Background
Phase Ib/II, randomized study. 80 patients with R/R DLBCL after ≥1 prior line (median 2 prior lines), transplant-ineligible. Polatuzumab vedotin is an anti-CD79b antibody-drug conjugate (MMAE payload). Tested as Pola-BR vs BR to establish the regimen that became standard salvage for transplant-ineligible R/R DLBCL.
Interventions and follow up
Arm A: Polatuzumab vedotin 1.8mg/kg IV day 1 + bendamustine 90mg/m² IV days 1–2 + rituximab 375mg/m² IV day 1, q21d × 6 cycles
Arm B: Bendamustine 90mg/m² IV days 1–2 + rituximab 375mg/m² IV day 1, q21d × 6 cycles
Primary endpoint: Complete response rate at end of treatment (PET-CT)
Median follow-up: 22.3 months
Arm B: Bendamustine 90mg/m² IV days 1–2 + rituximab 375mg/m² IV day 1, q21d × 6 cycles
Primary endpoint: Complete response rate at end of treatment (PET-CT)
Median follow-up: 22.3 months
Results
CR rate (end of treatment): 40.0% vs 17.5%, P=.026
ORR: 45.0% vs 17.5%
mPFS: 9.5 vs 3.7 months, HR 0.36, 95% CI 0.21–0.63, P<.001
mOS: 12.4 vs 4.7 months, HR 0.42, 95% CI 0.24–0.75, P=.002
mDOR: 12.6 vs 7.7 months
ORR: 45.0% vs 17.5%
mPFS: 9.5 vs 3.7 months, HR 0.36, 95% CI 0.21–0.63, P<.001
mOS: 12.4 vs 4.7 months, HR 0.42, 95% CI 0.24–0.75, P=.002
mDOR: 12.6 vs 7.7 months
Adverse events
Overall: Grade ≥3 AEs 77.5% vs 42.5%
Hematologic: Grade ≥3 neutropenia 46.2% vs 33.3%; thrombocytopenia 41.0% vs 23.3%; febrile neutropenia 10.3% vs 7.1%
Neurologic: Peripheral neuropathy (any grade) 43.6% vs 18.0%
Hematologic: Grade ≥3 neutropenia 46.2% vs 33.3%; thrombocytopenia 41.0% vs 23.3%; febrile neutropenia 10.3% vs 7.1%
Neurologic: Peripheral neuropathy (any grade) 43.6% vs 18.0%
Conclusions
Pola-BR significantly improved CR rate, PFS, and OS versus BR in transplant-ineligible R/R DLBCL, leading to FDA accelerated approval in 2019. This established polatuzumab vedotin as a key component of salvage therapy in this population.
Key Limitations
Phase Ib/II design with small sample size (n=80 randomized) — not a definitive Phase III trial. Accelerated approval based on CR rate; confirmatory data subsequently generated (POLARGO). Transplant-ineligible selection limits applicability to younger/fitter patients. High rate of peripheral neuropathy may limit tolerability. BR is a suboptimal comparator — better outcomes might be seen vs R-GemOx.
Clinical Context
FDA approved Pola-BR in June 2019 (EMA conditional approval 2020) for R/R DLBCL after ≥2 prior lines. Subsequently, POLARGO Phase III (2024) supported polatuzumab + R-GemOx improving PFS vs R-GemOx in 2L+ R/R DLBCL. Pola-R-CHP (POLARIX) moved polatuzumab into frontline. ESMO and ASCO guidance include Pola-BR as a salvage option for transplant-ineligible R/R DLBCL.