Cladribine shows no miscarriage, malformations
Dr. Kolarova noted that one of the studies, on cladribine, had a fairly robust sample size with its 180 pregnancy exposures. In that study, led by Kerstin Hellwig, MD, of Ruhr University in Bochum, Germany, data came from the global surveillance program MAPLE-MS, established to assess cladribine effects on pregnancy and infant outcomes. The researchers analyzed data from 76 mothers and 9 fathers who, at any time from 2017 to 2022, were taking cladribine during pregnancy or up to 6 months before pregnancy. Outcomes included live birth, miscarriage, stillbirth, elective abortion, ectopic pregnancy, and major congenital anomalies.
Just over half the mothers (53.9%) were exposed before pregnancy, and about a quarter (26.3%) were exposed during the first trimester. The timing was unknown for most of the other mothers (18.4%). Among the fathers, two-thirds (66.7%) were exposed before pregnancy, and one-third had unknown timing.
Among the 180 pregnancies in the maternal cohort, 42.2% had known outcomes. Nearly half the women (48.7%) taking cladribine had live births, 28.9% had elective abortions, and 21.1% had miscarriages. Only 9 of the 22 pregnancies in the paternal cohort had known outcomes, which included 88.9% live births and 11.1% miscarriages. None of the pregnancies resulted in stillbirth or in a live birth with major congenital anomalies.
”Robust conclusions cannot be made about the risks of adverse pregnancy outcomes with cladribine tablets, but no increase has been signaled thus far,” the researchers reported. ”It is necessary to counsel patients to prevent pregnancy and to use effective contraception during cladribine tablets intake and for at least 6 months after the last cladribine tablet intake in each treatment year.”
Emily Evans, MD, MBE, medical director at U.S. Neurology and Immunology in Rockland, Mass., speaking on behalf of the findings, said they were fairly encouraging.
“Of course, we don’t encourage patients to get pregnant within 6 months of their last dose of cladribine tablets,” Dr. Evans said, but “within those individuals who have gotten pregnant within 6 months of their last dose of cladribine, or who have fathered a child within 6 months of their last dose of cladribine tablets, we’re seeing overall encouraging outcomes. We’re specifically not seeing any differences in the rates of spontaneous abortions, and we’re not seeing any differences in the rates of congenital malformations.”
Ocrelizumab and ofatumumab: No infections so far
Current recommendations for ocrelizumab are to avoid pregnancy for 6 months after the last infusion and stop any breastfeeding during therapy. Yet these recommendations are only because of insufficient data rather than evidence of risk, according to Lana Zhovtis Ryerson, MD, of the NYU Multiple Sclerosis Comprehensive Care Center in New York. She and her colleagues identified all women of childbearing age who had received ocrelizumab within 1 year of pregnancy at their NYU institution. A retrospective chart review found 18 women, with an average age of 35, an average 11 years of an MS diagnosis, and an average 11 months taking ocrelizumab.
Among the 18 pregnancies, four women had a first trimester miscarriage, one had a second trimester miscarriage, and one had an abortion. The miscarriage rate could have been partly influenced by the older maternal population, the authors noted. Of the remaining 12 live births, one infant was premature at 34 weeks, and three infants stayed in NICU but were discharged within 2 weeks.
One patient experienced an MS relapse postpartum, despite receiving ocrelizumab within 45 days of delivery. Of the 16 women who agreed to participate in a Pregnancy Assessment Monitoring System (PRAMS) developed by the CDC, two women chose to breastfeed, and seven said their neurologist recommended against breastfeeding. None of the children’s pediatricians advised delaying vaccinations.
“This small sample observational study has not identified a potential additional risk with ocrelizumab for an adverse pregnancy outcome,” the authors concluded, but they added that ongoing studies, MINORE and SOPRANINO, can help guide future recommendations.
Though still limited, slightly more data exists on ofatumumab during pregnancy, including transient B-cell depletion and lymphopenia in infants whose mothers received anti-CD20 antibodies during pregnancy. However, research has found minimal IgG transfer in the first trimester, though it begins rising in the second trimester, and in utero ofatumumab exposure did not lead to any maternal toxicity or adverse prenatal or postnatal developmental effects in cynomolgus monkeys.
Riley Love, MD, of the University of California, San Francisco, Weill Institute for Neuroscience, and her colleagues both prospectively and retrospectively examined pregnancy and infant outcomes for up to 1 year post partum in women with MS who took ofatumumab during pregnancy or in the 6 months leading up to pregnancy. Their population included 104 prospective cases, most of which (84%) included first trimester exposure, and 14 retrospective cases. One in five of the prospective cases occurred during a clinical trial, while the remaining 80% occurred in postmarketing surveillance.
The prospectively followed women were an average 32 years old and were an average 7 weeks pregnant at the time of reporting. Among the 106 fetuses (including two twin pregnancies), only 30 outcomes had data at the cutoff time, including 16 live births, 9 abortions, and 5 miscarriages. None of the live births had congenital anomalies or serious infections. Another 30 pregnancies were lost to follow-up, and 46 were ongoing.
In the 14 retrospective cases, 57% of women were exposed in the first trimester, and 43% were exposed leading up to pregnancy. Half the cases occurred during clinical trials, and half in postmarketing surveillance. The women were an average 32 years old and were an average 10 weeks pregnant at reporting. Among the 14 pregnancies, nine were miscarriages, one was aborted, and four were born live with no congenital anomalies.
The authors did not draw any conclusions from the findings; they cited too little data and an ongoing study by Novartis to investigate ofatumumab in pregnancy.
“Therapies such as ofatumumab and ocrelizumab can lead to increased risk of infection due to transient B-cell depletion in neonates, but the two studies looking at this did not demonstrate increased infectious morbidity for these infants,” Dr. Kolarova said. “As with all poster presentations, I look forward to reading the full papers once they are published as they will often include a lot more detail about when during pregnancy medication exposure occurred and more detailed outcome data that was assessed.”