A ritish study raises questions about whether methotrexate – a disease-modifying antirheumatic drug and a first-line treatment for psoriatic arthritis, or PsA – actually does anything to slow down the disease.

The study, published in the August 2012 issue of the journal Rheumatology, is the first large, double-blind, placebo-controlled study of methotrexate,or MTX, for psoriatic arthritis.

A total of 221 PsA patients were recruited from 22 specialty rheumatology clinics in the U.K. For six months, the subjects received either methotrexate, with a target dose of 15 milligrams per week, or a placebo. Various measures of effectiveness were tallied at three and six months.

After six months, the researchers found methotrexate had no significant effect on objective measures of disease activity. But it did seem to offer subjective benefits for some – that is, doctors and patients seemed to agree the drug was beneficial based on doctor observation and how the patients reported they felt.

To grasp a firmer understanding of this research, we followed up with study co-author, Dr. Gabrielle Kingsley, consultant and reader in the department of rheumatology at Kings College, London.

Q&A:

Arthritis Today: So what did your study determine about the role of methotrexate in psoriatic arthritis therapy?

Dr. Kingsley: “We believe it is not a disease modifying anti-rheumatic drug [or DMARD] but a symptom-modifier in PsA, not that it has no effect at all. We also saw effects on the skin, which has been well demonstrated before.”

AT: Do you feel the study was slightly limited by the six-month duration of the therapy?