The US Food and Drug Administration (FDA) has granted fast track designation to RLF-100 (Aviptadil), which is being developed by NeuroRx and Relief Therapeutics to treat acute lung injury / acute respiratory distress syndrome caused by Covid-19.

RLF-100 is a synthetic version of human Vasoactive Intestinal Peptide (VIP), which decreases inflammation in the lungs. It is also known to protect the alveolar type II cells that act as an entry route for the SARS-CoV-2 into the lungs.

VIP is mainly concentrated in the lung and protects from various lung injuries. The FDA granted orphan drug designation to VIP for treating acute respiratory distress syndrome in 2001 and for pulmonary arterial hypertension in 2005.

Simultaneous to granting the latest fast track status, the FDA asked NeuroRx to submit a publicly-available expanded access policy.

This policy will enable physicians to request RLF-100 for treating patients in hospitals without participating in the ongoing Phase II / III clinical trials.

NeuroRx CEO and chairman Jonathan Javitt said: “We at NeuroRx are enormously appreciative of the FDA’s commitment to accelerating the development of any potential treatment for Covid-19. We hope to live up to the trust that has been placed in us by bringing a life-saving treatment to patients.”

The Phase II / III trials of RLF-100 are being performed at multiple medical centres, including the University of Miami, Houston Methodist Hospital, University of California-Irvine, NYU Langone Medical Center, and Rambam Healthcare Campus in Haifa, Israel.

This trial is meant for patients with critical Covid-19 and respiratory failure. It is expected that the drug candidate can reduce mortality and improve blood oxygenation by protecting alveolar type II cells from the SARS-CoV-2 virus.

NeuroRx and Relief Therapeutics begun enrolment earlier this month for a Phase IIb / III trial of RLF-100 to treat Covid-19-related acute respiratory distress syndrome.