Gomekli (mirdametinib)
An approved treatment for Neurofibromatosis Type 1.
The same compound appears under different names depending on the context. Here is how to identify Mirdametinib wherever you encounter it, plus the key facts at a glance.
- Generic name
- Mirdametinib
- Brand name
- Gomekli
- Development code
- PD-0325901
- Drug class
- MEK inhibitor
- Manufacturer
- SpringWorks Therapeutics (part of Merck KGaA, Darmstadt, Germany)
- How it's taken
- Taken by mouth twice daily at a dose of 2 mg/m² (based on body surface area), up to 4 mg twice daily.
The second FDA-approved MEK inhibitor for NF1 plexiform neurofibromas and the first approved for both adults and children aged 2 and older from the outset. Uses an intermittent dosing schedule (21 days on, 7 days off) that may improve tolerability.
Where Mirdametinib fits
Second MEK inhibitor approved for NF1 plexiform neurofibromas, expanding treatment options beyond selumetinib. Distinguished by its intermittent dosing schedule (21 on/7 off), CNS penetration, and adult-inclusive approval. Gives clinicians and patients a meaningful choice when selecting targeted therapy. Adults had no approved option before February 2025; selumetinib (Koselugo) was also approved for adults in November 2025.
How Mirdametinib works
Like selumetinib, mirdametinib blocks MEK1 and MEK2 to shut down the overactive RAS/MAPK signaling pathway that drives tumor growth in NF1. However, mirdametinib has a key advantage: it can cross the blood-brain barrier, meaning it can reach tumors in and around the brain and spinal cord.
Mirdametinib uses an intermittent dosing schedule of 21 days on treatment followed by 7 days off in each 28-day cycle. This 'on/off' approach was designed to maintain tumor-fighting activity while giving the body recovery time from side effects, potentially improving long-term tolerability compared to continuous daily dosing.
In the ReNeu trial, mirdametinib shrank tumors in both children and adults, with response rates of 52% in pediatric patients and 41% in adults. This made it the first MEK inhibitor to demonstrate efficacy in adult NF1 patients in a registrational trial.
Mechanism: Selective allosteric MEK1/2 inhibitor with CNS penetration, blocking the RAS/MAPK pathway to induce tumor shrinkage and apoptosis in NF1 plexiform neurofibromas
Side effects and safety
The most common side effects include acneiform rash and other skin reactions, diarrhea, nausea, vomiting, and musculoskeletal pain. Eye problems (blurred vision, retinal changes) occurred in approximately 28% of adult patients and require regular monitoring. Decreased heart pumping function (left ventricular ejection fraction) was reported in 16% of adults and about 27% of children, so an echocardiogram is done before starting, every 3 months in the first year, and then as needed. Rash was very common (92% of adults). It can harm an unborn baby: pregnancy status should be checked before starting, females who can become pregnant should use effective birth control during treatment and for 6 weeks after the last dose, and males with female partners who can become pregnant should use it for 3 months after the last dose. The intermittent dosing schedule allows a recovery week each cycle, which may help manage cumulative side effects.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Mirdametinib
Taken by mouth twice daily at a dose of 2 mg/m² (based on body surface area), up to 4 mg twice daily. It comes as capsules or as tablets that can be dissolved in water for people who cannot swallow capsules. The dosing schedule is 21 days on treatment followed by 7 days off in each 28-day cycle. Capsules should be taken with or without food. Treatment continues as long as the patient is benefiting.
Availability and cost
Only available as the brand-name product.
Help paying for Gomekli
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Commercially insured patients may pay as little as $0 per 21-day supply; may also cover some treatment-related tests and visits. Annual maximums apply.
For: private insurance · source - Free medicine program
Patient Assistance Program may provide Gomekli at no cost to uninsured patients, those lacking coverage, or with financial hardship; household income limits apply.
For: no insurance, underinsured · source - Insurance and case manager help
Nurse Advocates help with insurance coverage, financial options and treatment questions.
The official page does not say who qualifies. Ask the program. · source
Good to know: Program site is springworkstxcares.com (844-CARES-55). SpringWorks is now part of Merck KGaA, Darmstadt, Germany.
- From a charity · NORD RareCareNeurofibromatosis Type 1 Medical Assistance fundOpen
Pays for: Medical and medication costs.
The foundation says: “Accepting Applications” - From a charity · NORD RareCareNeurofibromatosis Type 1 Premium Copay Assistance fundOpen
Pays for: Insurance premiums and copays.
The foundation says: “Accepting new applications and re-enrollments for current year” - From a charity · The Assistance FundNeurofibromatosis fundOpen
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.” - From a charity · TotalAssist (formerly PAN Foundation)Neurofibromatosis fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $6,400 per year. Requires health insurance (any kind).
