Hereditary transthyretin-mediated amyloidosis (hATTR) is a type of amyloidosis, which is a group of diseases where abnormal proteins (amyloids) build up and damage areas of the body. When the amyloids build up in the nerves, it causes nerve damage, also called polyneuropathy. This can lead to painful sensations, difficulty with movement and strength, changes in your digestive system and other bodily functions.
Amvuttra is the medicine that can reduce the amount of abnormal proteins in your body to help decrease symptoms and possibly prevent further nerve damage.
How Does Amvuttra Work?
Hereditary transthyretin-mediated amyloidosis (hATTR) is a rare, long-term, progressive disease that causes a buildup of a protein called transthyretin (TTR). TTR protein is made in the liver, brain, and retina of the eye. It helps to carry a thyroid hormone (thyroxine) and vitamin A (retinol) around the body. People with hATTR have a change (also called a mutation) in the TTR gene, which causes a change in the shape of the protein. A collection of the abnormal protein is called an amyloid deposit. These deposits collect in different areas of the body. See the table below for some symptoms.
hATTR Details | Symptoms |
| Symptoms Related to Nerves
Digestive Symptoms
Other Symptoms
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Your health care provider will focus on treating your symptoms and recommend lifestyle changes for diet and exercise. Until recent studies, there was only symptom management and heart or liver transplant. Early treatment with new medicines may help reduce the amount of abnormal TTR proteins. Amvuttra is a new medicine that works with your body to decrease the amount of TTR proteins made in the liver. This reduces the amount of amyloid deposits in the body and reduces your symptoms. Amvuttra may prevent or slow the progression of the disease.
How Should I Use This Medicine?
Amvuttra is injected under the skin by a health care provider. It is given four times per year. You and your health care provider will determine the best place to get your injection, like at their office, in a clinic, or at home.
How Was It Studied?
One study has been done to look at the safety and efficacy of Amvuttra for the treatment of polyneuropathy caused by hATTR when compared with patients who received placebo in a similar hATTR study. Placebo-controlled studies help researchers see differences in the benefit or harm of a medicine when compared with no treatment. Additionally, the study included a smaller group of people receiving patisiran, which is like Amvuttra and has been shown to improve polyneuropathy in hATTR.
To be included in the study, people had to have a diagnosis of hATTR and polyneuropathy symptoms. Neuropathy was defined by the following measures.
Neuropathy Impairment Score (NIS) |
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Polyneuropathy disability (PND) score |
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Karnofsky Performance Status score |
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All people in the study were between 18 and 85 years old and had a diagnosis of hATTR with polyneuropathy. The median age of people in the study was 60. Most people in the study were White (70%), 17% were Asian, 3% were Black, and 9% identified as Other. There were 26 different TTR variants (gene mutations).
People were assigned to receive either Amvuttra or patisiran for 18 months. Everyone in the study was instructed to take the recommended daily amount of vitamin A.
- Amvuttra was injected under the skin every three months.
- Patisiran was given by intravenous injection every three weeks.
Efficacy in the study was based on changes in the modified Neuropathy Impairment Score +7 (mNIS+7) at nine months for the people receiving Amvuttra when compared with people receiving placebo. This assessment tool measures symptoms of neuropathy, including strength, reflexes, sensation, nerve conduction, and standing blood pressure. The score ranges from 0 to 304, with higher scores indicating worse symptoms. This assessment is specifically used for monitoring neuropathy progression in hATTR. Other measures used to look at efficacy included quality of life using the Norfolk Quality of Life-Diabetic Neuropathy (QoL-DN) total score, walking speed based on a 10-meter walking test, and nutritional health by measuring modified body mass index.
What Benefits Were Seen in the Studies?
Amvuttra improved nerve function and quality of life when compared with placebo after nine and 18 months of treatment.
Change in mNIS+7 Score. After nine months, patients who received Amvuttra had improvements in their mNIS+7 score with a reduction in the total score by 2.2 points, compared with an increase in the score by 14.8 points for people who received placebo. After 18 months, there was a 29-point improvement difference in the mNIS+7 score for people who received Amvuttra compared with people who received placebo. This shows that Amvuttra helped to improve symptoms and function compared with continued progression of symptoms and declining function with placebo. Also, 48% of people who received Amvuttra had better nerve function compared with only 4% of people who received placebo.
About half of the people who received Amvuttra (57%) reported having a better quality of life and better ability to do daily activities compared with only 10% of people who received placebo. Walking speed stayed the same for people who received Amvuttra compared with decreased speed with placebo. Nutritional health improved for people who received Amvuttra compared with a decline in health for people who received placebo.
Your results may differ from what was seen in clinical studies. You and your health care provider should determine if the benefits outweigh any potential risks.
When Will Your Medicine Start Working?
After a few months, you may see improvements in the frequency or severity of your symptoms. Amvuttra gradually works over time, so you may not see quick changes in your symptoms. The long-term goal is to slow progression, so it is important to track the following symptoms and review with your health care provider.
- Strength or ability to walk without assistance
- Numbness or tingling sensations in the hands, feet, arms, and legs
- Reflexes
- Blood pressure control when standing
Always keep your appointments for the injections even if you don’t feel immediate changes in your symptoms. Your health care provider may also monitor your progress through different blood, imaging, or physical tests.
How to Prevent and Manage Side Effects?
The most common side effects of Amvuttra include pain in your arms or legs, pain in your joints, and shortness of breath. Tell your health care provider if you have any of these symptoms.
Additionally, Amvuttra may cause you to have lower vitamin A levels in your blood. Your health care provider may check your blood levels before starting Amvuttra and during treatment. Keep a normal, healthy diet with the recommended amounts of vitamin A. If you have changes in your vision, contact your health care provider.
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What Monitoring or Blood Tests Might I Need?
Before starting Amvuttra, your health care provider may perform blood tests to check your vitamin A levels and may repeat this test if you have changes in your vision.
What Types of Interactions Can Happen?
There are no known interactions between food, drinks, or other medicines. Tell your pharmacist or health care provider about all the prescription or OTC medicines, vitamins/minerals, herbal products, or other supplements you take or have recently taken. Contact your health care provider if you believe you are having side effects due to a potential interaction.
Getting Your Medicine: What to Expect
Amvuttra is usually given by a health care professional in a doctor’s office or clinic. If covered by your insurance, you may be able to have the injection given in your home. The manufacturer has a program to help support the process for you and your health care provider. There is also a financial assistance program from the manufacturer. Whether you are eligible depends on whether you have prescription insurance and what type of insurance you have or based on specific financial criteria. You can find out more at www.amvuttra.com or by calling 833-256-2748.
