BACKGROUND: Contrast enhancing lesions (CEL) is a common endpoint in multiple sclerosis (MS) clinical trials. To minimize sample size or placebo exposure, a crossover design without a concurrent control group is attractive. Natural regression may confound this strategy. We assessed the degree of regression in monthly new gadolinium activity in relapsing-remitting (RR) placebo patients. METHODS: A post hoc analysis was performed on 65 RRMS placebo patients in the Prevention of Relapses and disability by Interferon beta-1a Subcutaneously in Multiple Sclerosis (PRISMS) trial. Patients were originally selected for relapses but not preselected for MRI activity. Eleven MRI scans were taken at screening, baseline, and months 1 through 9. Monthly new CEL rates were examined using a random effects Poisson model. Patients were analyzed as a single group and by screening CEL count level subgroups: no, low, and high (0, 1 to 3, >3 CEL). RESULTS:A total of 32, 19, and 14 patients had no, low, and high CEL counts at screening. The monthly new CEL rates (95% CI) of all patients at baseline, months 1 to 3, 4 to 6, and 7 to 9 were 2.0 (1.3, 2.9), 1.8 (1.3, 2.5), 1.4 (1.0, 2.0), and 1.2 (0.8, 1.7). Compared to baseline, the rate decreased by 10%, 27%, and 39%. The monthly rate of the no subgroup remained stable. The rates for both the low and high subgroups decreased by 4%, 29%, and 48% at months 1 to 3, 4 to 6, and 7 to 9 compared to baseline. CONCLUSIONS:Placeborelapsing-remitting multiple sclerosis patients experience a decline of new gadolinium activity over 9 months. A crossover design without a concurrent comparison group may overestimate the treatment effect.
RCT Entities:
BACKGROUND: Contrast enhancing lesions (CEL) is a common endpoint in multiple sclerosis (MS) clinical trials. To minimize sample size or placebo exposure, a crossover design without a concurrent control group is attractive. Natural regression may confound this strategy. We assessed the degree of regression in monthly new gadolinium activity in relapsing-remitting (RR) placebo patients. METHODS: A post hoc analysis was performed on 65 RRMS placebo patients in the Prevention of Relapses and disability by Interferon beta-1a Subcutaneously in Multiple Sclerosis (PRISMS) trial. Patients were originally selected for relapses but not preselected for MRI activity. Eleven MRI scans were taken at screening, baseline, and months 1 through 9. Monthly new CEL rates were examined using a random effects Poisson model. Patients were analyzed as a single group and by screening CEL count level subgroups: no, low, and high (0, 1 to 3, >3 CEL). RESULTS: A total of 32, 19, and 14 patients had no, low, and high CEL counts at screening. The monthly new CEL rates (95% CI) of all patients at baseline, months 1 to 3, 4 to 6, and 7 to 9 were 2.0 (1.3, 2.9), 1.8 (1.3, 2.5), 1.4 (1.0, 2.0), and 1.2 (0.8, 1.7). Compared to baseline, the rate decreased by 10%, 27%, and 39%. The monthly rate of the no subgroup remained stable. The rates for both the low and high subgroups decreased by 4%, 29%, and 48% at months 1 to 3, 4 to 6, and 7 to 9 compared to baseline. CONCLUSIONS: Placebo relapsing-remitting multiple sclerosispatients experience a decline of new gadolinium activity over 9 months. A crossover design without a concurrent comparison group may overestimate the treatment effect.
Authors: Frederik Barkhof; Jack H Simon; Franz Fazekas; Marco Rovaris; Ludwig Kappos; Nicola de Stefano; Chris H Polman; John Petkau; Ernst W Radue; Maria P Sormani; David K Li; Paul O'Connor; Xavier Montalban; David H Miller; Massimo Filippi Journal: Nat Rev Neurol Date: 2011-12-06 Impact factor: 42.937
Authors: R T Naismith; L Piccio; J A Lyons; J Lauber; N T Tutlam; B J Parks; K Trinkaus; S K Song; A H Cross Journal: Neurology Date: 2010-06-08 Impact factor: 9.910
Authors: E Waubant; D Pelletier; M Mass; J A Cohen; M Kita; A Cross; A Bar-Or; T Vollmer; M Racke; O Stüve; S Schwid; A Goodman; N Kachuck; J Preiningerova; B Weinstock-Guttman; P A Calabresi; A Miller; M Mokhtarani; D Iklé; S Murphy; H Kopetskie; L Ding; E Rosenberg; C Spencer; S S Zamvil Journal: Neurology Date: 2012-03-28 Impact factor: 9.910
Authors: R Zivadinov; B Weinstock-Guttman; K Hashmi; N Abdelrahman; M Stosic; M Dwyer; S Hussein; J Durfee; M Ramanathan Journal: Neurology Date: 2009-08-18 Impact factor: 9.910