Treatment-free interval as a metric of patient experience and a health outcome of value for advanced multiple myeloma: the case for the histone deacetylase inhibitor panobinostat, a next-generation novel agent.

BACKGROUND: Patients with relapsed or relapsed/refractory multiple myeloma (RRMM) face poor treatment options by the time third-line therapy is required, despite advances in overall survival in recent years. Treatment free interval (TFI) and opportunities to maintain quality of life (QoL) have been cited as additional measures of efficacy that can be utilized in personalized treatment decisions. METHODS: The clinical health outcomes data from PANORAMA-1, the pivotal phase-3 trial comparing panobinostat-bortezomib-dexamethasone (PAN-BTZ-DEX) with placebo (PBO)-BTZ-DEX in RRMM patients treated with 1 to 3 prior regimens, retrospectively assessed TFI as a health outcome measure and metric of patient treatment experience relevant to the RRMM population. RESULTS: PAN-BTZ-DEX shows promise for prolonged TFI (mean TFI, 7.49 months; 95% CI, 6.02 to 8.71) compared to PBO-BTZ-DEX (mean TFI, 3.86 months; 95% CI, 3.08 to 4.60) for heavily pre-treated advanced RRMM patients), due to the short duration of therapy and extended progression free-survival. Further, QoL during the TFI was similar to baseline. CONCLUSIONS: PAN-BTZ-DEX provides a treatment regimen with prolonged TFI benefits previously not available for RRMM patients. TFI has not been traditionally measured in clinical trials, but should be assessed in prospective data collection given its value to payers, providers, and patients.