OBJECTIVES: To present initial Real World Evidence (RWE) from a patient support program registry of patients with multiple sclerosis currently being treated with interferon beta-1a s.c. in Portugal.

METHODS: Properly anonymized data was retrieved from a patient support program database of multiple sclerosis patients being currently treated with interferon beta-1a s.c. in Portugal. Data was checked for missing values and descriptive analysis was run for the available information using Excel and STATA16. For all parameters missing data was not considered for the analysis. Information was available from a total of 42 hospitals and a total of 95 prescribing physicians. Cut-off date for the analysis was May 15^th, 2020.

RESULTS: Out of a total of 594 patients, 66,16% were female. Age data was available for 97,14% of patients, with the average being 40,10 years and the median being 49 years [min-max: 13-78 years]. Overall there were 6 pediatric patients included (age <18 years). Information regarding drug dosage and presentation was available for 98,7% of cases. From the available data, 2,04% of patients were on 22 µg dosage using pre-filled pens, 32,25% were on 22 µg dosage using the Rebismart^TM device, 2,90% were on 44 µg dosage using pre-filled pens, and 62,80% were on 44 µg using Rebismart^TM. Time on treatment was available for 87,88% of the population, with an average of 3.921 days (10,74 years), a median of 3.590 days (9,83 years), and a min-max of 1-11.306 days.

CONCLUSIONS: Characterization of RWE data is feasible and should be pursued. This analysis shows that a considerable number of patients stay on treatment with interferon beta-1a s.c. for a long period of time, thus showing that long term disease control with this medicine is possible and frequent. Further analysis should be carried-out over time to properly characterize this patient population.