In the phase 3 BOSTON study, patients with multiple myeloma (MM) after 1-3 prior regimens were randomized to once-weekly selinexor (an oral inhibitor of exportin 1 [XPO1]) plus bortezomib-dexamethasone (XVd) or twice-weekly bortezomib-dexamethasone (Vd). Compared with Vd, XVd was associated with significant improvements in median progression-free survival (PFS), overall response rate (ORR), and lower rates of peripheral neuropathy, with trends in overall survival (OS) favoring XVd. In BOSTON, 141 (35.1%) patients had MM with high-risk (presence of del[17p], t[4;14], t[14;16], or ≥4 copies of amp1q21) cytogenetics (XVd, n = 70; Vd, n = 71), and 261 (64.9%) exhibited 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. These data suggest that selinexor can confer benefits to patients with MM regardless of cytogenetic risk. ClinicalTrials.gov identifier: NCT03110562.

• MeSH
• Antineoplastic Agents adverse effects   therapeutic use   MeSH
• Bortezomib adverse effects   therapeutic use   MeSH
• Cytogenetic Analysis MeSH
• Dexamethasone adverse effects   therapeutic use   MeSH
• Progression-Free Survival MeSH
• Adult MeSH
• Hydrazines adverse effects   therapeutic use   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Multiple Myeloma drug therapy   genetics   MeSH
• Antineoplastic Combined Chemotherapy Protocols adverse effects   therapeutic use   MeSH
• Aged MeSH
• Triazoles adverse effects   therapeutic use   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial, Phase III MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH

Elderly and frail patients with multiple myeloma (MM) are more vulnerable to the toxicity of combination therapies, often resulting in treatment modifications and suboptimal outcomes. The phase 3 BOSTON study showed that once-weekly selinexor and bortezomib with low-dose dexamethasone (XVd) improved PFS and ORR compared with standard twice-weekly bortezomib and moderate-dose dexamethasone (Vd) in patients with previously treated MM. This is a retrospective subgroup analysis of the multicenter, prospective, randomized BOSTON trial. Post hoc analyses were performed to compare XVd versus Vd safety and efficacy according to age and frailty status (<65 and ≥65 years, nonfrail and frail). Patients ≥65 years with XVd had higher ORR (OR 1.77, p = .024), ≥VGPR (OR, 1.68, p = .027), PFS (HR 0.55, p = .002), and improved OS (HR 0.63, p = .030), compared with Vd. In frail patients, XVd was associated with a trend towards better PFS (HR 0.69, p = .08) and OS (HR 0.62, p = .062). Significant improvements were also observed in patients <65 (ORR and TTNT) and nonfrail patients (PFS, ORR, ≥VGPR, and TTNT). Patients treated with XVd had a lower incidence of grade ≥ 2 peripheral neuropathy in ≥65 year-old (22% vs. 37%; p = .0060) and frail patients (15% vs. 44%; p = .0002). Grade ≥3 TEAEs were not observed more often in older compared to younger patients, nor in frail compared to nonfrail patients. XVd is safe and effective in patients <65 and ≥65 and in nonfrail and frail patients with previously treated MM.

• MeSH
• Bortezomib administration & dosage   adverse effects   MeSH
• Dexamethasone administration & dosage   adverse effects   MeSH
• Progression-Free Survival MeSH
• Adult MeSH
• Gastrointestinal Diseases chemically induced   MeSH
• Hydrazines administration & dosage   adverse effects   MeSH
• Kaplan-Meier Estimate MeSH
• Clinical Trials, Phase III as Topic statistics & numerical data   MeSH
• Frailty complications   diagnosis   MeSH
• Hematologic Diseases chemically induced   MeSH
• Middle Aged MeSH
• Humans MeSH
• Multiple Myeloma complications   drug therapy   MeSH
• Multicenter Studies as Topic statistics & numerical data   MeSH
• Peripheral Nervous System Diseases chemically induced   MeSH
• Antineoplastic Combined Chemotherapy Protocols adverse effects   therapeutic use   MeSH
• Randomized Controlled Trials as Topic statistics & numerical data   MeSH
• Retrospective Studies MeSH
• Drug Administration Schedule MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Severity of Illness Index MeSH
• Triazoles administration & dosage   adverse effects   MeSH
• Age Factors MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH

