Background A study was presented during the 31st Meeting of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in October 2015 showing that extending the time frame between natalizumab doses from 4 to 8.5 weeks seems to neither increase the risk of relapse nor increase the risk of progressive multifocal leukoencephalopathy in patients diagnosed with relapsing remitting multiple sclerosis (RRMS). On May 2016, a joint protocol was created between the department of pharmacy and neurology to increase the standard interval for natalizumab to 5 weeks.

Purpose To assess compliance and the economic impact associated with progressive implementation of the aforementioned protocol in RRMS patients receiving treatment in our centre.

Material and methods A retrospective observational study including all RRMS patients under active natalizumab treatment was conducted from May to September, 2016. For the economic analysis, both direct and administration costs of the drug at the hospital’s outpatient care unit were taken into consideration. The estimated cost of administering the antibody every 4 weeks was calculated as per the data sheet. This estimate was then compared with the cost incurred by extending the administration interval to 5 weeks, bearing in mind the real compliance of the patients. In addition, we calculated the potential amount saved if all patients had started with the extended interval after protocol approval. Unit costs associated with outpatient care were gathered from the Oblikue Consulting’s e-Health healthcare costs (retrieved 2014).

Results Over the studied period, 53 patients were given natalizumab as treatment for RRMS. Progressively, 96% of patients started natalizumab every 5 weeks, as per the protocol. For our sample and during the studied period, the cost of administering natalizumab every 4 weeks was €515 540, and €423 708 for every 5 weeks. Therefore, the potential amount saved by switching from the first to the second administration schedule was €91.832€. As patients were progressively included into the new protocol, the real administration cost was calculated as €474 020, which is equal to only 45.21% of the amount that could actually have been saved.

Conclusion Administering natalizumab under an extended interval schedule has translated into a major saving for our health centre, both in direct costs and costs related to outpatient care.

No conflict of interest