What is an immune checkpoint inhibitor?
Immune checkpoint inhibitors are a subtype of immunotherapy. It uses specific drugs, usually monoclonal antibodies, to block certain proteins on immune cells. This type of cancer treatment helps your own immune system recognize and attack cancer cells more effectively.
Immune checkpoint inhibitors are used to treat many cancers, including:
→ What is immunotherapy?
What is checkpoint inhibitor-associated myocarditis?
Checkpoint inhibitors can have a few cardiac side effects, but one that can be the most serious is myocarditis, or inflammation of the heart muscle. While mild cases of myocarditis can occur, very serious complications are also possible, including cardiogenic shock, fatal arrhythmias, ventricular tachycardia, ventricular fibrillation, and even death.
What is this clinical trial hoping to prove?
The standard treatment for myocarditis is corticosteroids, which reduce inflammation. This trial is looking to see if giving the drug abatacept, along with corticosteroids, is more effective for treating myocarditis and reducing major cardiac events. Abatacept is currently used to treat several rheumatologic conditions, including rheumatoid arthritis. It works by reducing the activity of certain T cells that cause inflammation.
How is the abatacept administered?
It's an infusion. For the trial, patients get their first two infusions while they are in the hospital, then they get two more once they are out of the hospital.
When people are hospitalized with myocarditis, what kind of symptoms do they have?
It can be a spectrum of things. Some people are completely asymptomatic, and it's only because we are checking their labs and we’re evaluating with imaging, like a cardiac MRI, that we catch myocarditis. Other people are having abnormal heart rhythms, and that makes us think about myocarditis. Or people can be having heart failure symptoms, and that makes us think about myocarditis. It can be a wide range, from asymptomatic to typical cardiac symptoms like chest pain and shortness of breath.
If the trial is successful, and abatacept is proven effective in treating checkpoint inhibitor-associated myocarditis, what will that mean for patients going forward?
If we can get approval for abatacept for this particular indication, it would streamline the way that myocarditis is treated. Right now, with so many people getting immunotherapy across the country in different clinical settings, it would be helpful if we could give clinicians an algorithm for how to manage checkpoint inhibitor-associated myocarditis across the board.
When these side effects come up, maybe you’re at a place where they’ve seen it before and know how to treat it, or maybe you are able to be transferred to a tertiary center. But the reality is that we should be at a place where we have the data to say, “This does work, so it should be available regardless of your setting.” Not all hospitals even carry abatacept.
Another result of the trial could be that we start abatacept early, once we identify myocarditis, so we minimize the amount of time before we start treating it. It will be interesting to see if abatacept is beneficial, what the long-term outcomes are, and if getting people the drug early is one of the things that makes the difference. Right now, we just don’t know.