BACKGROUND: Selinexor combined with dexamethasone has shown activity in patients with heavily pre-treated multiple myeloma. In a phase 1b/2 study, the combination of oral selinexor with bortezomib (a proteasome inhibitor) and dexamethasone induced high response rates with low rates of peripheral neuropathy, the main dose-limiting toxicity of bortezomib. We aimed to evaluate the clinical benefit of weekly selinexor, bortezomib, and dexamethasone versus standard bortezomib and dexamethasone in patients with previously treated multiple myeloma. METHODS: This phase 3, randomised, open-label trial was done at 123 sites in 21 countries. Patients aged 18 years or older, who had multiple myeloma, and who had previously been treated with one to three lines of therapy, including proteasome inhibitors, were randomly allocated (1:1) to receive selinexor (100 mg once per week), bortezomib (1·3 mg/m2 once per week), and dexamethasone (20 mg twice per week), or bortezomib (1·3 mg/m2 twice per week for the first 24 weeks and once per week thereafter) and dexamethasone (20 mg four times per week for the first 24 weeks and twice per week thereafter). Randomisation was done using interactive response technology and stratified by previous proteasome inhibitor therapy, lines of treatment, and multiple myeloma stage. The primary endpoint was progression-free survival in the intention-to-treat population. Patients who received at least one dose of study treatment were included in the safety population. This trial is registered at ClinicalTrials.gov, NCT03110562. The trial is ongoing, with 55 patients remaining on randomised therapy as of Feb 20, 2020. FINDINGS: Of 457 patients screened for eligibility, 402 were randomly allocated-195 (49%) to the selinexor, bortezomib, and dexamethasone group and 207 (51%) to the bortezomib and dexamethasone group-and the first dose of study medication was given between June 6, 2017, and Feb 5, 2019. Median follow-up durations were 13·2 months [IQR 6·2-19·8] for the selinexor, bortezomib, and dexamethasone group and 16·5 months [9·4-19·8] for the bortezomib and dexamethasone group. Median progression-free survival was 13·93 months (95% CI 11·73-not evaluable) with selinexor, bortezomib, and dexamethasone and 9·46 months (8·11-10·78) with bortezomib and dexamethasone (hazard ratio 0·70 [95% CI 0·53-0·93], p=0·0075). The most frequent grade 3-4 adverse events were thrombocytopenia (77 [39%] of 195 patients in the selinexor, bortezomib, and dexamethasone group vs 35 [17%] of 204 in the bortezomib and dexamethasone group), fatigue (26 [13%] vs two [1%]), anaemia (31 [16%] vs 20 [10%]), and pneumonia (22 [11%] vs 22 [11%]). Peripheral neuropathy of grade 2 or above was less frequent with selinexor, bortezomib, and dexamethasone (41 [21%] patients) than with bortezomib and dexamethasone (70 [34%] patients; odds ratio 0·50 [95% CI 0·32-0·79], p=0·0013). 47 (24%) patients in the selinexor, bortezomib, and dexamethasone group and 62 (30%) in the bortezomib and dexamethasone group died. INTERPRETATION: A once-per-week regimen of selinexor, bortezomib, and dexamethasone is a novel, effective, and convenient treatment option for patients with multiple myeloma who have received one to three previous lines of therapy. FUNDING: Karyopharm Therapeutics.

• MeSH
• Antineoplastic Agents administration & dosage   adverse effects   MeSH
• Bortezomib administration & dosage   adverse effects   MeSH
• Dexamethasone administration & dosage   adverse effects   MeSH
• Progression-Free Survival MeSH
• Adult MeSH
• Hydrazines administration & dosage   adverse effects   MeSH
• Kaplan-Meier Estimate MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Multiple Myeloma drug therapy   MeSH
• Antineoplastic Combined Chemotherapy Protocols administration & dosage   adverse effects   MeSH
• Drug Administration Schedule MeSH
• Aged MeSH
• Triazoles administration & dosage   adverse effects   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial, Phase III MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH