Study suggests continuing DMT in pregnant women at greater risk for MS relapse
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Women with relapsing-remitting MS who had higher levels of disease activity and were managed on moderate- or high-efficacy therapy were at greater risk for relapse during pregnancy, researchers reported.
The findings, which were presented at MSVirtual2020 — the joint ACTRIMS-ECTRIMS meeting — suggest that women at high risk should continue taking Tsyabri (natalizumab, Biogen) up to 34 weeks’ gestation, rather than discontinuing therapy during pregnancy.
“Counter to historical studies that showed a decrease in disease activity during pregnancy, we demonstrated that pregnancy in women with more active disease — that is, those managed on moderate- and high-efficacy therapies — is not sufficient to suppress disease activity,” Vilija Jokubaitis, PhD, a senior research fellow in the department of neuroscience at Monash University, told Healio Neurology.
Wei Yeh, PhD, a doctoral student in Jokubaitis’ research group, and colleagues used the MSBase Neuro-Immunology Registry to assemble a cohort of 1,640 term and preterm pregnancies — the largest one to date, they said. The cohort included 449 pregnancies in women with MS treated with moderate- or high-efficacy disease-modifying therapy (DMT) before their pregnancy.
They found that intrapartum relapse occurred in 12% of the women. Those at greatest risk for relapse had higher levels of disease activity before pregnancy and were managed on higher efficacy DMT.
Specifically, among women who were taking either low-efficacy DMT or no therapy at all, annualized relapse rates (ARR) declined through pregnancy. The ARR among women taking moderate-efficacy DMT increased in the first trimester (0.55 [95% CI, 0.36-0.8] vs. 0.14 [95% CI, 0.10-0.21] for low-efficacy DMT), then decreased in the third trimester. Conversely, the researchers said, ARR “steadily increased throughout pregnancy for those on high-efficacy DMT” (third trimester: 0.42 [95% CI, 0.25-0.66] vs. 0.12 [95% CI, 0.07-0.19] for low-efficacy DMT). Higher efficacy DMT correlated with higher ARRs in the early postpartum period (high: 0.84 [95% CI, 0.62-1.1]; moderate: 0.9 [95% CI 0.65-1.2]; and low: 0.47 [95% CI, 0.38-0.58]).
Because women who withdraw from moderate- or high-efficacy therapy at conception or before conception are at increased risk for MS relapse during pregnancy, Jokubaitis suggested the “continuation of natalizumab up to the 34th week of pregnancy, or the planned use of highly effective therapies with long-lasting effect pre-conception.”
Jokubaitis noted that use of the moderate-efficacy therapy fingolimod is now contraindicated for pregnancy. She strongly encouraged joint clinician-patient decision-making regarding treatment during pregnancy.