P176 Minimal important difference, minimal detectable change and disease activity thresholds for two novel composite instruments, three visual analogue scale/VAS and four visual analogue scale/VAS, in patients with psoriatic arthritis: pooled analysis of three phase III studies
Authors: Tillett William , Coates Laura , Vis Marijn , Merola Joseph , Soriano Enrique , Perate Michelle , Shawi May , Zimmermann Miriam , Rampakakis Emmanouil , Sharaf Mohamed , Nash Peter , Helliwell Philip S 
Published: April 2023

Abstract

Background/Aims
Although continuous composite measures of disease activity for PsA assessment exist, more feasible abbreviated measures are needed for routine screening. The 3VAS and 4VAS scores, developed by abridging the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) Composite Exercise (GRACE) measure, are the first short multidimensional composite measures specifically for routine PsA care. 3VAS/4VAS showed superior performance vs. several established composite measures using small datasets. However, GRAPPA members recommended further testing of 3VAS/4VAS in observational and trial datasets.

Methods
This post hoc analysis used pooled data through W24 from all treatment groups in the DISCOVER 1/2 and COSMOS studies. Correlation of 3VAS/4VAS with DAPSA, PASDAS, PhGA and PtGA was assessed with Pearson’s correlation coefficient, minimal important difference (MID) with four distribution-based methods and minimal detectable change (MDC) with the standard formula (Table 1). Clinically relevant thresholds for low, moderate and high disease activity were estimated with receiver operating characteristic analysis and DAPSA (≤4, &gt;4-≤14, &gt;14-≤28, &gt;28), PASDAS (≤1.9, &gt;1.9-≤3.2, &gt;3.2-&lt;5.4, ≥5.4) and PhGA/PtGA (≤1, &gt;1-≤3, &gt;3-≤6, &gt;6 cm) as anchors.

Results
This analysis included 1405 patients: 51.3% were male, with a mean (sd) age of 47.1 (11.8) and PsA duration of 6.4 (6.5) years. The mean baseline 3VAS, 4VAS, DAPSA, PASDAS, PhGA and PtGA scores reflected high disease activity levels (Table 1). Through W24, 3VAS and 4VAS showed very strong correlation with PtGA (r3VAS=0.92, r4VAS=0.94) and PASDAS (r3VAS=0.81, r4VAS=0.82), strong with PhGA (r3VAS=0.77, r4VAS=0.74) and moderate-to-strong with DAPSA (r3VAS=0.59, r4VAS=0.61). Calculated MIDs were 0.9 for 3VAS and 0.9 for 4VAS; MDCs were 3.3 for 3VAS and 3.2 for 4VAS (Table 1). Cut-off values for low, moderate and high disease activity were 2.0, 3.4 and 4.9 for 3VAS, and 2.1, 3.5 and 5.1 for 4VAS.

Conclusion
Using a large pooled clinical trial dataset of patients with active PsA, we have calculated clinically relevant thresholds for improvement, as well as disease activity thresholds, for 3VAS and 4VAS. These estimates are generally comparable to those previously reported and may facilitate setting treatment targets and screening disease activity in routine care when resources are limited or in remote patient monitoring.
Disclosure
W. Tillett: Other; Received research funding, consulting, speaker fees and/or honoraria from AbbVie, Amgen, Celgene, GlaxoSmithKline, Janssen, Lilly, MSD, Novartis, Pfizer and UCB. L. Coates: Consultancies; AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer and UCB. Member of speakers’ bureau; AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer and UCB. Grants/research support; AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer and UCB. Other; National Institute for Health Research (NIHR) Clinician Scientist award. The research was supported by the NIHR Oxford Biomedical Research Centre, The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health, We acknowledge the support of the NIHR Clinical Research Network. M. Vis: Other; Received research grants and consulting or speaker fees from AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer, UCB and the Dutch Arthritis Foundation. J. Merola: Consultancies; Consultant and/or investigator for AbbVie, Arena, Biogen, Bristol Myers Squibb, Dermavant, Lilly, Janssen, Novartis, Pfizer, Sun Pharma and UCB Pharma. E. Soriano: Consultancies; AbbVie, Janssen, Novartis and Roche. Member of speakers’ bureau; AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Janssen, Novartis, Pfizer, Roche and UCB. Grants/research support; AbbVie, Janssen, Novartis, Pfizer, Roche and UCB. M. Perate: Shareholder/stock ownership; Employee of Janssen and owns stocks in Johnson & Johnson. M. Shawi: Shareholder/stock ownership; Employee of Janssen and owns stocks in Johnson & Johnson. M. Zimmermann: Shareholder/stock ownership; Employee of Janssen and owns stocks in Johnson & Johnson. E. Rampakakis: Consultancies; Employee of JSS Medical Research; paid consultant of Janssen. M. Sharaf: Shareholder/stock ownership; Employee of Janssen and owns stocks in Johnson & Johnson. P. Nash: Other; Received grants for research and clinical trials and honoraria for advice and lectures on behalf of AbbVie, Boehringer-Ingelheim, Gilead/Galapagos, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, Samsung,. P.S. Helliwell: Consultancies; AbbVie, Amgen, Novartis and Janssen. Other; Fees for educational services from AbbVie, Amgen, Novartis and Janssen.