I have posted several articles on the topic of pregnancy and MS, to which I would also like to refer here (e.g. Pregnancy and breastfeeding). There were now some interesting news on this topic at the last ECTRIMS meeting, which I would like to pick up.
Pregnancy itself has a protective effect on MS from the 2nd trimester, but the risk of disease activity increases again after childbirth (=postpartum). In particular, those women who were unstable before pregnancy and showed disease activity have an increased risk of postpartum relapses. Therefore, it is important in counseling women who wish to have children to ensure that the disease is well controlled before a woman with MS becomes pregnant. Especially because most women do not want or are not allowed to take medication during pregnancy and discontinue their MS therapies in most cases.
Strategy for Pregnancy in Women with Active Courses
In the case of moderate MS, this is not a problem, usually the protective effect of pregnancy is sufficient. However, in active courses, which are usually treated with high-efficacy therapies, discontinuation of MS treatment can be a problem. For this reason, it is important to have a strategy for this situation. For Natalizumab (Tysabri), such a strategy could be developed: Nowadays, Natalizumab is usually continued during pregnancy with an extended dosing interval and the medication is discontinued in the last trimester. However, Natalizumab (due to its side effect profile) is currently not as widely used as a highly effective MS therapy. The most commonly used concept for treating highly active MS is B-cell depletion – and there are now some new data on B-cell depletion and pregnancy that are strategically of great importance.
Pregnancy under Therapy with B-Cell Depletion
Data from 103 pregnant women from a total of 13 clinical studies of the Ocrelizumab study program were evaluated. Interestingly, MS disease activity remained low before and during pregnancy, but also in the postpartum phase. That is, the expected postpartum increase in relapse rate did not occur in this group. This means that women who became pregnant during therapy with Ocrelizumab were well protected from new disease activity (Vukusic S et al., ECTRIMS 2024; P591). Parallel to these results, the pregnancy registry with approx. 4,000 registered pregnancies in connection with Ocrelizumab therapy showed that exposure did not increase the risk of adverse events during pregnancy or in the infant compared to the normal population (Dobson R et al., ECTRIMS 2024; P085).
Even more precise data on the effects of Ocrelizumab exposure during pregnancy was provided by the Phase IV MINORE study, which investigated placental transfer and B-cell levels in infants after possible Ocrelizumab exposure during pregnancy. It was found that exposure did not change the B-cell concentration in the infant. Ocrelizumab was not detectable in the majority of cases in the cord serum at birth or in the infant’s serum in the 6th week of life, suggesting minimal placental transfer and low in utero exposure (Hellwig K et al., ECTRIMS 2024; P087). Finally, data from the prospective, multicenter Phase IV SOPRANINO study were presented at the last ECTRIMS. This study investigated the B-cell levels of infants and a possible transfer of Ocrelizumab into the breast milk of breastfeeding women. There was negligible transfer of the anti-CD20 antibody into breast milk, and the B-cell values of the infants were within the normal range. No measurable Ocrelizumab concentrations could be detected in the serum of the breastfed infants. Health status and development of the infants in the first year of life was normal (Bove R et al., ECTRIMS 2024; O039).
Positive Study Data
Taken together, these data now provide a clearer strategy with regard to B-cell depleting therapies and pregnancy. Ultimately, it is shown that women are well protected by Ocrelizumab in all phases of pregnancy. The data also show that a washout period and a temporary need for contraception after the last Ocrelizumab dose are not necessary. In addition, therapy can also be used during breastfeeding. It is therefore to be hoped that on the basis of these new findings an extension of the approval will take place and Ocrelizumab will be classified as a safe option for pregnant and breastfeeding women. This would significantly simplify family planning under a highly effective therapy.
This post was translated from German to English with the help of AI.
