Persistent T1 hypointensity as an MRI marker for treatment efficacy in multiple sclerosis

I J van den Elskamp1, J Lembcke, V Dattola

  • 1Department of Radiology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands. vandenelskamp@vume.nl

Multiple Sclerosis (Houndmills, Basingstoke, England)
|July 10, 2008
PubMed
Abstract

Insights

Assessing black hole evolution in multiple sclerosis (MS) MRI scans is feasible for clinical trials. However, a potent drug is needed to achieve sufficient statistical power with a manageable sample size.

Area of Science:

  • Neuroimaging
  • Clinical Trials
  • Neuroscience

Background:

  • Magnetic Resonance Imaging (MRI) is crucial for Phase II multiple sclerosis (MS) trials.
  • Persistent T1 hypointense lesions (black holes) indicate axonal damage and demyelination.
  • Black hole evolution has not been previously analyzed for power in MS trials.

Purpose of the Study:

  • To evaluate the feasibility of using black hole evolution on serial brain MR images as a primary outcome measure in MS proof-of-concept studies.
  • To determine sample size requirements for such trials.

Main Methods:

  • Analyzed MRI data from 169 active relapsing-remitting MS (RRMS) patients.
  • Determined cumulative contrast-enhancing lesions (CELs) evolving into persistent black holes (PBHs) over 3 months.
  • Calculated sample sizes using a parametric simulation procedure based on statistical distribution fitting.

Main Results:

  • 21.2% of observed CELs evolved into PBHs.
  • Ring-enhancing lesions (59.4%) and large lesions (>10mm, 57.4%) were most likely to become PBHs.
  • Sample sizes ranged from 30 to 200 subjects per arm, depending on the desired treatment effect (50-90% reduction in PBH evolution).

Conclusions:

  • Using CEL evolution into PBHs as a primary outcome in MRI-monitored Phase II MS trials is feasible.
  • A potent drug is necessary to achieve adequate statistical power with a feasible sample size.
  • This outcome measure can potentially monitor neuroprotective drug efficacy.