Axicabtagene Ciloleucel and Breastfeeding

Summary of use during lactation

There are no reports of breastfeeding during CAR-T cell therapy. Some information on the use of axicabtagene ciloleucel for CAR T-cell therapy indicates that CAR T-cells can persist and be found in breastmilk as long as 5+ years after therapy. However, two infants have been breastfed to some extent after maternal therapy. One was extensively followed-up and developed normally. If breastfeeding is attempted following axicabtagene ciloleucel CAR T-cell therapy, infants should be monitored carefully, particularly with B- and T-cell counts and immunoglobulin (IgA, IgG and IgM) blood levels.

Drug levels in milk and infant serum

Maternal Levels. A 35-year-old woman with diffuse large B-cell lymphoma received axicabtagene ciloleucel CAR T-cell therapy and achieved metabolic complete response. Five years later she became pregnant and delivered a healthy infant. Follow-up blood tests demonstrated persistent CAR T-cells with confirmation on T-cell clonality screening. Her breastmilk had detectable CAR T-cells.[1] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

Two mothers who received CAR-T cell therapy, one for transformed follicular lymphoma and the other for large B-cell lymphoma. One mother conceived spontaneously 10 months after axicabtagene ciloleucel. At delivery, she had a B-cell count of zero. Her female infant had a low B-cell count and a low IgG at birth and was started on prophylactic penicillin V. She was discharged home well and was breastfed (extent and duration not stated). At 4 weeks of age, the infant was thriving; her B lymphocyte count had normalized, but she continued to have a low IgG. She met age appropriate developmental milestones, and her physical examination was normal. She received her routine vaccinations as per the Irish national schedule and continued penicillin V prophylaxis. At 6 months of age, the infant was thriving and developmentally appropriate. She had 12/12 pneumococcal serotype-specific antibody titers above the protective range of 0.35 mg/mL, Haemophilus influenzae type B IgG titer above the optimum protective level (5.76 mg/L), and a protective tetanus IgG antibody titer (1.65 IU/mL). At 11 months of age, her penicillin prophylaxis was stopped, and she was discharged from immunology follow-up. The mother conceived 34 months after axicabtagene ciloleucel. She had a normal B-cell count at delivery. Her infant had a normal B-cell count at birth and was partially breastfed (extent and duration not stated). The infant’s CD19 count on day 1 of life was also normal. No further follow-up was reported.[2]

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

References

1. Canty E, White A, Broderick L. A healthy pregnancy and newborn despite persistence of maternal CAR T-cells after cancer therapy. Ann Allergy Asthma Immunol 2024;133:S177-S78. doi:10.1016/j.anai.2024.08.692
2. O'Reilly D, Jones C, Smith A, et al. Neonatal outcomes following 2 cases of maternal CAR-T therapy for high-grade B-cell lymphoma. Neonatology 2025;122:146-50.39510057 PubMed