Zero device-related adverse events were observed among the first 100 adult patients in SeaStar Medical’s NEUTRALIZE-AKI pivotal trial of its Selective Cytopheretic Device (SCD) used with CRRT. The independent DSMB reported a signal of potential clinical benefit and recommended continuing the study while re-estimating the sample size upward from 200 to 339 patients to strengthen statistical power. Enrollment stands at 137 patients. The trial’s primary endpoint is a composite of 90-day mortality or dialysis dependence; key secondary measures include 28-day mortality, ICU-free days through Day 28, MAKE90, and one-year dialysis dependence.
The core development is a midstream recalibration: the DSMB’s interim review supported safety and hinted at efficacy but indicated a larger cohort is needed to validate the effect. SeaStar plans to add sites and projects, completing enrollment near the end of 2026, extending timelines for an event-driven program that tracks outcomes beyond hospital discharge. In parallel, the company is advancing its pediatric SCD franchise (approved in 2024 as QUELIMMUNE) and has early registry data in 20 commercial patients showing no device-related events and 75% 28-day survival, although these uncontrolled findings are preliminary and small in scale.
Strategically, this is a bet on power over speed. An upward sample size re-estimation typically reflects either a smaller-than-expected effect size or variance higher than assumed at design, both common in heterogeneous ICU populations with sepsis and ARDS. The adjustment is consistent with adaptive plans and keeps the pivotal readout in play, but raises operational complexity and burn. For SeaStar, closing the adult indication would extend an immunomodulatory device model already de-risked on safety and workflow in pediatrics, but adult AKI on CRRT is a broader, noisier setting in which endpoint ascertainment and standard-of-care variability can dilute signals.
The shift affects stakeholders across the ecosystem. ICU research sites will need to sustain recruitment across longer timelines, standardize CRRT practices to limit inter-site variability, and manage integration of the SCD into existing circuits without adding complications that could inflate adverse event noise. Long-term follow-up for dialysis dependence will stress site-payer interfaces and data infrastructure, especially for patients transitioning out of the index hospital. CROs face increased monitoring load and event-adjudication rigor as the study scales. Regulators are likely to scrutinize subgroup consistency, particularly in sepsis and ARDS strata, and the durability of benefit at one year. If the composite endpoint trends are driven more by dialysis independence than mortality, payers and value analysis committees will want clear health-economic signals around ICU length of stay and post-acute dialysis avoidance; Breakthrough Device status may aid coverage discussions but will not substitute for robust effect sizes.
Next, watch enrollment velocity, site expansion, and event accrual against assumptions, as well as any subsequent DSMB updates clarifying the magnitude and consistency of benefit. The biggest risks are operational: heterogeneity in CRRT protocols, post-discharge data capture, and potential dilution from concomitant therapies. Financial runway becomes more salient as timelines extend. If the adult pivotal reads out positive on the composite and on dialysis dependence at one year, SeaStar will still need to convert ICU champions and hospital committees with implementation data and cost offsets; if the effect proves modest or variable by subgroup, the path to broad adoption will narrow despite a clean safety profile.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
