Uterine fibroids affects roughly half of all women aged 35 to 49. The non-cancerous tumors cause iron-deficiency anemia due to excessive menstrual bleeding.
“With no approved treatment for symptomatic fibroids, this study and its findings are very significant,” said corresponding author Kevin Fiscella of the Department of Family Medicine Research Program at the University of Rochester Medical Center.
The University of Rochester study is the first trial of mifepristone, also known as RU-486, to establish that it can be safely used at low doses to treat uterine fibroids.
According to the researchers, by the end of the study virtually every woman in the mifepristone group was certain she had been receiving the drug because of so many improvements, despite the study’s intentional design to keep everyone “blind” to the data and outcomes.
Results showed that the women on mifepristone reported a 135% improvement in quality of life after six months, compared to a 41% improvement in the placebo group.
Blood loss also improved among women taking mifepristone. For example, hemoglobin levels went up in the treatment group from 12.0 to 13.5 g/DL, compared to a decrease in hemoglobin levels in the placebo group. At the start of the study, 11 of 22 women 50% in the mifepristone group were anemic, but after six months of treatment only 9% were anemic.
Further studies should evaluate whether the drug can be safely taken for longer periods, and how long after stopping the drug would re-growth of fibroids occur, said the researchers.
A few deaths have been reported among women taking mifepristone at much higher doses for pregnancy termination. However, medical authorities have not established a causal relationship between mifepristone and the deaths.