PHILADELPHIA — Treatment with golimumab reversed structural joint damage in patients with psoriatic arthritis in a placebo-controlled, phase III study with about 400 patients.
The structural joint benefit from golimumab in this analysis complemented clinical improvements previously reported from the same study. Those benefits led the Food and Drug Administration to give marketing approval to golimumab for psoriatic arthritis (PsA) last April.
The results showed structural improvement with golimumab after 24 weeks of treatment (the primary end point of the radiographic assessment), independent of methotrexate co-treatment. The benefit continued through 52 weeks of follow-up, Dr. Arthur F. Kavanaugh said at the annual meeting of the American College of Rheumatology.
The GO-REVEAL (Golimumab—A Randomized Evaluation of Safety and Efficacy in Subjects With Psoriatic Arthritis Using a Human Anti-TNF Monoclonal Antibody) study enrolled patients at 58 sites in the United States, Canada, and Europe. It was the largest completed study of its kind (405 patients) with a biologic agent in patients with PsA. Subjects had active disease despite treatment with DMARDs or NSAIDs. Their average age was 47 years, their average duration of PsA was 8 years, 60% were men, 97% were white, and 48% were on methotrexate treatment.
Patients received subcutaneous injections of 50 mg golimumab (146 patients), 100 mg golimumab (146 patients), or placebo (113 patients) at week 0, and then every 4 weeks through week 20. Starting at week 24, all patients received golimumab.
The clinical outcomes published last April showed that treatment with golimumab led to an ACR 20 response in 51% of patients on the 50-mg dose and in 45% of those receiving a 100-mg dose at week 14, compared with 9% of placebo patients, which were statistically significant differences for the primary end point (Arthritis Rheum. 2009;60:976-86).
Golimumab treatment also produced significant improvements, compared with placebo, on a psoriatic index and other measures of clinical response.
The new analysis used total Sharp/van der Heijde scores to measure structural joint damage. At baseline, average scores were 18 in placebo patients, 24 in the 50-mg group, and 23 in the 100-mg group. After 24 weeks, the scores changed by an average of +0.27 in the placebo patients (a worsening), −0.16 in patients getting 50-mg doses, and −0.02 in those on 100-mg doses. The difference between the 50-mg group and placebo patients was statistically significant.
The difference between the 100-mg and placebo group did not reach statistical significance, said Dr. Kavanaugh, a rheumatologist and professor of clinical medicine at the University of California, San Diego.
The difference in average Sharp/van der Heijde scores between the placebo patients and those in both golimumab groups continued through 52 weeks of treatment, even though the placebo patients switched to golimumab treatment after the first 24 weeks of the study.
Another radiographic outcome—the percentage of patients with clear progression on their Sharp/van der Heijde scores—tallied 8% in the placebo group and 2% in the 50-mg group, a statistically significant difference.
Centocor Ortho Biotech Products LP, the company that developed and markets golimumab (Simponi), sponsored the study. Dr. Kavanaugh said that he and five of his associates on the study were researcher investigators for Centocor. Another five associates are Centocor employees.
The results showed structural improvement with golimumab after 24 weeks of treatment, the primary end point.
Source DR. KAVANAUGH