In patients with multiple myeloma who have received one to three previous therapies, selinexor/bortezomib/dexamethasone (SVd) significantly improves outcomes compared with bortezomib/dexamethasone (Vd) alone, according to results of the phase 3 BOSTON trial to be presented this week in the 2020 American Society of Clinical Oncology (ASCO) Virtual Scientific Program.
The trial enrolled 402 patients with multiple myeloma who had received one to three prior therapies. Patients were stratified based on number of previous treatments, number of prior proteasome inhibitor therapies, and Revised International Staging System disease stage and were randomized to receive SVd once weekly or Vd twice weekly. The median age was 67 years, and baseline characteristics were similar across treatment arms. The study's primary end point was progression-free survival, with secondary end points of overall response rate, overall survival, and incidence of peripheral neuropathy.
Compared with Vd, patients receiving SVd experienced a significantly longer median progression-free survival (13.93 vs 9.46 months) and an increased overall response rate (76.4% vs 62.3%). Median overall survival was not reached in patients receiving SVd, compared with 25 months for Vd. The most frequent grade 3 or higher treatment-related adverse events experienced by patients treated with SVd included thrombocytopenia (35.9%), fatigue (11.3%), and nausea (7.7%). Patients receiving SVd experienced a significantly lower incidence of peripheral neuropathy compared with Vd (21% vs 34.3%).
"BOSTON is the first phase 3 study to evaluate the clinical benefit of SVd for relapsed/refractory multiple myeloma," conclude the investigators, led by first author Meletios A. Dimopoulos, MD, Chairman of the Department of Clinical Therapeutics at National and Kapodistrian University of Athens School of Medicine in Athens, Greece. "The study met its primary end point: once weekly SVd significantly improved progression-free survival and overall response rate compared to twice weekly Vd. Rates of peripheral neuropathy were significantly reduced with numerically fewer deaths on SVd versus Vd."
For More Information
Dimopoulos MA, Delimpasi S, Simonova M, et al (2020). Weekly selinexor, bortezomib, and dexamethasone (SVd) versus twice weekly bortezomib and dexamethasone (Vd) in patients with multiple myeloma (MM) after one to three prior therapies: initial results of the phase III BOSTON study. J Clin Oncol (ASCO Virtual Scientific Program), 38(suppl_15). Abstract 8501. DOI:10.1200/JCO.2020.38.15_suppl.8501
Image credit: KGH. Licensed under CC BY-SA 3.0