NeuroRx Reports Positive RLF-100 Data for Critically Ill COVID-19 Patients

Coronavirus

A new readout from a Phase IIb/III trial showed intravenous RLF-100 (aviptadil) met the primary endpoint of improving survival and recovery at 60 days post-treatment for respiratory failure in critically ill patients with COVID-19, bolstering the case for sponsors NeuroRx and Relief Therapeutics to reapply for emergency use authorization (EUA).

The U.S. Food and Drug Administration (FDA) declined to grant an EUA last year based on an earlier open-label study.

Among the 196 patients enrolled in the randomized, double-blind trial, 75% of those receiving RLF-100 successfully recovered compared with 55% receiving a placebo, two months after treatment. Additionally, 84% of patients on RLF-100 survived, compared with 60% on the placebo.

All patients continued to receive standard-of-care treatment alongside RLF-100 or placebo. The companies said the trial was the first of its kind to demonstrate both survival and recovery improvements.

According to the companies, RLF-100 prevents apoptosis in lung alveolar type II cells by blocking damage from the cytokine storm inflammatory response observed in acute respiratory failure, the primary cause of COVID-19 death. According to NeuroRx founder and CEO Jonathan Javitt, earlier development for respiratory illnesses including sarcoid and sepsis-related acute respiratory distress syndrome was halted due to limited commercial opportunities.

RLF-100 is a synthetic formulation of naturally occurring vasoactive intestinal polypeptide, an anti-inflammatory and neurotransmitter that has been tested in clinical trials for a range of diseases. It has been approved for decades in Europe in combination with phentolamine to treat patients with erectile dysfunction, but has not been approved by FDA for any indication. Relief Therapeutics develops natural peptides and proteins with track records of clinical safety.

The partners have also launched an additional Phase II/III trial for an inhaled form of RLF-100 in patients with moderate-to-severe COVID-19, which dosed its first patient earlier this month. The peptide has also been included in the I-SPY COVID-19 trial, which compares multiple investigational therapeutics under a single master protocol and regulatory framework.

NeuroRx plans to resume clinical trials this year on its lead candidates NRX-100 and NRX-101, in the company’s core neurological disorders business. Both are being tested sequentially in Phase IIb/III trials for patients with bipolar depression and suicidal ideations. NRX-100 is a formulation of the anesthetic ketamine for inpatient treatment. NRX-101 is a combination of FDA-approved antibiotic D-cycloserine and antipsychotic Latuda (Lurasidone), given on an outpatient basis. Trials were on hold during the pandemic.

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