KEY TAKEAWAYS
- The BOSTON phase III trial aimed to determine the effects of prior therapies, including PI, on the safety and efficacy of SVd treatment for MM.
- Randomized RRMM pts with 1-3 prior therapies received either SVd or Vd. Subgroup analysis were performed based on prior PI therapy and prior regimens.
- The study found that extended follow-up data from the BOSTON trial reinforces the superior PFS of SVd over Vd in PI-naïve, bortezomib-naïve, and first-relapsed RRMM pts, underscoring the promise of SVd in these patient populations.
For a study, researchers aimed to determine the effects of prior therapies, including PI, on the safety and efficacy of SVd treatment for MM. Patients with RRMM and 1-3 prior therapies were randomly assigned to receive selinexor once a week (100 mg), bortezomib once a week (1.3 mg/m2), and dexamethasone twice a week (20 mg) (Vd) or the standard twice a week Vd.
Stratified efficacy and safety analysis was conducted based on subgroups categorized by prior PI therapy and the number of prior treatment regimens. Efficacy analyses were conducted using data from February 2021, while safety analyses were based on data cut from June 2022.
Of 402 pts, 198 had received one prior line of treatment (LOT), with 99 in each arm (SVd=99; Vd=99; median ages 67 and 69 y, respectively). Among these, 95 were PI-naïve (SVd=47; Vd=48; median ages 68 and 67.5 y, respectively), and 123 were bortezomib-naïve (SVd=61; Vd=62; median ages 68 y both arms). In pts with one prior LOT, the median progression-free survival (mPFS) was 21.0 vs. 10.7 months for SVd vs. Vd (HR 0.62; 95% CI 0.41-0.95, p=0.028).
For PI-naïve patients, mPFS was 29.5 vs. 9.7 months for SVd vs. Vd (HR 0.29; 95% CI 0.14-0.63, P< 0.001), and for bortezomib-naïve patients, mPFS was 29.5 vs. 9.7 months for SVd vs. Vd (HR 0.35; 95% CI 0.18-0.68, P=0.002). Overall response rates (ORR) were higher with SVd vs. Vd in all subgroups: 1 prior LOT 80.8% vs. 66.7%; PI-naïve 76.6% vs. 70.8%; bortezomib-naïve ORR 75.4% vs. 69.4%.
The most common (≥25%) treatment-emergent adverse events (AEs) with SVd vs. Vd in pts with one prior LOT were thrombocytopenia (61.6% vs. 28.6%), nausea (52.5% vs. 11.2%), fatigue (45.4% vs. 17.3%), peripheral neuropathy (38.4% vs. 52.0%), diarrhea (34.3% vs. 24.5%), and anemia (30.3% vs. 26.5%). Safety findings were similar in the PI-naïve and bortezomib-naïve subgroups.
The study found that extended follow-up data from the BOSTON trial reinforces the superior progression-free survival (PFS) of SVd over Vd in PI-naïve, bortezomib-naïve, and first-relapsed RRMM patients, underscoring the promise of SVd in these patient populations.
Clinical Trial: https://clinicaltrials.gov/study/NCT03110562
Mateos, M. V., Engelhardt, M., Leleu, X., Gironella Mesa, M., Cavo, M., Dimopoulos, M., Bianco, M., Merlo, G. M., La Porte, C., & Moreau, P. (2023). Selinexor, bortezomib and dexamethasone in patients with previously treated multiple myeloma: Updated results of Boston trial by prior therapies [Poster presentation]. 20th Congress of the European Hematology Association (EHA), Amsterdam, Netherlands.
