Immunotherapy drugs are riskier for treatment of cancer patients, study suggests

Washington [US], December 13 (ANI): A study published in the European Heart Journal, found that the risks of heart problems in cancer patients are higher if they are treated with immunotherapy drugs, which can even lead to death from heart attack.
The researchers from Department of Cardiology at Herlev og Gentofte Hospital, Hellerup, Denmark revealed that the patients diagnosed with either lung cancer or malignant melanoma (a type of skin cancer), are treated with immune checkpoint inhibitors such as a programmed cell death-1 (PD1) inhibitors or cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) inhibitors.
The lead researcher of the study, Dr Maria D'Souza, a medical doctor and postdoctoral research fellow and her colleagues found that one year after starting treatment with immune checkpoint inhibitors, nearly 10% of 743 lung cancer patients on PD1 inhibitors (either pembrolizumab or nivolumab) experienced some sort of heart problem, ranging from heart failure, irregular heartbeat (arrhythmia), inflammation of the heart (myocarditis or pericarditis) or heart-related death, such as a heart attack.
The researchers found that patients treated with immune checkpoint inhibitors had a higher risk of heart problems compared to those who were not being treated in this way. Within six months of starting treatment, patients with lung cancer on PD1 inhibitors had double the risk of heart problems; malignant melanoma patients had a 4.3-fold increased risk if they were being treated with PD1 inhibitors and a nearly five-fold risk if they were receiving the CTLA-4 inhibitor.
After six months, the risk of heart problems increased slightly for lung cancer patients receiving PD1 inhibitors to a 2.3-fold risk. However, the risk was not statistically significant for melanoma patients on PD1 and decreased slightly to a 3.5-fold risk for those receiving the CTLA-4 inhibitor.
Dr D'Souza said: "We believe this is the first study of this size, based on nationwide data on hospital admissions and drug administrations, to investigate the risk of heart problems in lung and melanoma patients treated with immune checkpoint inhibitors."
According to doctors, they were able to quantify the one-year absolute risks of heart problems in patients with lung cancer treated with PD1 inhibitors and in patients with malignant melanoma treated with either PD1 or CTLA-4 inhibitors.
The findings claimed that the risks were higher than previously estimated by drug safety studies, "We also found that in comparison to patients who were not receiving immune checkpoint inhibitors, those who were being treated with them were at greater risk of heart problems," said Dr D'Souza.
The study's results showed that increased risk of heart problems continued beyond the initial six months.
"Although these drugs will have been tested rigorously in randomised controlled clinical trials before being approved for clinical use, they may still have an impact on organs, causing both common and very rare side effects. Large scale epidemiological studies like ours may contribute to our knowledge on this with more accurate estimates of how often these side effects occur when the drugs are used for clinical treatment," Dr D'Souza stated.
The researchers say they need to find out more about the side effects of immune checkpoint inhibitor treatment, and they have launched an observational clinical study of patients receiving these drugs in order to monitor heart function.
As this was an observational study, treatment with immune checkpoint inhibitors, factors such as age, sex and time, clinical factors with cancer was not randomised.
Another limitation was that the study was not able to analyse reliably the risk of blood vessel problems, such as stroke, because these can take longer to develop than the average follow-up time in the study (164-326 days).
In an accompanying editorial, Dr Tomas Neilan, director of the cardio-oncology program at Massachusetts General Hospital (Boston, USA), and colleagues "Longer-term steps include broadening collaborations with our oncology and pharmaceutical partners, and expanded clinical research efforts in parallel and based on innovative basic experimental insights. These and other steps are needed to move this study forward so we can improve cardiovascular outcomes among our cancer patients treated with an ICI." (ANI)