PROJECT SUMMARY/ABSTRACT ENDEAVOR TO STOP NAUSEA/VOMITING ASSOCIATED WITH PREGNANCY (E-SNAP) Up to 85% of pregnant women experience nausea and vomiting of pregnancy (NVP), which impairs daily function and reduces quality of life. A severe form, hyperemesis gravidarum (HG), affects 0.3-3% of pregnant women and is the most common reason for hospitalization in the first half of pregnancy. Although NVP and HEG usually resolve by mid-pregnancy, symptoms persist into the third trimester in 15--20% of women. HG is associated with preterm birth and small-for gestational age infants as well as termination of desired pregnancies in 14.4% of affected women. Recent studies show that women with severe NVP (sNVP), defined by weight loss or continuation of symptoms beyond 20 weeks gestation, have offspring at risk for structural brain changes and cognitive developmental problems. Despite the frequency and complications of sNVP, only low-quality evidence is available to direct treatment. The NICHD report from the Task Force on Research Specific to Pregnant Women and Lactating Women stated that the drug pipeline for conditions specific to pregnancy is “minimal at best” and listed hyperemesis as an area of need for treatment research. This exploratory/developmental Clinical Trial Planning Grant is a Phase 2 study that will provide data on the acceptability, dose regimen, tolerability and safety of mirtazapine (Remeron®) for the treatment of sNVP that has not responded to at least two standard medications. We will to determine whether a larger randomized controlled trial to evaluate mirtazapine’s efficacy for sNVP is warranted. An FDA application for an IND will be submitted and a DSMB will be constituted. Mirtazapine is prescribed for nausea and vomiting during cancer chemotherapy. Rapid reduction of NVP during mirtazapine treatment has been reported in case series of pregnant women who have not responded to other medications. Mirtazapine impacts the serotonin receptor (similar to ondansetron) as well as three additional receptors involved in the physiologic cascade that results in nausea and emesis. It is a compelling candidate to consider for repurposing to expand therapeutic options for sNVP. Reproductive outcome data for mirtazapine do not indicate an increased risk for birth defects, although the number of women studied is relatively small (≈500). Additionally, pharmacogenetic factors that affect mirtazapine plasma concentrations and thereby affect its tolerability and safety will be considered in the proposed project.

PROJECT NARRATIVE This application describes a Phase 2 study to determine the acceptability, dose regimen, tolerability and safety of mirtazapine for the treatment of severe nausea and vomiting of pregnancy that has not responded to at least two standard medications. We will generate data necessary to inform the design of a large-scale randomized controlled trial to evaluate the efficacy mirtazapine for sNVP, an understudied but common problem in pregnant women.