Monoclonal antibody therapy against COVID-19 is safe but not as effective during pregnancy, according to a single-center study.
In pregnant women with mild to moderate COVID-19 treated with monoclonal antibodies, infusion reactions were rare, with 1.4% of patients experiencing mild Drug-related adverse events (AE) Medical Center and colleagues.
There were no differences in obstetric outcomes at delivery – including gestational age at birth, birth weight, stillbirth, maternal morbidity, etc. – in patients treated with mAbs compared to those who did not. They were noted in Annals of Internal Medicine compared to patients who received treatment.
However, in the efficacy analysis, there were no statistically significant differences in the combined outcome of COVID-related hospitalizations, emergency department visits, or gestational 28-day mortality between treated and untreated patients:
- Overall Population: Risk Ratio [RR] 0.71 (95% CI 0.37-1.40 )
- Propensity score matching analysis: RR 0.61 (95% CI 0.34-1.10)
McCreary told MedPage Today that this is one of the largest datasets describing the safety and efficacy of monoclonal antibodies for COVID-19 treatment in pregnancy. She emphasized that monoclonal antibody therapy may still be the right choice based on a patient’s individual risk profile for severe disease, in addition to efficacy outcomes.
“We still offer monoclonal antibodies to pregnant women,” McCreary said, and encouraged patient and provider discussions on a case-by-case basis regarding a patient’s medical history or potential hospitalization risks. “Most importantly, we know these monoclonal antibody therapies are safe,” she said. MedPage Today Study shows ‘no harm but no real benefit’ from monoclonal antibody treatment for COVID-19 in pregnancy. Aagaard, who was not involved in the study, added that the findings will help inform the decision of the Society of Medicine guidelines “to avoid the use of expensive therapies that do not provide a clear benefit.”
In May 2021, the emergency use authorization for monoclonal antibodies was updated to include pregnancy as a risk factor for severe COVID-19. However, McCreary’s group said limited studies have investigated the safety and effectiveness of these therapies in pregnant women.
SARS-CoV-2. All study participants were treated at the University of Pittsburgh Medical Center between April 2021 and January 2022.
By mid-December 2021, all patients treated with a monoclonal antibody received a product such as bamlanivimab-etesevimab, casirivimab-imdevimab or sotrovimab. After the Omicron variant, all treated patients received intravenous sotrovimab (between mid-December 2021 and January 2022). According to the authors, patients were treated in any outpatient infusion center, urgent care facility, or obstetric triage area, and both treated and untreated cohorts were followed for 28 days.
McCreary’s group assessed the safety of mAbs by provider- or patient-reported drug-related AEs and obstetric outcomes at each treatment site.
The likelihood of receiving treatment was modeled using multivariate logistic regression to generate propensity scores, including variables such as age, race, vaccination status, gestational age, insurance type, and medical comorbidities.
Of 944 pregnant patients (median age 30 years, mostly white), 58% received monoclonal antibody therapy. The mean gestational age at diagnosis of COVID-19 was 179 days, or more than 25 weeks’ gestation. Of all patients with known vaccine status, 62% were fully vaccinated.
A total of 60% of patients were treated within 4 days of symptom onset, with the majority receiving sotrovimab. Patients who received monoclonal antibody therapy were older, had commercial insurance, and were more likely to have a history of infertility, the researchers noted. In addition, treated patients were more likely to be vaccinated.
Overall, infusion reactions were rare and there were no serious drug-related AEs. There were no deaths in the cohort of patients who received monoclonal antibodies and one death in the untreated group. The researchers found that the associated hospitalization rates were higher than among untreated patients (2 percent versus 0.5 percent, respectively). However, there was no difference in propensity score matching rates (2.5% vs. 2%, respectively), suggesting “possibly unmeasured differences between groups unrelated to monoclonal antibody treatment,” the researchers said.
Study limitations included patient and provider reporting of drug-related AEs, so underreporting may be an issue. In addition, there are no data on the severity of symptoms in untreated patients at the time of testing and treatment.
If the emerging variants go on to prove resistance to monoclonal antibody therapy, their future use in pregnant women is uncertain, McCreary said. However, if antibodies that neutralize existing variants remain available, these therapies could be a viable option for pregnant women, she said.
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Amanda D’Ambrosio is a reporter for MedPage Today’s Corporate and Investigative team. She reports on obstetrics, gynecology and other clinical news, and writes features on the U.S. healthcare system. Follow
Disclosure
Some of the sotrovimab used in this study was provided by GSK /Vir Biotechnology donation.
McCreary and coauthors disclosed collaborations with Merck, AbbVie, Cidara, Shionogi, Ferring, Summit, La Jolla, LabSimply, Entasis, and Inotrem.
