Researchers investigating phase 2/3 clinical trials for cancer therapies found that 34% of trials studied excluded patients with cardiovascular disease from enrollment. These findings, published in Circulation, coupled with the prevalence of cardiovascular disease in patients with cancer, suggest that researchers should critically evaluate trial eligibility criteria and open up patient access to clinical trials for cancer treatment to better reflect real-world populations.

Overall,
the researchers looked at 189 trials that included 97,556 patients and 123 US
Food and Drug Administration-approved cancer treatments. While trials that were studying drug
classes known to have cardiotoxicity reports (eg, immune checkpoint inhibitors)
were more likely to exclude patients with cardiovascular toxicity (odds ratio,
3.09 [1.64-5.81]), this trend was also seen in trials that were studying
treatments without previous reports of cardiovascular disease risk (eg, immunotherapies).
One in 3 trials excluded patients with cardiovascular disease; more than 50% of
trials studying breast cancer treatments excluded patients based on heart
disease risk status.

Common exclusion criteria included heart failure (28%), coronary
disease (27%), arrhythmias (23%), and recent myocardial infarction within 12
months (20%). Thirty-seven (58%) trials had multiple cardiovascular disease
factors listed as exclusion criteria.

The researchers also noted that measures for cardiovascular disease
exclusion were incongruous across trials that were evaluating treatments with
known cardiotoxicity risk. “Many trials employed non-discrete or ill-defined reasons
for the exclusion of CVD … with the availability of more objective and reliable
CVD measures, inconsistent application of discrete criteria is inadequate,” Janice
Bonsu, MPH, of the division of cardiology, Cardio-Oncology Program at The Ohio
State University Medical Center in Columbus, and colleagues wrote.

Standardized cardiovascular disease definitions that may allow for
more practical interpretation of drug safety were defined as left ventricular
ejection fraction less than 50% for heart failure and blood pressure higher
than 180/100 mmHg for hypertension.

Nearly 30%
of patients who are diagnosed with cancer have concomitant cardiovascular
disease, which is known to lead to poorer outcomes compared with cancer alone.

The authors
warned that the lack of inclusion of patients with cardiovascular disease in cancer
clinical trials may play a role in the inconsistency between rates of
cardiovascular disease events reported in the trial setting compared with those
seen in real-world patients, and encouraged the inclusion of patients with
cardiovascular disease across cancer clinical trials, when feasible.

Reference

Bonsu J, Charles L, Guha A, et al. Representation of patients with cardiovascular disease in pivotal cancer clinical trials. doi: 10.1161/CIRCULATIONAHA.118.039180

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This article originally appeared on Cancer Therapy Advisor