Impact of Selinexor on Quality of Life and Minimal Clinically Important Differences in Multiple Myeloma

A recent study, led by Gabriel Tremblay, analyzed data from STORM—a phase IIb clinical trial on selinexor and low dose dexamethasone in patients with penta-exposed relapsed or refractory multiple myeloma (RRMM). The study sought to examine selinexor’s impact on patients’ health-related quality of life (HRQoL), and evaluate two anchor-based methods of calculating minimal clinically important differences (MCIDs) for the Functional Assessment of Cancer Therapy–Multiple Myeloma (FACT-MM) scoring tool.

According to the report published in BMC Cancer, the HRQoL in the majority of STORM patients did not diminish based on minimal clinically important differences during early treatment with selinexor and dexamethasone. Additionally, the authors observed that “an anchor-based approach utilizing patient-level data to define minimal clinically important differences for the FACT-MM gave consistent results with a distribution-based approach.”

For the first analysis, MCID was defined as 10% of the instrument range, an established threshold that has been associated with meaningful change in HRQoL for patients. The exploratory second method of analysis “anchored” HRQoL to differences in Eastern Cooperative Oncology Group Performance Status (ECOG PS) scores to calculate MCID.

Eighty patients from STORM were analyzed using mixed-effects regression models for changes from baseline in FACT-MM total score, FACT-trial outcome index (TOI), FACT-General (FACT-G), and an MM-specific subscale. Testing of different MCID thresholds consistently indicated that most patients did not experience significant HRQoL decline during the first six cycles of treatment. According to the study, responders experienced less decline in HRQoL from baseline to EOT than non-responders, which was significant for the FACT-G instrument, but not for other scores.

Authors noted, however, that their sample size was limited due to the lack of post-baseline HRQoL data which became more scarce as treatment continued, leading them to omit later cycles from analysis. FACT-MM compliance rate declined to 54% in cycle six as well, further limiting the power of the analysis.

Analysis of MCIDs, whether defined as 10% of the instrument range or as an ECOG-based anchor, consistently demonstrated that most patients did not experience HRQoL decline during early cycles of treatment with selinexor and low dose dexamethasone—generally consistent with prior research on the efficacy and tolerability of selinexor with low dose dexamethasone in patients with penta-refractory MM.