Comment on alemtuzumab and inclusion body myositis.

Sir, The recent Brain publication (Dalakas et al., 2009) describing a clinical study of alemtuzumab in patients with inclusion body myositis nicely demonstrates the feasibility of enrolling and following a cohort of these patients over a long period of time as participants in an intervention study. The authors state that ‘in [inclusion body myositis] one series of alemtuzumab infusions can slow down disease progression up to 6 months’. Prior to publication of this paper in Brain, two scientific meeting abstracts and an editorial similarly reported results of this study as showing that, in inclusion body myositis, alemtuzumab may have a role in improving the clinical condition of patients (Dalakas et al., 2007a, b; Dalakas, 2008). Based on the Methods and Results now published in Brain, I have concerns that these conclusions may require further analysis for several reasons.