Background and Importance Appropriate optimisation of biologic agents in immune-mediated inflammatory diseases can improve treatment efficiency by decreasing number of drug administrations.

Aim and Objectives To estimate economic impact of optimising the use of etanercept and adalimumab in patients with immune-mediated dermatological and rheumatological diseases.

Material and Methods A descriptive retrospective study was conducted between November 2021 and September 2022. Patients with psoriasis, spondyloarthritis, rheumatoid arthritis and psoriatic arthritis treated with etanercept or adalimumab therapies for at least 6 months uninterruptedly were screened. Therapy optimisations were quantified. Optimised therapies were defined as treatments with extended dosing regimens or treatment discontinuations due to adequate pathology control. These therapy optimisations were applied according to a multidisciplinary protocol of clinical decisions based on biochemical tests (including serum drug levels and presence of anti-drug antibodies), pharmaceutical interviews about patients’ perception of their disease course and medical criteria. Data recorded: medical departments, drugs, biochemical tests, pharmaceutical interviews, serum drug levels and presence of anti-drug antibodies. Regarding economic impact, savings from biological therapy optimisations were estimated as the difference between costs of real doses used with optimised regimens and the hypothetical costs with doses used prior to treatment optimisations. The number of decreased drug administrations was estimated.

Results This study screened 256 patients: 182 of Internal Medicine Department and 74 of Dermatology. Distribution of drugs was: 171 patients received etanercept and 85 adalimumab. There were 258 biochemical test and 258 pharmaceutical interviews (2 patients required 2 biochemical tests and 2 pharmaceutical interviews). Serum drug levels were outside the optimal therapeutic ranges of drugs according to the literature in 71.6% of cases. Presence of anti-drug antibodies were found in 15 patients. Treatment optimisations were performed in 115 patients: 86 (74.8%) of Internal Medicine Department and 29 (25.2%) of Dermatology. Total economic savings associated with optimisation of biological therapies were €68804.96, €53169,58 saved in Internal Medicine Department and €15635.38 saved in Dermatology. The average monthly savings for these treatment optimisations was €6255/month. Number of drug administrations avoided was 777.

Conclusion and Relevance The optimisation of etanercept and adalimumab regimens in our patients with immune-mediated dermatological and rheumatological diseases provided high efficiency by decreasing the number of drug administrations.

References and/or Acknowledgements None

Conflict of Interest No conflict of interest