Changing therapeutic strategies and persistence to disease-modifying treatments in a population of multiple sclerosis patients from Veneto region, Italy.

Background: The availability of new disease-modifying treatments (DMTs) in the last years has changed the therapeutic strategies used in Multiple Sclerosis (MS). We aimed to describe trend in DMTs utilization and persistence to treatment in a large sample of patients attending 10 MS centres from four provinces of Veneto, Italy.

Methods: Demographic, clinical and DMTs information of patients regularly followed from January 2011 to August 2018 were recorded and analysed. Persistence at 12, 24 months and at last follow-up was assessed by Kaplan Meier survival analysis. Multivariable Cox- proportional hazard model was used to identify predictors of persistence.

Results: Of 3025 MS patients 65.7% were in treatment al last follow-up. Dimethylfumarate (DMF) was the most prescribed single drug among first-line and fingolimod among second-line DMTs. In the cohort of 1391 cases starting any DMT since 2011 12.9% stopped within 6 months, 24% within 12 and 40.3% within 24 months. Disease duration > 5 years at therapy start was predictive of greater risk of discontinuation, while age and sex were not. DMF use was predictive of higher persistence at 12 and 24 months, but not at last follow-up when azathioprine and glatiramer acetate showed the highest persistence compared to other DMTs. Side effects represented the main reason of discontinuation.

Conclusion: The use of the new oral DMTs greatly increased since their approval but persistence in the long-term is not better than with old drugs. The treatment choice is still a challenge both for patients and their doctors.