Data Source

The PPD™ CorEvitas™ PsA/SpA Registry, which began enrolling patients in the USA in 2013, is a prospective multicenter, non-interventional registry for adult patients with PsA or SpA being treated by a rheumatologist. Demographics, disease duration, medical history (including current and prior treatments for PsA or SpA), smoking status, alcohol use, disease activity and severity, clinician- and patient-reported outcomes, comorbidities and adverse events, infections, hospitalizations, and other targeted safety outcomes are collected from patients and their rheumatologists during routine clinical visits using registry questionnaires. Blood collection and other diagnostic tests were not required for participation; however, relevant standard of care laboratory and imaging results were reported if available.

As of August 2023, the CorEvitas PsA/SpA Registry included patients from 68 private and academic clinical sites with 78 physicians throughout 30 states in the USA. The registry enrolled 6276 patients with PsA/SpA. The mean and median follow-up time for patients was 3.6 years and 2.9 years, respectively.

Patients were eligible to enroll in the Registry if they were ≥ 18 years old, able to provide written informed consent, and met one of the following criteria: (1) diagnosed with PsA and initiated (prescribed or started) an approved medication for the treatment of PsA at the time of enrollment; (2) met the Assessment of SpondyloArthritis international Society (ASAS) criteria for axSpA, including radiographic or non-radiographic criteria, and initiated (prescribed or started) an approved medication for the treatment of axSpA at the time of enrollment; (3) met the modified New York classification criteria for ankylosing spondylitis and initiated (prescribed or started) an approved medication for the treatment of ankylosing spondylitis at the time of enrollment. Patients were excluded from enrollment in the CorEvitas PsA/SpA Registry if they had a diagnosis of rheumatoid arthritis, systemic lupus erythematosus, or any other form of autoimmune inflammatory arthritis; or were participating in or planned to participate in a clinical trial of an interventional research study of a non-marketed or marketed investigational drug (e.g. phase 1–4 clinical drug trial, post-marketing study, or registry study where drug was being provided).

This study was performed in accordance with the Declaration of Helsinki and the Guidelines for Good Pharmacoepidemiology Practice. All participating investigators were required to obtain full board approval for conducting non-interventional research involving human patients with a limited dataset. Sponsor approval and continuing review were obtained through a central Institutional Review Board (IRB), namely, the New England Independent Review Board (NEIRB; no. 120160610). For academic investigative sites that did not receive authorization to use the central IRB, full board approval was obtained from their respective governing IRBs, and documentation of approval was submitted to the PPD™ clinical research business of Thermo Fisher Scientific (Waltham, MA, USA) before the site’s participation and initiation of any study procedures. All patients enrolled in the PPD™ CorEvitas™ PsA/SpA Registry were required to provide written informed consent and authorization before participating in the study.

PsA Study Population Criteria

The PsA observational cohort for this analysis included patients with PsA enrolled in the CorEvitas PsA/SpA Registry, who initiated (from April 2013–August 2022) and persisted on the same TNFi of any line of therapy at or after the enrollment visit. Patients could not switch to another TNFi to be included in this study. Patients had to have a clinical diagnosis of PsA made by the treating rheumatologist, not be in minimal disease activity (MDA)[28] at baseline, and have valid baseline, 6 (± 3)-month, and 12 (± 3)-month follow-up visits. MDA was defined as meeting at least five of the seven MDA components: body surface area (BSA) ≤ 3%, Health Assessment Questionnaire Disability Index (HAQ-DI) ≤ 0.5, tender joint count (TJC) ≤ 1, swollen joint count (SJC) ≤ 1, patient pain on visual analog scale (VAS 0–100) ≤ 15, patient global assessment of arthritis (VAS 0–100) ≤ 20; and Spondyloarthritis Research Consortium of Canada Enthesitis Index ≤ 1.

For data analysis, patients with PsA were stratified into one of four subgroups (sustained, improved, worsened, or never achieved status, respectively) according to their MDA status at the 6- and 12-month follow-up visits (Table 1).

Table 1 Cohort definitions for psoriatic arthritis (MDA status) and axial spondyloarthritis (BASDAI50 status)Clinical and QoL Outcomes in Patients with PsA

Clinical features, stratified by MDA status, were assessed at the 6- and 12-month follow-up visits for each of the four subgroups (sustained, improved, worsened, or never achieved status, respectively) and included Clinical Disease Activity in Psoriatic Arthritis low disease activity (cDAPSA LDA) composite score [29, 30], enthesitis and dactylitis counts, and BSA ≤ 3%. The composite disease activity score, cDAPSA, was calculated as the sum of TJC, SJC, patient pain assessment, and patient global assessment of arthritis activity. Higher cDAPSA scores indicate more severe disease activity, and cDAPSA LDA was defined as a score ≤ 13.

