Bortezomib maintenance was associated with lower rates of moderate-to-severe cGVHD in newly diagnosed multiple myeloma after allo-HSCT.
Findings from a retrospective single-center study showed that administration of bortezomib (Velcade) as maintenance therapy following allogeneic hematopoietic stem cell transplant (allo-HSCT) was associated with lower rates of moderate-to-severe chronic graft-vs-host disease (cGVHD) compared with no bortezomib maintenance therapy in patients with newly diagnosed multiple myeloma.1
However, the use of bortezomib was not linked with improved survival outcomes vs no maintenance.
Data presented at the
No differences were reported between the two arms in terms of progression-free survival (PFS; P = .62) and overall survival (OS; P = .49).
“More effective novel maintenance strategies in the post–allo-HSCT setting are required to decrease [incidence of] relapse,” lead study author Richard LeBlanc, MD, and colleagues wrote in a poster presentation of the data.
LeBlanc is a clinical associate professor in the Department of Medicine, medical chief of the Clinical Immunology Laboratory, and head of the Multiple Myeloma Clinical Research Unit team at Université de Montréal, as well as the Myeloma Canada Chair on Multiple Myeloma.
Although the emergence of modern therapies has led to a marked reduction in the utilization of allo-HSCT in patients with multiple myeloma—particularly for those with newly diagnosed disease—this modality remains the only potential curative approach for this malignancy.1,2 Despite this, more than half of patients who undergo allo-HSCT will still experience disease relapse.1
Investigators hypothesized that maintenance therapy following allo-HSCT could lead to lower rates of relapse following transplant. As such, the single-center retrospective study sought to evaluate outcomes of patients (n = 176) who received up-front tandem allo-HSCT and autologous HSCT between May 2001 and December 2024.
The analysis included patients who underwent bortezomib maintenance following allo-HSCT and patients who received no maintenance therapy. Among those given bortezomib, the agent was administered starting on day 120 following transplant and was given at 1.3 mg/m2 every 2 weeks for 26 total doses.
The primary end points of the retrospective study were OS and PFS. Secondary end points comprised outcomes such as relapse and non-relapse mortality; incidence of aGVHD and cGVHD; the rate of patients who received immunosuppressant therapy following transplant; and risk factors for relapse.
The median age at the time of allo-HSCT was 50 years (range, 33-65) in the bortezomib arm vs 52 years (range, 30-64) in the no maintenance arm; 58% and 53% of patients were male in these respective groups. Most patients in the bortezomib arm had an unrelated donor (65%), whereas most in the no maintenance arm had a sibling donor (91%). Additionally, 35% of patients in the bortezomib group 44% of patients in the no maintenance group had a positive cytomegalovirus status. A very good partial response or better prior to transplant was reported in 92% of patients in the bortezomib arm vs 69% of patients in the no maintenance arm; the respective 10-year NRM rates were 6.6% and 7.8%.
Furthermore, 77% of patients in the bortezomib arm received a bortezomib-based induction regimen; reported inductions for the no maintenance arm included vincristine, adriamycin, and dexamethasone or high-dose dexamethasone (60%) and bortezomib-based regimens (29%). In the bortezomib maintenance group, International Staging System classifications included stage I (30%), stage II (30%), stage III (35%), and missing (5%); these respective rates were 20%, 12%, 10%, and 58% in the no maintenance group.
Normal cytogenetics were reported in 27% of patients who received bortezomib maintenance vs 9% of patients who received no maintenance; notably, cytogenetic data were missing for 8% of patients in the bortezomib group vs 71% of patients in the no maintenance group. At least 2 cytogenetic abnormalities were reported in 27% of patients in the bortezomib group and 5% of patients in the no maintenance group.
Bortezomib maintenance was also associated with decreased use of oral, systemic immunosuppressants across multiple time points, including at 1 year following transplant (P < .0001), 2 years (P < .001), 3 years (P < .001), 4 years (P < .01), and 5 years (P < .01).
