OBJECTIVES : Despite significant advances in therapy, prognosis for patients with multiple myeloma (MM) remains relatively poor, with a highly refractory disease course. Selinexor, a novel oral selective inhibitor of nuclear export, was recently approved for use in relapsed refractory MM. A recent phase 2b, single-arm, open-label, multicenter trial evaluated the efficacy and safety of selinexor and dexamethasone in patients with MM pentarefractory to previous therapies. Quality of life (QOL) was measured using the Functional Assessment of Cancer Therapy - Multiple Myeloma (FACT-MM) at study screening, on Day 1 of each 4-week cycle beginning at Cycle 2, and at end of treatment (EOT).

METHODS : Analysis of change from baseline was performed for the following FACT-MM outcomes: total score, FACT-TOI, FACT-G, and MM-specific domain. Additional analyses were performed to examine minimal clinically important differences (MCID) in the FACT-MM, and differences in scores between treatment responders and non-responders, including a difference-in-difference (DID) analysis to compare change between groups from baseline to EOT.

RESULTS : 122 patients were present in the mITT population, of whom 80 had sufficient data to be included in longitudinal QOL analyses. MCID analyses demonstrated that most patients did not experience decline in the early cycles of treatment; this pattern was consistent with MCID defined either as 10% of the instrument range (Ringash 2007), or as an ECOG-based anchor. The DID analysis found that the mean change in QOL of non-responders decreased significantly between baseline and EOT, while responders had no significant change. This difference between responders and non-responders was significant for the FACT-G, but not for other endpoints.

CONCLUSIONS : Even with the limited sample size, the QOL analysis showed some important trends. The MCID decline in QOL for non-responders was greater than that of responders, and a DID approach also showed greater decline between baseline and EOT for non-responders.