BACKGROUND: Although targeted therapies (ie, tyrosine kinase inhibitors and antiangiogenesis agents) are effective as first-line treatment of metastatic renal cell carcinoma (mRCC), moderate-to-severe adverse events have been reported in clinical trials of these agents. Information concerning the economic burden of these events is limited.
OBJECTIVE: The purpose of this study was estimate the costs associated with adverse events in patients with mRCC receiving selected targeted agents indicated for first-line treatment of this disease.
METHODS: Retrospective study based on health care claims data for patients with mRCC, aged ≥18 years, receiving first-line treatment with targeted therapies. Adverse events of interest included abdominal pain, back pain, diarrhea, dyspnea, extremity pain, fatigue and/or asthenia, hand-foot syndrome, hypertension, lymphopenia, nausea and/or vomiting, neutropenia, proteinuria, and thrombocytopenia. Patients receiving care for these events were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis and procedure codes on health care claims. Costs were examined during a 30-day period, beginning with date of first mention of each event; nonevented patients similarly were assigned a shadow index date. We estimated total costs during 30 days after the index date for patients with and without adverse events, excluding the costs of targeted therapy.
RESULTS: Sixty-four percent of patients receiving targeted therapies for mRCC had health care encounters for ≥1 adverse events. Events that occurred with a frequency >20% included severe abdominal pain, back pain, fatigue and/or asthenia, and nausea and/or vomiting, respectively; 10% to 20% of patients had encounters for diarrhea, dyspnea, and extremity pain, respectively. Mean (SD) total costs of care during the 30-day, postevent period were substantially higher among patients with versus without adverse events-$12,177 ($19,621) versus $4070 ($8142). Adjusting for differences in baseline characteristics, the estimated cost difference was $11,373 (95% CI, $5286-$21,419).
CONCLUSIONS: Costs of adverse events are substantial in patients receiving targeted therapies, specifically, sunitinib, sorafenib, or bevacizumab, for mRCC. Efforts to prevent and/or better manage these events may reduce health care costs.
