Hope for oHCM: A Closer Look at Camzyos Medication

Camzyos (generic name Mavacamten) is a medication that treats symptomatic obstructive hypertrophic cardiomyopathy (oHCM).

What is Obstructive Hypertrophic Cardiomyopathy?

Obstructive hypertrophic cardiomyopathy is an inherited disease that causes heart muscle cells to contract with too much force, like a tug-of-war with fifty people pulling on the rope instead of five.  Over time, this contraction overworks the heart muscle, leading to abnormal thickness and stiffening of the heart’s muscular walls and septum.  As a result, the heart is unable to relax after each heartbeat (aka diastolic dysfunction) and does not effectively pump blood around the body.  

This dysfunction causes symptoms of congestive heart failure and may ultimately result in heart attack or death.

There is no known cure for Obstructive Hypertrophic Cardiomyopathy, but Camzyos has proven to be a successful tool for reducing symptoms of the disorder.

How does Camzyos work?

Camzyos works by inhibiting the action of a protein called myosin that resides in heart muscle cells.  This inhibition allows the heart muscle to contract with a bit less force and to stay in its relaxed state for slightly longer with each beat.  As a result, the heart can more easily fill with blood during relaxation (diastole) and pump blood out to the body during contraction (systole).

Why is Camzyos Important in Treating oHCM?

Camzyos reduces the need for invasive procedures and has proven effective in cases where other medications failed to control symptoms or are not tolerated due to side effects.  Camzyos is also significant because it directly addresses the underlying cause of oHCM, rather than just interrupting downstream effects.

More Effective and Better Tolerated

Historically, treatment options for oHCM have included medicines such as beta blockers and calcium channel blockers.  While effective in some cases, these medicines can often interact poorly with other drugs or health conditions, making them difficult to use.  They also sometimes have side effects that discourage patients from taking them as prescribed.

Addresses the Root Cause

Beta blockers and calcium channel blockers also work in a less specific way to treat symptoms of oHCM, but don’t address the root cause.  Eventually, many patients have worsening of symptoms despite use of beta blockers and calcium channel blockers.

Less Invasive than Surgery

Surgical Reduction Therapy (SRT) procedures such as Myectomy or Alcohol Septal Ablation are available to some patients who fail to improve with medications.  The goal of these procedures is to debulk the overgrown heart muscle tissue in order to improve blood flow.  

Considered the gold standard of treatment for severe oHCM, these procedures are typically extremely effective at managing symptoms.  However, all medical procedures carry the risk of complication or infection.

The VALOR-HCM study demonstrated that many patients taking Camzyos improved enough that they did not end up needing an SRT procedure.

How To Take Camzyos

You should take Camzyos by mouth once daily.  Each of the four strengths comes in a different-colored capsule, making them easy to tell apart.  You may take it with or without food, and it should be swallowed whole, not crushed or divided.

Precautions

Camzyos should not be taken with aromatase inhibitors for breast cancer or with certain antibiotics and antivirals.  It can also interact with medications used to treat indigestion.  Camzyos is not safe to take while pregnant or breastfeeding.  

It is important to inform your medical provider of all prescribed medicines, supplements, and over-the-counter medicines you are currently taking.  You should also tell your provider if you are being treated for any other health conditions.

Side Effects

The most common side effects of Camzyos are dizziness or fainting.

Because Camzyos relaxes the heart muscle, it carries a serious risk of Systolic Heart Failure, in which the heart contracts with too little force.  This is expressed in test results by a reduced Ejection Fraction (the percentage of blood pumped out of the heart with each beat) to 50% or lower.  

It is essential that you let your provider know right away if you experience symptoms of Heart Failure while taking Camzyos.

These symptoms include:

• Shortness of Breath

• Chest Pain

• Swelling (Edema) in the Legs or Abdomen

• Dry Cough

• Smothering Sensation with Lying Flat

• Rapid Weight Gain (more than 2 pounds in 24 hours or 5 pounds in 1 week)

• Fatigue or reduced exercise tolerance

• Lightheadedness, dizziness, or fainting

Requirements for Starting Camzyos

Before prescribing Camzyos, your medical provider will perform a physical exam and specific tests to determine if you meet the guidelines for starting Camzyos.  These tests will include an Echocardiogram (Echo), bloodwork, and possibly other tests, such as a heart catheterization or a stress test.

Because of the risk of Systolic Heart Failure with Camzyos, your heart’s Ejection Fraction must be at least 55% or higher in order to start therapy.  You will also need to have your Ejection Fraction rechecked via Echo at specific intervals while taking Camzyos, to ensure a safe medication response.

When you first start taking Camzyos, you will need to have a physical exam and an Echo at 4 weeks, 8 weeks, and 12 weeks.  After week 12, the monitoring frequency will decrease to once every 6 months.

The US Food and Drug Administration (FDA) requires Camzyos to be prescribed and taken through a REMS Program.  REMS stands for Risk Evaluation and Mitigation Strategy.  It is a program designed by the drug’s developer and approved by the FDA to ensure the drug is safe and effective for the patients taking it.

The REMS program lays out strict requirements for prescriber, pharmacy, and patient education and training.  Only pharmacies that are certified by the REMS program are allowed to dispense the medication.  

The program also outlines schedules for periodic monitoring, such as the exams and Echos mentioned above.  

If medical providers or patients fail to comply with REMS requirements, the drug's approval may be withdrawn.

Your provider will assist you in REMS program enrollment and follow-up as part of prescribing Camzyos.

For more information on Camzyos, visit Camzyos.com

References 

Bristol Myers Squibb. (2025, April). Camzyos [package insert]. Retrieved November 17, 2025, from https://packageinserts.bms.com/pi/pi_camzyos.pdf.

Bristol Myers Squibb. (n.d.). Safety and side effects. CAMZYOS (mavacamten). Retrieved November 17, 2025, from https://www.camzyos.com/taking-camzyos/safety-and-side-effects.

Calcium puts myosin to work [video]. Khan Academy. Retrieved September 11, 2025, from https://www.khanacademy.org/science/health-and-medicine/circulatory-system/heart-muscle-contraction/v/calcium-puts-myosin-to-work. 

Canadian Agency for Drugs and Technologies in Health. (2023). Mavacamten (Camzyos) In CADTH reimbursement recommendation. Canadian Journal of Health Technologies, 3(5). https://www.ncbi.nlm.nih.gov/books/NBK594405/

Harris, C., Croce, B., & Munkholm-Larsen, S. (2017). Hypertrophic obstructive cardiomyopathy. Annals of cardiothoracic surgery, 6(4), 429. https://doi.org/10.21037/acs.2017.07.06. 

Iapoce, C.. (2022, April 2). Mavacamten Reduces Eligibility for SRT in Obstructive Hypertrophic Cardiomyopathy. Hcplive.com; HCPLive. https://www.hcplive.com/view/mavacamten-reduces-eligibility-srt-obstructive-hypertrophic-cardiomyopathy 

U.S. Food & Drug Administration.  (2025, May 20). Risk Evaluation and Mitigation Strategies | REMS.  Retrieved November 17, 2025, from https://www.fda.gov/drugs/drug-safety-and-availability/risk-evaluation-and-mitigation-strategies-rems. 

Assessed and Endorsed by the MedReport Medical Review Board