An ethical dilemma: a randomised switch study from natalizumab to interferon-beta

It is about time we took an ethical stand on underpowered studies? #MSBlog #MSResearch

"The study below aims to look at satisfaction and adherence to treatment in MSers on natalizumab, who are at high risk of PML, being randomised to either stay on natalizumab or switch to interferon-beta-1b. This is a very small study (19 MSers); I am sure it is not large enough to answers the questions it set out to answer. If you were high risk of getting PML would you necessarily want to stay on natalizumab? What would your anxiety levels be if you couldn't be switched, compared to those who did switch? In our centre this study would not have got ethical approval; it is underpowered and the statistician would have comeback and said no."


"A study is underpowered if there are too few subjects in it to give it a reasonable chance of providing a definitive answer. In the paper the author's acknowledge this and state 'Given the small samples size we applied a correction for Type I error using for each neuropsychological end point an adjustment for multiple comparisons following the Bonferroni method'. In 2014 should we be doing underpowered studies? Is it ethical to randomise MSers to studies that are unlikely to give an answer? Will this study change clinical practice?"

"I have always justified the use of underpowered studies when the purpose is to allow trainees to learn research techniques and the scientific method on existing samples and data. In other words opportunistic research that does not expose study participants to any risks. It is, however, very different when the research involves clinical trials of investigational medicinal products (CTIMPs) that require informed consent. CTMPS come with risks. Can you imagine the ethical fall-out if one of the MSers who was randomised to stay on natalizumab in this study developed PML?"



Epub: Zecca et al. Treatment satisfaction, adherence and behavioral assessment in patients de - escalating from natalizumab to interferon beta. BMC Neurol. 2014 Feb 28;14(1):38.

BACKGROUND: De-escalating natalizumab (NTZ) to interferon beta 1b (IFN B 1B) is a possible treatment option in MSer interrupting NTZ because of increased risk of progressive multifocal leukoencephalopathy (PML). 


AIM: The aim of this study was to evaluate satisfaction and adherence to treatment, behavioral and fatigue changes in MSers switched to IFN B 1B compared to continued NTZ treatment.

METHODS: A 1 year, prospective, randomized, rater-blinded, parallel-group study. Nineteen relapsing remitting (RR) MSers, randomly assigned to undergo either NTZ (n = 10) or IFN B 1B (n = 9) treatment, who had previously received NTZ for at least 12 months with disease stability and fearing or at risk for PML were included. MSers underwent behavioral and treatment assessments at baseline, after 24-week and 1 year follow-up. Behavioral assessment included measures of cognition, fatigue and quality of life. Treatment assessment included measures of satisfaction, persistence and adherence to treatment. Clinical-radiological disease activity and safety were also assessed.

RESULTS: Baseline characteristics of MSers were similar between groups except for Euro Quality Visual Analogue Scale, being higher in the NTZ group (p = 0.04). Within-group comparisons at the three time points, as well as interaction analysis of treatment effect over time did not show any statistically significant differences in behavioral or treatment assessments, but a coherent trend favoring NTZ over IFN B 1B.

CONCLUSIONS: De-escalating NTZ to IFN B 1B is feasible and associated with overall good MSers related outcome and persistently stable behavioral measures.

CoI: multiple

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