New anticancer agents may lead to greater toxicity, discontinuation rates than standard therapy

New anticancer agents that offer improved efficacy compared with standard therapy also increase morbidity and treatment-related mortality, according to a meta-analysis published August 20 in the Journal of Clinical Oncology.

Eitan Amir, MD, of the Division of Medical Oncology, Princess Margaret Hospital, Toronto, Ontario, and colleagues, identified and analyzed 38 randomized clinical trials (RCTs) evaluating anticancer agents for the treatment of solid tumors between 2000 and 2010. They reviewed the three end points of safety and tolerability in the RCTs: treatment-related death, treatment-discontinuation related to toxicity, and grade 3 or 4 adverse events.

“Compared with controls, the odds of toxic death was greater for new agents (OC, 1.40; 95% CI, 1.15-1.70; P<.001) as were the odds of treatment-discontinuation (OR, 1.33, 95% CI, 1.22-1.45; P<.001),” the authors reported.

Patients taking the new agents also experienced more grade 3 or 4 adverse reactions, including nonhematologic events such as diarrhea, skin reactions, and neuropathy, Dr. Amir noted.

The authors concluded, "The balance between efficacy and toxicity may be less favorable in clinical practice because of selection of fewer patients with good performance status and limited comorbidities. Patients’ baseline health characteristics should be considered when choosing therapy."