(90)Y-ibritumomab tiuxetan followed by reduced-intensity conditioning and allo-SCT in patients with advanced follicular lymphoma

Reduced-intensity conditioning (RIC) hematopoietic SCT (HSCT) is a potentially curative therapeutic option for patients with advanced follicular lymphoma (FL), but disease relapse remains the most common cause of failure. Radioimmunoconjugates administered before RIC allo-HSCT may enhance cytoreduction and allow more time for GVL effect to develop without the associated toxicity of a myeloablative HSCT. We performed a retrospective study to describe the outcomes of patients with relapsed, refractory or transformed FL who received yttrium-90 ((90)Y)-ibritumomab tiuxetan followed by fludarabine and low-dose BU RIC allogeneic HSCT at the Dana-Farber Cancer Institute between 2006 and 2009, inclusively. Twelve patients were identified with a median age of 55 (40-66) years and a median number of lines of therapy of 5 (2-10). Two patients (17%) had transformed to a more aggressive histology and five (42%) had chemorefractory FL. Cumulative incidences of grade II-IV acute GVHD at 100 days were 17% (±11%) and chronic GVHD at 12 months were 63% (±19%). Two-year non-relapse mortality was 18% (±12%). Two-year OS and PFS were 83% (±11%) and 74% (±13%), respectively. This treatment is associated with favorable outcomes including acceptable rates of GVHD and relapse in advanced FL patients, and warrants prospective studies.