Patient-reported outcomes (PROs) were also evaluated at the 6- and 12-month follow-up visits for the four subgroups of patients with PsA. These outcomes included the HAQ-DI, which is used to assess the impact of PsA on physical function [31] and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), which is a broad composite score consisting of six questions that assess the severity of fatigue, spinal and peripheral joint pain, localized tenderness, and morning stiffness [32, 33]. The BASDAI score has a range of 0 to 10 with scores ≥ 4 considered to indicate high disease activity [34]. PROs included individual VAS (0–100) scores for patient pain, patient fatigue, and severity of morning stiffness. Overall work impairment was derived from the work time missed and impairment while working domains of the Work Productivity and Activity Impairment (WPAI) questionnaire [35].

axSpA Study Population Criteria

The axSpA observational cohort for this analysis included patients with axSpA enrolled in the CorEvitas PsA/SpA Registry who initiated (from August 2013–August 2022) and persisted for 12 months on the same TNFi of any line of therapy, at or after the enrollment visit. Patients could not switch to another TNFi to be included in this study. Patients had to have a clinical diagnosis of axSpA as determined by the treating rheumatologist and have valid baseline and 6 (± 3)- and 12 (± 3)-month follow-up visits. BASDAI was used to determine patient-reported disease activity in patients with axSpA. BASDAI50 was defined as a ≥ 50% improvement from the original BASDAI score at baseline.

For analysis of data, patients with axSpA were stratified into one of four subgroups (sustained, improved, worsened, or never achieved status, respectively) according to their BASDAI50 status at the 6- and 12-month follow-up visits (Table 1).

Clinical and QoL Outcomes in Patients with axSpA

Clinical features of axSpA, stratified by BASDAI50 status, were assessed at the 6- and 12-month follow-up visits for each of the four subgroups (sustained, improved, worsened, or never achieved status, respectively), and included the composite measures of Ankylosing Spondylitis Disease Activity Score (ASDAS), LDA, and ASAS40. The ASDAS consists of five questions about back pain, peripheral pain/swelling, duration of morning stiffness, patient global assessment of arthritis, and C-reactive protein; the ASDAS LDA is defined as an ASDAS score < 2.1 [32, 36]. The ASAS40 response is defined as a ≥ 40% improvement and an absolute improvement from baseline of ≥ 2 units (range 0–10) in ≥ 3 of the four components (patient’s global assessment of disease activity, spinal pain, physical function as measured by Bath Ankylosing Spondylitis Functional Index [BASFI], and stiffness) without any worsening in the remaining component [37]. PROs were also evaluated at the 6- and 12-month follow-up visits for the four subgroups of patients with axSpA stratified by BASDAI50 status. Outcomes included the ASAS Health Index (ASAS HI), BASDAI, and BASFI. ASAS HI contains 17 items that address a broad range of functioning, disability, and health relevant to axSpA [38], and scores range from 0 to 17, with lower scores indicating better overall health status. BASFI consists of eight questions regarding function and two questions assessing a patient’s ability to cope with everyday life [39], and scores range from 0 to 10, with higher scores indicating greater functional disability. Additional PROs included individual VAS (0–100) scores for patient pain, patient fatigue, and morning stiffness severity. Overall work impairment was derived from the work time missed and impairment while working domains of the WPAI Impairment questionnaire [35].

Data Analysis in PsA and axSpA Cohorts

Baseline patient characteristics were summarized as the mean and standard deviation (SD) or as frequencies and percentages. The baseline visit was defined either as the visit coinciding with the reported TNFi initiation date or—if the initiation was between visits—as the visit immediately prior to the report of initiation if that visit occurred ≤ 4 months prior to the reported treatment initiation. If the visit at which initiation was reported > 1 month after initiation, the patient was excluded from the analysis for lack of treatment index data. For patients in the sustained and never achieved subgroups, the frequency and proportion of patients achieving functional, clinical, and QoL outcomes were reported at the 6- and 12-month follow-up visits. Rates of achievement were calculated among patients who were not in the outcome state at baseline.

Poisson regression models, adjusting for age, race, sex, work status, time since PsA or axSpA diagnosis, and line of therapy (0, 1, 2+ prior biologic/targeted synthetic disease-modifying antirheumatic drug [DMARD] therapies) were used to estimate the association between disease status group (sustained vs never achieved status) and achievement of clinical outcomes as well as those who met or exceeded a minimum clinically important difference (MCID) in PROs at the 6- and 12-month follow-ups; covariate-adjusted relative risk ratios (95% confidence intervals [CIs]) were reported at both follow-up visits. MCIDs for PROs are summarized in Table 2.

Table 2 Minimum clinically important differences for patient-reported outcomes