The addition of pegylated liposomal doxorubicin to bortezomib did not improve overall survival compared with bortezomib monotherapy in patients with relapsed/refractory multiple myeloma, long-term data published in Cancer have shown.1
Results from an interim analysis of this open-label, phase 3 study demonstrated that pegylated liposomal doxorubicin in combination with bortezomib was superior to single-agent bortezomib in patients who had received 1 or more prior therapies. Now, researchers are reporting final survival data after a median follow-up of 103 months.
Final results showed that median overall survival was 33 months (95% CI, 28.9-37.1) with pegylated liposomal doxorubicin plus bortezomib compared with 30.8 months (95% CI, 25.2-36.5) with bortezomib alone (HR, 1.047; 95% CI, 0.879-1.246; P = .6068). At the time of clinical cutoff, 79% of patients in the combination arm had died vs 78% of those in the bortezomib group.
Salvage therapies, which included conventional and novel drugs, after disease progression on bortezomib with or without liposomal doxorubicin were well balanced between the 2 treatment arms.
Previous results demonstrated that bortezomib plus pegylated liposomal doxorubicin induced a superior time to progression vs bortezomib alone.
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For the phase 3 trial, researchers had enrolled 646 patients with relapsed/refractory multiple myeloma. Participants were randomly assigned 1:1 to receive bortezomib 1.3 mg/m2 intravenously on days 1, 4, 8, and 11 of every 21-day cycle, or bortezomib plus pegylated liposomal doxorubicin 30 mg/m2 administered intravenously on day 4.
The investigators hypothesized that subsequent lines of therapy may have impacted the inability to sustain the survival advantage observed earlier, thus highlighting the need for long-term follow-up of phase 3 trials.
- Orlowski RZ, Nagler A, Sonneveld P, et al. Final overall survival results of a randomized trial comparing bortezomib plus pegylated liposomal doxorubicin with bortezomib alone in patients with relapsed or refractory multiple myeloma [published online ahead of print May 18, 2016]. Cancer. doi: 10.1002/cncr.30026.