Myqorzo (aficamten) is an oral medicine used for people with obstructive hypertrophic cardiomyopathy (oHCM).
Hypertrophic cardiomyopathy (HCM) is an inherited condition (passed down in families) that causes the heart muscle to thicken. This can make it harder for your heart to properly pump blood to the rest of your body.
There are different forms of HCM. About two-thirds of all people with HCM have the obstructive form (oHCM), which can cause symptoms such as shortness of breath, tiredness, or chest pain.
Myqorzo is the second medicine approved by the FDA for the treatment of people with oHCM who have symptoms. It may improve symptoms and the ability to do physical activity.
How Does Myqorzo Work?
In people with oHCM, a heart muscle protein called myosin is more active than normal. This causes the heart muscle to contract with more force and have difficulty relaxing. As a result, the heart muscle gets thicker and stiffer. This can make it hard for the heart to fill up with blood as well and to pump blood out to the body. All of this can lead to heart failure, heart rhythm changes like atrial fibrillation, a stroke, or thromboembolism. Symptoms of oHCM worsen over time and can limit your daily activities.
Myqorzo binds to myosin inside the heart, which reduces the force with which the heart pumps blood. This helps open the pathway to let blood flow out of the heart more easily. These two actions help reduce the strain on the heart over time, which can help improve symptoms.
How Should I Take Myqorzo?
Myqorzo is a tablet that should be taken at the same time each day. Your health care provider will start you at the beginning dose. They may change your dose over time if you have an illness (like a serious infection) or heart rhythm changes, if you start or stop certain medicines, or based on symptoms or test results. Take Myqorzo as prescribed. Do not change your dose unless your health care provider tells you to.
What Do I Need to Know About Drug-Drug Interactions With Myqorzo?
There are many medicines that interact with Myqorzo. Some medicines, such as rifampin, should not be used at all with Myqorzo. Other medicines, including fluconazole, fluvoxamine, and voriconazole, may increase your risk of side effects while taking Myqorzo.
The dose of Myqorzo may need to be reduced, or additional tests may need to be ordered if you take certain medicines together with Myqorzo. It is very important to let your health care provider and pharmacist know about all medicines and over-the-counter medications that you take before starting and while taking Myqorzo.
What Side Effects Do I Need to Know About and How Can I Manage Them?
Myqorzo can cause high blood pressure, known as hypertension, and heart failure.
High blood pressure
It can cause symptoms such as severe headaches, chest pain, dizziness, trouble breathing, nausea, vision changes, confusion, ringing in your ears, or other symptoms. Talk to your health care provider if you have any of these symptoms or if you are getting high blood pressure readings at home. However, some people do not feel any symptoms at all if their blood pressure is high. Steps you can take to lower your risk for high blood pressure include eating a healthy diet, getting plenty of rest and exercise, avoiding tobacco and alcohol, managing your stress, and maintaining a healthy weight.
Heart failure
Your health care provider may do an echocardiogram before you start Myqorzo. This test is used to see how your heart muscle and valves are working. It specifically measures left ventricular ejection fraction (LVEF), which is the amount of blood leaving the left chamber (ventricle). This is where blood is pumped out of your heart to the rest of the body. A higher percentage is linked with better heart function. A lower percentage is a sign of damage, like heart failure.
Heart failure is a condition where the heart is not pumping blood as well as it should, which can be serious. Certain health conditions may have a higher risk of heart failure with Myqorzo. Tell your health care provider about all of your health conditions. Your health care provider may do tests to check your heart before starting Myqorzo. While taking Myqorzo, tell your health care provider right away if you have any of the following new or worsening symptoms of heart failure:
- Shortness of breath or trouble breathing, especially while lying down
- Swelling in your feet, ankles, or legs
- Unusually fast weight gain
- Unusual tiredness
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 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
How Was Myqorzo Studied for oHCM?
Myqorzo was studied in 282 people with oHCM. Their average age was 59 years, and about 59% were male, while the rest were female. About 79% of people in this study were White, 19% were Asian, 1% were Black, and 1% were classified as Other. People in this study received either Myqorzo or a placebo pill once a day for six months. Placebo pills do not contain any active medicine. All people in this study taking Myqorzo started with a dose of 5 milligrams (mg). After two, four, and six weeks, people had an echocardiogram; based on the results, the dose could be increased by 5 mg at each of these visits, up to a maximum dose of 20 mg. After eight weeks, most people were taking either 15 mg or 20 mg. The table below shows how many people were taking each dose after eight weeks.
| Myqorzo Dose | Percentage of People Taking This Dose After 8 Weeks |
|---|---|
| 5 mg | 3.6% |
| 10 mg | 12.9% |
| 15 mg | 35.0% |
| 20 mg | 48.6% |
The New York Heart Association (NYHA) classification system is used to classify the severity of heart failure based on your symptoms. See the definitions of each classification in the table below.
