Reduced-intensity induction therapy with a bortezomib-based regimen followed by maintenance is safe and effective for older patients with newly diagnosed multiple myeloma, a new study suggests.
The study by Maria-Victoria Mateos, MD, of University Hospital of Salamanca, Spain, and her colleagues, which was published online in The Lancet Oncology, showed that major responses to induction therapy were achieved in similar percentages of patients but serious toxicity was significantly reduced with less frequent dosing.
“This is an important study that immediately affects clinical practice and provides important answers about how new agents such as bortezomib can be incorporated effectively in the overall treatment strategy,” writes S. Vincent Rajkumar, MD, of the Mayo Clinic, Rochester, Minnesota, in an accompanying editorial.
A total of 260 patients aged 65 years or older with previously untreated multiple myeloma were randomized to receive six cycles of bortezomib, melphalan, and prednisone (VMP) or bortezomib, thalidomide, and prednisone (VTP) as induction therapy. Patients received one cycle of bortezomib twice a week for 6 weeks plus either melphalan or thalidomide daily and prednisone. After the first cycle, they received five cycles of bortezomib once a week plus melphalan or thalidomide and prednisone. The 178 patients who completed induction therapy were randomized to bortezomib plus prednisone or bortezomib plus thalidomide for up to 3 years.
During the induction phase, 105 (81%) patients assigned to the VTP group and 104 (80%) in the VMP group achieved partial responses or better, with 36 (28%) and 26 (20%) complete remissions, respectively.
Patients in the VTP group had twice as many serious adverse events (40 vs 20) and more often discontinued therapy than did those in the VMP group. The most frequent grade 3 or worse toxicities were infection (in one VTP and nine VMP patients), cardiac events (11 vs 0 ), and peripheral neuropathy (nine vs 12).
After maintenance therapy, the complete remission rates were 42% with bortezomib plus thalidomide and 39% with bortezomib plus prednisone. No grade 3 or worse hematologic toxicities occurred during maintenance therapy. Peripheral neuropathy developed in two patients treated with bortezomib plus prednisone and six of those in the bortezomib plus thalidomide group.