Inhibikase Therapeutics, a developer of products to treat infectious diseases with little or no resistance, has received Orphan Drug Designation for imatinib to treat progressive multifocal leukoencephalopathy (PML) from the FDA.

PML is a rare side effect of small molecule and antibody drugs given to patients with autoimmune diseases like arthritis and multiple sclerosis (MS); PML also occurs in 1%-3% of clinical AIDS patients. Certain drugs used to treat autoimmune disease suppress the ability of a patient to fight infection, particularly for the virus known as JC (for John Cunningham virus). JC lives inside most people, but when the immune system is suppressed, JC can occasionally migrate into the brain, “blowing up” certain brain cells that results in a debilitating loss of cognitive and motor neuron function, often culminating in a patient's death.

"MS can be a very disabling disease. To date, Tysabri is our most effective treatment," said neurologist Dr. Jeffrey B. English, director of Clinical Research at the MS Center of Atlanta.  "Unfortunately, it carries a risk of a life threatening brain infection that can lead to PML. There are ways to screen for PML early, but we have no effective treatments for this disease."

Imatinib, the active ingredient in the company's lead product IkT-001Pro, is a host-directed protein kinase inhibitor that disrupts the ability of JC virus to reproduce in the patient.  IkT-001Pro delivers imatinib to its targets using a proprietary technology that should reduce the dose and side effects of imatinib therapy while simultaneously enhancing imatinib's ability to suppress the causative virus of PML. Imatinib also is the active ingredient in the anti-cancer drug Gleevec, developed by Novartis and used to treat certain forms of blood and stomach cancer.

"The anti-JC virus activity of imatinib cannot be achieved by simply altering the frequency or amount of Gleevec given to patients," said Milton H. Werner, Ph.D., president and CEO of Inhibikase.  "Early trial work has already shown this. To succeed, we're talking reengineering how imatinib is absorbed and distributed in the body."

"The granting of Orphan Drug Designation is a pivotal milestone in the development of IkT-001Pro to treat this rare and debilitating illness," said Werner. "The designation will enable resources for continued development, but more importantly the designation provides an additional avenue for discussion with the FDA on the best path for bringing IkT-001Pro to market. PML is a rare side effect of at least 13 beneficial medications, and PML also may arise as a side effect of many more medications now in clinical development. IkT-001Pro, when administered as a companion therapeutic, could reduce the risks of these marketed and investigational treatments, thereby improving patient safety and focusing treatment decisions on the efficacy of the treatment, not just on the risk of an unintended and potentially fatal side effect."

"PML can pose a grave risk to people with MS and other disorders who use powerful immune-modulating therapies, and this risk often forces people to avoid or limit the use of otherwise very effective treatments," said Dr. Timothy Coetzee, chief advocacy, services and research officer at the National MS Society. "This Orphan Drug Designation by the FDA should provide incentive to develop a program focusing on the unmet need of a treatment for PML."