A cancer diagnosis can be devastating, especially when treatment options come with their own risks. A study in the November 2016 issue of the New England Journal of Medicine found that Opdivo and Yervoy, two powerful checkpoint inhibitors that work by helping the body's immune system see and attack tumors, come with a risk of serious heart damage.
What Are Checkpoint Inhibitors?
Checkpoint inhibitors are part of the immunotherapy approach to cancer treatment. These medications are made of antibodies and are designed to cause a patient's immune system to attack cancer cells. The first checkpoint inhibitor was approved by the U.S. Food and Drug Administration (FDA) in 2011.
T cells, a type of white blood cell, are constantly patrolling the body looking for signs of infection. When they encounter a cell, they evaluate the proteins on the surface to determine if it's healthy.
If the T cells think the cell is infected or cancerous, they initiate an attack. The body's immune system then releases additional molecules to prevent the T cell attack from harming the surrounding normal tissues in the body. These molecules are sometimes called immune system checkpoints.
Tumor cells can sometimes create proteins that trick the body's T cells into thinking they are harmless. Checkpoint inhibitors help the T cells accurately recognize these cells as cancerous.
What Problems Did the Study Find?
The problem appears to be a result of the drugs becoming too aggressive in targeting tissue. When Opdivo and Yervoy are taken together, the immune system can sometimes attack the heart and surrounding muscles as well as the tumor. This can lead to dangerous inflammation and heart rhythm problems.
Cases of serious heart problems have been found among 0.09% of the 20,594 patients receiving one or both of the medications. Among people taking both medications, the complication rate was 0.27%
Two people discussed in the study died from complications after being treated with both drugs. Neither of these patients had a previous history of heart disease. Autopsies found that their bodies had rejected their hearts as if they'd received an incompatible organ transplant.
Do Other Medications Have Similar Risks?
Opdivo and Yervoy are manufactured by Bristol-Myers Squibb. The doses examined in the New England Journal of Medicine article were to treat patients with melanoma. Opdivo and Yervoy can also be used in different doses to treat certain lung cancers.
Genentech's Centriq to treat bladder cancer and Merck & Co.'s Keytruda to treat melanoma that has spread to the brain are two other examples of checkpoint inhibitors. The study didn't evaluate these drugs, but it's possible they could create similar issues. More research is needed to accurately determine the risks.
What Should Patients Do?
The study's authors cautioned that their findings don't necessarily mean patients should abandon this course of treatment. Immunotherapy is a promising approach to cancer treatment with the potential to save lives. People have been placed in lasting remission after treatment, despite previously being told their cancer was too advanced to respond to other therapies.
It's recommended that doctors take care to inform patients of all risks and provide close monitoring with extra cardiac testing. This includes echocardiograms and blood tests for troponin, a type of protein released by a damaged heart muscle. If trouble develops, steroids and other drugs that quell the immune response can be used to minimize complications.
As a patient, the best way to protect yourself is to be an active participant in your care. This includes:
- Ask questions about any medication or treatment you don't understand.
- Consider bringing a friend or family member to appointments to help you take notes.
- Take all prescribed medications as directed.
- Don't skip doctor's appointments.
- Call your provider if you don’t hear back about test results.
Experiencing complications from cancer treatment doesn’t necessarily mean your care provider is guilty of wrongdoing. However, Louisiana residents who believe they’ve suffered harm due to negligent treatment of their cancer are urged to contact Neblett, Beard & Arsenault to schedule a free, no-obligation case evaluation.