Clinical trial results
The ReNeu Phase 2b trial enrolled 114 patients (both children aged 2 and older and adults) with NF1 and symptomatic plexiform neurofibromas that could not be fully removed by surgery. The confirmed objective response rate was 41% in adults and 52% in children. This was the first trial to demonstrate MEK inhibitor efficacy in adults with NF1 plexiform neurofibromas, leading to FDA approval in February 2025 for patients aged 2 and older with no upper age limit.
Development history
Mirdametinib was originally developed by Pfizer as PD-0325901 and studied in oncology. SpringWorks Therapeutics licensed the compound and repositioned it for NF1 plexiform neurofibromas, recognizing the unmet need in adults (who had no approved option at the time). The ReNeu trial was designed to include both adults and children from the start. FDA approval came on February 11, 2025, making mirdametinib the second MEK inhibitor approved for NF1 and the first with a broad age range from the initial approval.
Explore Neurofibromatosis Type 1 trials
Other Neurofibromatosis Type 1 treatments
Common questions about Mirdametinib
▸What is Mirdametinib (Gomekli)?
The second FDA-approved MEK inhibitor for NF1 plexiform neurofibromas and the first approved for both adults and children aged 2 and older from the outset. Uses an intermittent dosing schedule (21 days on, 7 days off) that may improve tolerability.
▸How does Mirdametinib work?
Like selumetinib, mirdametinib blocks MEK1 and MEK2 to shut down the overactive RAS/MAPK signaling pathway that drives tumor growth in NF1. However, mirdametinib has a key advantage: it can cross the blood-brain barrier, meaning it can reach tumors in and around the brain and spinal cord.
Mirdametinib uses an intermittent dosing schedule of 21 days on treatment followed by 7 days off in each 28-day cycle. This 'on/off' approach was designed to maintain tumor-fighting activity while giving the body recovery time from side effects, potentially improving long-term tolerability compared to continuous daily dosing.
In the ReNeu trial, mirdametinib shrank tumors in both children and adults, with response rates of 52% in pediatric patients and 41% in adults. This made it the first MEK inhibitor to demonstrate efficacy in adult NF1 patients in a registrational trial.
▸What are the side effects of Mirdametinib?
The most common side effects include acneiform rash and other skin reactions, diarrhea, nausea, vomiting, and musculoskeletal pain. Eye problems (blurred vision, retinal changes) occurred in approximately 28% of adult patients and require regular monitoring. Decreased heart pumping function (left ventricular ejection fraction) was reported in 16% of adults and about 27% of children, so an echocardiogram is done before starting, every 3 months in the first year, and then as needed. Rash was very common (92% of adults). It can harm an unborn baby: pregnancy status should be checked before starting, females who can become pregnant should use effective birth control during treatment and for 6 weeks after the last dose, and males with female partners who can become pregnant should use it for 3 months after the last dose. The intermittent dosing schedule allows a recovery week each cycle, which may help manage cumulative side effects.
▸How is Mirdametinib taken?
Taken by mouth twice daily at a dose of 2 mg/m² (based on body surface area), up to 4 mg twice daily. It comes as capsules or as tablets that can be dissolved in water for people who cannot swallow capsules. The dosing schedule is 21 days on treatment followed by 7 days off in each 28-day cycle. Capsules should be taken with or without food. Treatment continues as long as the patient is benefiting.
▸Is Mirdametinib FDA approved?
Yes, Mirdametinib (Gomekli) is FDA approved (2025) for the treatment of Neurofibromatosis Type 1.
▸Is mirdametinib approved for adults with NF1?
Yes. Mirdametinib (Gomekli) was FDA-approved in February 2025 for patients aged 2 and older with no upper age limit, making it the first MEK inhibitor approved for adults with NF1 plexiform neurofibromas from initial approval.
▸What is the dosing schedule for Gomekli?
Gomekli uses an intermittent schedule: 21 days on treatment followed by 7 days off in each 28-day cycle. This on/off approach may improve tolerability compared to continuous daily dosing.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. Food and Drug Administration · February 11, 2025. FDA approves mirdametinib for adult and pediatric patients with neurofibromatosis type 1 who have symptomatic plexiform neurofibromas not amenable to complete resection. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-mirdametinib-adult-and-pediatric-patients-neurofibromatosis-type-1-who-have-symptomatic
- SpringWorks Therapeutics. Mirdametinib in NF1 Plexiform Neurofibromas — ReNeu Phase 2b. https://www.springworkstx.com/pipeline/mirdametinib
- SpringWorks Therapeutics. SpringWorks CareConnections Patient Support. https://www.gomekli.com/patient-support-program