Side Effects of Mavacamten (Camzyos)

I was originally miss diagnosed as an asthmatic for 16 years, when my breathing kept getting worse. I was an arson investigator and former fire fighter. Then I experienced a sudden cardiac arrest. Mayo knew that I had HOCM.

Best to You!!
Prayers your way!!

Thank you for the encouragement! It sounds like you have had a tough time with this. I hope you have good quality of life now.

Sorry that happened but your doc didn’t order PYP scan to rule out Amyloidosis first? Can’t be treated with Camzyos if you have Amyloidosis...

I went to the Mayo Clinic. And had 5 days of testing to confirm the Amyloidosis.
I did 5 months is weekly shots, chemo and steroids.
My light chain numbers started @ 133, they went down to 44. I went back to Mayo, got a new oncologist/hematologist she changed things up a bit. I have since September taken 1 shot a month and take Venclexta daily. My numbers are finally in the normal range. I feel more like myself again.
I am waiting to see a cardiologist @Mayo that specializes in HCM & Amyloid. ( there are 8 @ Rochester). It’s funny I had never even heard of Amyloid and they have 8 cardiologists that specialize In it.

I saw your post when I searched pericardial effusion on this site. I also have a new pericardial effusion and have been on Camzyos over a year. Did yours resolve on its own and did they ever find out the cause? I am getting frustrated with the watch and wait approach to see if mine resolves. Thanks.

I should start by saying I am not a patient at the Mayo clinic. I live near a big city on the East Coast. My experience with Camzyos was about 50/50.

I gained about 50 lbs in the two years I was on it. I reported it to BMS pharmacovigilance. They argued with me. Really! They said it wasn't something reported during clinical trials and it must have been my habits that caused the weight gain.

I was told to stop taking it about four months ago. My ejection fraction dropped to about 40 between echo number 8 and echo number 9.

Coming off Camzyos was no picnic for me. The first two weeks were fine. The shortness of breath slowly returned. Then I began to have terrible anxiety and panic attacks. That coincided with the beginning of a bout of insomnia that lasted about 5 weeks. The insomnia was absolute torture. My psychiatrist and my PC consulted with my cardiologist and I was given some Klonopin and a sleep aid that did nothing. Sleep deprivation is literally a form of torture.

Again I reported this to BMS pharmacovigilance. Again, I was told that it was not consistent with the data that they had from the clinical trials. I call BS on BMS.

While I was on the drug, despite the weight gain, I had no acid reflux and I was able to run up stairs and not be short of breath. That was a treat after 30 plus years of HCM symptoms. But the insomnia that I suffered during the withdrawal was unbelievable. The Klonopin did not help me sleep, but it did decrease the anxiety. The sedative was useless.

During those weeks of insomnia, my work performance was severely impacted and I was unable to get the "Doctor's note" because insomnia was not something that was recorded in the clinical trials. My family had to tolerate my unbearable moodiness. I did start to drop weight though.

Hopefully what I reported has been recorded and added to other data from other patients. Hopefully future patients will get that information so they know what to expect.

I really want to trust doctors, but I've had so many terrible experiences in my 49 years, starting with my pediatrician laughing at me when I told him I didn't think I was getting enough air. I think other HCM patients can probably identify with that. 'Doctor when I'm out riding bikes with my friends. I can't breathe and keep up with them." "Well, son, you're just need to try harder."

I feel like my Camzyos experience has been an extension of that same conversation. Like I chose to gain the weight and I chose weeks and weeks of sleep deprivation.

I wish everyone the best. Please do your research. Ask every question. Be your own advocate. I know that Camzyos has been life changing for many patients. Good luck.

Hello @myidismine, and welcome to Mayo Clinic Connect.
Mayo Clinic Connect is for all patients or caregivers, you don't have to be a Mayo patient, which is so wonderful.
Gosh...
Your story is awful to hear. I feel sad that you are going through this challenge with HCM and the side effects of Camzyos. And the terrible time coming off it!! Not being able to sleep will definitely make you a little crazy!
It sounds like you had symptoms even as a child.
The thing about HCM and HOCM is that it really does take a doctor with knowledge in this condition to get you on the right treatment plan or surgery. So many times patients are not diagnosed correctly for years, and miss out on treatments for their true condition.

What is your next step? When do you see your doctor again?
You mention you live near a big city, but are you near a Center of Excellence?
Have you considered a second opinion?
Sorry for all the questions, but feeling like you have not been heard is difficult to deal with because we are supposed to trust our doctors.
You need to feel confident in your doctor, the plan they give you and deep down in your hypertrophic heart know you are in a good place.
Have you considered a opinion from the Mayo Clinic, Rochester? They are the leading experts in Hypertrophic Cardiomyopathy and the treatment of this weird disease.

I posted two links to Mayo Clinic HCM articles and one from the Hypertrophic Cardiomyopathy organization. All these make for good reading, even though you may already know much about your condition, it never hurts to learn more!
Your life is yours, and you owe it to yourself to find the best answers to your dilemma on Camzyos and next steps.
I know I asked before, but have you considered a second or third opinion?
https://www.mayoclinic.org/diseases-conditions/hypertrophic-cardiomyopathy/symptoms-causes/syc-2035019
https://www.mayoclinicproceedings.org/article/S0025-6196(24)00357-4/fulltext
https://www.4hcm.org/

Mavacamten was not for me. I tried it for 6 months and I felt awful. They also said that nobody reported bad side effects to them. LOL
Mavacamten is a cardiac myosin inhibitor.
So I signed up for a clinical trial of Aficamten. It was a double blind study. After only 2 days on Aficamten, I got very sick again....then realizing it was also acardiac myosin inhibitor. I was homebound for months.
No more cardiac myosin inhibitors for me. Lesson learned. It's not for everyone. ;-(

I have been on Camzyos 1 year and a half. I have some difficulty sleeping but not too bad. When I am under stress it is hard to sleep my 7 hours and I can only sleep 4 to 5 hours so I am very misserable those days. In general I tried not to worry about anything so I am able to sleep now 6.5 to 7 hours and I feel a lot better. No other side effects at all. I controlled my weight by walking 2 to 3 miles every single day. I eat very healthy diet now avoiding too many carbs. In general, I have been very lucky to have reduced my septum size from 2.3 cm (my heart almost fully blocked with limited blood circulation) to 1.3 cm all of that in a few weeks but I cooperated by having very strict died and a lot of walking so I lost 20 pounds in only 8 weeks which helped my condition. I am still on Camzyos and since my Medicare covers it in full, I am not planning to be out of it for the rest of my life since all the chest pressure is gone from the 1st week I started that medicine. I am very sorry that Camzyos is not for everyone but I am blessed by God it works really very well on me with almost no side effects other than slight insomnia. That insomnia I learned to control it by trying to be relaxed and happy which is not easy but I am still able to do that. God bless everyone and I hope all will get better of this inherited condition of Hypertrophic Obstructive Cardiomyopathy.