Everolimus in an mTOR inhibitor that is approved to be use in combination with exemestane for the treatment of postmenopausal patients with hormone receptor positive metastatic breast cancer. In this study we evaluate the patterns of care and complications associated with the use of this medication.
Breast cancer patients treated with everolimus between 2009-2014 were identified in the MarketScan database, a nationwide, employment-based database that includes claim data of employees and its dependents. The everolimus treatment pattern was evaluated. The frequency of toxicities as well as associated emergency room (ER) visits and hospitalizations between the first claim and 30 days after the last claim for everlimus were identified. Descriptive statistics were used.
In all, 2949 everolimus-treated breast cancer patients were identified; the median age was 60 years old. The median of cumulative days of supply was 112 days, at the time of the first claim the initial prescribed dose was 10mg in 76.9% of the patients; 2.7% received a dose of 7.5mg; 17.8% 5mg and 2.6% received a 2.5mg prescription. Compared to the initial dose, 77.3% of the patients maintained the same dose, 16.7% decreased it and 6% increased it. A total of 1488 patients (50.5%) had claims associated with known everolimus-related toxicities; nausea, vomiting and electrolyte imbalances were identified in 31.7% of the patients, 17.9% had metabolic toxicities, 11.9% hematological toxicities, 5.1% stomatitis, 4.7% rash and 0.4% had a claim for pneumonitis. A total of 644 patients (21.8%) were hospitalized or had an ER visit associated with the toxicities above.
Half of the patients receiving everolimus had a claim for a known everolimus-related toxicity and 21.8% were hospitalized or visited the ER while on everolimus for a toxicity. We cannot rule out that symptoms that lead to the hospitalizations/ER visit were not related to the breast cancer or to other causes, but this data provides real world information of the toxicities associated with everolimus treatment. The pattern of toxicities differs from what has been reported in clinical trials, it is possible that only serious toxicities are associated with a claim.
Legal entity responsible for the study
The University of Texas MD Anderson Cancer Center
Susan G. Komen, The Duncan Family Institute, CIPRIT
M. Chavez-Macgregor: I have received research support form Novartis (institutional). I have served as a Consultant for Pfizer and Roche. All other authors have declared no conflicts of interest.