Orphan Drug Status Granted to MediciNova’s Krabbe Disease Therapy

The U.S. Food and Drug Administration (FDA) granted orphan drug status to an investigational therapy being developed by MediciNova, Inc. to treat Krabbe disease. The company expects MN-166 (ibudilast) to become a treatment option for the rare genetic degenerative condition that affects children at early age, causing the weakening of the muscles and often killing patients before two years old.

The orphan drug designation is granted by the FDA to drugs that show promise in becoming safe and effective options to prevent, diagnose or treat rare conditions that affect fewer than 200,000 people in the country. The status makes MediciNova eligible to receive seven years of marketing exclusivity after FDA approval of MN-166, among other benefits such as reduced fees.

“We are very pleased to receive orphan-drug designation for MN-166 for Krabbe disease, a rare disease for which hematopoietic stem cell transplantation, the only currently available treatment option, is not without potential risk to the patient and is limited in efficacy,” stated the president and CEO of MediciNova, Yuichi Iwaki, MD, PhD.

The product candidate is a first-in-class, orally bioavailable, small molecule phosphodiesterase (PDE) -4 and -10 inhibitor and a macrophage migration inhibitory factor (MIF) inhibitor developed to eliminate pro-inflammatory cytokines and enhance neurotrophic factors. The anti-neuroinflammatory and neuroprotective capacities of MN-166 were already demonstrated in pre-clinical and clinical studies, making it a promising option to treat neurodegenerative conditions.

The company had already submitted an investigational new drug (IND) application for MN-166 to the U.S. Division of Neurology Products (DNP), while it is being commercialized for the treatment of  post-stroke complications and bronchial asthma in both Japan and Korea since 1989. “As we already have an open IND, we plan to finalize a protocol and submit it to FDA in order to conduct a clinical trial of MN-166 in Krabbe disease,” added Iwaki.

There is currently no cure for Krabbe disease, a rare condition with four clinical subtypes according to age of onset. The majority of patients develop the first symptoms during the first six months of life, including irritability, limb spasticity, absent reflexes, muscle weakness, feeding difficulties, episodes of fever with no sign of infection, stiff posture, and slowed or regressed neurocognitive development. With the progression of the disease, the symptoms become more severe, and most infants die before the two years.

In addition to the type 1 early infantile form of the disease, there are also types 2 to 4, which include only about 10% of the patients and is characterized by the onset of symptoms later in life, until adulthood. Progressive loss of vision, difficulty walking, decline in thinking skills, loss of manual dexterity, and muscle weakness are among the most common initial symptoms, and despite the severity of the disease, late-onset Krabbe disease patients have a longer life expectancy than children.