FDA approves ODD for selumetinib for treating neurofibromatosis type 1 (NF1): Merck

AstraZeneca and Merck, known as MSD outside the U.S. and Canada, announced that the U.S. FDA has granted Orphan Drug Designation (ODD) for selumetinib, a MEK 1/2 inhibitor, for the treatment of neurofibromatosis type 1 (NF1).

NF1 is an incurable genetic condition that affects one in 3,000 births with highly-variable symptoms including cutaneous (skin), neurological (nervous system) and orthopedic (skeletal) manifestations. NF1 can cause secondary complications including learning difficulties, visual impairment, pain, disfigurement, twisting and curvature of the spine, high blood pressure and epilepsy.

Plexiform neurofibromas (PNs) are tumors that arise from nerve fascicles and tend to grow along the length of the nerve. PNs, a neurological manifestation of NF1,occur in approximately 20-50 percent of NF1 patients causing pain, motor dysfunction and disfigurement.

Sean Bohen, executive vice president, global medicines development and chief medical officer, AstraZeneca, said, “Neurofibromatosis type 1 is a devastating condition that can lead to life-threatening complications. There is no known cure for neurofibromatosis and there are limited treatment options to manage symptoms.”

Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories, said, “This is an important collaborative effort with our colleagues at AstraZeneca addressing an area of significant unmet medical need to potentially benefit patients with neurofibromatosis type 1.”

The potential benefit of selumetinib in NF1 is being explored in the U.S. National Cancer Institute-sponsored phase 1/2 SPRINT trial in pediatric patients with symptomatic NF1-related PNs. Phase II trial results are expected later in 2018.

The FDA’s ODD program provides orphan status to medicines that are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the U.S.

In addition to NF1, selumetinib is being investigated in the phase 3 ASTRA trial of patients who are diagnosed with differentiated thyroid cancer (DTC) following surgery and treatment with radioactive iodine. Selumetinib was granted ODD by the US FDA for the adjuvant treatment of stage 3/4 DTC in 2016. It is also being explored as a monotherapy and in combination with other treatments in phase 1 trials.