Aggressive, early intervention with disease-modifying drugs improves outcomes for psoriatic arthritis patients

Psoriatic arthritis is a type of arthritic inflammation that occurs in about 15 percent of patients who have a skin rash called psoriasis. This particular arthritis can affect any joint in the body, and symptoms vary from person to person.

Research has shown that persistent inflammation from psoriatic arthritis can lead to joint damage, and researchers at the University of Leeds in the United Kingdom investigated the differences in outcome measurements among two groups of psoriatic arthritis patients. The first group was treated according to a tight control approach, following specific guidelines on use of disease-modifying antirheumatic drugs (called DMARDs) to reach set targets in disease-related measurements. The second group was treated with a standard care approach.

The researchers' overarching goal was "to replicate similar findings in other inflammatory arthropathies, notably rheumatoid arthritis, where a treat-to-target approach is known to favorably influence long-term outcomes for these patients," says Philip Helliwell, MD; senior lecturer in rheumatology; Leeds Institute of Rheumatic and Musculoskeletal Medicine; and an investigator in the study.

Using data from eight medical treatment centers in the UK from 2008 to 2012, the researchers identified 206 people with psoriatic arthritis and tracked their progress for 48 weeks according to their treatment protocol. The patients in the tight control group were treated with escalating therapy if they did not meet minimal disease activity criteria at set time intervals. These patients were started on the DMARD methotrexate with rapid escalation to a dose of 25mg after six weeks if they tolerated the drug. After 12 weeks, if their disease was not controlled according to the criteria, these patients received a more powerful combination of DMARDs.

After another 12 weeks, if these patients had three or more tender or swollen joints, they were given anti-tumor necrosis factor (Anti-TNF) therapy. If they had less than three tender or swollen joints, but still did not meet the minimal disease activity criteria, they were given methotrexate and an alternative DMARD in combination. The standard treatment group was treated with DMARDS, but with no set time limits for drug therapy escalation or measurements to reach.

The researchers measured the outcomes of the two groups of patients according to the ACR20, ACR50 and ACR70 criteria for disease activity (essentially representing 20, 50, and 70 percent improvement). In the tight control group, 55 percent achieved ACR20, 44 percent achieved ACR50 and 33 percent achieved ACR70. In the standard care group, 37 percent achieved ACR20, 21 percent achieved ACR50 and 15 percent achieved ACR70.

These significant differences show that an aggressive, targeted approach to treating psoriatic arthritis greatly improves disease-activity outcomes for patients with psoriatic arthritis, the researchers concluded. "For the first time, it has been shown that aggressive treatment of inflammation in psoriatic arthritis gives better outcomes," explains Dr. Helliwell. "Further, the target used in the study -- minimal disease activity -- assesses a wide spectrum of disease features, including skin and enthesitis, and not just the articular aspects of this complex disease. Patients with this disorder have to endure several different disease manifestations. This study has shown that appropriate targeted therapy can be effective across all these aspects, an important finding for the person with this disorder."