title: Full-dose 90Y ibritumomab tiuxetan therapy is safe in patients with prior myeloablative chemotherapy.
abstract: OBJECTIVE
  Targeted radioimmunotherapy with yttrium-90 (90Y)-labeled ibritumomab tiuxetan (Zevalin, IDEC-Biogen, San Diego, CA) has shown significant activity in the treatment of relapsed or refractory CD20+ non-Hodgkin's lymphoma. Eligibility criteria used in phase I trials, and adopted in phase II and III trials, excluded patients with prior myeloablative therapy. We treated eight patients with 90Y ibritumomab tiuxetan who had prior autologous stem cell transplant, but met all other treatment criteria.
  
  
  METHODS
  Eight patients with CD20+ non-Hodgkin's lymphoma had extensive prior therapy including myeloablative chemotherapy but did not receive total body irradiation. Each had bone marrow cellularity of >15%, platelet count of >100,000/mm3, and one had documented lymphomatous bone marrow involvement of <25%. The standard course of 0.3 to 0.4 mCi/kg of 90Y ibritumomab tiuxetan was administered to patients at full dose. 18-Flouro-deoxyglucose positron emission tomography/computed tomography scans were done at pretreatment and approximately 12 weeks after treatment to assess patient response. Maximum toxicities were monitored and classified according to the Common Terminology Criteria for Adverse Events (ver. 3.0).
  
  
  RESULTS
  Toxicities observed included grade 4 thrombocytopenia in three of eight evaluable patients and grade 4 neutropenia in one of eight evaluable patients. One patient had a neutropenic fever; all patients were off blood product support 12 weeks post-zevalin. Complete response by 18-flouro-deoxyglucose positron emission tomography/computed tomography imaging occurred in one of seven evaluable patients and one patient treated as consolidation had no evidence of disease.
  
  
  CONCLUSIONS
  Our experience suggests that 90Y ibritumomab tiuxetan treatment is safe for use in patients with prior myeloablative therapy when the general inclusion criteria are fulfilled. In this small series, the response rates, however, are limited. Nevertheless, 90Y ibritumomab tiuxetan treatment may provide clinical benefit in carefully selected extensively pretreated patients.
authors.affiliation: University of Pittsburgh Cancer Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15232, USA.
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Jacobs
authors.forename: Nicholas
authors.initials: N
authors.lastname: Vidnovic
authors.forename: Judith
authors.initials: J
authors.lastname: Joyce
authors.forename: Barry
authors.initials: B
authors.lastname: McCook
authors.forename: Frank
authors.initials: F
authors.lastname: Torok
authors.forename: Norbert
authors.initials: N
authors.lastname: Avril
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000096:biosynthesis; D001792:Blood Platelets / Q000378:metabolism; D002986:Clinical Trials as Topic; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D010996:Pleural Effusion / Q000473:pathology; D049268:Positron-Emission Tomography; D016499:Radioimmunotherapy / Q000379:methods*; D012008:Recurrence; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D000911:Antibodies, Monoclonal; D018951:Antigens, CD20; D015021:Yttrium Radioisotopes; D019788:Fluorodeoxyglucose F18; C422802:ibritumomab tiuxetan; D007770:L-Lactate Dehydrogenase