A study published in 2010 found that ipilimumab — an immunotherapy drug that blocks cytotoxic T-lymphocyte antigen-4, used against advanced melanoma — caused severe side effects in nearly 20 percent of patients.
Another study published in 2015 found adverse events in 24 percent of patients receiving ipilimumab, and when used in combination with nivolumab, another immunotherapy drug, severe adverse reactions occurred more than half the time.
Despite that, the study, funded by Bristol-Myers Squibb, concluded that the combination therapy “had an acceptable safety profile.”
Most recently, a study published this summer found 30 percent of patients receiving either pembrolizumab or nivolumab suffered “interesting, rare or unexpected side effects” from the treatment.
No less than 242 different side effects were noted in all, including skin, gastrointestinal, liver, endocrine and renal system effects, diabetes mellitus and pancreatitis. One-quarter of these reactions were severe or life-threatening and required hospitalization.
Novartis is now seeking approval for CTL109, a drug shown to be effective against pediatric B-cell acute lymphoblastic leukemia.6 In its phase 2 study, 82 percent of pediatric and young adult patients experienced complete remission.
However, for many the victory was short-lived. Six months later, 40 percent of them had relapsed. Some of the side effects were also severe. Fifteen percent of patients experienced grade 3 neurological and psychiatric events, including encephalopathy (abnormal brain function) and delirium.