Background Ankylosing spondylitis (AS) represents a considerable socioeconomic burden due to early disease onset, development of functional disability and life-time costs. The impact of originator adalimumab on the extent of outpatient attendance, hospitalizations and sick leave in relation to clinical outcomes is not known in Central and Eastern Europe (CEE).

Objectives To evaluate disease activity, physical function, selected health care resource utilization and sick leaves in patients treated with adalimumab in clinical practice in CEE countries.

Methods This was a 52-week multi-center post-marketing observational study conducted in 5 countries in CEE. Eligible AS patients were prescribed originator adalimumab according to the local practice; 5 study visits (V) were performed approx. 3 months apart. Disease activity was measured by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Index (ASDAS_CRP), treatment response as BASDAI50 and ΔASDAS≥-2 (at study end), physical function by Bath Ankylosing Spondylitis Functional Index (BASFI). Data on AS related healthcare resource utilization and sick leave during the study was recorded prospectively through a systematic interview with the patient at each study visit. For pre-and post-treatment comparison, the same sort of data were recorded retrospectively at baseline visit for the 3-month period preceding adalimumab therapy, verified against chart review, then multiplied by 4 to match the prospective follow-up duration. Descriptive statistics were used; last observation carried forward data are presented herein.

Results 452 patients were enrolled, 360 completed the study. Mean age was 42.9 (±12.1) yrs; 68.7% were male and 62.7% were employed at baseline. Average disease duration was 7.7 (±8.7) yrs. Mean BASDAI and ASDAS decreased from 6.3 (±2.1) and 4.0 (±1.1) at baseline to 2.3 (±2.0) and 1.9 (±1.1) at study end, respectively; mean BASFI from 6.2 (±2.3) to 2.6 (±2.3). BASDAI and ASDAS based treatment response was seen at study end in 72.3% and 58.9% of patients, respectively. The mean number of hospital admissions and inpatient days decreased from 2.8 (±3.9) to 0.9 (±2.8) and from 23.0 (±40.8) to 3.9 (±17.7), respectively (pre- and post-treatment). The mean number of sick leaves and sick leave days decreased from 3.2 (±8.8) to 1.1 (±5.6) and from 32.2 (±69.2) to 5.1 (±24.5), respectively (employed patients only, n=282). The reduction of hospital admissions/days, sick leaves and sick leave days were higher in treatment responders compared to non-responders. No new safety signal was detected.

Conclusions Treatment with adalimumab in routine clinical practice in 5 CEE countries resulted in clinically meaningful improvements in disease activity and physical function as well as reduced healthcare resource utilization and sick leaves.

Acknowledgements The design, study conduct, and financial support for the clinical trial were provided by AbbVie. AbbVie participated in the interpretation of data, drafting, review, and approval of the abstract.

Disclosure of Interest D. Opris-Belinski Consultant for: Abbvie, BMS, Pfizer, Roche, Teva and consulting fees from Abbvie, BMS, Pfizer, Roche, Teva., S. Erdes Consultant for: Abbvie, MSD, Pfizer, USB, BIOCARD, Gedeon Richter, Dr. Reddy's, Novartis., S. Grazio Consultant for: Abbvie/Abbott Lab, Roche, MSD, Eli Lilly, Pfizer, Boehringer Ingelheim, Grünenthal, Stada, Sanofi-Aventis, PharmaSwiss, Berlin-Chemie, Pliva/Teva, Belupo, Krka, consulting fees from: Abbvie/Abbott Lab, Roche, MSD, Eli Lilly, Pfizer, Grünenthal, L. Šenolt Consultant for: AbbVie, Bristol-Myers Squibb, Celgene Corporation, Eli Lilly, Merck Sharp and Dohme, Novartis, Pfizer, Samsung, Takeda, UCB., M. Hojnik Employee of: AbbVie, O. Nagy Employee of: AbbVie, L. Iosub Employee of: AbbVie, S. Szántό Consultant for: Abbvie, Bristol Myers-Squibb, Novartis, Pfizer, Roche, Teva