Rapid, Durable Benefit of Upadacitinib Across Oligo‑ and Polyarticular Psoriatic Arthritis: Primary Findings from the Real‑World UPJOINT Study

Highlight

– Upadacitinib therapy was associated with rapid MDA achievement by week 4 and substantial increases in MDA at weeks 24 and 48 in both oligoarticular and polyarticular PsA.

– After 24 weeks, 41.5% of patients overall achieved MDA (55.8% in oPsA; 32.0% in pPsA); benefits were largely maintained to week 48.

– VLDA and DAPSA remission rates rose from 0% at baseline to clinically meaningful levels at week 48, particularly in oPsA.

– Safety outcomes were consistent with prior clinical trials: infections were the most common events and no new signals were identified.

Background: clinical need and therapeutic context

Psoriatic arthritis (PsA) is a heterogeneous inflammatory disease that couples musculoskeletal inflammation (peripheral arthritis, enthesitis, axial disease) with skin and nail psoriasis. Disease burden ranges from oligoarticular presentations with few swollen joints to polyarticular forms with widespread synovitis, progressive structural damage and impaired quality of life. Treatment goals include rapid control of signs and symptoms, prevention of structural damage, and improvement in patient function and quality of life. Minimal disease activity (MDA) is a validated treat‑to‑target composite for PsA that captures multiple disease domains and is increasingly used both in trials and in practice.

Janus kinase (JAK) inhibitors, including the JAK1‑preferential inhibitor upadacitinib, have demonstrated efficacy in phase 3 randomized trials in PsA across multiple endpoints. However, randomized controlled trials (RCTs) enroll selected populations and may not reflect routine care heterogeneity. Real‑world data are therefore valuable to understand effectiveness, onset of action, and safety across clinical phenotypes encountered in everyday practice.

Study design: UPJOINT overview

UPJOINT is a post‑marketing, multicenter, observational study (ClinicalTrials.gov NCT04758117) designed to evaluate effectiveness and safety of upadacitinib in patients with active PsA treated according to local labeling over 48 weeks. Key design features:

• Population: patients with active PsA receiving upadacitinib as part of routine care. Subgroups defined by oligoarticular (oPsA) versus polyarticular (pPsA) phenotype were prespecified.
• Intervention: upadacitinib prescribed at the treating physician’s discretion in line with the local label; treatment initiation was independent of study participation.
• Endpoints: Primary endpoint was the proportion achieving MDA at week 24 during continuous upadacitinib treatment. Secondary endpoints included maintenance of MDA at week 48 among week‑24 responders, rates of very low disease activity (VLDA), and DAPSA remission at multiple time points (baseline, weeks 4, 12, 24, 36 and 48).
• Analysis: effectiveness dataset comprised 364 patients in an as‑observed analysis. Safety data were collected in a separate dataset using standardized AE documentation and MedDRA coding.

Key findings

Baseline characteristics and clinical context

At baseline, MDA was uncommon: only 3.6% overall (7.1% oPsA and 1.3% pPsA) were in MDA prior to starting upadacitinib, indicating that most treated patients had active disease despite prior care. Detailed demographic and prior therapy data were not included in the primary summary but are relevant to interpret real‑world effectiveness and potential differences between phenotypes.

Primary outcome — MDA at week 24 and maintenance to week 48

The proportion of patients achieving MDA increased markedly after initiating upadacitinib. At week 24, 41.5% of patients overall achieved MDA. When stratified by phenotype, 55.8% of patients with oligoarticular PsA and 32.0% of patients with polyarticular disease reached MDA at week 24.

Importantly, improvements were largely sustained: at week 48, 47.5% of oPsA patients and 35.1% of pPsA patients were in MDA. The pattern suggests higher absolute response rates in oPsA versus pPsA but clinically meaningful benefit across both phenotypes.

Speed of onset

Notably, meaningful improvements were observed early. By week 4, 38.4% of oPsA patients and 16.3% of pPsA patients were already in MDA. This rapid early response is clinically relevant because prompt symptom relief can reduce disability and improve adherence.

Other composite outcomes: VLDA and DAPSA remission

Rates of stringent disease control also improved. VLDA and DAPSA remission were both 0% at baseline in both phenotypes but rose by week 48. VLDA was achieved in 22.2% of oPsA and 14.3% of pPsA patients at week 48. DAPSA remission at week 48 was observed in 24.2% of oPsA and 14.9% of pPsA patients. These outcomes reflect deeper disease quiescence beyond MDA and are encouraging given the broad inclusion of routine patients.

