Selinexor Triplet Therapy Shows Significant Survival Benefit in PI-Naive Multiple Myeloma Patients
核心洞察
The BOSTON trial demonstrated that selinexor, bortezomib, and dexamethasone (SVd) combination achieved a median progression-free survival of 29.5 months in proteasome inhibitor (搜索)-naive patients, compared to 9.7 months with bortezomib/dexamethasone alone.
The SVd regimen showed significant overall survival benefit with a hazard ratio of 0.54 in PI-naive patients, representing a substantial improvement over standard therapy.
Despite higher rates of cytopenia and gastrointestinal events, the adverse event profile was manageable with once-weekly dosing and supportive care measures.
A selinexor-based triplet therapy has demonstrated remarkable efficacy in proteasome inhibitor (搜索) (PI)-naive multiple myeloma (搜索) patients, with updated subgroup analysis from the phase 3 BOSTON trial showing a median progression-free survival of 29.5 months compared to 9.7 months with standard bortezomib and dexamethasone therapy.
The combination of selinexor (Xpovio), bortezomib (Velcade), and dexamethasone (SVd) achieved a hazard ratio of 0.29 for progression-free survival in PI-naive patients, representing a highly significant clinical benefit according to Dr. Binod Dhakal, associate professor of medicine in the Division of Hematology at the Medical College of Wisconsin.
Significant Survival Advantages in Second-Line Setting
The PI-naive patient population represents most patients receiving second-line therapy, making these results particularly relevant for clinical practice. In addition to the progression-free survival benefit, the SVd combination demonstrated substantial overall survival improvement with a hazard ratio of 0.54 compared to bortezomib and dexamethasone alone.
"When you look at this PI-naive patient population, which will be most of the patients in second line, and you just look at the subgroup in this SVd arm in the PI-naive patient population, the median PFS in those patients was 29.5 months. I think that is quite impressive," Dhakal noted.
Manageable Safety Profile with Once-Weekly Dosing
The BOSTON trial utilized a novel once-weekly administration schedule for both selinexor and bortezomib within 35-day cycles, differentiating it from traditional twice-weekly regimens. Selinexor was administered at 100 mg on days 1, 8, 15, 22, and 29, while bortezomib was given weekly on the same days as selinexor.
While the SVd arm showed higher rates of cytopenia and gastrointestinal events in PI-naive patients, the adverse event profile was considered manageable. Thrombocytopenia occurred more frequently in the SVd arm as expected, with nausea present in 9% versus none in the control arm, and diarrhea in 6% versus 2%. Notably, peripheral neuropathy was actually lower in the SVd group at 4% compared to 10% with bortezomib alone.
"With a lot of other supportive measures, including the strong anti-emetics, hydration, we have been able to manage it," Dhakal explained, emphasizing the improved tolerability compared to previous twice-weekly selinexor dosing schedules.
Trial Design and Overall Efficacy Results
The BOSTON trial randomized patients 1:1 to receive either the selinexor combination or bortezomib/dexamethasone alone, with treatment continued until disease progression. The primary endpoint was progression-free survival, with secondary endpoints including response rate, depth of response, and overall survival.
Overall response rates were 62% for the selinexor combination versus 77% for bortezomib/dexamethasone alone. However, the median duration of response favored the selinexor arm at 20 months compared to 13 months. The median progression-free survival across all patients was approximately 14 months with the selinexor combination versus 9 months with the control regimen, achieving statistical significance.
The once-weekly dosing approach not only demonstrated efficacy but also aimed to improve patient quality of life by reducing treatment burden and clinic visits associated with traditional biweekly bortezomib administration. This combination represents a relevant treatment option for patients who may not be candidates for chimeric antigen receptor (CAR) T-cell therapy or other advanced treatments.