Background Therapeutic decision-making for biologic-therapies (BT) dose optimisation should be based on optimal disease activity results. The goal of BT optimisation is to guarantee long-term effectiveness and safety, maximising economic savings.

Purpose To evaluate BT optimisation patterns in patients with rheumatic diseases (RD) and associated economic savings.

Material and methods Observational and retrospective study.

All patients with RD (rheumatoid arthritis (RA), spondyloarthropathies (SA) and psoriatic arthritis (PSA)) treated with BT from January 2014 to June 2018 were included.

BT optimisation, by dose reduction or prolonging the dosing interval, was indicated when patients had more than 6 months in clinical remission (DAS28 <2.6 for RA and PSA and BASDAI <2 for SA) or minimal clinical activity (DAS28 <3.2 and BASDAI <4).

Variables were described as frequencies and means. Diagnosis, subcutaneous BT (Abatacept, Adalimumab, Certolizumab, Etanercept, Golimumab, Secukinumab, Tocilizumab and Ustekinumab), dose regimens, total treatment duration, time on BT optimisation (TO) and treatment costs were collected.

Cost savings were calculated per patient by comparing optimisation treatment costs to conventional treatment and globally by comparing real cost to theoretical conventional doses cost.

Results A total of 448 patients were included in the study, receiving 579 BT treatments. Switching was observed in 29%. From all patients, 47% were in BT optimisation (according to diagnosis: 53.7% with RA, followed by 47.7% with SA and 33.1% with PSA).

Sixty per cent of patients with BT optimisation were treated with adalimumab and etanercept, being also the most common BT used in RD treatment.

Mean TO duration was 2.2 years. The longest TO were achieved with adalimumab and golimumab (2.7 years) and PSA patients preserved BT optimisation for a mean of 2.8 years.

BT optimisation allowed a 50% saving per patient against the use of conventional therapy resulting in a reduction of the total cost of €3,000,000 in the past 4 years, which represents a total economic savings of 21%.

Conclusion Therapeutic decision-making based on validated disease activity scales has allowed BT optimisation in approximately 50% of patients with RD.

Patients remain clinically controlled after BT optimisation for a mean time of 2 years.

BT optimisation allows a reduction in costs while maintaining effectiveness.

References and/or acknowledgements No conflict of interest.