US FDA Grants Orphan Drug Designation for Retrotope’s RT001 in the Treatment of Progressive SupraNuclear Palsy (PSP)
Retrotope announced today that the U.S. Food and Drug Administration (FDA) Office of Orphan Products Development granted orphan drug designation for its chemically-modified polyunsaturated fatty acid drug (RT001) for the treatment of Progressive SupraNuclear Palsy (PSP).
Physicians collaborating with Retrotope have previously received approval from the FDA’s Division of Neurology Products to test RT001 in Expanded Access trials of three patients having PSP, an orphan neurodegenerative disorder that causes progressive impairment of balance and walking; impaired eye movement, abnormal muscle rigidity; dysarthria; and dysphagia and eventual death. PSP is a serious neurodegenerative disease that profoundly affects the quality and length of life in adults. Patients are typically severely disabled within 3-5 years of disease onset. It affects an estimated 17,500 adults in the US. In addition to the motor deficits noted above, affected individuals frequently experience personality changes and cognitive impairment.
Symptoms typically begin after age 60 but can begin earlier. The exact cause of PSP is unknown, and is often misdiagnosed as Parkinson disease due to the similarity of symptoms in the early stage of disease. The cause of PSP is not known, but it is a form of tauopathy, in which abnormal phosphorylation and accumulation of the protein tau in the mid brain leads to destruction of vital protein filaments in nerve cells, causing their death. Most cases appear to be sporadic as an acquired tauopathy and there is no approved drug therapy.
A regionally specific increase in lipid peroxidation has been observed in PSP and mitochondrial structures and functions are compromised, leading to profound oxidation damage. RT001 is a chemically stabilized fatty acid that confers resistance to lipid peroxidation in mitochondrial and cellular membranes via a novel mechanism. RT001 has been shown to decrease levels of lipid peroxidation in PSP patient mesenchymal stem cells, and restore mitochondrial structure and function to damaged cells. As RT001 is distributed, as an essential fat, throughout tissues in human, it is expected to lower the amount of lipid peroxidation, restore normal mitochondrial function and prevent mitochondrial cell death.
Robert Molinari, Ph.D. CEO of Retrotope commented: “We want to sincerely thank the FDA’s OOPD for this designation which allows us accelerated review and more flexibility in pursuing this indication. We are also grateful to the researchers, patients and clinicians whose work contributed to the results supporting our filing an investigational new drug (IND) application to FDA in this terrible disease.” Peter Milner, MD, Chief Medical Officer of Retrotope, added, “PSP is a disease involving modification and dysfunction of tau protein. RT001’s mechanism of action both lowers lipid peroxidation and prevents mitochondrial cell death of neurons which is associated with disease onset and progression. Also RT001 has a synergistic downstream benefit in the pathophysiology of PSP. This orphan designation encourages clinical trials and rapid review of data from trials to treat this intractable disease.”
About the Orphan Drug Act The US FDA
Orphan Drug Act (ODA) provides orphan designation for drugs and biological products to treat a rare disease or condition upon request of a sponsor. Orphan drugs are usually defined as those products intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 200,000 people in the U.S., or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug. Orphan designation qualifies the sponsor of the drug for various development incentives of the ODA, including tax credits for qualified clinical testing.
A marketing application for a prescription drug product that has received orphan designation is not subject to a prescription drug user fee unless the application includes an indication for other than the rare disease or condition for which the drug was designated.
RT001 is a patented, first-in-class, orally available D-PUFA, a deuterated polyunsaturated fatty acid, that incorporates into mitochondrial and cellular membranes and stabilizes them. Retrotope and others have discovered that lipid peroxidation, the free-radical damage of polyunsaturated fats (PUFAs) in mitochondrial and cellular membranes, may be the primary source of cell death in several degenerative diseases. The presence of D-PUFAs (RT001) can help protect (“fireproof”) against this attack and potentially restore cellular health.