USE OF BENRALIZUMAB, MEPOLIZUMAB, RESLIZUMAB OR TEZEPELUMAB IN PREGNANCY

Six biologic monoclonal antibody (mAb) therapies are licensed for the management of severe asthma: mepolizumab, reslizumab, benralizumab, omalizumab, dupilumab, and tezepelumab. This monograph summarises the available data for mepolizumab, benralizumab, tezepelumab, and reslizumab. For further information on omalizumab and dupilumab, please see the separate UKTIS monographs.

There are limited published human pregnancy data relating to mepolizumab and benralizumab. Data regarding reslizumab are very limited. No published human pregnancy exposures to tezepelumab have been identified. Data are derived from case reports (mepolizumab-exposed n=3; benralizumab-exposed n=6) and a pharmacovigilance analysis including 154 mepolizumab exposed, 774 benralizumab exposed, and 25 reslizumab-exposed pregnancies. The nature and size of these datasets limit the assessment of the risk of adverse pregnancy outcomes. mAbs do not actively cross the placenta in the first trimester and are therefore not expected to result in direct fetal exposure; this may lead to a lower risk of teratogenic/embryotoxic effects.

It is critically important to ensure that maternal asthma is well-controlled in pregnancy. Where a woman’s asthma is well-controlled with a mAb, particularly when conventional treatments have been ineffective, the risks and benefits of continuing treatment during pregnancy should be assessed on a case-by-case basis and discussed with the patient as part of a shared decision-making process.

Guidance from the UK Health Security Agency (UKHSA) [issued 2017] advises that live vaccines should be avoided until the infant is at least 6 months of age following in utero exposure to biologic immunosuppressant therapies. While mAbs used to treat asthma are not broadly immunosuppressant, the effects of in utero exposure on the neonatal or infant immune system are largely unknown. Please contact UKTIS for an individualised risk assessment where BCG vaccination is indicated in an infant under 6 months of age with prenatal asthma mAb exposure.

Exposure to asthma mAbs at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy or any additional fetal monitoring. However, other risk factors which could independently increase the risk of adverse pregnancy outcome may be present in individual cases. Such factors are important to consider when performing case-specific risk assessments.