Interferon beta-1b 250 mug subcutaneously every other day delayed conversion to clinically definite multiple sclerosis, and should be considered as a therapeutic option in patients presenting with a first clinical event suggestive of multiple sclerosis.
Magnetization transfer ratio (MTR) is a sensitive parameter to quantify the integrity of myelinated white matter in patients with multiple sclerosis. Lesional MTR decreases in the acute phase due to demyelination, and subsequently shows recovery depending on the degree of remyelination in the absence of axonal loss. Recovery of average lesion MTR therefore might prove a viable outcome measure to assess the effect of remyelinating agents. Our objective was to determine the required sample size for phase II multicentre clinical trials using the recovery of average lesion MTR as primary outcome measure. With 7-monthly MRI scans, the MTR evolution of 349 new enhancing lesions before and after enhancement was assessed in 32 MS patients from 5 centres. Multilevel models were fitted to the data yielding estimates for the variance components, which were applied in power calculations. Sample sizes were determined for placebo-controlled, multicentre trials using lesional MTR recovery post-enhancement as primary outcome measure. Average lesion MTR decreased slightly in the build-up to enhancement, decreased dramatically during enhancement and showed recovery in the period after cessation. The power calculations showed that for a power of 80%, approximately 136 patients per trial (mean number of 6 lesions per patient) are required to detect a 30% increase in lesional MTR post-enhancement compared with placebo, whereas 48 subjects are required to detect a 50% increase in lesional MTR compared with placebo. Recovery of lesion MTR is a feasible outcome measure for future multicentre clinical trials measuring the effect of remyelinating agents.
Since 1989 we have used serum prostate specific antigen (PSA) levels as an indication for ultrasound guided systematic biopsies of the prostate. Realizing that the PSA level in part reflects prostatic glandular epithelial volume, we reviewed the accumulated data on our last 2,340 biopsies to determine if the quotient of PSA and prostatic volume, prostate specific antigen density, provided any further diagnostic information. There were evaluable data for 2,020 patients. Prostate specific antigen density levels are shown to have a strong correlation with the diagnosis of prostate cancer and provide a more reliable indication for ultrasound guided biopsy of the prostate than PSA alone.
Objective:To compare interferon -1b (IFN-1b) and glatiramer acetate (GA) on new lesion (NL) (gadolinium-enhancing, new T2) evolution into permanent black holes (PBH)-a marker of irreversible tissue damage-in patients with relapsing-remitting multiple sclerosis (RRMS).Methods: BEYOND was a large, phase III, clinical trial comparing IFN-1b 250 g, IFN-1b 500 g, and GA (2:2:1). Patient scans were reexamined post hoc for PBH in a rater-blinded manner. Two predefined coprimary endpoints compared IFN-1b 250 g with GA: first, number of PBH per patient at year 2 evolving from year 1 NL, then proportion of year 1 NL evolving into PBH at year 2. IFN-1b 500 g and GA were compared in an exploratory fashion.Results: Approximately 90% (1,957/2,244) of patients had NL at year 1 with follow-up at year 2. Mean numbers of PBH per patient at year 2 evolving from year 1 NL were lower for IFN-1b 250 g than GA (0.30 vs 0.43; p ϭ 0.0451). The proportion of NL evolving into PBH was similar (IFN-1b 250 g vs GA: 21.6% vs 23.5%; p Ͼ 0.20). For IFN-1b 500 g, both the mean PBH number per patient at year 2 evolving from year 1 NL (0.26 vs 0.43; p ϭ 0.0037) and proportion of NL evolving into PBH (16.3% vs 23.5%; p ϭ 0.0409) were lower relative to GA.
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