Safety of prolonged therapy with bortezomib in relapsed or refractory multiple myeloma. Academic Article uri icon



  • BACKGROUND: Bortezomib, a first-in-class proteasome inhibitor, is active with manageable toxicities in relapsed and/or refractory myeloma. METHODS: Bortezomib 1.0 or 1.3 mg/m2 was administered Days 1, 4, 8, and 11 every 21 days for up to 8 cycles to patients with relapsed and/or refractory myeloma participating in two Phase II trials. Dexamethasone could be added because of progressive disease after 2 cycles or stable disease after 4 cycles. Continuation of or retreatment with bortezomib was offered to patients who, in the investigator's opinion, would benefit from extended treatment. RESULTS: Sixty-three patients with relapsed/refractory myeloma treated in this extension trial received a median of 7 additional cycles of therapy, for a total of 14 cycles (range, 7-32) over a median duration of therapy of 45.1 weeks in the parent and extension studies. Seventy-eight percent of patients completed this study at the same or higher bortezomib dose than they started on during this study, and the treatment schedule of twice-weekly administration remained unchanged in 89%. Overall, 75% of patients received dexamethasone in combination with bortezomib for a median of 5 cycles starting either in the parent or extension study. The safety profile was similar between the extension and parent trials, with no evidence of new cumulative toxicity. The most commonly reported Grade 3/4 toxicities were thrombocytopenia (29%), with a consistent pattern of recovery during the rest period of each cycle, diarrhea (11%), anemia (11%), and neutropenia (10%). Neuropathy was reported less frequently. CONCLUSIONS: Retreatment with or continuation of bortezomib +/- dexamethasone beyond 6 months was safe, and toxicities were manageable, in patients with relapsed and/or refractory myeloma.

publication date

  • November 15, 2005



  • Antineoplastic Agents
  • Boronic Acids
  • Drug Resistance, Neoplasm
  • Multiple Myeloma
  • Neoplasm Recurrence, Local
  • Pyrazines


Scopus Document Identifier

  • 27644510071

PubMed ID

  • 16206291

Additional Document Info


  • 104


  • 10