NeuroRx to File for Emergency Use Authorization in This Patient Population if Positive Results Continue to be Demonstrated at Day-60 Endpoint in Line with FDA's New Guidance
RADNOR, Pa., Feb. 23, 2021 /PRNewswire/ -- NeuroRx, Inc. announced today that the Phase 2b/3 trial* of ZYESAMI™ (aviptadil, previously RLF-100™) for the treatment of Respiratory Failure in critically ill patients with Covid-19 has demonstrated multidimensional benefit around its prespecified primary endpoint of Recovery from Respiratory Failure with discharge from hospital and ICU (without relapse) by day 28 in patients with critical Covid-19 who were treated with High Flow Nasal Oxygen. Although not envisioned at the start of the clinical trial, High Flow Nasal Oxygen has become the predominant form of treatment in Covid-19 respiratory failure, with mechanical ventilation reserved for those whose blood oxygen levels cannot be maintained on this less invasive modality. The trial was conducted at 10 U.S. hospitals under the direction of NeuroRx in collaboration with RELIEF THERAPEUTICS Holding AG (SIX: RLF; OTCQB: RLFTF). NeuroRx has signed an agreement to complete a business combination with Big Rock Partners Acquisition Corporation (NASDAQ:BRPA).
The clinical trial was originally approved as a 28-day study at FDA's direction. In December, NeuroRx added a 60-day endpoint based on the recognition that the traditional 28-day endpoint adopted in the 1990s for trials in Acute Respiratory Distress Syndrome is not appropriate for critically ill patients with Covid-19, who are frequently maintained in the ICU with advanced technologies well beyond this time point. NeuroRx and other clinical trial sponsors alerted FDA to this trend and yesterday the FDA published formal guidance† changing the required time for measuring the prespecified endpoint of "alive and free of respiratory failure" in critically ill patients to 60 days. Interim data are being reported because they were unblinded as per the original protocol and the last patient in the trial reached day 60 yesterday. Therefore, study conduct cannot be adversely influenced by release of these interim findings.
At 28 days, patients treated with ZYESAMI™ demonstrate 35% higher likelihood of recovery from respiratory failure with continued survival compared to patients treated with placebo (Hazard Ratio 1.53; P=.08). In tertiary care hospitals, ZYESAMI-treated patients were 46% more likely to recover and return home before day 28 (Hazard Ratio controlling for age and severity 1.84; P=.058). Should these trends continue through day 60, they have the potential to reach statistical significance. At day 28, a highly significant 10-day difference in median time to recovery and hospital discharge has emerged in ZYESAMI-treated patients compared to those treated with placebo (P