RIT with 90Y Ibritumomab Tiuxetan in Patients with Non-Hodgkin Lymphoma Over 65 Years.

90Y Ibritumomab tiuxetan (90Y-IT) has become an efficient alternative to therapy in non-Hodgkin Lymphoma, mainly in elderly patients. The aim of this study is to analyse our updated information of patients treated with 90YIbritumomab/tiuxetan in a prospective study according clinical practice setting and to analyse treatment outcome.

39 non Hodgkin lymphoma patients were included in a clinical protocol conducted by a multidisciplinary team and treated in the same centre. According the inclusion criteria: patients over 65 years old diagnosed as CD20+ NHL with neutrophils ≥ 1,5 × 10⁹/L, platelets ≥ 100 × 10⁹/L, bone marrow lymphocytes CD20+ ≤ 25%. All patients received 0,3 or 0,4 mCi /kg IV (88%) of 90YIbritumomab/tiuxetan and response evaluation was performed 12 weeks after. Period of study: September 2005/July 2012. The 90Y-IT was administered as consolidation of first line therapy (Rituximab alone, R-COP, R-CHOP21) or in relapsed/refractory status.

Objective response rate (ORR), time to relapse (PFS) overall survival (OS) and safety. Other clinical prognostic factors were observed to assess their possible influence upon treatment value.

Until May 2012, 39 patients had received treatment with 90YIbritumomab/tiuxetan and completed the evaluation protocol and were considered to analysis; M/F 18/21 mean age 72.8 years (65–87); ECOG 0–1 92.3%. According OMS classification: NHL-follicular 27 (69.2%), mantle cell Lymphoma 7 (17.9%), DLBCL 4 (10.3%) and 1MALT (2.6%). Score distribution: low risk 19 (48.7%), intermediate 12 (30.8.2%) and advanced 8 (20.5%). Previous therapy schedules ≤2 (66.7%), >2 (33.3%). The median follow-up time: 42.0 months (95% CI: 4.0; 62.0), mean PFS: 38.1 months (95% CI: 30.8; 45.4) median NR. 13 patients received 90Y-IT as consolidation of first line therapy (33.3%) and 26 relapsed/refractory (66.6%). ORR was 84.6 % CR: 29 (74.3%); PR 4 (10.2%) and 6 failures (15.4%) in relapsed/refractory disease. Mean estimated OS since ⁹⁰Y-IT: 54.4 months (95% CI: 49.4; 59.3) and mean estimated OS since diagnosis 159 months. Median PFS was NR. The mean PFS for patients in consolidation therapy was 54.2 months (95% CI: 47.4; 61.1). Safety: thrombocytopenia being the most frequent, G3–4 (35.9%), median time to developed haematological toxicity: fourth week, and neutropenia G3–4 (41.0%), the median time to recover normal values was 4.2 and 2.6 weeks respectively. In 5 (12.9%) of patients red blood cell transfusion was required, and 10 platelet transfusions (25.6%). The most frequent non haematological toxicity was asthenia. One patient developed a severe mucositis. Four patients have concomitant associated tumours (colon, breast, lung and prostate) and two patients over 77 years developed a rectum carcinoma after 18 months of 90Y-IT and another prostate and renal tumour after 8 years.

In our experience 90Y Ibritumomab tiuxetan is a safety and effective therapy in patients with NHL over 65 years. According to obtained PFS results, it seems like the use of this kind of therapy as used in early part of therapy offers good and maintained response rate with lower toxicity in this fragile population. The OS in this population was not inferior to observed in younger NHL patients.

No relevant conflicts of interest to declare.