MS Speaks

Mult Scler. 2017 Aug 1:1352458517726381.

Switching natalizumab to fingolimod within 6 weeks reduces recurrence of disease activity in MS patients

Leurs CE1, van Kempen ZL1, Dekker I2, Balk LJ1, Wattjes MP3, Rispens T4, Uitdehaag BM1, Killestein J1.

Author information

1
Department of Neurology, Neuroscience Amsterdam, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
2
Department of Neurology, Neuroscience Amsterdam, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands / Department of Radiology and Nuclear Medicine, Neuroscience Amsterdam, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
3
Department of Radiology and Nuclear Medicine, Neuroscience Amsterdam, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
4
Department of Immunology, Landsteiner Laboratory Sanquin Research, Amsterdam, The Netherlands.

BACKGROUND:

Natalizumab is an effective treatment in relapsing-remitting multiple sclerosis (MS). Mainly because of the risk of progressive multifocal leukoencephalopathy (PML), a substantial proportion of John Cunningham (JC) virus-positive patients switch to fingolimod. Previous reports show a clear benefit when the duration of a washout (WO) period of natalizumab is 0-3 months in comparison to longer WO periods. However, there is no consensus regarding the optimal duration of a WO period under 3 months.

OBJECTIVE:

We compared MS disease activity after different WO periods. In addition, we investigated several factors that possibly influence recurrence of disease activity, including serum natalizumab concentration and lymphocyte counts.

METHODS:

From a prospective observational cohort study of natalizumab-treated patients, we selected 52 patients who switched to fingolimod. We divided the patients in three groups (<6 weeks, 6-8 weeks, >8 weeks WO). Serum natalizumab concentration and lymphocyte count were assessed during and after natalizumab treatment.

RESULTS:

Patients with a WO period of >8 weeks had a significant higher recurrence of disease activity (odds ratio, 6.8; 95% confidence interval, 1.4-32. compared to patients with a WO period of <6 weeks. Serum natalizumab concentration and lymphocyte count did not predict recurrence of disease activity.

INTERPRETATION:

A short WO period decreases the risk of recurrence of disease activity. The possible impact of a short WO period on the risk of carry-over PML in JC virus-positive patients remains uncertain.