AZ’s selumetinib for rare disease gets FDA breakthrough status

AstraZeneca and Merck & Co/MSD’s selumetinib has been given a breakthrough designation from the US FDA for a rare paediatric disease, after failing to make the grade in other cancers. The MEK 1/2 inhibitor has picked up the breakthrough status for neurofibromatosis type 1 (NF1), an incurable genetic condition that affects one in 3,000-4,000 newborns worldwide and for which it also received an orphan drug designation from the EMA last year. NF1 can cause lumps under the skin, pigmentation and in around 25% of cases benign tumours on nerve sheaths called plexiform neurofibromas that can cause pain, motor dysfunction and disfigurement. Some patients also experience other complications such as learning difficulties, visual impairment, twisting and curvature of the spine, high blood pressure, and epilepsy. There are no approved therapies for the disease. The new status marks something of a renaissance for selumetinib, which has previously failed as a monotherapy in various solid tumours including thyroid cancer, lung cancer, and uveal melanoma.