Leflunomide Helpful in Psoriatic Arthritis

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Leflunomide Helpful in Psoriatic Arthritis

By Anne Harding

NEW YORK (Reuters Health) Jul 16 - Oral leflunomide can ease both skin and

joint symptoms in patients with psoriatic arthritis (PsA) and psoriasis,

according to multinational researchers.

Treatments for patients with PsA, an inflammatory condition seen in some

patients with psoriasis, are often ineffective and poorly tolerated, Dr. J.

Kaltwasser of J.W. Goethe-Universitat in furt, Germany, and

colleagues note in the June issue of Arthritis & Rheumatism.

Although tumor necrosis factor inhibitors and other biologic agents show

promise for treating PsA, the researchers say, these drugs must be given by

injection or infusion and are costly. Oral drugs like methotrexate and

sulfasalazine are active at only one site.

Leflunomide is an orally administered disease-modifying antirheumatic drug

approved in the US, Europe and many other countries for treating rheumatoid

arthritis. Small studies have suggested it may also be effective for PsA.

The drug inhibits T cell activation and proliferation by blocking pyrimidine

synthesis.

To investigate, the researchers randomized 190 patients with PsA and

psoriasis with at least 3% skin involvement to receive leflunomide or

placebo. Patients in the treatment arm of the study took a 100 mg/day

loading dose of the drug for three days, and then 20 mg daily thereafter,

for a total of 24 weeks.

At the close of the study, 58.9% of patients on leflunomide showed a

clinical response as measured by the Psoriatic Arthritis Response Criteria

(PsARC). This was true of 29.7% of patients on placebo.

In terms of psoriasis, 22.4% of patients treated with leflunomide showed

improvement in the Psoriasis Area and Severity Index . Such scores for

patients on placebo declined by an average of 2.2%. Patients on leflunomide

also reported greater improvement in quality of life.

Lack of efficacy was the major reason for withdrawal in both the placebo and

treatment groups, with 19 patients on leflunomide and 33 on placebo dropping

out of the study. The researchers note that the delayed action of the drug

--changes in arthritis symptom measures like PsARC are seen after four to

six weeks, while skin symptom improvement takes longer to appear -- may be

responsible for withdrawals in the treatment group.

The most common side effects in the leflunomide group were diarrhea and

increases of alanine aminotransferase enzymes, but no serious liver toxicity

was seen.

However, Dr. Kaltwasser told Reuters Health that patients on leflunomide

must have liver enzyme monitoring, and the drug has limited indications for

patients with liver disease. Women of childbearing age, he added, must be on

reliable contraception while taking the agent, which is a known teratogen.

Arthritis Rheum 2004;50:1939-50.