Observational, retrospective analysis of patients treated with natalizumab between 2008 and 2011. Study data were obtained from clinical records.

Results 31 patients were treated with natalizumab, 26 women (83.9%) and 5 men (16.1%). Mean age was 38.8 years (SD = 9.1). Mean time between diagnosis and natalizumab start was 7.8 years (SD = 5.9). 29 patients (93.5%) had RRMS, 1 secondary-progressive MS (SPMS) and the other an intermediate disease between RRMS and SPMS. The mean number of relapses before treatment started was 3.7 (SD = 1.5) and the mean score for the expanded disability status scale was 3.3 (range 1–6). 27 patients (87.1%) had previously been treated with immunomodulatory drugs (interferon beta). In 4 patients (12.9%) natalizumab was first line treatment. All were diagnosed with rapidly evolving severe RRMS with gadolinium-enhancing lesions in brain magnetic resonance imaging and more than 2 disabling relapses in the previous year. At the end of the study 22 patients continued treatment and 9 had finished. These latter patients were categorised in two groups: short treatment duration (4 patients, median 5 months) and long treatment duration (5 patients, median 24 months).

Conclusions In our population, adequacy of criteria for starting treatment with natalizumab is appropriate and the drug was used for the authorised indications in more than 90% of patients.

No conflict of interest.