Resolve Therapeutics, a company developing targeted therapies for underserved autoimmune diseases has announced that the US Food and Drug Administration (FDA) has approved a New Investigational Drug application for its lead candidate, RSLV-132, to initiate a Phase II clinical trial in patients with long Covid.

“It is estimated that up to 30% of patients infected with SARS-CoV-2, the virus that causes Covid-19, have ongoing, debilitating symptoms lasting several months up to one year following the acute phase of the infection. The most common symptom by far is severe, debilitating fatigue,” said Resolve Therapeutics.

Additionally, the firm states that some Covid-19 patients appear to have an autoimmune element to their infection, as seen in numerous studies that have observed the development of various autoantibodies following infection.

“Recent studies suggest that viral RNA and RNA-containing autoantibodies in the central nervous system of patients with long Covid may be causing inflammation resulting in fatigue and brain fog,” said the firm.

Resolve Therapeutics’ lead compound RSLV-132 is a novel targeted biologic drug designed to remove pro-inflammatory nucleic acids from the circulation of patients. These acids are thought to be one of the key triggers of multiple pro-inflammatory cascades. The compound consists of a catalytically active human RNase moiety fused to a human IgG1 Fc domain that digests RNA circulating in the blood, thereby decreasing inflammation.

“Based on our previous positive phase II clinical trial with RSLV-132 in autoimmune fatigue, we are hopeful that removing circulating RNA in long Covid patients will have a similar improvement in their fatigue and brain fog,” said Resolve Therapeutics CEO Dr James Posada.

Resolve Therapeutics is also evaluating RSLV-132 in a Phase II lupus study, and is preparing to initiate registration studies with RSLV-132 in patients with Sjögren’s syndrome.