The study is a new piece of evidence supporting previous concerns that this type of treatment may increase risk for autoimmune disorders.
The case report, “Relapsed Myasthenia Gravis after Nivolumab Treatment,” was published in the journal Internal Medicine.
Opdivo is an immunotherapy used to treat several cancers. It works by reactivating the ability of immune cells to detect and effectively kill cancer cells. Specifically, Opdivo inhibits a protein called programmed cell death (PD-1) that is used by cancer cells as an immune evasion strategy.
The downside of such therapies is that a hyperactivation of the immune system may turn it against the body’s healthy tissues, leading to autoimmune disorders.
Researchers report the case of a 62-year-old Japanese woman diagnosed with cancer in the trachea. She was submitted to cytotoxic chemotherapies that resulted in a decrease in the tumor’s mass, but the disease progressed and reached the lymph nodes.
Because she developed side effects from the previous chemotherapy regimen, clinicians conducted a thorough medical history, confirming she had no history of any autoimmune diseases, including myasthenia gravis, researchers wrote.
The patient was put on Opdivo. After two rounds of treatment the size of her lymph nodes decreased, a sign that the treatment was working. However, the patient started feeling fatigued and reported muscle weakness 25 days after the first round of Opdivo.
Blood tests showed a significant increase in the levels of the creatine phosphokinase enzyme, a marker of tissue damage, although her levels were normal before starting Opdivo.
The patient was immediately admitted to the hospital with a diagnosis of polymyositis, a rare and gradually progressive autoimmune inflammatory disease of skeletal muscle, accompanied with damaged skeletal muscle (rhabdomyolysis) due to Opdivo.
She began treatment with corticosteroids, which gradually improved her symptoms and brought the levels of creatine phosphokinase back to normal.
During this period, although the patient was reported to have no history of autoimmune disease, clinicians realized that she had been treated 15 years before for ocular type myasthenia gravis.
The patient is being followed closely without any treatment, researchers said, but the tumor size and metastasis have remained the same size.
“This was a rare case in which [Opdivo] treatment was strongly associated with the exaggeration of a ‘pre-existing’ autoimmune disease (in our case, [mystaenia gravis]),” researchers wrote.
They also emphasized the importance of paying close attention to the patient’s personal medical history before administering this therapy.
“Underlying autoimmune disorders require close monitoring, but they might not be an absolute contraindication to [Opdivo] treatment in the era of personalized medicine,” the study concluded.