In Psoriatic Arthritis, Traditional Therapies May Improve Persistence with Novel Biologic Therapies

Methotrexate, a traditional disease-modifying antirheumatic drug, may enhance the likelihood of therapeutic persistence with novel biologic agents.

The use of traditional disease-modifying antirheumatic drugs with biologic agents was found to offer improved persistence compared with novel biologic therapies used alone for the treatment of psoriatic arthritis, according to the results of a recent study.

In a registry study of patients with psoriatic arthritis by Bente Glintborg and colleagues at the Department of Rheumatology in Glostrup Hospital, in Copenhagen, Denmark, investigators attempted to determine the typical dosage regimens, dosage escalation patterns, and resulting clinical outcome in patients using tumor necrosis factor (TNF) inhibitors for psoriatic arthritis.¹

To accomplish the study, researchers made use of 2 registries: the nationwide Danish Rheumatologic Database (DANBIO), and the Center for Rheumatology Research (ICEBIO) Icelandic patient registry database.¹

To assess differences between treatment groups and to detect differences in the treatment of varying types of patients, each patient was stratified by several prespecified characteristics, such as the patient's country of origin and the dosage of infliximab used (on a mg/kg basis). Clinical outcomes were assessed based on the percentages of patients acheiving a ≥20%, ≥50%, or ≥70% improvement on the American College of Rheumatology arthritis severity score. Responses were measured at 6 months and at 12 months.¹

Of 462 patients included in the study, the majority were Danish (n = 376) and the remainder were Icelandic (n = 86). The dose of infliximab used was not associated with improved response or better persistence with therapy over the 1-year trial. Use of methotrexate in combination with infliximab predicted a greater likelihood of drug persistence. Patients receiving methotrexate were significantly more likely to continue using infliximab over the course of the 1-year registry study (P = .009).¹

Methotrexate has been a mainstay of therapy for psoriatic arthritis and has been shown to reduce the production of excess dead skin cells through suppression of the immune system. Although side effects may include elevated liver enzyme levels, use of methotrexate with biologic therapies may benefit patients with psoriatic arthritis.² As the results of this trial demonstrate, the use of methotrexate may improve persistence of therapy with TNF inhibitors, and optimizing therapy with this traditional disease-modifying antirheumatic drug may be associated with improved persistence with novel biologic therapies.

References:

• Glintborg B, Gudbjornsson B, Steen Krogh N, et al. Impact of different infliximab dose regimens on treatment response and drug survival in 462 patients with psoriatic arthritis: results from the nationwide registries DANBIO and ICEBIO [published online June 17, 2014]. Rheumatology (Oxford).
• Gladman DD, Rictchlin C. Psoriatic arthritis overview. UpToDate.com. Accessed July 2014.