Phase 3 Maternal Safety & Immunogenicity Trial of MVA-BN® in DRC

Summary

This Phase 3 open-label study aims to assess the safety and immune response of the MVA-BN mpox vaccine when administered subcutaneously to pregnant and postpartum women in the Democratic Republic of the Congo (DRC), a population at high risk of mpox infection. The study will be conducted in Boende, Tshuapa Province, DRC. A total of 359 maternal participants, aged 16 to 35 and in their second or third trimester of pregnancy, will be enrolled. Participants will be randomly assigned to receive two subcutaneous doses of the MVA-BN vaccine, given 28 days apart, either during pregnancy (Maternal Group 1) or within 72 hours after delivery (Maternal Group 2). Additionally, pregnant women in any trimester who have been recently exposed to a confirmed mpox case will be enrolled in the post-exposure prophylaxis (PEP) arm (Maternal Group 3), receiving the vaccine as soon as possible after exposure-ideally within four days but up to 14 days if they remain asymptomatic. The study will evaluate the safety, reactogenicity, and immune responses of vaccinated pregnant women compared to healthy adults in the POX-MVA-045 study (NCT06549530) through non-inferiority analyses. Participants will be monitored for immunogenicity and safety for 13 months post-delivery, while neonates will be observed for safety over the same period. The trial will also compare outcomes between women vaccinated during pregnancy and those vaccinated postpartum, assess the transfer of maternal immunity to neonates, and explore correlations between maternal antibody levels in serum and breast milk. This study seeks to provide strong evidence supporting the safety and immunogenicity of the MVA-BN mpox vaccine in pregnancy, contributing to global public health efforts to protect at-risk women and their infants in mpox-endemic regions.

Timeline

Start

2025-06-23

Primary completion

2026-06

Completion

2027-05

Publications

• Background Lemey G, Lariviere Y, Zola TM, Maketa V, Matangila J, Mitashi P, Vermeiren P, Thys S, De Bie J, Muhindo HM, Ravinetto R, Van Damme P, Van Geertruyden JP. Algorithm for the support of non-related (serious) adverse events in an Ebola vaccine trial in the Democratic Republic of the Congo. BMJ Glob Health. 2021 Jun;6(6):e005726. doi: 10.1136/bmjgh-2021-005726.
• Background Zola Matuvanga T, Lariviere Y, Lemey G, De Bie J, Milolo S, Meta R, Esanga E, Vermeiren PP, Thys S, Van Geertruyden JP, Van Damme P, Maketa V, Matangila J, Mitashi P, Muhindo-Mavoko H. Setting-up an Ebola vaccine trial in a remote area of the Democratic Republic of the Congo: Challenges, mitigations, and lessons learned. Vaccine. 2022 May 31;40(25):3470-3480. doi: 10.1016/j.vaccine.2022.04.094. Epub 2022 May 9.
• Background Puri A, Pollard AJ, Schmidt-Mutter C, Laine F, PrayGod G, Kibuuka H, Barry H, Nicolas JF, Lelievre JD, Sirima SB, Kamala B, Manno D, Watson-Jones D, Gaddah A, Keshinro B, Luhn K, Robinson C, Douoguih M; EBL4001 Study Group. Long-Term Clinical Safety of the Ad26.ZEBOV and MVA-BN-Filo Ebola Vaccines: A Prospective, Multi-Country, Observational Study. Vaccines (Basel). 2024 Feb 17;12(2):210. doi: 10.3390/vaccines12020210.
• Background Salloum M, Paviotti A, Bastiaens H, Van Geertruyden JP. The inclusion of pregnant women in vaccine clinical trials: An overview of late-stage clinical trials' records between 2018 and 2023. Vaccine. 2023 Nov 22;41(48):7076-7083. doi: 10.1016/j.vaccine.2023.10.057. Epub 2023 Oct 28.
• Background Lariviere Y, Zola T, Stoppie E, Maketa V, Matangila J, Mitashi P, De Bie J, Muhindo-Mavoko H, Van Geertruyden JP, Van Damme P. Open-label, randomised, clinical trial to evaluate the immunogenicity and safety of a prophylactic vaccination of healthcare providers by administration of a heterologous vaccine regimen against Ebola in the Democratic Republic of the Congo: the study protocol. BMJ Open. 2021 Sep 28;11(9):e046835. doi: 10.1136/bmjopen-2020-046835.
• Background Schwartz DA, Pittman PR. Mpox (Monkeypox) in Pregnancy: Viral Clade Differences and Their Associations with Varying Obstetrical and Fetal Outcomes. Viruses. 2023 Jul 28;15(8):1649. doi: 10.3390/v15081649.
• Background Schwartz DA. High Rates of Miscarriage and Stillbirth among Pregnant Women with Clade I Mpox (Monkeypox) Are Confirmed during 2023-2024 DR Congo Outbreak in South Kivu Province. Viruses. 2024 Jul 13;16(7):1123. doi: 10.3390/v16071123.
• Background Kozlov M. Monkeypox virus: dangerous strain gains ability to spread through sex, new data suggest. Nature. 2024 May;629(8010):13-14. doi: 10.1038/d41586-024-01167-5. No abstract available.
• Background Bunge EM, Hoet B, Chen L, Lienert F, Weidenthaler H, Baer LR, Steffen R. The changing epidemiology of human monkeypox-A potential threat? A systematic review. PLoS Negl Trop Dis. 2022 Feb 11;16(2):e0010141. doi: 10.1371/journal.pntd.0010141. eCollection 2022 Feb.

Drugs

Indications

No indication recorded.