Measuring cardiopulmonary complications of carfilzomib treatment and associated risk factors using the SEER-Medicare database

Background: Carfilzomib improves survival in patients with recurrent myeloma. Given the strict eligibility criteria in clinical trials, the actual frequency of cardiac adverse events (CAEs) and pulmonary adverse events (PAEs) and the risk factors associated with these AEs in the general population need to be established. Methods: The authors extracted myeloma cases in the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database from 2000 through 2013 and corresponding claims through 2014. They then identified patients who received carfilzomib during their disease course. Subsequently, the International Classification of Diseases, Ninth Revision (ICD-9) was used to identify all the codes for CAEs, PAEs, and respiratory infections associated with carfilzomib use. Preexisting diagnoses corresponding to the CAEs and PAEs of interest were excluded to distinguish toxicity from comorbidity. Multivariate Cox regression was performed to determine those variables independently associated with the development of CAEs and PAEs. Results: Of the 635 patients analyzed, the median age was 72 years (range, 36-94 years); 55% of the patients were male and 79% were white. The median duration of carfilzomib treatment was 58 days (range, 1-716 days). Overall, approximately 66% of the patients had codes for either CAEs or PAEs. In terms of CAEs, approximately 22% of patients developed hypertension, 15% developed peripheral edema, and 14% experienced heart failure. With regard to PAEs, approximately 28% of patients developed dyspnea, 15% developed cough, and 15% developed pneumonia. Only chronic obstructive pulmonary disease (COPD) was found to be independently associated with the development of CAEs. Patients with preexisting COPD were found to have a 40% increase in their hazard of developing CAEs (adjusted hazard ratio, 1.40; 95% CI, 1.03-1.90). Conclusions: In older adults with myeloma who are undergoing treatment with carfilzomib, new cardiac and pulmonary diagnoses were common. Patients with preexisting COPD were found to be at an increased risk of developing CAEs.