Prof. Hervé Tilly (University of Rouen, France) explained that R-CHOP, the standard-of-care regimen for patients with DLBCL, cures 60 to 70% of patients with this condition. In the last 20 years, adaptations to the R-CHOP treatment regimen have not succeeded in meeting the unmet need in this population. The current, randomised, double-blind, phase 3 POLARIX trial (NCT03274492) added polatuzumab vedotin, an antibody drug conjugate targeting CD79b, to rituximab, cyclophosphamide, doxorubicin, and prednisone.
Patients with previously untreated DLBCL (n=879) were randomised 1:1 to 6 cycles of Pola-R-CHP (1.8 mg/kg IV polatuzumab vedotin on day 1 of 21-day cycle) or R-CHOP. The primary endpoint was progression-free survival.
After a median follow-up of 28 months, the Pola-R-CHP regimen showed superiority over the R-CHOP regimen regarding progression-free survival (HR 0.73; P<0.02). Similarly, patients in the Pola-R-CHP arm displayed higher event-free survival rates than patients in the R-CHOP arm (HR 0.75; P=0.02).
Although overall response rates did not significantly differ between treatment groups, disease-free survival rates (HR 0.70) indicated that patients who achieved a complete response in the Pola-R-CHP arm were more likely to maintain remission than patients in the R-CHOP arm who reached a complete response. The overall survival rates were 88.6% in both groups. Notably, patients treated with Pola-R-CHP received fewer subsequent therapies (22.5%) than patients treated with R-CHOP (30.3%).
Exploratory subgroup analyses are ongoing to further specify the results of the POLARIX trial. The safety profiles of the 2 regimens were comparable, with approximately 57% of the patients in both treatment groups experiencing grade 3 or 4 adverse events (AEs). Although febrile neutropenia and diarrhoea were more common in the Pola-R-CHP condition, treatment with Pola-R-CHP led to fewer dose reductions (9.2%) than treatment with R-CHOP (13.2%). The prevalence of peripheral neuropathy was similar in both research arms.
Reference:
1. Tilly H, et al. The POLARIX Study: Polatuzumab Vedotin with Rituximab, Cyclophosphamide, Doxorubicin, and Prednisone (Pola-R-CHP) Versus Rituximab, Cyclophosphamide, Doxorubicin, Vincristine and Prednisone (R-CHOP) Therapy in Patients with Previously Untreated Diffuse Large B-Cell Lymphoma. LBA-1, ASH 2021 Scientific Sessions, 11-14 December.