Walking the Tightrope of Treat to Target in Psoriatic Arthritis Save

In the last few years, new studies have been published examining if early intervention and tight control (TC) of psoriatic arthritis (PsA) disease activity will have the same beneficial outcomes as it does for rheumatoid arthritis (RA).  

The Tight Control of Inflammation in Early Psoriatic Arthritis (TICOPA) study1 published in the Lancet journal in 2015 reported that patients in the TC arm who received close monitoring and protocol driven aggressive therapy escalation had a greater chance of achieving ACR20, ACR50, and ACR70, and PASI75 responses than those who received standard of care.   

However, no significant differences were detected in the rate of radiographic progression between the two arms at 48 weeks, and the mean cost of providing TC was twice the cost of standard of care.    Furthermore, patients in the TC arm had higher incidences of serious adverse events related to therapy and increased number of hospitalizations.  

The study authors concluded that while TC may improve disease outcomes, it resulted in higher cost and greater adverse events.  

So should we abandon ship and forget about tight control?  Is “some control” good enough?    Putting cost aside, there are many benefits of tight disease control. Dr. Iain McInnes in his review of Psoriatic Arthritis at the ACR meeting in Chicago on October 20, 2018 noted that patients with PsA have extra-articular and extra-cutaneous manifestations that can cause high morbidity, including: cardiovascular and gastrointestinal disease, metabolic syndrome, osteoporosis, lymphoma and other malignancies as well as depression and anxiety.  The TICOPA study did not account for the benefits of TC on these manifestations and the potential for extended life and work productivity for these patients 10-20 years later.  

The Treat to target (T2T) paradigm has been shown to revolutionize outcomes for chronic diseases as diabetes mellitus, hypertension, hyperlipidemia, and rheumatoid arthritis.  Multiple organizations including EULAR, GRAPPA-OMERACT support the treat to target strategy in PsA given the benefits of tight disease control2, 3. 

In PsA, disease remission or minimal disease activity (MDA) should be the goal.  The international taskforce4 acknowledges that implementing T2T may be difficult in clinical practice due to multiple domains being measured as PsA has heterogeneic manifestations; e.g. synovitis, dactylitis, enthesitis, spondylitis and psoriasis/ nail involvement.  

Use of a simplified disease assessment tool (DAPSA) may streamline assessments, and the role of imaging is being defined to help diagnose and to follow disease activity.  MRI and ultrasound have been able to detect subclinical inflammatory changes within articular and periarticular structures; patients with sonographic evidence of enthesitis and synovitis, have poorer prognosis and long-term, progressive radiographic damage.  

While there is uncertainty in the strategies and frequency of clinic visits to optimally manage PsA, patients and physicians agree that the ultimate goal is achieve a state of remission or near remission.  The only way to do this is to consistently measure disease activity, and borrowing the title from Dr. Yusuf Yazici article on assessing RA disease remission, “…any [tool] will do, let's just pick one and start measuring.”  

References

1. Laura C Coates, Anna R Moverley, et al. Effect of tight control of inflammation in early psoriatic arthritis (TICOPA): a UK multicentre, open-label, randomized, controlled trial. Lancet. 2015 December 19; 386(10012): 2489–2498

2. Coates LC, et al. Group for research and assessment of psoriasis and psoriatic arthritis/outcome measures in rheumatology consensus based recommendations and research agenda for use of composite measures and treatment targets in psoriatic arthritis. Arthritis Rheumatol. 2018;70(3):345–55

3. Gossec L, et al. European League Against Rheumatism (EULAR) recommendations for the management of psoriatic arthritis with pharmacological therapies: 2015 update. Ann Rheum Dis. 2016;75(3):499–510

4. Smolen JS, et al. Treating axial spondyloarthritis and peripheral spondyloarthritis, especially psoriatic arthritis, to target: 2017 update of recommendations by an international task force. Ann Rheum Dis. 2018;77(1):3–17.