Pretransplant induction therapy with subcutaneous bortezomib, lenalidomide, and dexamethasone (VRD) deepened responses in patients with newly diagnosed multiple myeloma, according to an interim analysis of a phase 3 study.
Overall, the regimen was well tolerated, with a minimal number of patients discontinuing treatment because of treatment-emergent adverse events.
The ongoing, open-label, randomized, phase 3is designed to compare two transplant-conditioning regimens – intravenous busulfan plus melphalan versus melphalan – in patients who received VRD induction and consolidation, wrote Laura Rosiñol, MD, PhD, of the August Pi i Sunyer Biomedical Research Institute in Barcelona, and colleagues. The findings were published in .
The PETHEMA/GEM2012 study included 458 patients with newly diagnosed multiple myeloma who were eligible for autologous stem cell transplantation. Study patients were previously untreated and aged younger than 65 years.
All patients received VRD induction, which consisted of subcutaneous bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11 of each cycle; lenalidomide 25 mg/day on days 1-21; and dexamethasone 40 mg on days 1-4 and 9-12 at 4-week intervals for six cycles. Posttransplant consolidation consisted of two cycles of VRD.
The researchers conducted a grouped-response analysis of three different treatment phases: induction, transplant, and consolidation.
After analysis, the researchers found that responses deepened over the duration of treatment. In patients who started the sixth induction cycle, the response rates were 55.6%, 63.8%, 68.3%, and 70.4% after cycles 3, 4, 5, and post induction, respectively.
After six cycles of induction, the complete response rate was 33.4%, with a rate of undetectable minimal residual disease of 28.8%, which further increased at transplant (42.1%), and consolidation (45.2%).
With respect to safety, the most frequently reported grade 3 or higher treatment-emergent adverse events were neutropenia (12.9%) and infection (9.2%). The rate of grade 2 or higher peripheral neuropathy throughout induction was 17.0%, with lower rates of grade 3 (3.7%) and 4 (0.2%) toxicities.
“The regimen [used in the present study] has the highest lenalidomide and dexamethasone dose intensity per cycle and a lower bortezomib dose intensity per cycle than the 21-day regimens, which may offer high activity with low levels of toxicity, thereby enabling delivery of all planned induction cycles,” the researchers wrote, adding that “these results confirm that VRD is an effective pretransplant induction regimen and may be considered a new standard of care.”
The study was supported by Celgene, Janssen, Pierre Fabré, and the Instituto de Salud Carlos III. The authors reported financial affiliations with Celgene, Janssen, and several other companies.
SOURCE: Rosiñol L et al. Blood. 2019 Sep 4. .