Assessing the Safety of Biologics for Asthma During Pregnancy

Severe or uncontrolled asthma during pregnancy is associated with adverse maternal and neonatal/fetal outcomes. Therefore, controlling asthma-related symptoms in women who are pregnant remains an important goal of care. There are several classes of drugs approved by the US Food and Drug Administration (FDA) for the treatment of patients with asthma, including inhaled corticosteroids, leukotriene modifiers, long-acting beta agonists, and quick-relief medications. In addition, several biologics have recently been approved for treating asthma-related symptoms. However, there remains a lack of human safety data regarding the use of these newer agents in pregnant women.

In an interview with Respiratory Practice Management (RPM), Jennifer A. Namazy, MD, an allergist-immunologist at Scripps Clinic, La Jolla, CA, explained the importance of implementing effective strategies for controlling asthma-related symptoms in patients during pregnancy and discussed initiatives aimed at capturing human data on the safety of biologics in this population of patients.

RPM: Can you discuss some of the adverse outcomes associated with asthma during pregnancy?

Dr Namazy: Studies have shown that pregnant women with asthma are at increased risk for experiencing gestational diabetes, preeclampsia, placental dysfunction, and other adverse events.1 Asthma can also lead to poor neonatal outcomes, including pre‑term birth, low birth weight, small for gestational age, congenital malformations, and fetal mortality.1,2

In 2012, we conducted a meta‑analysis that identified several maternal and infant adverse outcomes associated with asthma.2 The results underscored the importance of providing safe and effective treatment options for women who have asthma-related symptoms during pregnancy.

RPM: How are biologics used for the treatment of asthma being evaluated for safety in pregnant women?

Dr Namazy: Targeted biologic agents can be effective in the treatment of certain patients with asthma but it is vital to assess the safety of these medications during pregnancy. For ethical reasons, it is not feasible to conduct randomized controlled trials to determine the safety of biologics in vulnerable populations, such as pregnant women, which has made it more difficult to gather the necessary data. Registries play an important role in collecting safety data on treatments used during pregnancy.

Omalizumab (Xolair; Genentech) was the first biologic approved to treat asthma. The manufacturer of this drug, as per an agreement with the FDA, created a postmarketing registry for pregnant women called EXPECT, which enrolled 250 women with asthma exposed to omalizumab during pregnancy. Results showed that pregnant women taking this drug during their first trimester had no apparent increased risk for major congenital anomalies compared with a disease-matched population of pregnant women who did not take this drug.3 These are reassuring data regarding omalizumab use during pregnancy.

Mepolizumab (Nucala; GlaxoSmithKline), benralizumab (Fasenra; AstraZeneca), dupilumab (Dupixent; Regeneron/Sanofi), and reslizumab (Cinqair; Teva) are additional biologics that have been approved by the FDA for the treatment of certain patients with asthma.

Pregnant women who take mepolizumab, benralizumab, or dupilumab can enroll in a registry developed by MotherToBaby (, where they will be followed during pregnancy and monitored for outcomes. This registry can potentially provide more human data than we would otherwise have, which can shed further light on the effects of biologics used to treat asthma during pregnancy.

In addition, when a pregnant patient enrolls in a registry such as MotherToBaby, they have access to information that can be very helpful, and there is staff available to chat with them in real time to answer any questions they may have.

I feel that raising awareness among physicians and patients regarding the MotherToBaby registry is very important. A survey sent to members of the American Academy of Allergy, Asthma, and Immunology (AAAAI) showed that most clinicians who treat patients with asthma were unaware of pregnancy registries for biologic medications, and only 60% were aware of the EXPECT registry for omalizumab. In addition, the overwhelming majority of survey respondents indicated that the availability of published human safety data is a key factor in deciding whether to prescribe biologics for pregnant women with asthma. Therefore, it is vital that healthcare professionals are provided with literature about this registry so they know how to enroll their patients.

RPM: What can you tell us about the ongoing VAMPSS project?

Dr Namazy: The Vaccine and Medication During Pregnancy Surveillance System (VAMPSS) is a collaborative project jointly sponsored by the AAAAI, the Organization of Teratology Information Specialists Research Center at the University of California-San Diego, the Slone Epidemiology Center at Boston University, and the Harvard Pregnancy Research Group. This national surveillance system is designed to monitor the use and safety of vaccines and asthma drugs during pregnancy, using 2 data collection approaches to obtain information on how these medications may affect a patient’s baby.

This is an important initiative because there is a lack of adequate safety information regarding the use of most medications during pregnancy. The VAMPSS surveillance system aims to collect this information in a systematic fashion and help close the knowledge gap.

More information about VAMPSS can be found at


  1. Murphy VE, Namazy JA, Powell H, et al. A meta-analysis of adverse perinatal outcomes in women with asthma. BJOG. 2011;118:1314-1323.
  2. Murphy VE, Wang G, Namazy JA, et al. The risk of congenital malformations, perinatal mortality and neonatal hospitalization among pregnant women with asthma: a systemic review and meta-analysis. BJOG. 2013;120:812-822.
  3. Namazy JA, Blais L, Andrews EB, et al. Pregnancy outcomes in the omalizumab pregnancy registry and a disease-matched comparator cohort. J Allergy Clin Immunol. 2020;145:528-536.e1. doi: 10.1016/j.jaci.2019.05.019. Epub 2019 May 27.

Related Items