From high- to low-frequency administered interferon-beta for multiple sclerosis: a multicenter study.
OBJECTIVE
To investigate whether clinical and magnetic resonance imaging (MRI) outcomes of patients with multiple sclerosis (MS) who required a reduction of administration frequency of interferon-beta (IFNB) were similar to those of patients who did not.


METHODS
We identified three subgroups of patients under treatment for 24 months with subcutaneous (sc) high-frequency IFNB-1a or -1b: those continuing to receive IFNB according to the drug label (recommended frequency group), those reducing the administration frequency of sc IFNB-1a or -1b (reduced frequency group), and those switched to once weekly intramuscular (im) IFNB (switched group). All patients were followed for further 24 months. The occurrence of relapse, MRI activity and disability worsening were considered as outcome measures.


RESULTS
We identified 308 patients, 201 in the recommended frequency group, 70 in the reduced frequency group, and 37 in the switched group. Patients in the reduced frequency group had increased risk for relapses (HR = 1.95, p < 0.001) and MRI activity (HR = 1.41, p < 0.001), while patients in the switched group had increased risk for relapses (HR = 1.67, p = 0.012), but not for MRI activity (HR = 1.26, p = 0.08) than those in the recommended frequency group. Predictors for disease activity re-start after the reduction of IFNB administration frequency were younger age, higher pre-IFNB relapse rate, and reducing sc IFNB frequency to twice weekly rather than switching to im IFNB-1a once weekly.


CONCLUSIONS
Our findings discourage the reduction of sc IFNB administration frequency, especially in younger patients with a higher pre-IFNB relapse rate. However, switching to im IFNB-1a may be considered in some selected cases.
S. Andrea Hospital, Sapienza University, Rome, Italy.
Luca
L
Prosperini
Chiara Rosa
CR
Mancinelli
Carlo
C
Pozzilli
Maria Grazia
MG
Grasso
Alessandro
A
Clemenzi
Sara
S
Collorone
Simona
S
Pontecorvo
Ada
A
Francia
Veronica
V
Villani
Tatiana
T
Koudriavtseva
Fabio
F
Buttari
Diego
D
Centonze
Giancarlo
G
Di Battista
Giovanni
G
Frisullo
Simonetta
S
Galgani
Claudio
C
Gasperini
D000328:Adult; D000367:Age Factors; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage*; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D000068556:Interferon beta-1a; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000008:administration & dosage*; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012384:Rome; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D007155:Immunologic Factors; D000068576:Interferon beta-1b; D016899:Interferon-beta; D000068556:Interferon beta-1a