# Impact of dactylitis and enthesitis resolution on disease control in guselkumab-treated psoriatic arthritis patients with TNFi-IR: COSMOS post hoc analysis

## TL;DR

This study shows that resolving dactylitis and enthesitis with guselkumab improves long-term disease control in psoriatic arthritis patients who didn't respond to previous treatments.

## Contribution

The study demonstrates a novel link between early resolution of dactylitis and enthesitis and improved long-term disease outcomes in psoriatic arthritis patients treated with guselkumab.

## Key findings

- Guselkumab treatment led to higher rates of dactylitis and enthesitis resolution compared to placebo by week 24.
- Early resolution of dactylitis and enthesitis at week 24 was strongly associated with achieving stringent disease control measures by week 48.
- Patients with dactylitis or enthesitis at baseline had more severe joint and skin involvement compared to those without.

## Abstract

To evaluate guselkumab efficacy on dactylitis resolution (DR) and enthesitis resolution (ER), and their impact on subsequent disease control, in patients with active psoriatic arthritis (PsA) and prior inadequate response to tumour necrosis factor inhibitors (TNFi-IR).

In the Phase IIIb COSMOS trial, 285 adults with TNFi-IR PsA were randomized (2:1) to receive guselkumab 100 mg or placebo at Week (W)0, W4, then every 8 weeks until W44. The Dactylitis Severity Score (DSS) and Leeds Enthesitis Index (LEI) assessed dactylitis and enthesitis, respectively. This post hoc analysis evaluated associations between W24 DR or ER and W48 achievement of stringent disease control measures using logistic regression.

At baseline, 103/285 (36.1%) patients had dactylitis (DSS ≥ 1) and 190/285 (66.7%) had enthesitis (LEI ≥ 1). Patients with dactylitis were more likely to have enthesitis, more joint (SJC/DAPSA) and skin involvement, higher PGA score and lower BMI vs those without dactylitis. Patients with enthesitis were more likely to be female, and have dactylitis, more joints affected (SJC/TJC/DAPSA) and worse physical functioning (HAQ-DI/SF-36 PCS) vs those without enthesitis. Greater proportions of guselkumab- vs placebo-treated patients achieved DR/ER (W24: 44.8%/39.7% vs 25.0%/18.8%); rates increased through W48 among guselkumab-randomized patients (67.2%/55.6%). W24 resolution was associated with W48 achievement of stringent measures, including ACR50/70, DAPSA LDA/remission, PASI100, PASDAS LDA/VLDA and MDA/VLDA (odds ratios: DR, 3.28–13.38; ER, 2.88–6.09).

Guselkumab treatment resulted in high DR/ER rates through W48 in TNFi-IR PsA patients. W24 DR/ER was associated with W48 disease control, providing valuable insights for clinical decision-making based on W24 treatment responses.