A 8-year retrospective cohort study comparing Interferon-β formulations for relapsing-remitting multiple sclerosis

Area of Science:

• Neurology
• Immunology
• Pharmacology

Background:

• Interferon-β (IFNβ) is approved for relapsing-remitting multiple sclerosis (RRMS).
• Its long-term efficacy in preventing disability progression and conversion to secondary progressive multiple sclerosis (SPMS) remains debated.
• Comparative studies on different IFNβ formulations are crucial for optimizing patient management.

Purpose of the Study:

• To compare the long-term clinical outcomes of RRMS patients treated with different IFNβ formulations.
• To evaluate the impact of IFNβ formulation on disability accrual and conversion to SPMS.
• To identify potential differences in efficacy among subcutaneous (SC) IFNβ-1a 44mcg, intramuscular (IM) IFNβ-1a 30mcg, and SC IFNβ-1b 250mcg.

Main Methods:

• A cohort of 507 newly-diagnosed RRMS patients was followed for 8.5 years.
• Patients received SC IFNβ-1a 44mcg, IM IFNβ-1a 30mcg, or SC IFNβ-1b 250mcg.
• Propensity score matching was used to control for baseline characteristics including age, gender, disease duration, and EDSS score.
• Outcomes included relapse occurrence, 1-point EDSS progression, reaching EDSS 4.0, and conversion to SPMS.

Main Results:

• The rate of conversion to SPMS was significantly higher for SC IFNβ-1b 250mcg (HR=2.054, p=0.042) compared to SC IFNβ-1a 44mcg.
• Reaching an Expanded Disability Status Scale (EDSS) score of 4.0 was not significantly higher for SC IFNβ-1b 250mcg (HR=1.207, p=0.063) or IM IFNβ-1a 30mcg (HR=1.363, p=0.095) versus SC IFNβ-1a 44mcg.
• IM IFNβ-1a 30mcg showed a non-significantly higher rate of SPMS conversion (HR=1.884, p=0.081) compared to SC IFNβ-1a 44mcg.

Conclusions:

• SC IFNβ-1a 44mcg demonstrated a marginally reduced risk of long-term disability accrual compared to SC IFNβ-1b 250mcg and IM IFNβ-1a 30mcg.
• The formulation, administration frequency, and dosage of IFNβ may influence the long-term clinical trajectory of RRMS.
• These findings suggest that SC IFNβ-1a 44mcg may offer better long-term disease control in RRMS patients.