Gomekli (mirdametinib) is the first treatment that is FDA approved for both adults and children with neurofibromatosis type 1 (NF1) who have plexiform neurofibromas (PN). Selumetinib, a drug that works similarly to mirdametinib, is only approved for children with this condition.
How Does Gomekli Treat NF1?
Mirdametinib is a medicine that helps people with NF1 who have PN, which are tumors that can't be fully removed by surgery. Gomekli works by blocking specific enzymes in the body called mitogen-activated kinases 1 and 2 (MEK1 and MEK2). These enzymes send signals that help tumors grow. By stopping these signals, Gomekli slows tumor growth and can shrink tumors. Since surgery isn’t always an option (because tumors grow around important body parts like nerves and organs), Gomekli gives people another way to manage their condition.
How Is Gomekli Used?
Your health care provider will decide the correct dose of Gomekli based on your height and weight.
Gomekli is taken by mouth twice a day, about 12 hours apart. The treatment follows a 28-day cycle, where you take Gomekli twice daily for 21 days, followed by seven days without Gomekli.
If you have trouble swallowing Gomekli capsules, the Gomekli tablets are grape-flavored and can be mixed with water to make an oral liquid. To prepare the liquid, add the prescribed number of tablets to a dosing cup with 5 to 10 milliliters of water. Gently swirl for two to four minutes until the tablets dissolve completely. The liquid will look white and cloudy. Drink it immediately from the cup or use an oral syringe. After drinking, add 5 to 10 milliliters of water to the cup, swirl to mix any leftover medicine, and drink it to ensure the full dose is taken. Throw away any leftover liquid that is not taken within 30 minutes of mixing.
How Was Gomekli Studied for the Treatment of NF1?
The ReNeu study evaluated the effectiveness and safety of Gomekli in 111 people 2 years old and older with NF1 with PN who had tumors that made them uncomfortable or affected their movement and that could not be removed by surgery. People in the study took Gomekli twice a day for 21 days, followed by seven days off, in repeating 28-day cycles. The dose of Gomekli was based on height and body weight. People continued treatment for up to 24 cycles or until their disease worsened or they had side effects that required stopping treatment. To measure effectiveness, people in the study received MRI scans to track tumor size.
A total of 58 adults and 56 children received Gomekli. The median (middle) age of adults was 35 (and ranged from 18 to 69); 64% were female, 85% were White, 9% were Black or African American, 3.4% were Asian, 3.4% were other races; and 1.7% were Hispanic or Latino. The median age of children was 10 (and ranged from 2 to 17); 54% were female; 66% were White, 20% were Black or African American, 9% were other races, 3.6% were Asian, 1.8% were Native American or Alaska Native; and 14% were Hispanic or Latino. More than half of the people in the study had progressive PN (tumors that have demonstrated continuous growth) at the start of the study (adults, 53%; children, 62%) and some had previously received treatment with a MEK inhibitor (adults, 7%; children, 11%). Prior surgery was reported in 69% of adults and 36% of children. People in the study commonly had other complications, including pain (adults, 90%; children, 70%), disfigurement or major deformity (adults, 52%; children, 50%), and problems with movement and coordination (adults, 40%; children, 27%).
What Were the Results of the ReNeu Study?
Results of the ReNeu study showed that 41% of adults and 52% of children experienced at least a 20% reduction in their tumor size. Additionally, some people saw an even greater shrinkage of their tumors, with 62% of adults and 52% of children having more than a 50% reduction in their tumor size. Among those who responded, tumor shrinkage started as early as four months. The median time to first tumor shrinkage was 7.8 months for adults and 7.9 months for children. Treatment response lasting at least 12 months was reported in 88% of adults and 90% of children. Treatment response lasting at least 24 months was reported in 50% of adults and 48% of children.
Your results may differ from what was seen in clinical studies.
How Strong Is the Evidence for Gomekli?
Based on the ReNeu study, Gomekli appears safe and effective for adults and children with NF1 who have PNs that cannot be removed by surgery. Experts in the management of NF1 suggest that MEK inhibitors play an important role in treating people with NF1.
