(P-408) Nucala Exposure in Women of Childbearing Age and in Pregnant Women in US Claims Data, 2016-2019

Background: Pharmaceutical companies with medicines that may be used by women often seek to identify women who may be exposed to medications or vaccines during pregnancy or childbearing years. Describing the number of women exposed to medications can contextualize expected recruitment into ongoing company sponsored pregnancy registries and help plan additional safety studies.

Objectives: To quantify the number of women of childbearing age (aged 15-50) and pregnant women aged 15-50 with an exposure to Nucala across national health insurance claim databases from 2016 to 2019.

Methods: Using IBM MarketScan® Commercial and Multi-State Medicaid claims data from 2016 to 2019, we applied a pregnancy algorithm developed by GSK to estimate the number and proportion of women with a Nucala exposure among (i) women of childbearing age (aged 15-50) and (ii) pregnant women aged 15-50. Nucala exposure was calculated using index date of prescription or administration plus 90 days to account for the medication’s half-life.

Results: In the MarketScan Commercial database, 791 out of 13,217,622 (0.0060%, 95% confidence interval (CI): 0.0056% to 0.0064%) women aged 15-50 were exposed to Nucala; 27 out of 1,913,924 (0.0014%, 95% CI: 0.0009% to 0.0021%) women aged 15-50 with a pregnancy were exposed to Nucala during pregnancy. In the MarketScan Medicaid database, 243 out of 4,370,439 (0.0056%, 95% CI: 0.0049% to 0.0063%) women aged 15-50 were exposed to Nucala; 21 out of 1,356,728 (0.0015%, 95% CI: 0.0010% to 0.0024%) women aged 15-50 with a pregnancy were exposed to Nucala during pregnancy.

Conclusions: Few women of childbearing age were exposed to Nucala and even fewer during pregnancy. This information can be used in several ways; the first is to provide context to ongoing pregnancy registry enrollment to identify whether low enrollment is reflective of issues with recruitment or of low prevalence of medication use during pregnancy. Second, the proportion of pregnancies exposed to Nucala can be used to calculate projected sample size for studying medication exposure during pregnancy in other databases. Third, in designing future studies, this approach of assessing medication use in women of childbearing age can be used to make decisions about whether studying a medication in pregnancy may be feasible.

Funding: GSK (215246)