Class | Symptoms |
|---|---|
I | No limits on physical activity. Usual physical activity does not cause symptoms such as fatigue, fast heartbeat, or shortness of breath. |
II | Slight limits on physical activity, but people are comfortable while resting. Usual physical activity causes symptoms such as fatigue, fast heartbeat, or shortness of breath. |
III | A lot of limitations on physical activity, but people are comfortable at rest. Less than usual activity causes symptoms such as fatigue, fast heartbeat, or shortness of breath. |
IV | Symptoms of heart failure at rest. Any physical activity can cause further discomfort. |
To be in this study, people had to have oHCM, moderate heart failure (NYHA Class II and III), and reduced ability to exercise. About 76% of people were NYHA class II, and the rest were NYHA class III. People also had to have an LVEF of 60% or higher and a left ventricular outflow gradient (a measure of blood flow from the heart) of 30 mm Hg or higher at rest and 50 mm Hg or higher after the Valsalva maneuver.
People in the study were allowed to continue taking certain medicines for oHCM. Below is a summary of the oHCM medicines that people in the study continued to take:
- Beta-blockers (61%)
- Non-dihydropyridine calcium channel blockers (29%)
- Disopyramide (13%)
- No medicine for oHCM (15%)
What Were the Main Benefits of Myqorzo Based on the Study?
To see if Myqorzo worked, researchers looked at the peak oxygen consumption, which is the maximum amount of oxygen used by the body during exercise. In general, a higher peak oxygen consumption means that a person has a higher ability to exercise. The peak oxygen consumption at the end of the six-month study in people taking Myqorzo increased by about 1.8 mL/kg/min. People in the placebo group had no change in their peak oxygen consumption.
Although not the primary focus of the study, researchers also looked at other changes to see if Myqorzo was better than placebo. Examples of these changes include patient questionnaires about symptoms and improvements in their heart failure classification. The Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) is a scoring tool used to measure symptoms of people with heart failure. Higher scores mean better overall health status. In particular, the KCCQ-CSS scores increased by about 11 points at weeks 12 and 24 for people in the Myqorzo group compared to about 5 points for people in the placebo group. About 59% of the people taking Myqorzo had an improvement in their NYHA functional class, compared to about 24% of people taking a placebo.
Myqorzo was also well tolerated. In fact, fewer people taking Myqorzo (5.6%) reported having a serious side effect during the study compared to 9.3% of people taking a placebo. Only one person had to completely stop taking Myqorzo because of side effects, compared to two people in the placebo group.
The benefits seen in this study were seen regardless of sex, age, NYHA functional class, LVEF, or beta-blocker use. Keep in mind, your results may differ from those seen in clinical studies. You and your health care provider should determine if the benefits are greater than any potential risks.
How Do I Know if Myqorzo Is Working?
Even though Myqorzo starts working right away, it may take a few months for your symptoms to happen less often or become less severe. It is important to track your symptoms and let your health care provider know if they are getting better or worse. Your health care provider may also monitor your heart with physical, blood, or imaging tests. You should never stop your medicine without consulting your health care provider.
What to Expect When Getting Your Medication
Myqorzo is part of the FDA Risk Evaluation and Mitigation Strategy (REMS) program. This program is required by the FDA for certain medicines that may have serious side effects. The purpose of a REMS program is to make sure that you and your health care provider know about possible risks when taking the medicine and how to prevent or manage them. You should receive counseling from your health care provider about the risks of heart failure. You will need to get an echocardiogram to check your heart before starting and during treatment with Myqorzo. A Myqorzo Navigator can help you by:
- Explaining any cost or support options that may be available
- Teaching you about the REMS program and assisting you with the REMS requirements
- Coordinating your shipment of Myqorzo
- Providing ongoing lifestyle support and refill reminders
You can find out more information on the Myqorzo REMS program at this website or by calling 844-285-7367.
Is There Any Cost Assistance Available for Myqorzo?
There may be cost assistance to help you afford Myqorzo. You may have options even if you do not have health insurance. Your health care provider can help you get started, or you can call a Myqorzo Navigator from the Myqorzo & You Personalized Patient Support program at 833-MYQORZO (833-697-6796). You can also enroll online at hcp.iAssist.com.
