NeuroRx Announces ZYESAMI™ Met the Primary Endpoint of Its Phase 2b/3 Clinical Trial and Also Demonstrated a Meaningful Benefit in Survival from Critical COVID-19

RADNOR, Pa. -- NeuroRx, Inc. today reports 60-day results of the Phase 2b/3 trial of intravenously-administered ZYESAMI™ (aviptadil acetate) for the treatment of respiratory failure in critically-ill patients with COVID-19, which is being developed in collaboration with Relief Therapeutics Holding AG (SIX:RLF,OTCQB:RLFTF). Across all patients and sites, ZYESAMI™ met the primary endpoint for successful recovery from respiratory failure at days 28 (P = .014) and 60 (P = .013) and also demonstrated a meaningful benefit in survival (P = < .001) after controlling for ventilation status and treatment site.

In addition to the robust overall significance across all 196 treated patients at all 10 clinical sites, the prespecified analysis of recovery from respiratory failure is clinically and statistically significant in the 127 patients treated by High Flow Nasal Cannula (HFNC) (P = .02), compared to those treated with mechanical or non-invasive ventilation at tertiary care hospitals. In this group, ZYESAMI™ patients had a 71% chance of successful recovery by day 28 vs. 48% in the placebo group (P = .017) and a 75% rate of successful recovery by day 60 vs. 55% in the placebo group (P = .036).  Eighty-four percent (84%) of HFNC patients treated at tertiary medical centers with ZYESAMI™ survived to day 60 compared with 60% of those treated with placebo (P = .007).

To the company's knowledge, ZYESAMI™ is the first COVID-19 therapeutic to demonstrate advantages in both survival and recovery from critical COVID-19 in a randomized, double-blind multicenter trial. On the basis of these findings, NeuroRx plans to apply immediately to the United States Food and Drug Administration ("FDA") for Emergency Use Authorization (EUA) and to subsequently submit a New Drug Application (NDA).

Recovery from respiratory failure (without relapse) with discharge from acute care and survival through the observation period was the prespecified primary endpoint specified by FDA for the study, originally intended to be assessed at 28 days and then extended to 60 days based on recently-published FDA guidance. The above analysis includes all 196 participants who were randomized and treated in the placebo-controlled, double-blind clinical trial ( NCT04311697) conducted at 10 US hospitals. Treatment with ZYESAMI™ or placebo was in addition to standard of care treatment that included steroids, convalescent plasma, antiviral therapy, anticoagulants, and various anti-cytokine drugs.

NeuroRx has announced the commencement of a clinical trial of inhaled ZYESAMI™ for the treatment of patients with moderate and severe COVID-19 with the aim of preventing progression to respiratory failure. NeuroRx has also announced the inclusion of inhaled ZYESAMI™ in the I-SPY clinical trial platform for patients with COVID-19 respiratory failure. The company has signed a clinical trial participation agreement with the National Institutes of Health.

The study's coordinating committee, including Professors Dushyantha Jayaweera, MD, FACP (University of Miami), Richard Lee, MD, (UC Irvine), and J. Georges Youssef, MD (Houston Methodist Hospital) commented, "The 60-day observation framework implemented last month by FDA for critically ill patients with COVID-19 is more consistent with the clinical course of this lethal disease than the 28-day time frame originally adapted from other conditions that cause respiratory distress. The association of baseline oxygenation status (high flow nasal oxygen vs. ventilation) is not surprising in that patients who require mechanical or noninvasive ventilation in order to maintain blood oxygen are likely to have substantially more damage to the lining of their lungs compared to patients whose blood oxygen level can be maintained with high-flow oxygen delivered to the nose. The finding that patients fared substantially better in tertiary care centers as compared to regional hospitals may be influenced by the intensity of the public health crisis at the regional hospitals that participated in the study, all of which were operating at 200% or higher overcapacity in their intensive care units with implementation of temporary ICU beds and shortages of critical care staff."

Prof. Jonathan Javitt, MD, MPH, Chairman and CEO of NeuroRx, said, "ZYESAMI has now demonstrated itself in a phase 2/3 trial, conducted under FDA Fast Track Designation, not only to shorten hospitalization (as was previously reported) but also to save lives and increase the likelihood of patients returning safely home to their families. In exactly 12 months, a lifesaving drug has advanced from concept to clinical success in partnership with Relief Therapeutics in the midst of a public health emergency that has claimed the lives of millions. Today's findings confirm the often dramatic clinical success that has been seen in numerous patients treated in the US and abroad under emergency use protocols. We look forward to working with the National Institutes of Health, the Department of Defense, the FDA, and regulators around the world to bring this treatment to patients as quickly as possible."

About Relief Therapeutics Holding AG
Relief focuses primarily on clinical-stage programs based on molecules of natural origin (peptides and proteins) with a history of clinical testing and use in human patients or a strong scientific rationale. Currently, Relief is concentrating its efforts on developing new treatments for respiratory disease indications. Its lead drug candidate RLF-100™ (aviptadil) is being investigated in two placebo-controlled U.S. phase 2b/3 clinical trials in respiratory failure due to COVID-19. Relief also holds a patent issued in the United States and various other countries covering potential formulations of RLF-100™. Relief is listed on the SIX Swiss Exchange under the symbol RLF and quoted in the U.S. on OTCQB under the symbol RLFTF.

Jonathan C. Javitt, M.D., MPH
Chairman and Chief Executive Officer  

Ryan Sheffield  
(484) 254-6134, ext. 723

Greg Parasmo  
(484) 254-6134, ext. 724

Nice Insight

Nice Insight, established in 2010, is the research division of That’s Nice, A Science Agency, providing data and analysis from proprietary annual surveys, custom primary qualitative and quantitative research as well as extensive secondary research. Current annual surveys include The Nice Insight Contract Development & Manufacturing (CDMO/CMO), Survey The Nice Insight Contract Research - Preclinical and Clinical (CRO) Survey, The Nice Insight Pharmaceutical Equipment Survey, and The Nice Insight Pharmaceutical Excipients Survey.

NeuroRx, Inc.

NeuroRx draws upon more than 100 years of collective drug development experience from senior executives of AstraZeneca, Eli Lilly, Novartis, Pfizer, and PPD. In addition to its work on Aviptadil, NeuroRx has been awarded Breakthrough Therapy Designation and a Special Protocol Agreement to develop NRX-101 in suicidal bipolar depression and is currently in Phase 3 trials. Its executive team is led by Prof. Jonathan C. Javitt, MD, MPH, who has served as a health advisor to four Presidential administrations and worked on paradigm-changing drug development projects for Merck, Allergan, Pharmacia, Pfizer, Novartis, and Mannkind, together with Robert Besthof, MIM, who served as the Global Vice President (Commercial) for Pfizer's Neuroscience and Pain Division. NeuroRx recently announced a plan to complete a business combination with Big Rock Partners Acquisition Corp (NASDAQ:BRPA) ("BRPA"), and intends to apply for listing on the NASDAQ under the proposed symbol "NRXP".