23 November 2023

SpA highlights from ACR23

Axial spondyloarthritis Psoriatic Athritis

At Rheumatology Republic’s post-ACR webinar, The abstracts that will change practice, Professor Peter Nash discussed some of the key presentations in PsA and axSpA.

The first looked at a potential window of treatment opportunity in psoriatic arthritis (abstract 1641). Rheumatoid arthritis patients treated within 12 weeks of symptom onset have better outcomes than those who start later. Does the same apply to psoriatic arthritis, where diagnostic delays of more than a year are common?

The Dutch team categorised over 800 DMARD-naïve PsA patients into three groups based on diagnostic delay: <12 weeks, 12-52 weeks and >52 weeks. The groups were compared on their probability of achieving minimal disease activity and Disease Activity in PSoriatic Arthritis (DAPSA) remission, with radiographic progression and functional impairment also assessed.

Those diagnosed and treated within 12 weeks had significantly better outcomes than those with over 52 weeks’ delay. The 12-week group also had numerically superior outcomes to those with between 12-52 weeks’ delay.

Next were two abstracts on predicting difficult-to-treat spondyloarthropathies, with questions now around what to do with this information.

“Because there’s been an effort to treat difficult-to-treat rheumatoid arthritis, they’re now trying to define difficult-to-treat axial spondyloarthritis,” said Professor Nash.

In abstract 0514, French researchers defined it as the failure of three biologic/targeted synthetic DMARDs or two b/tsDMARDs with different modes of action.

From a database of over 23,000 patients, around 9% were classified as having difficult-to-treat axSpA, and it’s more common in women and in patients with peripheral involvement, psoriasis, depression and hypertension.

“So what are the implications, what do you do with these people? Should you diagnose them early? Should you look for risk factors early? Should we start more aggressively with combination therapy?”

A similar, though smaller, study was conducted in psoriatic arthritis patients (abstract 0777), where difficult-to-treat PsA was defined as failure of at least two b/tsDMARDs with different mechanism of action among TNF inhibitors, anti-IL17, anti-IL23 and JAK inhibitors.

“There was no difference in fibromyalgia, depression or smoking, but they did show [increased risk of difficult-to-treat PsA] if you’re obese, if you had axial involvement, if you already had structural damage, if you couldn’t control skin, so you had change therapies because of skin, and previous treatment with adalimumab, which I think just means you failed a TNF inhibitor,” said Professor Nash.

“And the same thing applies: what implication is there? Do we treat them more aggressively? We have to test if that’s worthwhile or not. Maybe combination therapy?”

A study looking at targeted therapies persistence in women versus men with PsA found women were less likely than men to persist with TNFi and IL17i, but there was no difference for IL12/23i, IL23i and JAKi (abstract 0779).

“Women have high disease activity at baseline, they respond less well to therapy, and all trials going forward really should stratify for gender to account for that,” said Professor Nash.  

He added that there’s a very large GRAPPA project underway to try and work out why that might be, and to do something about it.

A research team looked at the recently developed 3 Visual Analogue Scale (3VAS) and 4VAS, which are short multidimensional composite measures specifically for use in PsA routine clinical care, to determine whether early improvement in 3VAS/4VAS predicts radiographic change in patients treated with guselkumab (poster 2228).

“Now, one of the commonest questions we get asked is, ‘What objective measure can I use practically in the clinic to follow disease activity in my psoriatic arthritis patients?’

“This 3VAS/4VAS is just a simple questionnaire you can leave in the clinic, and while they’re waiting to see you, they can fill it out.

“It correlates very nicely with disease activity, it changes over time, it’s responsive over time, and it correlates – if you improve the 3VAS and 4VAS you get more low disease activity.”

The researchers, which included Professor Nash, also reported the questionnaires may predict long-term radiographic changes, with the 3VAS being more sensitive.

“This is a practical disease activity measure, rather than PASDAS and some of these others that are clinical trial measures. It’s something that might be easy to use,” said Professor Nash.

A Spanish study looking at the prevalence of undiagnosed inflammatory bowel disease in patients with spondyloarthritis found that 4.4% met IBD diagnostic criteria based on faecal calprotectin levels with endoscopic or radiological confirmation (poster 0495). Only 30% of them were symptomatic, and it was mostly Crohn’s disease.

The cut-off the team used for determining whether further examination was warranted was FC ≥80µg/g, which Professor Nash pointed out is much lower than the gastros recommend.

“This test is quite sensitive. If it’s under 50, you do not have significant inflammation in your gut, you are very unlikely to have IBD. If it’s over 150, you’ve got a very high chance of having gut inflammation, and the endoscopic examination is worthwhile.

“So, there’s this sort of background of 5% of IBD floating around in the SpA population if you use that very low FC cut off and examine them.”

Rheumatology Republic’s post-ACR webinar, The abstracts that will change practice was held on Tuesday 21 November, featuring Professor Peter Nash, Dr Claire Owen, Professor Rebecca Grainger and Dr David Liew. You can register here to watch a recording.