Nano24 reports Phase 2b results for inhaled EXO-CD24 in ARDS, including improved Day 7 respiratory recovery, lower mortality and shorter hospital stays.
Written By: Sravani Pamanji, PharmD
Reviewed By: Pharmacally Editorial Team
Israeli biotechnology company Nano24 Ltd., based in Tel Aviv, reported positive Phase 2b results for its investigational inhaled therapy EXO-CD24 in patients with acute respiratory distress syndrome (ARDS). Presented at the CHEST Annual Meeting 2026 in Phoenix, Arizona, the findings showed improved Day 7 respiratory recovery, a lower estimated hazard of death at 28 days, and shorter hospital stays compared with placebo. EXO-CD24 remains investigational and has not been approved for commercial use.
Phase 2b Trial Shows Improved Respiratory Recovery
The Phase 2b trial (NCT05947747) enrolled 90 patients who were randomized in a 2:1 ratio to receive inhaled EXO-CD24 (60 patients) or placebo (30 patients). Treatment consisted of (10^ {10}) exosome particles per dose, administered twice daily for five consecutive days. Patients were followed through Day 28, with additional assessments extending to six months.
The trial met its reported primary endpoint. At Day 7, 85% of patients receiving EXO-CD24 met the study-defined criterion for being free from respiratory failure, compared with 33.3% in the placebo group (p<0.0001). The endpoint was defined as an oxygen saturation-to-inspired oxygen fraction ratio (SpO₂/FiO₂) greater than 315.
The difference suggests improved early respiratory recovery with EXO-CD24. However, the endpoint represents a defined oxygenation threshold at a specific time point and should not be interpreted as evidence that all aspects of respiratory dysfunction had resolved.
Mortality Findings Favor EXO-CD24, but Require Confirmation
An adjusted Cox proportional hazards analysis found a lower estimated hazard of death at 28 days in the EXO-CD24 group than in the placebo group (hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.084–0.902; p=0.033). This corresponds to a 72% lower estimated hazard of death in the treatment group.
The reported difference persisted at six months. All-cause mortality was 13.3% among patients receiving EXO-CD24, compared with 43.3% among those receiving placebo (p=0.003), representing a reported 69% relative reduction in six-month mortality.
These findings are clinically notable because ARDS can lead to respiratory and multiorgan failure despite supportive care. Nevertheless, the trial included only 90 patients, and the confidence interval around the 28-day hazard ratio indicates uncertainty about the magnitude of the treatment effect. The results support further evaluation but do not yet establish a definitive survival benefit.
Shorter Hospitalization and Preliminary Safety Findings
Mean hospital stay through Day 28 was 6.5 days in the EXO-CD24 group, compared with 14.4 days in the placebo group (p=0.0001). If reproduced in a larger trial, this difference could have implications for recovery and healthcare resource use.
Nano24 reported that EXO-CD24 was well tolerated, with no treatment-related serious adverse events and fewer serious and non-serious adverse events overall than placebo. However, the available results do not establish the therapy’s longer-term safety profile or exclude uncommon adverse effects.
EXO-CD24 Targets Inflammation in ARDS
ARDS is a life-threatening condition characterized by lung inflammation and impaired oxygen exchange. It can develop following infections, trauma, acute pancreatitis and other forms of lung injury.
EXO-CD24 combines engineered exosomes with CD24, an immunomodulatory protein. The inhaled therapy is designed to act directly in the lungs and regulate damage-driven inflammatory responses while preserving immune functions needed to recognize and eliminate pathogens.
This proposed mechanism provides the biological rationale for investigating EXO-CD24 in ARDS. However, the reported clinical outcomes do not independently demonstrate that modulation of inflammation caused the observed differences in respiratory recovery or mortality.
Clinical Interpretation and Next Steps
The Phase 2b findings identify EXO-CD24 as a candidate warranting further investigation, with favorable reported results across respiratory recovery, mortality and hospitalization outcomes. The consistency across these measures strengthens the rationale for additional clinical evaluation, although the small sample size limits the certainty of the conclusions.
The findings were presented at a medical congress and have not yet been reported in a comprehensive peer-reviewed publication, according to the cited coverage. Nano24 plans to advance EXO-CD24 into a larger international Phase 3 trial to further evaluate its efficacy and safety. The next study will be important in determining whether the observed benefits are reproducible and clinically meaningful in the intended ARDS population.
References
Nano24 Ltd. Nano24 Reports Positive Phase 2b Results for Inhaled EXO-CD24 in Acute Respiratory Distress Syndrome (ARDS) at the CHEST Annual Meeting 2026. Press release, October 20, 2026.
Safety and Efficacy of EXO-CD24 in Preventing Clinical Deterioration in Patients with Mild-Moderate ARDS, ClinicalTrials.gov ID NCT05947747
About the Writer
Sravani Pamanji is a PharmD (LinkedIn) professional with experience in scientific writing, medical literature review, drug profile preparation, and clinical case documentation. She has contributed to scientific publication and presented at the 74th Indian Pharmaceutical Congress. Her training includes ICH GCP E6(R3), scientific research, and medication safety. She is passionate about evidence-based medical communication and accurate dissemination of clinical and pharmaceutical information.