2563 - Bendamustine and rituximab followed by 90Y-ibritumomab tiuxetan for relapsed follicular lymphoma; a preliminary analysis of a multicenter, prospective phase II study (BRiZ2012).

Background

Bendamustine and rituximab (BR) is a standard treatment for relapsed or newly diagnosed follicular lymphoma (FL). Despite, the role of ⁹⁰Y-ibritumomab tiuxetan (⁹⁰YIT) has been evaluated as consolidative therapy in FL responding to frontline chemotherapy, this consecutive therapy has not been well evaluated in relapsed setting.

Methods

This is a planned preliminary analysis of a prospective phase II study to clarify the efficacy and safety of BR followed by consolidative ⁹⁰YIT in relapsed FL patients. Inclusion criteria is defined as following conditions: relapsed patients with biopsy proven FL (Grade 1/2 or 3a); limitation of one or two previous regimens; age of 20 - 74 years; performance status of 0 - 2; having measurable lesion(s); no severe organ dysfunction; 3 months or longer life expectancy; and written informed consent. BR consisted of intravenous rituximab (375 mg/m², day 1) and bendamustine (90 mg/m², day 2 and 3), repeated every 4 weeks up to 4 cycles. Patients who achieved complete response (CR) or partial response received 14.8 MBq/kg of ⁹⁰YIT continuously. In this analysis, overall response (OR) rates and CR rates after 4 cycles of BR and ⁹⁰YIT, and toxicities were evaluated.

Results

Between February 2013 and November 2015, a total of 30 patients were registered. Seven patients were excluded from this analysis because of pathological diagnostic mismatch (n = 3), unmet criteria (n = 2), comorbidity with other active cancer (n = 1), and reviewed data incompletion (n = 1). Twenty-three patients with a median 60 years (range 47–74) were evaluable. Fourteen, 7, and 2 patients were categorized into low, intermediate, and high risk in the FLIPI 2, respectively. OR rates and CR rates were 91% (n = 22) and 74% (n = 18) after BR, and 88% (n = 21) and 83% (n = 20) after ⁹⁰YIT, respectively. Hematological toxicities commonly observed, however these were generally tolerable. Grade ≥3 non-hematological toxicities were rare and there was no treatment-related death.

Conclusions

Combination with BR followed by ⁹⁰YIT was safe and effective for selected patients with relapsed FL. The further investigation of Long-term effect has been on going.

Clinical trial identification

UMIN000008793, release date: 03. September 2012.

Legal entity responsible for the study

Society of Lymphoma Treatment in Japan.

Funding

NP-ACRO (Advanced Clinical research Organization).

Editorial Acknowledgement

Disclosure

All authors have declared no conflicts of interest.