title: Rituximab therapy for hairy cell leukemia: a retrospective study of 41 cases.
abstract: The purine analogs (PAs) cladribine and pentostatin have transformed the prognosis of hairy cell leukemia (HCL). However, some patients still relapse after PAs, or fail to reach an optimal response, and new agents are needed to further improve treatment outcome. We retrospectively studied 41 HCL patients from 10 centers in France and Belgium, who received 49 treatment courses with the anti-CD20 monoclonal antibody rituximab. Most of the patients were treated at relapse (84 % of cases) and rituximab was combined to a PA in 41 % of cases. Overall, response rate is 90 % including 71 % complete hematologic responses (CHRs). Frontline treatment, combination therapy, and absolute neutrophil count were associated with response in multivariate analysis. Three-year relapse-free and overall survivals are 68 and 90 %, respectively. When combined to a PA, rituximab yields a 100 % response rate, even beyond frontline therapy. In contrast, response rate is only 82 % (59 % CHR) when rituximab is used alone. In this latter setting, relapse rate is 56 % and median time to relapse is 17.5 months. All eight patients who were treated two times with the antibody responded again to re-treatment. We confirm the high efficacy of the combination rituximab + PA. However, when rituximab is used as monotherapy, response rate is lower and the high relapse rate is a concern. Prospective clinical trials are needed to confirm the superiority of the combination rituximab + PA over PA alone, both as frontline therapy and at relapse.
authors.affiliation: Centre Hospitalier Universitaire (CHU) de Reims, Hôpital Robert Debré, Service d'Hématologie Clinique, Reims, France, matleclerc@hotmail.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Leclerc
authors.forename: Felipe
authors.initials: F
authors.lastname: Suarez
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Noël
authors.forename: Anne
authors.initials: A
authors.lastname: Vekhoff
authors.forename: Xavier
authors.initials: X
authors.lastname: Troussard
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Claisse
authors.forename: Catherine
authors.initials: C
authors.lastname: Thieblemont
authors.forename: Frédéric
authors.initials: F
authors.lastname: Maloisel
authors.forename: Yves
authors.initials: Y
authors.lastname: Beguin
authors.forename: Jérôme
authors.initials: J
authors.lastname: Tamburini
authors.forename: Coralie
authors.initials: C
authors.lastname: Barbe
authors.forename: Alain
authors.initials: A
authors.lastname: Delmer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage*; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D007943:Leukemia, Hairy Cell / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000069283:Rituximab; D016896:Treatment Outcome
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab