title: An observational, retrospective analysis of retreatment with bortezomib for multiple myeloma.
abstract: OBJECTIVE
  The aim of this retrospective chart review of patients with multiple myeloma (MM) was to describe patterns of retreatment with bortezomib-based therapy and responses to retreatment in a community-based setting.
  
  
  METHODS
  Data were retrospectively extracted from the medical records of patients treated in US Oncology-affiliated community oncology clinics who received 2 separate treatments with bortezomib-based therapy. Eligible patients had > or = 60 days between treatments and > or = 4 bortezomib doses during initial treatment. Responses were determined primarily by laboratory values. Response categories included (1) very good partial response (VGPR), > or = 90% M-protein decrease; (2) partial response (PR), 50%-89% decrease; and (3) less than PR (< PR), < 50% decrease, excluding progressive disease (PD).
  
  
  RESULTS
  Retreatment response data were available for 82 patients; 5 (6%) had VGPR, 12 (15%) had PR, 52 (63%) had < PR, 5 (6%) had PD, and 8 (10%) died. Among 62 patients with response assessments for initial treatment and retreatment, VGPR/PR rates to retreatment were 44%, 23%, and 13% among patients with VGPR, PR, and < PR to initial treatment, respectively. Median time between bortezomib treatments was 9.7 months; 29% of patients received non-bortezomib therapy between treatments. The most common treatment pattern (58% of patients) was single-agent bortezomib at initial treatment and retreatment. Toxicity contributed to discontinuation in 38% of patients during initial treatment and 22% during retreatment; rates of neuropathy contributing to discontinuation were 18% and 6%, respectively.
  
  
  CONCLUSIONS
  Retreatment with bortezomib-based therapy is feasible, with predictable toxicities. This observational analysis supports bortezomib alone or in combination as a retreatment option after initial bortezomib treatment in patients with relapsed MM.
authors.affiliation: Independent Outcomes Researcher, Austin, TX, USA.
authors.forename: Therese M
authors.initials: TM
authors.lastname: Conner
authors.forename: QuynhChau D
authors.initials: QD
authors.lastname: Doan
authors.forename: Ian B
authors.initials: IB
authors.lastname: Walters
authors.forename: Annette L
authors.initials: AL
authors.lastname: LeBlanc
authors.forename: Roy A
authors.initials: RA
authors.lastname: Beveridge
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001897:Boronic Acids / Q000008:administration & dosage* / Q000009:adverse effects; D000069286:Bortezomib; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D008297:Male; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000378:metabolism; D011719:Pyrazines / Q000008:administration & dosage* / Q000009:adverse effects; D012008:Recurrence; D012189:Retrospective Studies; D014481:United States
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D007136:Immunoglobulins; C009823:M-proteins (Myeloma); D011719:Pyrazines; D000069286:Bortezomib