Multicentre, randomised, double blind, placebo controlled, phase III study of weekly, low dose, subcutaneous interferon beta-1a in secondary progressive multiple sclerosis. Placebo-controlled multicentre randomised trial of interferon beta-1b in treatment of secondary progressive multiple sclerosis. European Study Group on interferon beta-1b in secondary progressive MS. Interferon beta-1b in secondary progressive MS: results from a 3-year controlled study. Benefit of interferon beta-1a on MSFC progression in secondary progressive MS.
Interferon (IFN) beta has repeatedly shown benefit in multiple sclerosis (MS) in reducing the rate of relapse, the disease activity as shown with magnetic resonance imaging and, to some degree, the progression of disability; however, it is unknown how much the therapeutic response depends on the dose, the subgroup involved, and the disease stage. This multicentre, double blind, placebo controlled study explored the dose-response curve by examining the clinical benefit of low dose IFN beta-1a (Rebif), 22 micro g subcutaneously once weekly, in patients with secondary progressive MS.
                A total of 371 patients with clinically definite SPMS were randomised to receive either placebo or subcutaneous IFN beta-1a, 22 micro g once weekly, for 3 years. Clinical assessments were performed every 6 months. The primary outcome was time to sustained disability, as defined by time to first confirmed 1.0 point increase on the Expanded Disability Status Scale (EDSS). Secondary outcomes included a sensitive disability measure and relapse rate.
                Treatment had no beneficial effect on time to confirmed progression on either the EDSS (hazard ratio (HR) = 1.13; 95% confidence interval (CI) 0.82 to 1.57; p = 0.45 for 22 micro g v placebo) or the Regional Functional Status Scale (HR = 0.93; 95% CI 0.68 to 1.28; p = 0.67). Other disability measures were also not significantly affected by treatment. Annual relapse rate was 0.27 with placebo and 0.25 with IFN (rate ratio = 0.90; 95% CI 0.64 to 1.27; p = 0.55). The drug was well tolerated with no new safety concerns identified. No significant gender differences were noted.
                This patient population was less clinically active than SPMS populations studied in other trials. Treatment with low dose, IFN beta-1a (Rebif) once weekly did not show any benefit in this study for either disability or relapse outcomes, including a subgroup with preceding relapses. These results add a point at one extreme of the dose-response spectrum of IFN beta therapy in MS, indicating that relapses in this phase may need treatment with higher doses than in the initial phases. The beneficial effects of interferon beta have only been shown for patients in the relapsing-remitting phase of multiple sclerosis (MS). The role of interferon beta in the treatment of patients who are in the secondary progressive phase of the disease (SP-MS), and for whom no effective drug treatment is available, has not been assessed.
                In this multicentre, double-masked, randomised, placebo-controlled trial, outpatients with SP-MS having scores of 3.0-6.5 on the Expanded Disability Status Scale (EDSS) received either 8 million IU interferon beta-1b every other day subcutaneously, or placebo, for up to 3 years. The primary outcome was the time to confirmed progression in disability as measured by a 1.0 point increase on the EDSS, sustained for at least 3 months, or a 0.5 point increase if the baseline EDSS was 6.0 or 6.5. A prospectively planned interim analysis of safety and efficacy of the intention-to-treat population was done after all patients had been in the study for at least 2 years.
                358 patients with SP-MS were allocated placebo and 360 were allocated interferon beta-1b; 57 patients (31 placebo, 26 interferon beta-1b) were lost to follow-up. There was a highly significant difference in time to confirmed progression of disability in favour of interferon beta-1b (p=0.0008). Interferon beta-1b delayed progression for 9-12 months in a study period of 2-3 years. The odds ratio for confirmed progression was 0.65 (95% CI 0.52-0.83). This beneficial effect was seen in patients with superimposed relapses and in patients who had only progressive deterioration without relapses. Positive results were also obtained regarding time to becoming wheelchair-bound, relapse rate and severity, number of steroid treatments and hospital admissions, as well as on magnetic resonance imaging variables. The drug was safe and side effects were in line with previous experience with interferon beta-1b. The study was stopped after the interim results gave clear evidence of efficacy.
                Treatment with interferon beta-1b delays sustained neurological deterioration in patients with SP-MS. Interferon beta-1b is the first treatment to show a therapeutic effect in patients with SP-MS. To evaluate the efficacy and safety of interferon beta-1b (IFNbeta-1b) in subjects with secondary progressive multiple sclerosis (SPMS).
                This 3-year, multicenter, double-blind, placebo-controlled, randomized trial of IFNbeta-1b included 939 subjects from the United States and Canada with SPMS and Expanded Disability Status Scale (EDSS) scores ranging from 3.0 to 6.5. Subjects were randomly assigned to receive either placebo or IFNbeta-1b (250 microg or 160 microg/m2 body surface area), administered subcutaneously every other day. The primary outcome was time to progression by > or =1.0 EDSS point (0.5 point if EDSS score was 6.0 to 6.5 at entry) confirmed at 6 months. Secondary outcomes included mean change in EDSS score from baseline, relapse-related measures, MRI activity, and a standardized neuropsychological function test.
                There was no significant difference in time to confirmed progression of EDSS scores between placebo-treated patients and either of the IFNbeta-1b treatment groups. However, IFNbeta-1b treatment resulted in improvement on secondary outcome measures involving clinical relapses, newly active MRI lesions, and accumulated burden of disease on T2-weighted MRI. Effects were similar for both IFNbeta-1b treatment groups. Neutralizing antibodies to IFNbeta-1b were detected in 23% of 250-microg and 32% of 160-microg/m2 recipients, but their presence did not consistently affect clinical or MRI outcomes. IFNbeta-1b was also well tolerated at both doses.
                Although no treatment benefit was seen on the time to confirmed progression of disability, relapse- and MRI-related outcomes showed significant benefit with both dosing regimens tested, a result consistent with the outcomes of earlier clinical trials. Interferon beta-1a (IFNbeta-1a, Avonex) is efficacious in relapsing forms of MS. Studies of other IFNbeta preparations in secondary progressive MS (SPMS) yielded conflicting results. This study was undertaken to determine whether IFNbeta-1a slowed disease progression in SP-MS.
                A total of 436 subjects with SPMS and Expanded Disability Status Scale (EDSS) score 3.5 to 6.5 were randomized to receive IFNbeta-1a (60 micro g) or placebo by weekly intramuscular injection for 2 years. The primary outcome measure, used for the first time in a large-scale MS trial, was baseline to month 24 change in the MS Functional Composite (MSFC), comprising quantitative tests of ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test [9HPT]), and cognition (Paced Auditory Serial Addition Test [PASAT]).
                Median MSFC Z-score change was reduced 40.4% in IFNbeta-1a subjects (-0.096 vs -0.161 in placebo subjects, p = 0.033), an effect driven mainly by the 9HPT and PASAT. There was no discernible benefit on the EDSS, which in this range principally reflects walking ability. IFNbeta-1a subjects had 33% fewer relapses (p = 0.008). There was significant benefit on eight of 11 MS Quality of Life Inventory subscales. New or enlarging T2-hyperintense brain MRI lesions and gadolinium-enhancing lesions were reduced at months 12 and 24 (both p < 0.001). IFNbeta-1a was well tolerated by the majority of subjects. Neutralizing antibodies developed in 3.3% of IFNbeta-1a-treated subjects.
                IFNbeta-1a demonstrated benefit on MSFC progression, relapses, quality of life, and MRI activity in SPMS.