The U.S. Food and Drug Administration (FDA) has approved SpringWorks Therapeutics’ GOMEKLI (mirdametinib), SpringWorks’ MEK inhibitor, for the treatment of adult and pediatric patients 2 years of age and older with neurofibromatosis type 1 (NF1) who have symptomatic plexiform neurofibromas (PN) not amenable to complete resection. With the approval, SpringWorks was granted a rare pediatric disease priority review voucher (PRV) by the FDA.
“The NF1-PN patient community has a great need for more treatment options. With today’s approval, we are honored to serve both adults and children with NF1-PN and provide them with a therapy that has the potential to shrink their tumors and offer meaningful symptomatic relief,” said Saqib Islam, Chief Executive Officer of SpringWorks.
“We are grateful to each clinical trial participant, their families, the investigators, and the patient advocacy groups involved in the journey towards making GOMEKLI available in the U.S. I am proud that we are delivering on our commitment to patients with devastating diseases with our company’s second FDA approval in less than 18 months.”
NF1 is a genetic disorder that currently affects approximately 100,000 children and adults in the United States. Patients with NF1 have approximately a 30-50% lifetime risk of developing plexiform neurofibromas, or PNs, which are tumors that grow in an infiltrative pattern along the peripheral nerve sheath and that can cause severe disfigurement, pain and functional impairment.
There are approximately 40,000 people in the United States living with NF1-PN, the majority of whom are adults that have not had an approved medicine until GOMEKLI. Plexiform neurofibromas can transform into malignant peripheral nerve sheath tumors, an aggressive and potentially fatal disease. Surgical removal can be challenging due to the infiltrative tumor growth pattern of plexiform neurofibromas along nerves, and up to approximately 85% of plexiform neurofibromas are considered not amenable to complete resection.
“Patients with NF1-PN often face significant challenges with their health and have had limited treatment options to manage this devastating condition,” said Christopher Moertel, M.D., Medical Director Pediatric Neuro-Oncology and Neurofibromatosis Programs and Kenneth and Betty Jayne Dahlberg Professor of Pediatrics, University of Minnesota, and lead investigator of the ReNeu trial.
“It was very encouraging in the ReNeu trial to see that GOMEKLI provided deep and durable responses, with a manageable safety profile that enabled patients to stay on therapy. This approval represents an important advance, especially for adults who previously did not have an approved treatment.”
GOMEKLI was approved under Priority Review and SpringWorks received a rare pediatric disease priority review voucher from the FDA. GOMEKLI was previously granted Orphan Drug and Fast Track designations for the treatment of NF1-PN.
The FDA approval of GOMEKLI is based on results from the Phase 2b ReNeu trial, which enrolled 114 patients with NF1-PN ≥2 years of age (58 adults and 56 pediatric patients). GOMEKLI met the primary endpoint of confirmed objective response rate (ORR), as assessed by blinded independent central review, demonstrating a 41% ORR (N= 24/ 58) in adults and 52% in children (N=29/56). Tumor volume reductions were deep and durable; the median best percentage change in target PN volume was -41% (range: -90 to 13%) in adults and -42% (range: -91 to 48%) in children.
88% percent of adults and 90% of children with a confirmed response had a response of at least 12 months duration, and 50% and 48%, respectively, had a response of at least 24 months duration. Patients in both cohorts also experienced early and sustained significant improvements from baseline in pain, and quality of life, as assessed across multiple patient-reported outcome tools.
GOMEKLI demonstrated a manageable safety and tolerability profile. The most common adverse events (>25%) reported in adults receiving GOMEKLI were rash, diarrhea, nausea, musculoskeletal pain, vomiting and fatigue. The most common adverse events (>25%) occurring in children were rash, diarrhea, musculoskeletal pain, abdominal pain, vomiting, headache, paronychia, left ventricular dysfunction, and nausea.
GOMEKLI is available in 1 and 2 mg capsules and in a 1mg tablet for oral suspension, which dissolves easily in water.
SpringWorks’ Marketing Authorization Application for mirdametinib for the treatment of children and adults with NF1-PN was validated by the European Medicines Agency (EMA) and is currently under review; a decision is expected from the European Commission in 2025.
