RLF-100 Given Fast Track Designation for Treatment of COVID-Related Respiratory Distress
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RLF-100 Given Fast Track Designation for Treatment of COVID-Related Respiratory Distress


It amazes me how quickly the numbers change each time I write about COVID-19, the novel coronavirus declared a global pandemic in March 2020. As of the afternoon of June 25, there are nearly 9.5 million diagnoses and 484,000 fatalities attributed to this virus. 2.43 million diagnoses, and 124,000 deaths, exist in the United States alone. While most people will not experience a severe reaction to COVID-19, some patients experience severe respiratory distress. Recently, a press release announced that the drug therapy (RLF-100) developed by NeuroRX received Fast Track Designation for the treatment of acute lung injury and acute respiratory distress syndrome stemming from COVID-19.


RLF-100 (Aviptadil) is a synthetic version of human Vasoactive Intestinal Peptide (VIP). First discovered in 1970, VIP is a 28-amino-acid peptide secreted in the intestinal tract and produced throughout the body. According to a variety of studies, VIP promotes anti-cytokine activity and reduces inflammation. Around 70% of VIP is bound to alveolar type II cells in the lungs, which promote oxygen transmission. For over 20 years, it has been used in clinical trials for sarcoidosis, asthma, allergies, pulmonary hypertension, and pulmonary fibrosis.

VIP was granted Orphan Drug Designation from the FDA twice: once in 2001 for the treatment of acute respiratory distress syndrome, and once in 2005 for the treatment of pulmonary arterial hypertension (PAH). Additionally, it received Orphan Drug Designation from the European Medicines Agency (EMA) for the treatment of acute lung injury and sarcoidosis.

In this case, RLF-100 is a patented injectable therapy that aims to both reduce inflammation in the lungs and protect alveolar type II cells. Many doctors believe that these cells are an entryway for COVID-19. Additionally, these cells allow for easy COVID-19 replication. Since alveolar type II cells have high VIP receptors, researchers believe RLF-100 could protect alveolar type II cells from COVID-19 damage.

What is Fast Track Designation?

According to the FDA, the fast track process is:

designed to facilitate the development, and expedite the review of, drugs to treat serious conditions and fill an unmet medical need.

The FDA has no distinct definition of serious conditions, but notes that drug therapies which treat these will improve:

factors such as survival, day-to-day functioning, and [disease progression.]

Examples of serious conditions include cancer, epilepsy, AIDS, and heart failure. In terms of filling an unmet medical need, the FDA defines this as:

providing a therapy where none exists or providing a therapy which may be potentially better than available therapy.

To receive a Fast Track designation, a drug therapy must:

  • Not have similarly severe side effects as existing therapies
  • Show improved outcomes and effectiveness compared to existing therapies
  • Increase efficacy while decreasing toxicity
  • Address an emerging health need

As a result, drugs (and their sponsors) receiving Fast Track designation are eligible for:

  • More frequent written communication and meetings with the FDA
  • Accelerated Approval and Priority Review
  • Rolling review – submitting completed BLA or NDA sections without waiting until every section is complete

Currently, RLF-100 is the subject of Phase 2/3 clinical trials to test its impact on blood oxygenation and mortality rates for hospitalized patients with respiratory failure from COVID-19. However, the FDA also requested that NeuroRX submit an expanded access policy so that patients outside of clinical trials can receive the drug.

What are your thoughts about RLF-100 receiving Fast Track Designation? Share your stories, thoughts, and hopes with the Patient Worthy community!

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.