Why should women stay away from Gilenya when pregnant?
Quite a few women taking part in the clinical trials on fingolimod (Gilenya) fell pregnant despite taking precautions; the outcomes for the foetus and baby were very disturbing.
Women taking Gilenya should take every possible precaution not to fall pregnant, or re-consider their choice of medication. Some MS drugs have not been associated with foetal abnormalities when women taking them fall pregnant.
Authorities generally advise that Gilenya should be stopped two months before trying to conceive.
In the case of fingolimod (Gilenya) however, there is very strong evidence from animal studies that it is potentially very damaging for the developing foetus if taken during the first trimester of pregnancy when the foetus is rapidly developing and growing new organ systems. Human data has been lacking.
Gilenya and pregnancy: Recent scientific studies
However, this recently published paper, describing the effects on the foetus of fingolimod during pregnancy strongly underlines the importance of taking every precaution not to get pregnant while on the drug. Five of the authors of the paper are in fact employees of Novartis, the company making Gilenya.
They describe the pregnancy outcomes of women who inadvertently fell pregnant during the pivotal fingolimod controlled trials that first showed the efficacy of the drug in MS. The outcomes are very disturbing. The paper notes that women in these trials were advised to take precautions against falling pregnant.
Despite this 89 women in these early studies did fall pregnant, the great majority (74) in the fingolimod group. This in itself is quite concerning; there is no reason given for the great discrepancy between the small number of women taking placebo who fell pregnant (11) and the large number taking fingolimod who fell pregnant (74).
Gilenya birth defects
Of the 74 pregnancies in the fingolimod group, 66 were exposed to fingolimod during the pregnancy. Of these 66, one outcome was unknown; of the remaining 65, there were 28 live births (2 with deformities, one very serious), 9 spontaneous miscarriages, 24 planned abortions, and at the time of writing, 4 pregnancies still going.
In the group who had planned abortions, there was one serious congenital abnormality, a death in utero, and one failure to grow.
While the authors contend that the study does not permit firm conclusions to be drawn about the safety of fingolimod in human pregnancy, one wonders to what extent that conclusion is influenced by the fact that the study was funded by Novartis, 5 of the 8 authors were employees of Novartis, and all other authors had received payments from Novartis.
The OMS view is that this study raises serious safety concerns about fingolimod during pregnancy, and that women of child-bearing age taking the drug for MS should take every possible precaution not to fall pregnant, or consider switching to one of the MS drugs that is safer during pregnancy.
Advice on Fingolimod (Gilenya) from ABN Guidelines in 2019
Women with MS should be advised that fingolimod does not interact with hormonal contraception.
Men and women with MS should be advised that there is no evidence in human studies of fingolimod resulting in reduced fertility or increased congenital malformation or miscarriage rates.
There is limited information about the safety of fingolimod in pregnancy and women with MS should be advised to use effective contraception while taking it.
Women with MS planning to become pregnant should be advised to stop fingolimod at least 2 months before conception and should discuss alternative treatments.
Patients should be advised to stop the treatment immediately in the event of an unplanned pregnancy.
Pregnancies in women on fingolimod should be treated as high-risk and we recommend referral to an obstetrician for consideration of a fetal medicine scan.
Women should not take fingolimod while breastfeeding.
Updated: 26 September 2019