Comparative analysis of first-year fingolimod and natalizumab drug discontinuation among Swedish patients with multiple sclerosis.
BACKGROUND
Natalizumab (NTZ) and fingolimod (FGL) are mainly used second line in relapsing-remitting multiple sclerosis (MS), although pivotal trials included mainly treatment-naïve patients.


OBJECTIVE
This study aims to provide real-world data on safety and discontinuation rates.


METHODS
Using IMSE, a drug monitoring registry for all newer MS drugs in Sweden, we analysed differences in baseline characteristics and 1-year drug survival for patients registered 2011-2013, initiating treatment with NTZ (n=640) or FGL (n=876). Among FGL initiators, n=383 (44%) had previously used NTZ (FGL(afterNTZ)).


RESULTS
Compared with NTZ, the FGL cohort was older and more often male (36/38 years, 24%/33% males). Baseline Expanded Disability Status Scale was similar across groups, but MS Severity Score was higher in NTZ patients, and Symbol Digit Modalities Test and MS Impact Scale (MSIS-29) was higher in FGL(afterNTZ) versus FGL(NTZ-naïve) patients. Proportion on drug after 1 year was high, NTZ=87%, FGL(NTZ-naïve)=83% and FGL(afterNTZ)=76%. Adverse events was the most frequent reason for discontinuing FGL (FGL(NTZ-naïve)=9%, FGL(afterNTZ)=12%), and was significantly higher than on NTZ (3%). In contrast, the proportion of patients stopping treatment due to lack of effect was more similar: NTZ=4%, FGL(NTZ-naïve)=3%, FGL(afterNTZ)=8%.


CONCLUSIONS
FGL and NTZ were both well tolerated, but FGL less so than NTZ, especially in patients switching to FGL from NTZ. Group differences were not explained by differences in recorded baseline characteristics.
Clinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, Solna, Sweden thomas.frisell@ki.se.
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T
Frisell
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
L
L
Forsberg
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
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N
Nordin
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
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C
Kiesel
Institute of Environmental Medicine, Karolinska Institutet, Solna, Sweden.
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L
Alfredsson
Clinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, Solna, Sweden/Rheumatology Unit, Department of Medicine, Karolinska Institutet, Solna, Sweden.
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J
Askling
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
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J
Hillert
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
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T
Olsson
Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden.
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F
Piehl
D000328:Adult; D005260:Female; D000068876:Fingolimod Hydrochloride / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy*; D000069442:Natalizumab / Q000009:adverse effects / Q000627:therapeutic use*; D012042:Registries; D012720:Severity of Illness Index; D012737:Sex Factors; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome
D007155:Immunologic Factors; D000069442:Natalizumab; D000068876:Fingolimod Hydrochloride
Multiple sclerosis; drug survival; fingolimod; health services research; natalizumab; treatment outcome