AstraZeneca and MSD have announced that the U.S. Food and Drug Administration (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 3000 births, with highly-variable symptoms, including cutaneous (skin), neurological (nervous system) and orthopaedic (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 a neurological manifestation of NF1 and arise from nerve fascicles that tend to grow along the length of the nerve. PNs occur in approximately 20-50% of NF1 patients causing pain, motor dysfunction and disfigurement.
The potential benefit of selumetinib in NF1 is being explored in the US National Cancer Institute-sponsored Phase I/II SPRINT trial in paediatric patients with symptomatic NF1-related PNs. Phase II trial results are expected later in 2018.
The FDA’s ODD programme 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 US.
In addition to NF1, selumetinib is being investigated in the Phase III ASTRA trial of patients who are diagnosed with differentiated thyroid cancer following surgery and treatment with radioactive iodine. Selumetinib was granted ODD by the US FDA for the adjuvant treatment of stage III/IV DTC in 2016. It is also being explored as a monotherapy and in combination with other treatments in Phase I trials.
Sean Bohen, Executive Vice President, Global Medicines Development and Chief Medical Officer, at 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.”
Roy Baynes, Senior Vice President and Head of Global Clinical Development, Chief Medical Officer, at MSD Research Laboratories, said: “We’re looking forward to working with our colleagues at AstraZeneca to develop selumetinib and understand how it may benefit patients with NF1.”