Background: Biosimilars may represent an important opportunity to improve allocation efficiency in the biologics market due to their lower cost compared to that of originator biologics and are expected to generate significant savings for healthcare systems in even more countries of emerging economies

Objectives: Determine the economic impact of the switch to biosimilars in a cohort of patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) who attend a comprehensive management program at Risk of Fracture S.A-CAYRE and describe their clinical characteristics

Methods: Descriptive observational study of a cohort of adult patients diagnosed with RA and EAS who had been receiving the reference products and switched to treatment with the biosimilars available in the country (rituximab, adalimumab, infliximab and etanercept) over a time horizon of 1 year. from December 1, 2022 to November 30, 2023. To calculate the value of the medicines, the SISPRO platform was used, averaging the price of the medicine. TRM US dollar: COP $3929.79.

Results: In our cohort we have 1308 patients with RA and 219 patients with SpA. In the group of patients with RA, 301 (23%) receive biological therapy and of them 141 (47%) were switched to biosimilars. For the SpA group, 138 (63%) receive biological therapy and of these 82(59%) patients were switched to biosimilars. The average age for patients receiving biosimilars with RA and SpA is 57.5 years (DS11.7) and 50.2 years (DS12.9) respectively. 89% are women in the RA group and 68% are men in the SpA group. The average disease duration for RA and SpA is 15.6 years (SD10.6) and 9.3 (SD8.9) respectively. 77% are double seropositive in RA. 56% in the SpA group are HLA B27 positive and sacroiliitis is present in 59% of patients. In patients with RA, 28% and 24% have erosions on X-rays of their hands and feet, respectively. Regarding concomitant medications in RA, 28.1% receive methotrexate and 20% leflunomide, with 24% receiving biosimilars in monotherapy. In 50% and 71% the biosimilar is the first line of biological treatment for patients with RA and SpA respectively and in the second line in 27% and 17% respectively. Prior to the start of the use of the biosimilar, patients with RA were in remission and low activity measured by DAS28 64% and 12% respectively and one year after receiving the biosimilar they were in remission and low activity 77% and 9% respectively. In the case of patients with SpA, the measurement by ASDAS prior to the start of the biosimilar showed inactivity of the disease 55% and low activity 25% and after one year of receiving biosimilar the inactivity was 75% and 14% in low activity. The savings from biosimilar use during the year in patients with RA was USD 166771 and in patients with SpA was USD 180711. Only 2 patients receiving adalimumab returned to the reference product, 1 with RA and another with SpA.

Conclusion: With the switch to biosimilars in this cohort of patients with RA and SpA, significant savings are evident for the health system while maintaining adequate control of the disease, without an increase in adverse effects.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: Edwin Jauregui abbvie, biopass, Deisy Restrepo: None declared, Jorge Palacio: None declared, JEIMY A CHAPARRO: None declared, Rossana Alicia Mejia Romero Jannsen, Juan Salazar Jannsen, Alejandro Rodriguez: None declared.