NRx hopes 'guided missile' COVID-19 antiviral will get FDA clearance on 2nd attempt

The FDA told NRx Pharmaceuticals to try again in September when they attempted to obtain authorization for a COVID-19 therapy. Now, the biotech thinks they have the data they need to finally get the nod. 

Radnor, Pennsylvania-based NRx filed for emergency use authorization yesterday with the FDA for aviptadil-acetate, or Zyesami, to be used in COVID-19 patients with respiratory failure. 

Zyesami is already being used in the Caucasus region, including the Republic of Georgia, Ukraine, Uzbekistan and Tajikistan, where “the pandemic is absolutely raging,” said Chairman and CEO Jonathan Javitt, M.D., in an interview. The therapy was found to increase the likelihood of patients being free of respiratory failure at 60 days compared to those with placebo in a phase 2b/3 clinical trial. The study of 196 people at 10 U.S. hospitals also showed patients who took Zyesami experienced a significantly shorter hospital stay. 

Javitt said the U.S. regulator already “knew a lot about our drug,” and he's expecting a prompt reply. The agency typically responds to emergency use authorization requests within 60 days.

The CEO is no stranger to the FDA process, having previously worked on drug development for Big Pharmas like Novartis, Pfizer, Merck and Allergan as well as serving in healthcare roles under four presidents.

NRx had sought permission from the FDA in September to allow the “most desperately ill patients who had the least chance of survival” to take the treatment without randomized data, but the FDA declined.

“They requested prospective data, but they did say in the letter that they were very interested in this drug and that they would review randomized data promptly, so this is the first time we're giving them randomized data on this drug,” Javitt said.

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NRx hit another bend in the road last month when Relief Therapeutics issued comments on the COVID-19 drug in which the Swiss company claimed collaboration agreement disputes, such as refusing to share clinical trial data.

“We originally went into this with the expectation that Relief would fund all of the development, and they decided not to do that," Javitt said. "They decided to fund part of the development, but of course we’re not going to let that slow us down in any way, shape or form with regard to the drug getting to patients."

Zyesami is a synthetic version of vasoactive intestinal polypeptide (VIP), which is primarily in the lungs but first purified in the intestinal tract. VIP binds to alveolar type II cells (ATII) in the alveolus, stimulating the cells to make surfactant, which Javitt analogized as a “soap bubble that coats the inside of the lung.” COVID-19 binds to ATII and shuts down surfactant production, which causes respiratory failure.

“If nature were to design a guided missile against the effects of the coronavirus, this would probably be pretty close to that,” Javitt said of the therapy.

Few treatments have been approved for treating COVID-19, and the ones that have can only be used for very narrow indications for specific patients. Gilead Sciences' Veklury, also know as remdesivir, is one. That therapy is approved for treating COVID-19 in hospitalized adult and pediatric patients ages 12 years and up. It's also authorized for younger hospitalized pediatric patients.

Veklury is a “systemic antiviral,” whereas Zyesami has antiviral effects concentrated within ATII, according to Javitt.

NRx also plans to see whether Zyesami can be used earlier in the treatment process for COVID-19 patients and if the current intravenous formulation can be turned into an inhaled formulation. The company is also working on a phase 3 multicenter, multi-country clinical trial sponsored by the National Institutes of Health and funded by the US Government COVID-19 Therapeutics Response.

“We’re hoping that if you treat people earlier, you can keep them out of the ICU in the first place,” Javitt said.

All of this is happening amid the backdrop of NRx commencing trading last week on the Nasdaq through a merger with Big Rock Partners Acquisition, a special purpose acquisition company (SPAC).

Javitt said the SPAC process came together before the company could think about a traditional IPO. The deal happened “just in the nick of time” as the Securities and Exchange Commission has heightened oversight of SPAC accounting rules.

“The traditional IPO players have not necessarily rushed to do transactions around COVID,” Javitt said. "There's been some sentiment that COVID is a temporary phenomenon."

NRx’s stance, though, is that “COVID will be with the human race as long as the flu.”

“It'll hopefully stop being a pandemic, but it's always going to be out there lurking and therapeutics that treat COVID will be needed for the foreseeable future,” the CEO added.

The pandemic did put a roadblock in the company’s original mission: NRX-101, an investigational drug for suicidal bipolar depression. NRx was “well established” in a phase 3 program when the pandemic shut down most of the psychiatry beds being used, Javitt said. The company is now “re-establishing that drug in the clinic."