Safety

Safety data were captured in a separate standardized dataset. Among patients evaluable for safety, 127 (33.3%) experienced a total of 213 adverse events deemed to have a reasonable possibility of being related to upadacitinib. Forty‑one serious adverse events occurred in 26 patients (6.8%). Infections were the most frequently reported events of special interest. Importantly, no new or unexpected safety signals were identified relative to prior clinical trials and the known safety profile of upadacitinib.

Interpretation and expert commentary

UPJOINT provides real‑world evidence that complements phase 3 randomized data by demonstrating that upadacitinib is effective and generally well tolerated in routine clinical practice across oligo‑ and polyarticular phenotypes of PsA. Several points merit emphasis:

• Consistency with RCTs: The magnitude and trajectory of response—rapid onset and sustained improvements through 48 weeks—align with observations from phase 3 programs, supporting external validity.
• Phenotype differences: Higher absolute MDA, VLDA and DAPSA remission rates were seen in oligoarticular disease compared with polyarticular disease. This may reflect lower baseline joint burden, differential structural damage, or differences in prior treatment exposure; such subgroup responses are clinically plausible but require careful interpretation.
• Rapid effect: The emergence of MDA in a substantial fraction of patients by week 4 supports a fast pharmacodynamic effect, relevant to symptom control and patient expectations.
• Safety profile: Rates of infections and serious adverse events were within expected ranges; absence of new signals is reassuring but continued pharmacovigilance in larger, longer cohorts remains important.

Limitations and generalizability

UPJOINT’s observational design confers strengths (broad applicability, real‑world practice heterogeneity) and inherent limitations. There was no randomized comparator, so effectiveness measures are not controlled for secular trends or regression to the mean. The as‑observed analysis does not account for missing data due to treatment discontinuations or loss to follow‑up; this may bias estimates if discontinuations were nonrandom. Confounding by indication and heterogeneity in prior therapies or comorbidities could influence observed outcomes. The separate safety dataset and lack of comparator limit causal inference about adverse events. Finally, detailed baseline characteristics (e.g., prior biologic exposure, duration of disease, structural damage) are needed to contextualize subgroup differences.

Clinical implications

For clinicians, UPJOINT supports that upadacitinib can produce rapid and durable control of disease activity in routine care settings for both oligo‑ and polyarticular PsA. The data reinforce that patients with less extensive joint involvement can achieve particularly high rates of MDA and VLDA. Decisions regarding sequencing with other targeted agents should still weigh individual patient factors (prior therapy failures, comorbidities, infection risk, pregnancy planning) and align with local guidance.

Conclusions and future directions

The primary analysis from UPJOINT demonstrates that upadacitinib yields clinically meaningful and rapid improvements in composite measures of disease control in a heterogeneous, real‑world PsA population, with a safety profile consistent with prior clinical trials. Benefits were apparent as early as week 4 and were maintained through week 48 in many patients, across oligo‑ and polyarticular phenotypes.

Future work should seek to:

• Provide adjusted analyses accounting for baseline confounders and prior therapies to refine effect estimates.
• Compare upadacitinib with other targeted therapies head‑to‑head in routine practice using propensity methods or pragmatic designs.
• Explore predictors of sustained deep remission (VLDA/DAPSA remission) and characterize structural outcomes over longer follow‑up.
• Expand safety surveillance to larger populations and longer durations to refine rare event risk estimates.

Funding and trial registration

The study is a post‑marketing, multicenter observational study (NCT04758117). Funding and sponsor details are reported in the original publication (Werner et al., Rheumatol Ther. 2025). ClinicalTrials.gov identifier: NCT04758117.

References

Werner SG, Schwarze I, Baraliakos X, Fiene M, Walter J, Girard T, Laliberté MC, Jeromin K, Baschuk N, Allard‑Charmard H, Bessette L, Hueber AJ. Effectiveness and Safety of Upadacitinib in Treating Oligoarticular and Polyarticular Psoriatic Arthritis: Primary Analysis from the UPJOINT‑Study. Rheumatol Ther. 2025 Nov 5. doi: 10.1007/s40744-025-00802-5. Epub ahead of print. PMID: 41191276.

AI thumbnail prompt

High‑resolution image of a modern rheumatology clinic: a middle‑aged patient with mild psoriasis on the forearm and visibly swollen finger joints sits across from a clinician viewing a tablet that displays improving clinical graphs (declining swollen/tender joint counts, DAPSA scores) and calendar timelines; warm, hopeful lighting, professional attire, neutral background, clear focus on the tablet screen and the patient’s hands.