# Clinical and radiological outcomes of directed treatment transitions from Gilenya® to generic fingolimod

## TL;DR

Switching from Gilenya® to generic fingolimod in multiple sclerosis patients may lead to faster disease activity and more side effects.

## Contribution

This study provides empirical evidence on the clinical impact of switching from brand to generic fingolimod in MS patients.

## Key findings

- Generic fingolimod was associated with shorter time to MRI activity and relapse compared to Gilenya®.
- Patients on generic fingolimod experienced a 2.45-fold increase in side effects compared to Gilenya®.
- ALC increased by 8.81% with generic fingolimod treatment relative to Gilenya®.

## Abstract

Gilenya® (fingolimod), a sphingosine-1-receptor agonist, is an effective treatment for multiple sclerosis (MS). However, increased relapse activity has been observed after transitioning to generic fingolimod despite prior prolonged disease stability.

To quantify the clinical and radiological impact of transitioning from Gilenya® to generic fingolimod in people with MS (PwMS).

Retrospective data were evaluated from a single tertiary MS care center. Time to magnetic resonance imaging (MRI) activity and clinical relapse was assessed during Gilenya® and generic fingolimod treatment. Differences in absolute lymphocyte count (ALC) and side effects were also measured by treatment group.

The cohort included 88 PwMS (71 female; 76 White, mean age when starting Gilenya® was 39.6 years (standard deviation (SD) = 10.6 years), and mean age when starting generic fingolimod was 46.9 years (SD = 11.2 years)). A shorter time to MRI activity (p = 0.0026) and time to relapse (p = 0.0027) was observed during generic fingolimod treatment. The ALC increased by 8.81% after generic fingolimod treatment, relative to Gilenya® (95% CI = (2.00%, 16.08%), p = 0.01), with an intersubject variability of 1.97%. A 2.45-fold increase in side effects was observed with generic fingolimod relative to Gilenya® (95% CI = (1.38, 4.36), p = 0.002).

Measures of disease stability appear less optimal with generic fingolimod based on serological, clinical, and radiological measures.