Although the relapse risk is increased after birth in women with relapsing multiple sclerosis (RMS), only a very few disease-modifying therapies (DMTs) are approved during breastfeeding. Glatiramer acetate (GA, Copaxone®) is one of three DMTs that can be used in breastfeeding. The real-world safety of Copaxone® in Offsprings of Breastfeeding and treated RMS pAtients (COBRA) study demonstrated that offspring parameters (hospitalisations, antibiotic use, developmental delays, growth parameters) were similar between offspring breastfed by mothers taking GA or no DMT (control) during breastfeeding. COBRA data analyses were extended to provide further safety data on the impact of maternal GA treatment during breastfeeding on offspring.

COBRA was a non-interventional, retrospective study using German Multiple Sclerosis and Pregnancy Registry data. Participants had RMS, gave birth and had GA or no DMT during breastfeeding. Offspring total adverse events (AEs), non-serious AEs (NAEs) and serious AEs (SAEs) up to 18 months postpartum were assessed. Reasons for offspring hospitalisations and antibiotic treatments were explored.

Baseline maternal demographics and disease characteristics were similar between cohorts. Each cohort had 60 offspring. Numbers of offspring AEs were comparable between cohorts; total AEs: 82 (GA) vs 83 (control); NAEs: 59 vs 61; SAEs: 23 vs 22. AEs in both cohorts were diverse with no specific patterns. Duration of GA-exposed breastfeeding was 6 to >574 days for offspring with any AE. For all-cause hospitalisations, 11 offspring had 12 hospitalisations (GA cohort) and 12 control offspring had 16 hospitalisations. Most common reason for hospitalisation was infection: 5/12 (41.7%; GA) vs 4/16 (25.0%, control). Two out of 12 (16.7%) hospitalisations due to infection occurred during GA-exposed breastfeeding; the others occurred 70, 192 and 257 days after discontinuation of GA-exposed breastfeeding. Median (range) duration of GA-exposed breastfeeding was 110 (56 to ≥285) days for offspring hospitalised for infections and 137 (88–396) days for those hospitalised for other reasons. Nine offspring had 13 antibiotic treatments (GA cohort) and nine control offspring had 10 treatments. Ten out of 13 (76.9%) antibiotic treatments occurred during GA-exposed breastfeeding, of which four were primarily due to double kidney with reflux. Other antibiotic treatments occurred 193, 229 and 257 days after discontinuation of GA-exposed breastfeeding.

GA treatment of mothers with RMS during breastfeeding did not increase AEs, hospitalisations or antibiotic use in their offspring versus control offspring. These data support previous COBRA data that the benefit of maternal RMS treatment with GA during breastfeeding outweighs the potential, apparently low risk of untoward events, in their breastfed offspring.