Research method
The pilot study, co-authored by Professor Manu Vatish, Dr Ana Sofia Cerdeira, and Professor Tim James from the Nuffield Department of Women’s & Reproductive Health, used a specialised blood-filtering device designed to reduce circulating sFlt-1 without introducing a drug into the mother’s bloodstream.
sFlt-1, a protein produced by the placenta, is a key biological driver known to contribute to the development of preeclampsia. The research team developed an antibody-based adsorption column that selectively removes sFlt-1 from circulating blood during apheresis, a procedure in which plasma is filtered and returned to the patient.
The work was first assessed in pregnant baboons and healthy volunteers before being studied in women with very preterm preeclampsia. Across the pilot trial, the treatment reduced circulating sFlt-1 levels, was generally well tolerated, and was associated with reductions in blood pressure.
The significance of the study
Preeclampsia is a serious pregnancy complication marked by high blood pressure and other signs of organ stress, and it can become life-threatening for both mother and baby. In very preterm cases, the condition often worsens quickly, and early delivery is frequently the only definitive treatment.
Current care focuses on monitoring the mother and baby, managing symptoms, and determining the safest time for delivery. While these measures are essential, they do not address the underlying cause.
A treatment that safely reduces the biological driver of preeclampsia could delay delivery, giving the baby more time to grow and mature in the womb. Even a short delay may be clinically meaningful in very preterm pregnancy, where each additional day can improve outcomes.
Key findings
- The sFlt-1 adsorption device was able to selectively remove sFlt-1 from blood.
- In pregnant baboons, the treatment reduced circulating sFlt-1 by about 50% per session.
- In women with very preterm preeclampsia, the procedure was generally safe and well-tolerated.
- Blood pressure fell modestly after treatment, and the drop in blood pressure was linked to the drop in sFlt-1.
- No major treatment-related harms were seen in mothers or babies.
- The main side effects were mild, including low calcium, minor bleeding at the needle site, and one episode of false labour.
- Pregnancy was prolonged in several participants, sometimes by days to weeks.
Implications of the findings
These initial findings indicate that the targeted removal of sFlt-1 could represent a promising novel approach for the management of very preterm preeclampsia. The treatment was shown to be feasible in a hospital setting and did not exhibit any apparent safety concerns in this preliminary study.
This pilot study offers proof of concept and establishes a foundation for larger, controlled trials. If future studies confirm these results, the approach could help doctors manage preeclampsia more effectively, safely extend pregnancy, and improve outcomes for babies born far too early.
Outlook
This study marks an encouraging step towards a targeted, non-pharmacological treatment for preeclampsia. Larger trials will now be needed to determine the approach's effectiveness, which patients are most likely to benefit, and if effective, how best to integrate it into existing obstetric care.
Contributions & Collaborations
Thank you to all the participants in the study, without whom this important work would not have been possible.
The study was funded by Miltenyi Biomedicine and Aggamin Pharmaceuticals, and led by an international team of clinicians and researchers spanning obstetrics, nephrology, reproductive medicine, clinical biochemistry, and neonatal care, with contributions from industry partners.
Professor Manu Vatish, Dr Ana Sofia Cerdeira, and Professor Tim James co-authored the study.
Publication
Read the full publication in Nature Medicine.