The safety and efficacy of a JAK inhibitor in patients with active rheumatoid arthritis: Results of a double-blind, placebo-controlled phase IIa trial of three dosage levels of CP-690,550 versus placebo

In the article by Kremer et al in the July 2009 issue of Arthritis and Rheumatism(pages 1895–1905), there was an error in the proportion of patients classified as EULAR responders. The fifth paragraph in the “Efficacy assessments” section of Results (page 1899) should have read “Using the European League Against Rheumatism criteria (21), the percentage of patients in whom a moderate response was achieved in the CP-690,550 treatment arms was numerically superior to placebo at all time points (49%, 76%, 84%, and 92% for placebo and CP-690,550 5 mg, 15 mg, and 30 mg twice daily, respectively, at week 6). No patient in any treatment arm was a good responder.” In addition, in Table 4 there were errors in the total cholesterol data and the ratio of total cholesterol to high-density lipoprotein for each treatment arm. At baseline, the mean ± SD total cholesterol values (mg/dl) should have read 189 ± 42 (n = 55), 207 ± 40 (n = 59), 189 ± 42 (n = 51), and 194 ± 36 (n = 49) for CP-690,550 5 mg twice daily, CP-690,550 15 mg twice daily, CP-690,550 30 mg twice daily, and placebo, respectively. At week 6, these values should have read 219 ± 53 (n = 55), 249 ± 46 (n = 55), 239 ± 63 (n = 50), and 197 ± 41 (n = 44), respectively. The percentage change from baseline in the ratio of total cholesterol to high-density lipoprotein (least squares mean ± SD) should have read 2.3 ± 2.2, 2.6 ± 2.2, −1.6 ± 2.3, and 1.6 ± 2.5, respectively.