FDA Reviewers Have Concerns About Artificial Womb Trials in Humans

FDA staff raised concerns that need to be addressed prior to potential human tests of artificial womb technology (AWT), a device that simulates a womb for extremely premature infants, as detailed in briefing documents released ahead of a Pediatric Advisory Committee meeting next week.

AWT devices are intended to treat extremely premature infants, who have increased risks of mortality and morbidity -- especially those born at less than 28 weeks' gestation. The current standard of care involves treatments related to respiratory care, cardiovascular support, thermoregulation, nutrition, and neurodevelopmental impairment in the neonatal intensive care unit (NICU).

"The goal of AWT is to provide a bridge from extreme preterm birth to later gestation within a physiologic environment that mimics the womb in order to reduce prematurity-associated morbidity associated with standard NICU care," FDA staff wrote in the briefing documents.

Noting the "challenges in assessing the benefit-risk profile of this type of highly innovative technology, and the complexities related to the vulnerable neonatal population," FDA reviewers have asked the committee to discuss four major points on September 19 and 20. First, the strengths and weaknesses of large animal models and what additional data are needed to inform the proof of concept. Next, they are being asked to consider gaps in knowledge that could be answered with nonclinical studies. They're also going to consider whether the existing data are enough to support first-in-human studies and what guidelines would need to be followed for patient safety. Lastly, the panel will discuss how to obtain informed consent in an AWT trial and what challenges may arise in doing so.

Several large animal models have already assessed AWT. The University of Michigan in Ann Arbor, Tohoku University in Japan, the University of Western Australia, and Children's Hospital of Philadelphia have all done studies using lambs, and the University of Toronto used miniature pigs in a previous study.

Because AWT inherently involves neonatal patients, the FDA reviewers pointed out there are additional ethical considerations. For instance, a trial must have minimal risk and the investigational device must "offer a prospect of direct clinical benefit to the child, the risk must be justified by the anticipated benefit, and the anticipated benefit-risk profile must be at least as favorable as that presented by accepted alternative treatments," they wrote.

Therefore, there must be adequate data that show AWT would have benefits "at least as favorable as" the standard of care provided in the NICU before a first-in-human trial could begin.

FDA staff also detailed necessary components of a first-in-human study design. For instance, the AWT study should include "a robust plan for safety monitoring and adverse event reporting, pre-established individual and study stopping rules, oversight by an independent Data and Safety Monitoring Board (DSMB), endpoints to evaluate for a clinically meaningful treatment effect, and an effective informed consent process."

In sum, a clinical development program for an AWT device should provide evidence that using AWT would "support normal growth and organ maturation, while reducing high rates of prematurity-associated morbidities observed with current NICU standard of care, in infants born extremely premature," the reviewers wrote.

While the FDA is not required to follow the recommendations of its advisory committees, it typically does.

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