Preliminary results of a phase II randomized study (ROMULUS) of polatuzumab vedotin (PoV) or pinatuzumab vedotin (PiV) plus rituximab (RTX) in patients (Pts) with relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL)

8519 Background: PoV and PiV, antibody drug conjugates (ADC) containing the anti-mitotic MMAE targeting CD79b (PoV) and CD22 (PiV), showed clinical activity in Phase I. The current study aims to compare PoV and PiV + RTX in R/R DLBCL and R/R follicular lymphoma (FL). Methods: Pts were randomized to receive PoV or PiV + RTX (ADC 2.4 mg/kg + RTX 375 mg/m2) every 21 days. Tumor assessments were performed every 3 months. Results: As of 8 November 2013, 58 received PoV + RTX (38 DLBCL; 20 FL), 63 PiV + RTX (42 DLBCL; 21 FL). Median prior therapies [DLBCL, 3 (1-10); FL, 2 (1-8)] were balanced between treatment arms; 46% were RTX refractory. Median treatment (tx) cycles in DLBCL: 5 for both ADC (1-15); FL: 8.5 PoV (3-15) and 6 PiV (1-13). Overall safety profiles of both regimens were similar. Tx-emergent adverse events (AE) >25%: fatigue (52%), diarrhea (42%), nausea (37%), peripheral neuropathy (PN) (32%), constipation (26%). Grade ≥ 3 AE >3%: neutropenia (21%), diarrhea (6%), dyspnea (4%), febrile neutropenia ...