Regional patterns of advanced therapy use and unmet disease control in axial spondyloarthritis across Latin America: a report from the ESPALDA-PANLAR registry.

OBJECTIVES

To evaluate regional patterns of current biologic/targeted synthetic DMARD use in patients with axSpA across Latin America, explore clinical differences between patients receiving and not receiving b/tsDMARDs, and quantify disease activity among patients not receiving b/tsDMARDs.

METHODS

Observational, cross-sectional analysis of the PANLAR-ESPALDA registry. Adults fulfilling the ASAS 2009 criteria were included from nine countries and grouped into South (Argentina, Chile, Uruguay, Paraguay), Andean (Colombia, Peru, Venezuela, Ecuador), and North (Mexico) regions. Current b/tsDMARD use, drug class (TNFi, IL-17i, JAKi), and treatment line were recorded. Disease activity was assessed by BASDAI and ASDAS-CRP; unmet disease control was described among patients not receiving b/tsDMARDs.

RESULTS

Among 419 patients, 198 (45%) were receiving b/tsDMARDs (70% TNFi, 20% IL-17i, 10% JAKi); 66% were on first-line, 20% on second-line, and 13% on third-line b/tsDMARD therapy. Overall, treated patients more frequently had uveitis (59% vs 41%; p = 0.04), chronic MRI changes (56% vs 44%; p = 0.01), and a younger age at back pain onset (median 30 vs 36 years; p = 0.02). b/tsDMARD use varied by region (South 44%, Andean 43%, North 56%) with region-specific correlates. Among patients not receiving b/tsDMARDs (n = 206), BASDAI > 4 was observed in 50% across regions; ASDAS moderate/high disease activity remained common (South 42%/29%; Andean 37%/20%; North 39%/16%). Extra-musculoskeletal manifestations were frequent among patients not receiving b/tsDMARDs.

CONCLUSIONS

In this Latin American registry, current b/tsDMARD use varied across participating regions, while substantial disease activity persisted among many patients not receiving advanced therapies. These findings suggest potential unmet disease control in routine care, although treatment eligibility and factors influencing treatment decisions were not systematically captured. Key Points • Current b/ts DMARD use in ESPALDA varied across Latin American regions, ranging from 44 to 56%. • Patients receiving b/ts DMARDs more frequently had uveitis and chronic MRI changes and had earlier back pain onset. • Among patients not receiving b/tsDMARDs, half had BASDAI > 4 and many had moderate or high ASDAS disease activity, indicating persistent disease activity and potential unmet disease control.