In a recent study posted to the medRxiv* preprint server, researchers assessed the efficacy and safety of monoclonal antibodies (mAbs) for treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy.
Various studies have reported a decrease in hospitalization and mortality in patients with mild to moderate coronavirus disease 2019 (COVID-19) infection. However, extensive research is needed to estimate the effectiveness and adverse effects associated with mAb treatment during pregnancy.
About the study
In the present study, the researchers estimated the mAb-related adverse events post-treatment in SARS-CoV-2-infected pregnant persons, as well as the rate of related safety outcomes among people who gave birth.
The study consisted of persons eligible for mAb treatment who were aged 12 years or older and had a pregnancy episode. The participants had tested positive for SARS-CoV-2 by a polymerase chain reaction or an antigen test between 30 April 2021 and 21 January 2022. Before 23 December 2021, all participants who were treated with mAb received the drug via a central management system. From 23 December 2021 to 21 January 2022, all the participants were treated with sotrovimab due to the rise in transmission of the SARS-CoV-2 Omicron variant.
Patients who received the mAb treatment in an urgent care facility, an outpatient infusion center, or an obstetric triage area were considered to be mAb-treated, while the ones who were not treated with mAb were considered non-treated. Furthermore, patients treated in obstetric emergency departments were deemed as outpatients. The treated and the non-treated groups were subjected to a follow-up after 28 days which started from the day of mAb treatment and the day after the positive SARS-CoV-2 diagnosis, respectively.
The primary safety outcomes included the rates of mAb-related adverse effects among persons who were treated with mAb and experienced obstetric-related outcomes including birth weight, gestational age at delivery, neonatal intensive care unit (NICU) admission, stillbirth, diagnosis of hypertension at the time of delivery, maternal ICU visit, and severe maternal morbidity. The primary outcome for determining mAb effectiveness was the risk-adjusted correlation of the mAb treatment with a composite of COVID-19-associated delivery, COVID-19-related hospital admission or ED visit, or mortality.
The team defined a COVID-19-related hospital admission as an antepartum hospitalization for supportive oxygen or respiratory support. A COVID-19-associated delivery was defined as a delivery induced due to COVID-19-related complications including fetal distress due to pathognomonic SARS-CoV-2-related placentitis and maternal respiratory failure. Furthermore, the secondary outcomes of the study included 28-day non-COVID-19-related hospital admissions and rates of individual components of the composite outcome.
Results
The study results showed that out of the 944 pregnant persons eligible, 58% received mAb treatment. The median age of the patient cohort was 30 years, 79.5% were White and 62% were fully vaccinated while a few of the patients reported comorbidities. Notably, the patients treated with mAb were older, had higher odds of reporting a history of infertility, and had received full vaccination. The median gestational period during COVID-19 diagnosis or receipt of treatment was 179 days. Of the treated cohort, 58% were treated with mAb within four days of COVID-19 symptom onset with 69% of the patients receiving sotrovimab, 20% receiving casirivimab and imdevimab, and 11% receiving bamlanivimab and etesevimab.
Almost 2% of the treated patients experienced mild drug-related adverse events while none suffered from a severe infusion-related reaction. Among the 276 persons who gave birth during the follow-up period, the study found no significant differences between the treated and the untreated groups with respect to birth weight, gestational age at delivery, NICU admission, stillbirth, hypertension at the time of delivery, maternal ICU visit, and severe maternal morbidity.
In the primary analysis, the team observed a composite 28-day risk-adjusted frequency of a COVID-19-associated outcome of four per 100 persons in the mAb-treated group while the same was 3.7 per 100 persons in the non-treated group. Furthermore, no deaths were reported among the patients treated with mAb while one death was reported in the non-treated group. Notably, the number of non-COVID-19-related hospitalizations in the mAb-treated group was higher than that in the non-treated group and was indicated by preterm contractions and intrahepatic cholestasis of pregnancy.
Conclusion
In summary, the study findings showed that adverse events after treatment with mAb were mild and rare in pregnant persons suffering from mild to moderate SARS-CoV-2 infection. Furthermore, mAb treatment correlated with comparable 28-day composite COVID-19-related outcomes and more non-COVID-19-related hospitalizations as compared to the non-treated cohort.
*Important notice
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
