Single agent bortezomib results in response rates of 51% in patients with newly diagnosed multiple myeloma and is touted to be especially effective in high-risk disease. We are the first to prospectively explore single agent bortezomib as primary therapy (induction, maintenance and re-induction) without consolidative autologous stem cell transplant in a cohort selected to have high-risk multiple myeloma. Patients received eight cycles of induction, followed by maintenance bortezomib every other week, indefinitely. Patients relapsing on maintenance had the full induction schedule resumed. On an intention-to-treat basis, the response rate (partial response) was 48%. Among seven patients who progressed on maintenance bortezomib and received re-induction, two responded to the treatment. With a median follow-up of 48.2 months, 1- and 2-year overall survival probabilities were 88% (95% confidence interval (CI) 79-98%) and 76% (95% CI 60-86%), respectively. Median progression-free survival was 7.9 months (95% CI 5.8-12.0). Twenty-three and thirty-four patients had grade 3 hematological and non-hematological toxicity, respectively, with treatment-emergent neuropathy in 7% with motor grade 1-2, 56% with sensory grade 1-2 and 2% with grade 3, and in 14% with neuropathic pain grade 1-2 and 2% with grade 3. In high-risk patients, upfront bortezomib results in response rates that are comparable to those reported for unselected cohorts, but single agent bortezomib is not sufficient as primary therapy.
- clinical trial
- proteasome inhibitors
ASJC Scopus subject areas
- Cancer Research
- Anesthesiology and Pain Medicine