Observational Study of Switching from Natalizumab to Immunomodulatory Drugs

Area of Science:

• Neurology
• Immunology
• Pharmacology

Background:

• Natalizumab (NTZ) is an effective treatment for relapsing-remitting multiple sclerosis (RRMS).
• Discontinuation of NTZ can lead to disease activity rebound.
• Disease-modifying drugs (DMDs) such as glatiramer acetate (GA) and interferon are alternative treatments for MS.

Purpose of the Study:

• To evaluate the impact of switching from natalizumab (NTZ) to disease-modifying drugs (DMDs) on disease activity rebound in patients with RRMS.
• To assess the efficacy of GA and interferon in maintaining disease control after NTZ cessation.

Main Methods:

• A cohort of 21 RRMS patients treated with NTZ for at least one year were switched to GA or interferon.
• Patients were followed for 12 months, with clinical assessments every 3 months and MRI at 12 months post-discontinuation.
• Annualized relapse rate (ARR) and MRI outcomes were compared to pre-NTZ and during-NTZ periods.

Main Results:

• After switching to DMDs, the ARR remained low (0.3 vs. 0.1 during NTZ use; p=0.083) and did not return to pre-NTZ levels (1.61; p<0.001).
• 71.4% of patients remained relapse-free.
• 62.5% of patients showed no evidence of radiological activity on MRI 12 months after NTZ discontinuation.
• Patients on DMDs had lower Expanded Disability Status Scale scores compared to those who relapsed.

Conclusions:

• Switching from natalizumab to glatiramer acetate or interferon is a viable strategy for managing RRMS in patients with moderate disability.
• DMDs effectively control disease activity and MRI progression after NTZ cessation.
• This switch offers a safe alternative, avoiding the risk of progressive multifocal leukoencephalopathy associated with NTZ.