LAUSR

least 12 patients showing a Partial or Complete Response (PR/CR) in stage I. According to the Ray and Rai method less than 15/23 adverse events were also required for the safety coprimary endpoint. Results: From January 2017 to December 2017, 24 newly diagnosed frail DLBCL were enrolled in 8 Italian centers. Median age was 83 years (range 76-89) and 79% had stage III/IV; 42% of pts were male, and 44%, had elevated LDH. All pts were confirmed eligible and started R2 treatment. The planned 6 courses of R2 were completed in 13 pts (54%). The median number of R2 cycles was 4.6. Treatment was discontinued in 11 pts for the following reasons: lymphoma progression in 4 cases, malignancy in 2, extra-hematological toxicities in 2 cases, consent withdrawal and investigator choice after 4 cycles in CR in 1 case each. Response assessment after 6 R2 cycles showed 12 pts in CR, that was higher than the inferior limit of 11 required by the Simon optimal design. Regarding safety coprimary endpoint 13 events were reported including 9 extra-hematological toxicities > grade 2 CTCAE (3 cardiovascular and 6 respiratory events, all resolved) and 4 deaths (2 patients due visceral arterial ischemia and 2 due infectious disease). The rate of adverse events was lower than the superior limit of 15 allowed the first stage of the study, according to Ray and Rai method. Conclusions: The results of the planned interim analysis of our study confirmed the initial efficacy and safety hypotheses of R2 combination in untreated elderly pts with DLBCL. Since August 2018 the enrollment in the stage II of the trial has been resumed and it is currently ongoing. Treatment of elderly frail DLBCL pts with R2 holds promise in terms of both ORR and safety.