BOSTON Trial: Bortezomib and Dexamethasone With and Without Selinexor in Multiple Myeloma

An international phase III study compared treatment outcomes between once-weekly selinexor plus bortezomib-dexamethasone (XVd), and twice-weekly bortezomib-dexamethasone alone (Vd) in patients with multiple myeloma (MM) after prior treatments. Their research found significantly improved outcomes in the XVd group.

According to Shambavi Richard, MD, and colleagues, “XVd provided a non-[immunomodulatory drug]-based regimen with superior benefits over Vd” in a number of outcomes across both test groups. Their study was published in the American Journal of Hematology.

A total of 402 patients with MM who had undergone one to three prior treatment regimens were randomized to either once-weekly XVd (n = 195), or twice-weekly Vd (n = 207) groups. The primary endpoint was progress-free survival (PFS), assessed by an independent review committee. Secondary endpoints included overall survival, overall response rate, duration of response (DOR), time to next therapy (TTNT), rates of grade II or higher peripheral neuropathy, and safety.

Of the participants, 141 patients with MM displayed high-risk cytogenetics (XVd, n = 70; Vd, n = 71), and 261 displayed standard-risk cytogenetics (XVd, n = 125; Vd, n = 136). Among patients with high-risk MM, median PFS was 12.91 months for XVd and 8.61 months for Vd (HR=0.73; 95% CI, 0.4673-1.1406, p = 0.082), and ORRs were 78.6% and 57.7%, respectively (OR=2.68; p = 0.004). In the standard-risk subgroup, median PFS was 16.62 months for XVd and 9.46 months for Vd (HR=0.61; p = 0.004), and ORRs were 75.2% and 64.7%, respectively (OR=1.65; p = 0.033). The safety profiles of XVd and Vd in both subgroups were consistent with the overall population.

The authors addressed several limitations of their study, including the fact that the trial was not designed to statistically compare outcomes between high-risk and standard-risk patients.

Ultimately, the researchers suggested that selinexor can confer benefits to patients with MM regardless of cytogenetic risk and associated the XVd regimen with superior median outcomes relative to the Vd regimen.