Health-related quality of life (HRQL) associated with bortezomib compared with high-dose dexamethasone in relapsed multiple myeloma (MM): Results from APEX study

6535 Background: A large randomized phase 3 study (APEX) (Blood 2004;104: Abstract 336.5) in relapsed MM demonstrated significant clinical benefits (time to progression, response, and survival) associated with bortezomib therapy over high-dose dexamethasone, with comparable grade 3 and 4 toxicities. HRQL data were prospectively collected during the study. Methods: Two HRQL instruments (EORTC QLQ-C30 and FACT/GOG-NTX) were administered at baseline, weeks 6, 12, 18, 24, 30, 36, and 42, or until discontinuation of protocol treatment. Data were analyzed based on modified intention-to-treat analysis; 44 of 642 patients were excluded due to no baseline or no follow-up HRQL data. At baseline, the 2 treatment groups were comparable on demographic and clinical characteristics, NTX score, and on most EORTC scores. There were substantial missing HRQL data (from 12.5% at week 6 to 75.6% at week 42), primarily due to premature closure of the study and disease progression. Extensive statistical analyses were undertaken...