A Phase 2 clinical trial has shown how the pregnancy hormone estriol can help patients with relapsing-remitting multiple sclerosis (RRMS) avoid relapses. It’s been known that the number of relapses among women with RRMS decreases during the second half of pregnancy. Findings from the study are published in Lancet Neurology.

A group of UCLA researchers found a link between increased estriol levels in the blood and decreased relapses. The trial also revealed how estriol treatment could possibly improve cognitive disabilities associated with MS. To date, there is no FDA-approved treatment for MS that improves disabilities. Estriol naturally increases in pregnant woman’s blood by means of the fetal placenta. Dr. Rhonda Voskuhl, study’s lead author, hypothesized that the increased hormone level was a way to suppress a woman’s immune system so that the fetus was not rejected as a foreign body.

The first pilot study (n=10) conducted in 2002 confirmed Dr. Voskuhl’s hypothesis that estriol could be a protector against MS, demonstrating a 70% drop in inflammatory lesions in the brain after 6 months of treatment.

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For this Phase 2, randomized, placebo-controlled 2-year study, a total of 164 patients were enrolled: 83 assigned to the estriol group, and 81 to the placebo group. Both study groups continued their injectable glatiramer acetate therapy. The results showed that patients taking estriol had one-third to one-half as many relapses as those taking the placebo. Patients with the highest estriol levels also experienced less atrophy of the brain area and improvements in cognitive functions. Researchers reported that estriol was well tolerated among the study participants with irregular menstruation being the only major side effect.

“These findings hopefully will pave the way for oral, safe treatments that are more widely accessible, since estriol is simple and naturally occurring,” said Dr. Voskuhl. Study authors hope for a Phase 3 study to confirm these findings. 

For more information visit Neurology.ucla.edu