title: Follicular lymphoma at relapse after rituximab containing regimens: comparison of time to event intervals prior to and after 90 Y-ibritumomab-tiuxetan.
abstract: Radioimmunotherapies with Zevalin® (RIT-Z) showed encouraging results in patients with relapsed/refractory follicular lymphoma (FL), leading frequently to failure-free intervals longer than those achieved by the last previous therapy. We compared time-to-event variables obtained before and after RIT-Z in patients with relapsed FL, previously exposed to rituximab. All patients with relapsed non-transformed, non-refractory, non-rituximab-naïve FL who have been treated with RIT-Z in two different centres in Europe were included. Staging and response were assessed by contrast-enhanced CT in all patients; PET/CT was performed according to local availability. Event-free survival (EFS) and time to next treatment (TTNT) following the last previous therapy and after RIT-Z were compared. Pre-therapy characteristics were tested in univariate analyses for prediction of outcomes. A description of the patterns of relapse was also provided. Among 70 patients treated, only 16 fulfilled the inclusion criteria. They were treated with a median of 3 prior lines of chemo-immunotherapies, including a median of 2 rituximab-containing regimens; 6 patients had undergone myeloablative chemotherapy with autologous stem cell rescue (ASCT). Overall response rates were 10 (62%) CR/CRu, 3 (19%) PR and 3 (19%) PD; response rates were similar in patients with prior ASCT. After RIT-Z only few patients obtained EFS and TTNT longer than after the last previous therapy. All four patients receiving rituximab maintenance were without progression 12 months after RIT-Z. Relapses occurred in both previously and newly involved sites; a significant association was found between the number of pathologic sites involved prior to RIT-Z and subsequent TTNT. Despite the excellent response rate, the duration of response was shorter than the previous one confirming the known trend of relapses to occur earlier after subsequent treatments. Rituximab maintenance after RIT-Z showed encouraging results in terms of prolonging EFS, warranting further studies.
authors.affiliation: Department of Nuclear Medicine, Sant'Andrea Hospital, University La Sapienza of Rome, Rome, Italy. f.cicone@iol.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Cicone
authors.forename: Eleonora
authors.initials: E
authors.lastname: Russo
authors.forename: Andrea
authors.initials: A
authors.lastname: Carpaneto
authors.forename: John O
authors.initials: JO
authors.lastname: Prior
authors.forename: Angelika Bischof
authors.initials: AB
authors.lastname: Delaloye
authors.forename: Francesco
authors.initials: F
authors.lastname: Scopinaro
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ketterer
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008224:Lymphoma, Follicular / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016499:Radioimmunotherapy / Q000379:methods*; D012008:Recurrence; D012189:Retrospective Studies; D000069283:Rituximab; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D015021:Yttrium Radioisotopes; D000069283:Rituximab; C422802:ibritumomab tiuxetan