Safety of a cytomegalovirus-specific hyperimmunoglobulin in the prevention of maternal-fetal transmission after primary infection-results of an open-label, single-arm, prospective trial.

PURPOSE: This phase 3, open-label, single-arm, prospective, multicenter clinical trial investigated the use of CMVIG to prevent maternal-fetal transmission. METHODS: Pregnant women with confirmed recent primary CMV infection with gestational age ≤ 14 weeks were treated with biweekly i.v. 200 U/kg BW CMVIG until at least GW 17. An amniocentesis was performed between GW 19-22. RESULTS: Fourty eight women were treated with a mean (range) number of 5.1 (4-7) infusions of CMVIG. Maternal-fetal transmission at AC was found in 11 cases (22.9%), of them 9 in the periconceptional (n = 37, 24.3%) and 2 in the first trimester subgroup (n = 11, 18.2%). One additional maternal-fetal transmission was diagnosed at birth (total 12 cases, 25.0%). Twenty three mothers, fetuses and newborns (24.0% of 96 total lives) experienced 27 serious adverse events, including the maternal-fetal transmissions. Of these, 18, 6 and 3 events were classified as mild, moderate and severe, respectively. Sixty three of the total lives (65.6%) experienced 386 adverse events (AEs) after the start of the treatment, predominantly of mild severity. Twenty one mild AEs in 6 women were related to the CMVIG administration. The only adverse drug reaction that was observed in more than one woman was headache (4 = 8.3%). No AEs were observed that led to death, abortion, trial withdrawal, CMVIG dose interruption, infusion rate or dose reduction. The newborn data were comparable to the general population, without evidence for an increased risk of premature birth or growth retardation. CONCLUSION: Despite a favorable safety profile, the benefit of treatment with CMVIG to prevent a maternal-fetal CMV transmission could not be demonstrated in our trial.