Background Over the past years, introduction of biologics for treatment of psoriatic arthritis (PsA) has improved the treatment responses in all clinical domains. However, little is known regarding the characteristics of patients who discontinue/switch biologics in non-clinical trial setting.

Objectives To characterize PsA patients who discontinue/switch the index biologic and evaluate the reasons for discontinuation in the Corrona PsA/Spondyloarthritis (SpA) registry, a large US national cohort of patients with PsA/SpA.

Methods PsA patients enrolled in the registry between 3/2013 and 7/2015, with a biologic at baseline (registry enrollment) and at least 2 follow-up visits were included. Two cohorts were identified: patients who discontinued/switched the index biologic (group 1) and those who stayed on the index biologic by the 2nd follow-up visit approximately 15 months after the enrollment (group 2). Descriptive analyses on patient demographics, clinical outcomes (eg. clinical disease activity index (CDAI), dactylitis, enthesitis), patient reported outcomes (eg. pain, fatigue, work productivity and activity impairment (WPAI)) and treatment at time of enrollment were examined. Chi-square tests and t-tests were used for continuous and categorical variables respectively to evaluate differences.

Results Of the 251 PsA patients meeting the inclusion criteria, 26% (n=65) discontinued/switched the index biologic and 74% (n=186) stayed on the index biologic by the 2nd follow-up visit. A significantly greater percent of females discontinued/switched the index biologic (56% vs 41%, p<0.05). However both cohorts were similar in age (mean: 55 yrs vs 53 yrs), and disease duration (12 vs 12 yrs.). Group 1 patients reported significantly higher scores for pain (mean: 42 vs 27) and fatigue (mean: 48 vs 33) compared to Group 2 (p<.0001). Almost one-third of patients in Group 1 reported greater overall work impairment (mean: 30% vs 15%, p<0.01) compared to Group 2. Patients in Group 1 were most likely to have higher disease activity (mean CDAI: 13 vs 9, p<0.0001) and enthesitis (26% vs 15%, p<0.05) vs. group 2. Overall a majority of patients had a history of prior biologic use (97%), with about 55% on current monotherapy. The major reason for discontinuing the index biologic was lack of efficacy (60%), followed by other reasons (16%) and side effects (12%).

Conclusions About a quarter of patients discontinued their index biologic over an average of 15 months follow up period. Those patients were more likely to have higher disease activity (CDAI) and poorer patient reported outcomes (pain, fatigue, WPAI) at enrollment. The most common reason for switching was lack of efficacy.

Acknowledgement The design, study conduct, and financial support for this analysis was provided by Novartis. Corrona LLC: In the last two years, AbbVie, Amgen, BMS, Crescendo, Genentech, Horizon Pharma USA, Janssen, Eli Lilly, Novartis, Pfizer, and UCB have supported Corrona LLC through contracted subscriptions.

Disclosure of Interest P. Mease Grant/research support from: Celgene, Novartis, Abbvie, Amgen, BMS, Janssen, Lilly, Pfizer, UCB, Consultant for: Celgene, Corrona, Merck, Novartis, Abbvie, Amgen, BMS, Crescendo, Genentech, Janssen, Lilly, Merck, Pfizer, UCB;, Speakers bureau: Abbvie, Amgen, BMS, Crescendo, Genentech, Janssen, Lilly, Novartis, Pfizer, UCB, C. Karki Employee of: Corrona, LLC, M. Liu Employee of: Corrona, LLC, A. Kavanugh Grant/research support from: Amgen Abbvie Janssen Pfizer Novartis, C. Ritchlin Grant/research support from: Amgen, Janssen, and UCB, Consultant for: Abbvie, Amgen, Janssen, Regeneron, and UCB, D. Huynh Speakers bureau: AbbVie, BMS, R. Pandurengan Employee of: Corrona, LLC, V. Herrera Employee of: Novartis Pharmaceuticals Corporation, J. Palmer Employee of: Novartis Pharmaceuticals Corporation, J. Greenberg Shareholder of: Corrona, LLC, Consultant for: AstraZeneca, Celgene, Genentech, Janssen, Novartis and Pfizer, Employee of: Corrona, LLC