The pooled analysis included 121 patients: 63 who received carfilzomib at 70 mg/m2 once weekly and 58 who received carfilzomib at 36 mg/m2 twice weekly.
There were no significant differences in baseline characteristics between the dosing groups. For the entire cohort, the median age at diagnosis was 72 years (range, 55-86), and the median follow-up was 39 months.
A total of 119 patients started induction (63 in the once-weekly group and 56 in the twice-weekly group), and 90 patients received maintenance (47 and 43, respectively). Patients received maintenance for a median of 17 months in the once-weekly group and 20 months in the twice-weekly group (P = .17).
There was no significant difference between the groups with regard to PFS or OS, either from enrollment or the start of maintenance.
From enrollment, the median PFS was 35.7 months in the once-weekly group and 35.5 months in the twice-weekly group (hazard ratio [HR] = 1.39; P = .26). The 3-year OS was 70% and 72%, respectively (HR = 1.27; P = .5).
From the start of maintenance, the 3-year PFS was 47% in the once-weekly group and 51% in the twice-weekly group (HR = 1.04; P = .92). The 3-year OS was 72% and 73%, respectively (HR = 0.82; P = .71).
There were no significant between-group differences in the rates of grade 3-5 adverse events (AEs) or the need for carfilzomib dose reduction or discontinuation.
Grade 3-5 hematologic AEs occurred in 24% of patients in the once-weekly group and 30% of those in the twice-weekly group. Grade 3-5 nonhematologic AEs occurred in 38% and 41%, respectively.
Twenty-nine percent of patients in the once-weekly group required a reduction in carfilzomib dose, as did 30% of patients in the twice-weekly group. Common AEs leading to dose reduction were acute kidney injury, infections, and hypertension.
AEs leading to carfilzomib discontinuation occurred in 27% of patients in the once-weekly group and 30% of those in the twice-weekly group. Common AEs leading to discontinuation were cardiac injury, infections, and thromboembolism.
Both trials were sponsored by Stichting Hemato-Oncologie voor Volwassenen Nederland in collaboration with Fondazione Neoplasie Sangue ONLUS and supported by funding from Amgen (Onyx Pharmaceuticals). Dr. Bringhen reported relationships with Amgen and other companies. Coauthor Antonio Palumbo, MD, is an employee of Takeda, and other authors reported relationships with a range of companies.
SOURCE: Bringhen S et al. Haematologica. 2019 Feb 7. doi: 10.3324/haematol.2018.208272.