Results from the phase III BOSTON clinical trial reported that once-weekly selinexor, bortezomib, and dexamethasone (SVd) significantly prolonged progression-free survival for patients with relapsed/refractory multiple myeloma (MM) compared with twice-weekly bortezomib and dexamethasone alone (Vd). However, a study presented at the 2020 ASH Annual Meeting found that SVd is unlikely to be cost-effective under current pricing compared with Vd.
Selinexor is currently priced at nearly $22,000 per month. “The price of selinexor would need to be decreased substantially in order to reduce the incremental cost-effectiveness ratio (ICER) of SVd to widely acceptable values,” the researchers wrote.
Researchers used a Markov model in which simulated patients mirrored the cohort studied in the BOSTON trial. Median patient age was 66 years, 57% were male, and all had received one to three prior lines of therapy. Patients entered the model with relapsed/refractory MM and received treatment with SVd or Vd.
The base-case model followed SVd/Vd progression sequentially with daratumumab, carfilzomib, and dexamethasone (DKd); pomalidomide and dexamethasone (Pd); and best supportive care. Transition probabilities were derived from large, randomized trials using parametric survival modeling. The utility of each health state and the costs of treatment, adverse events, and terminal care were derived from literature and Medicare fee schedules.
Researchers calculated the ICER from a U.S. payer perspective, using a lifetime horizon, an annual discount rate of 3%, and a willingness-to-pay threshold of $150,000 per quality-adjusted life year (QALY).
Per the model, SVd was associated with an improvement of 0.37 QALYs compared with Vd alone (3.43 vs. 3.06 QALYs); however, the incremental lifetime cost of SVd was $177,126 ($1,013,851 vs. $836,725), leading to an ICER of $479,572/QALY.
“The monthly cost of selinexor would need to be decreased by approximately 51%, from $21,424 to $10,415, in order for SVd to be cost-effective compared with Vd alone,” the researchers wrote.
The model was most sensitive to the hazard ratio (HR) of SVd relative to Vd; decreasing the HR from 0.70 to 0.53 decreased the ICER to $285,251/QALY, while increasing the HR to 0.93 increased the ICER to $1,738,546/QALY.
The researchers also incorporated two scenario analyses; in the first, patients in the Vd arm received therapy with selinexor and dexamethasone after progression from Pd, before receiving best supportive care. In this scenario, SVd was associated with an incremental cost of $112,445 ($1,013,851 vs. $901,406), an incremental effectiveness of 0.24 QALYs (3.43 vs. 3.19 QALYs), and an ICER of $464,557/QALY.
In the second scenario analysis, they assumed that patients had received DKd prior to SVd/Vd; as a result, patients that progressed on SVd or Vd subsequently received Pd followed by best supportive care. SVd was associated with an incremental cost of $222,864 ($418,526 vs. $195,662), an incremental effectiveness of 0.49 QALYs (1.90 vs. 1.41 QALYs), and an ICER of $456,080/QALY.
Patel K, Parker TL, Di M, et al. Cost-Effectiveness of Once-Weekly Selinexor, Bortezomib, and Dexamethasone (SVd) Versus Twice-Weekly Bortezomib and Dexamethasone (Vd) in Relapsed or Refractory Multiple Myeloma. Abstract 1594. Presented at the 62nd American Society of Hematology Annual Meeting & Exposition, Dec. 2-11, 2020.