How Long Until I See the Full Effects of Gomekli?
People who respond to Gomekli can have tumor shrinkage in as soon as four months. In the ReNeu study, the median time to first tumor shrinkage was between seven and eight months for adults and children. However, some people did not start to see tumor shrinkage until about 19 months after starting Gomekli.
Your results may differ from what was seen in clinical studies.
How Do I Know If Gomekli Is Working?
Your health care provider will check your progress using MRI scans to see if your tumors are shrinking. You may also feel less pain or have improved movement if the tumors were causing discomfort.
In the ReNeu study, people taking mirdametinib had less pain and a better quality of life from the beginning of the study to cycle 13. These improvements started as early as cycle 3 and lasted throughout the study.
By cycle 5 in adults:
- 55% to 59% had a meaningful drop in pain scores.
- 50% had less pain interference.
- 42% reported better quality of life.
By cycle 13 in adults:
- 78% to 79% had less pain.
- 58% had less pain interference.
- 37% reported better quality of life.
By cycle 5 in children:
- 57% had a meaningful drop in pain scores.
- 33% to 45% had less pain interference.
- 39% to 41% reported better quality of life.
By cycle 13 in children:
- 73% had a meaningful drop in pain scores.
- 50% to 60% had less pain interference.
- 45% to 47% reported better quality of life.
Also, 71% of adults and 79% of children said they felt at least a little better overall by the end of the study.
Your results may differ from what was seen in clinical studies.
What Are the Most Common Side Effects of Gomekli and How Can I Manage Them?
The most common side effects of Gomekli in adults who take the medicine include rash; nausea; vomiting; diarrhea; muscle, bone, or joint pain; and tiredness.
The most common side effects of Gomekli in children who take the medicine include rash; abdominal pain; nausea; vomiting; diarrhea; muscle, bone, or joint pain; headache; skin redness, swelling, or pain around the fingernails or toenails; and heart problems.
If you have nausea or vomiting, try eating smaller meals slowly. You can also try avoiding foods that are fried, greasy, or sweet; eating bland, low-fat foods like crackers, toast, and rice; and avoiding lying down after eating. If you experience diarrhea or vomiting, make sure to drink plenty of fluids to stay hydrated.
Getting plenty of rest and drinking enough water can help with headaches. Headaches and muscle or joint aches and pains can also be managed with over-the-counter pain-relieving medications such as acetaminophen or ibuprofen.
Depending on the severity of your side effects, your health care provider may pause, reduce the dose, or permanently discontinue Gomekli.
These are not all of the possible side effects of Gomekli. Talk with your health care provider if you are having symptoms that bother you. You can also report side effects to the FDA at 800-FDA-1088 (800-332-1088).
What Do We Know About Long-Term Safety?
Among 133 people who received Gomekli in clinical trials, 62% were exposed for one year or longer, 38% were exposed for two years or longer, and 12% were exposed for three years or longer. It is not known what long-term side effects may occur with extended therapy using Gomekli.
What Are Other Unique Considerations to Be Aware of During Treatment?
Gomekli can cause serious eye, heart, and skin problems.
Before you start taking Gomekli, your health care provider should check your vision with a comprehensive eye exam. Your health care provider will also monitor your vision regularly during treatment and check for any new or worsening vision problems, such as blurred vision.
Before you start taking Gomekli, your health care provider should also check your heart’s pumping ability (ejection fraction) using an echocardiogram. Your ejection fraction should be monitored every three months during the first year of treatment with Gomekli, and then as needed.
Gomekli may cause harm to a fetus. Your health care provider will do a pregnancy test before starting Gomekli treatment if you are able to become pregnant. If you are able to become pregnant, you should use effective birth control during treatment and for six weeks after the last dose. If you are able to get someone pregnant, you should use effective birth control during treatment and for three months after the last dose.
Is There Any Cost Assistance Available?
Yes. There is a cost savings and support program offered by the drugmaker that may allow you to pay $0 for your prescription. Whether you are eligible depends on whether you have prescription insurance and what type of insurance you have. You can find out more at www.gomekli.com/patient-support-program.
