Download Disease modifying treatments during pregnancy

Use of DMTs during pregnancy
The US Food and Drug Administration (FDA) recognizes five categories of medications in
pregnancy:
Category A: Adequate and well-controlled human studies have failed to demonstrate a
risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later
trimesters).
Category B: Animal reproduction studies have failed to demonstrate a risk to the fetus
and there are no adequate and well-controlled studies in pregnant women OR Animal
studies have shown an adverse effect, but adequate and well-controlled studies in
pregnant women have failed to demonstrate a risk to the fetus in any trimester.
Category C: Animal reproduction studies have shown an adverse effect on the fetus and
there are no adequate and well-controlled studies in humans, but potential benefits may
warrant use of the drug in pregnant women despite potential risks.
Category D: There is positive evidence of human fetal risk based on adverse reaction
data from investigational or marketing experience or studies in humans, but potential
benefits may warrant use of the drug in pregnant women despite potential risks.
Category X: Studies in animals or humans have demonstrated fetal abnormalities and/or
there is positive evidence of human fetal risk based on adverse reaction data from
investigational or marketing experience, and the risks involved in use of the drug in
pregnant women clearly outweigh potential benefits.
To determine whether a medication is safe during pregnancy, studies of the drug during
pregnancy are needed in several animal species, followed by human studies of thousands of
pregnant women on the drug. Though animal studies with disease modifying therapies have been
done, there is very little experience in humans. Because there is insufficient information about
safety in human pregnancy, the ratings of MS drugs for pregnancy safety are based on animal
studies.
Fingolimod (Gilenya®): Category C: In pregnant rats and rabbits fingolimod causes serious fetal
malformations. Fingolimod persists for about 2 months in the body, so it should be discontinued
about 2 months before trying to get pregnant.
Glatiramer acetate (Copaxone®): Category B: In rats and rabbits, glatiramer acetate did not cause
any adverse effects. Because it does not stay in the bloodstream very long, glatiramer acetate can
be stopped a few days before attempting pregnancy.
Interferons (Avonex®, Betaseron®, Extavia®, Rebif®): Category C: Animal studies have found an
slightly increased risk of miscarriage with interferons. Because it does not stay in the
bloodstream very long, interferons can be stopped a few days before attempting pregnancy.
Multiple Sclerosis Center
1600 East Jefferson St., Suite A
Seattle, WA 98122
T 206.320-2200
F 206.320-2560
www.swedish.org/ms or
www.swedishmscenter.org
Mitoxantrone (Novantrone): Category D: Doses used in humans have not been studied in
animals, but lower doses in pregnant animals have caused slowed fetal growth or miscarriage.
Because this medication interferes with DNA formation, it has the potential to cause fetal
malformations.
Natalizumab (Tysabri): Category C: Doses 7 times higher than human doses in pregnant guinea
pigs decrease fetal survival. Doses 2.3 times higher than human doses in pregnant monkeys
affect blood forming cells. Because of the long time that Tysabri remains in the body, it should
be stopped 2-3 months before attempting pregnancy.
Can I stay on DMTs during pregnancy? The listing of DMTs as category B or C is because
little human pregnancy data exists. However, animal data suggests that the risk is low,
particularly for glatiramer acetate and interferons. For some women, the risk of stopping these
medications is greater than the risk of staying on the medications through pregnancy. This is
especially true for women with a lot of MS attacks prior to starting the medication and also for
those who may have difficulty getting pregnant. Women who want to stay on medication while
attempting to get pregnant should discuss the risks and benefits with their physician.
Fortunately, once a woman becomes pregnant, the risk of MS attacks decreases. This decreases
the risk of being off the medication during pregnancy.
Multiple Sclerosis Center
1600 East Jefferson St., Suite A
Seattle, WA 98122
T 206.320-2200
F 206.320-2560
www.swedish.org/ms or
www.swedishmscenter.org