Full Breakdown
Apheresis Therapy Shows Promise for Treating Preterm Preeclampsia
4/29/2026, 4:14:54 AM
Background: Preeclampsia Overview
Preeclampsia, a hypertensive disorder affecting up to 8 % of pregnancies, can cause maternal organ injury and progress to eclampsia, which involves seizures and possible death. Delivery remains the only definitive treatment, often preterm, exposing infants to respiratory and developmental complications, especially before 32 weeks gestation.
Pilot Study of sFlt-1 Apheresis
Dr. Ravi Thadhani’s team at Cedars-Sinai Medical Center conducted a pilot trial (Nature Medicine, April 27) of apheresis, a blood-filtering method that removes soluble fms-like tyrosine kinase-1 (sFlt-1). Sixteen women with early-onset preeclampsia (<=34 weeks) were enrolled; seven received one session, nine received up to three. All procedures were well tolerated, and each session lowered sFlt-1 by roughly 17 % in humans (?50 % in a baboon model). Treated patients remained hospitalized a median of 10 days after admission versus four days for an untreated historical cohort, suggesting a possible extension of pregnancy.
Data Summary
- Prevalence of preeclampsia: up to 8 % of pregnancies.
- Median gestational age at enrollment: 30 weeks.
- sFlt-1 reduction: ~50 % per session in baboons; ~17 % per session in humans.
- Median pregnancy extension after treatment: 10 days (treated) vs. 4 days (untreated).
Expert Perspectives
Dr. Thadhani described the therapy as a step toward a targeted treatment that could “prevent this disease from getting worse and forcing the hand of the obstetrician to deliver” prematurely, and he stressed that safety for mother and fetus was confirmed. Dr. Lana McClements, who was not involved in the trial, called the findings “promising” but noted that the modest sFlt-1 reductions and occasional rebounds raise questions about efficacy. She also highlighted ongoing debate over whether sFlt-1 drives preeclampsia or merely reflects other pathological processes, suggesting that single-target approaches may be insufficient.
Conflicting Reports & Gaps
The baboon model achieved a 50 % sFlt-1 drop, whereas human participants showed only about a 17 % decrease, indicating a species-specific efficacy gap. The study lacked a contemporaneous untreated control group, limiting definitive conclusions about clinical benefit. Long-term outcomes for infants and mothers were not reported.
Verbatim Quotes
- “we're finally on the verge of developing a targeted treatment for this condition,” — Dr. Ravi Thadhani, nephrologist and chief medical officer, Cedars-Sinai Medical Center.
- “prevent this disease from getting worse and forcing the hand of the obstetrician to deliver” — Dr. Ravi Thadhani.
- “The camps are still split on whether it has a role in preeclampsia development or it's a consequence of something else happening in the body,” — Dr. Lana McClements, leader, Cardio-Obstetrics Research Group, University of Technology Sydney.
- “promising,” — Dr. Lana McClements, commenting on the pilot study.
Next Steps
Thadhani plans a randomized, placebo-controlled trial that will enroll patients earlier in pregnancy to allow multiple apheresis sessions. The trial aims to determine whether sustained sFlt-1 reduction can reliably extend gestation and improve maternal-fetal outcomes.
