The U.S. Food and Drug Administration (FDA) approved mirdametinib (Gomekli, SpringWorks) for the treatment of adult and pediatric patients aged two and older with neurofibromatosis type 1 (NF1) who have symptomatic plexiform neurofibromas (PN) that are not amenable to complete resection.
Gomekli is an oral, small molecule MEK inhibitor.
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 now.
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,” says Christopher Moertel, MD, Medical Director of Pediatric Neuro-Oncology and Neurofibromatosis Programs and Kenneth and Betty Jayne Dahlberg Professor of Pediatrics at University of Minnesota in Minneapolis, MN, 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. Eighty-eight 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
“We are excited to celebrate the extraordinary milestone of our partners and long-term friends at SpringWorks for the NF1-PN community. This FDA approval shows the power of collaboration to advance innovative science for drugs that may otherwise not have been taken forward,” says Annette Bakker, PhD, Chief Executive Officer of the Children’s Tumor Foundation. “When industry, researchers, and organizations like ours driving treatment innovation join forces, scientific progress moves faster, and patients gain access to the therapies they need. Every treatment approval is hard-won, built on research, persistence, and partnership. Today, that work delivers a critical new option for NF patients of all ages.”
“NF1-PN is a complex, devastating disease that affects not only individual patients, but entire families. Treatment advances are crucial to achieving better outcomes for patients and this FDA approval offers hope for NF patients and their families,” adds Kim Bischoff, Executive Director, NF Network.
SpringWorks is dedicated to helping patients with NF1-PN access GOMEKLI and to providing support throughout their treatment journey. The SpringWorks CareConnections™ program is a comprehensive patient support program that offers personalized support services and resources to eligible GOMEKLI patients, including insurance coverage information and access support, financial assistance and personalized educational and emotional support. Physicians and patients can contact 1-844-CARES-55 (1-844-227-3755) or visit www.springworkstxcares.com for more information.
GomekliI is available in 1mg and 2mg capsules and in a 1mg tablet for oral suspension, which dissolves easily in water. It is expected to be available through a specialty pharmacy and specialty distributor network in the United States within two weeks.
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.
