Radioimmunotherapy for Mantle Cell Lymphoma: 5-Year Follow-up of 90 Patients from the International RIT-Registry
Authors: Hohloch Karin , Windemuth-Kieselbach Christine , Zinzani Pier Luigi , Cacchione Roberto E. , Jurczak Wojciech , Suh Cheolwon , Truemper Lorenz , Scholz Christian W 
Published: November 2019

To assess the efficacy of radioimmunotherapy (RIT) with 90yttrium-ibrutinib-tiuxetan (90Y-IT) in mantle cell lymphoma, data from 90 patients registered in the RIT Network with a median follow-up (FU) of 5.5 years after RIT were evaluated. 90Y-IT was given as first-line therapy in 45 (50%) (consolidation 44 pts., primary therapy 1 pt.) and at relapse in 45 (50%) patients (consolidation 24 pts., recurrence 12 pts., therapy refractory 3 pts., conditioning 2 pts., other 4 pts.). As a first-line treatment, 30 patients (pts.) (67%) achieved CR, 10 pts. (22%) PR%., 1 pt. (2%) PD, and for 4 pts. (9%) no response data was available. At relapse, CR was achieved in 17 pts. (38%), PR in 6 pts. (13%), SD in 2 pts. (4%), and 6 pts. (13%) had PD, while the response was not documented for 14 pts. (31%). After a median FU of 5.5 years, median PFS for all patients was 2.11 (95%CI: 1.03-2.32) years, and median OS was 4.05 (95%CI 2.79-7.21) years. Eleven pts. (12.2%) developed second malignancy. In conclusion, this is the largest report of MCL pts. treated with 90Y-IT to date. 90Y-IT was most often used as consolidation after first- and second-line chemotherapy and may improve the results achieved using chemoimmunotherapy alone. However, the results are less encouraging compared to treatment with small molecules such as ibrutinib.

Disclosures
Zinzani: TG Therapeutics: Honoraria, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy. Jurczak:Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Research Funding; Roche: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Bayer: Research Funding; Gilead: Research Funding; MorphoSys: Research Funding; Incyte: Research Funding; Novo Nordisk: Research Funding; Servier: Research Funding; TG Therapeutics: Research Funding; Celtrion: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Truemper:Seattle Genetics, Inc.: Research Funding; Takeda: Consultancy, Research Funding; Roche: Research Funding; Nordic Nanovector: Consultancy; Mundipharma: Research Funding; Janssen Oncology: Consultancy. Scholz:Janssen-Cilag: Consultancy; Hexal: Consultancy; Takeda: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Pfizer: Speakers Bureau; Roche: Consultancy; GILEAD: Consultancy, Speakers Bureau; Daiichi Sankio: Consultancy.

OffLabel Disclosure:
Yttrium 90 (90Y) Ibritumomab Tiuxetan (Zevalin) is approved for treatment of patients with relapsed follicular lymphoma and as consolidation therapy after chemo(immuno)therapy of patients with follicular lymphoma.