FDA OKs first human trial of oral MS remyelination therapy PTD802

The U.S. Food and Drug Administration (FDA) has given Pheno Therapeutics the green light to begin clinical testing of PTD802, the company’s oral lead treatment candidate for boosting myelin repair in people with multiple sclerosis (MS) and other neurological diseases.

The experimental remyelination therapy aims to potentially restore lost function in MS patients and those with conditions marked by loss of myelin, the protective coating surrounding nerve fibers.

With the FDA’s clearance of its investigational new drug (IND) application, Pheno will now move forward with a first-in-human U.S. Phase 1 clinical trial. Such testing will first evaluate PTD802’s safety and tolerability in healthy volunteers, according to a company press release announcing the regulatory agency’s decision.

“FDA IND clearance is an important milestone for our PTD802 programme, and a step further toward our ultimate goal of providing an effective treatment for neurological diseases associated with demyelination,” said Fraser Murray, PhD, CEO of Pheno.

The developer received a similar authorization from U.K. regulators early last year.

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In MS, the immune system launches inflammatory attacks against myelin, the fatty coating that insulates nerve fibers and helps electrical signals travel efficiently. As myelin is lost, nerve fibers become damaged, disrupting communication between nerve cells and contributing to a wide range of MS symptoms.

While existing disease-modifying therapies can reduce inflammation and prevent or slow further damage, no approved therapy can directly restore myelin that has already been damaged or lost.

Given this, researchers have long sought therapies capable of promoting remyelination — essentially, the repair of damaged myelin and production of new myelin — as a way to reverse damage and possibly restore lost function.

PTD802 aims to stimulate body’s own myelin repair processes

PTD802 was designed as such a therapy, to address this unmet need. Developed by Pheno under an exclusive worldwide agreement with Belgium-based UCB, PTD802 is a selective small molecule antagonist, or inhibitor, of the GPR17 receptor protein.

This receptor acts as a brake on the maturation of oligodendrocytes, the cells responsible for producing myelin in the brain and spinal cord.

By releasing that brake, the therapy is designed to stimulate the body’s natural myelin repair processes and promote remyelination. According to Pheno, PTD802 may ultimately be used alongside existing MS treatments to better control disease progression. Also, by reversing demyelination, it may help patients potentially regain some lost function.

Pheno called the FDA decision a “milestone.”

Added Murray: “As the first company to gain approval to begin clinical trials for a selective GPR17 antagonist, we are proud to be leading the way, and believe this approach has the potential to offer real patient benefit, in MS and beyond.”