Purpose: Bortezomib, a boronic acid dipeptide, has been recently introduced as a new approach to treating multiple myeloma (MM). The goal of this work was to evaluate the added value of patient-reported outcomes (PRO) in the interpretation of bortezomib clinical trial outcomes.

Patients and methods: Two hundred two patients with relapsed, refractory MM were treated with bortezomib as part of the SUMMIT (Study of Uncontrolled Multiple Myeloma Managed with Proteasome Inhibition Therapy) study. Patients were administered the following four PRO measures at several time points: the European Organisation for Research and Treatment of Cancer (EORTC) core Quality of Life Questionnaire (QLQ-C30) and the myeloma-specific module (QLQ-MY24), the Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue scale, and the Functional Assessment of Cancer Therapy (FACT)/Gynecologic Oncology Group (GOG) Neurotoxicity (Ntx) scale. Minimal important difference (MID) thresholds were used to define patients as improved, stable, or worsened. A survival analysis was conducted to assess the predictive power of PRO data.

Results: For the total population, there was a positive change between baseline and best end point. Consistent with the clinical responses, change in PRO scores showed statistically significant differences between response groups with PRO improvement in patients with complete response (CR) or partial response (PR), mostly stable scores in patients with minor response or no change, and deterioration in most scores for patients with progressive disease. Change in scores for neuropathy-related symptoms was reasonably stable. In contrast, fatigue scores significantly improved for patients with CR or PR. When various MID thresholds were applied, the proportion of improved patients exceeded 35% for several domains within all change group definitions. Moreover, survival analysis results demonstrated the additional prognostic information PRO data can provide to supplement clinical data.

Conclusion: This study demonstrated the complementary value for PRO assessments in further interpreting clinical response, the impact of adverse effects, and patient prognosis in clinical trials.