The randomized, placebo-controlled phase 3 PANORAMA 1 trial demonstrated that panobinostat, a potent pan-deacetylase inhibitor, in combination with bortezomib/dexamethasone (PAN/BTZ/Dex) resulted in significant prolongation of progression-free survival (PFS) of approximately 4 months compared with placebo plus bortezomib/dexamethasone (Pbo/BTZ/Dex) in patients with relapsed/refractory multiple myeloma (RRMM); the greatest PFS benefit was noted among patients who had received at least 2 prior regimens, including bortezomib and an immunomodulatory drug (IMiD).1 San-Miguel and colleagues presented the final overall survival (OS) analysis for the overall population and for the patient subgroup that had received ?2 prior regimens.2
In the overall population (n = 768), the median OS was similar between the 2 treatment cohorts (40.8 months vs 35.8 months; hazard ratio, 0.94; P = .5435). The OS results might have been confounded by a higher proportion of patients in the Pbo/BTZ/Dex treatment arm having received poststudy therapy (37.7% vs 48.8%) compared with the PAN/BTZ/Dex arm. In the patient subgroup that had received at least 2 prior lines of therapy, including bortezomib and an IMiD (n = 147), the median OS was numerically higher with PAN/BTZ/Dex treatment (25.5 months vs 19.5 months with Pbo/BTZ/Dex), but this difference did not reach statistical significance. A higher proportion of patients treated with Pbo/BTZ/Dex in this subgroup also had received poststudy therapy (35.6% vs 66.2%). Based on the final OS analysis of the PANORAMA 1 trial, the authors concluded that the significant PFS benefit achieved with PAN/BTZ/Dex treatment did not translate into a statistically significant OS advantage in either the overall population or the subgroup that had received at least 2 prior regimens, including bortezomib and an IMiD.
