Phase II study hints at oestriol effect in multiple sclerosis

By Eleanor McDermid, Senior medwireNews Reporter

Oestriol, given in combination with glatiramer acetate, may reduce the risk of relapse in women with relapsing–remitting multiple sclerosis, suggest findings from a phase II trial.

During 24 months of treatment, 82 patients took glatiramer acetate (20 mg/day) plus oral oestriol 8 mg, together with daily progestin for 2 weeks every 3 months so they were not taking unopposed oestrogen.

These patients had a relapse rate of 0.25 per year, report Rhonda Voskuhl (University of California, Los Angeles, USA) and co-researchers in The Lancet Neurology.

A further 76 patients took glatiramer acetate plus placebo and had a relapse rate of 0.37 per year, giving an adjusted rate ratio of 0.63. The p value for the difference between the groups was 0.077, which met the researchers’ prespecified criterion of p<0.10 for showing a clinical effect within the confines of a phase II trial.

Voskuhl et al therefore believe that oestriol merits further assessment in a phase III trial, adding that as it is simple and relatively inexpensive compared with other treatments, it would be “more accessible to economically disadvantaged patients throughout the world.”

But in an accompanying commentary, Annette Langer-Gould (Kaiser Permanente, Pasadena, California, USA) describes the researchers’ conclusion as “overly optimistic”.

All the patients underwent brain magnetic resonance imaging (MRI) at baseline and after 12 and 24 months, and at no time was there any significant difference between the two groups in the number or volume of active lesions, or the proportion of patients with active lesions.

“Showing no positive effect on any brain MRI measure of neuroinflammation yet a positive effect on annualised relapse rate is unprecedented in trials of relapse-remitting multiple sclerosis and challenges plausibility”, says Langer-Gould, suggesting that the clinical difference could have been a chance finding.

She also highlights a recent trial in which high doses of progesterone, combined with low-dose oestradiol, failed to affect women’s risk of relapse after pregnancy.

“Both studies, although disappointingly negative, indicate that the profound immunological changes that occur during pregnancy defy reduction to exogenous ingestion of sex hormones”, concludes Langer-Gould.

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