Mirdametinib for treating neurofibromatosis type 1-associated plexiform neurofibromas

Mirdametinib is in development for the treatment of adult and paediatric patients with neurofibromatosis type 1 (NF1) associated inoperable plexiform neurofibromas (PNs) that are causing significant morbidity. NF1 is a common genetic tumour predisposition syndrome which frequently leads to different types of peripheral nerve sheath tumours. 5-15% of individuals with NF1 will develop PNs, a type of tumour in the sheathing that surrounds and protects the nerves, which can develop almost anywhere within the body. Symptoms depend on the location and size of the tumour, with larger tumours causing nerves to thicken and change shape, which can affect the structure and function of nearby bones, skin, and muscle. As such, symptoms can vary widely between individuals, with common symptoms including severe pain, mobility problems, vision and hearing loss, high blood pressure, as well as physical development issues. Until recently, the only intervention options for NF1 associated PNs was surgery, which is often difficult or sometimes not possible due to the location of the growth, with few pharmacological alternatives.