Elizabeth Lihua Budde, MD, PhD, breaks down the design and baseline characteristics of the phase 3 POLARIX trial that led to the approval of polatuzumab in combination with R-CHP for certain patients with diffuse large B-cell lymphoma.
Elizabeth Lihua Budde, MD, PhD, associate professor in the division of lymphoma in the department of hematology & hematopoietic cell transplantation and executive medical director of the Enterprise Immune Effector Cell Program, at City of Hope in Duarte, California, discusses the design and patient makeup of the phase 3 POLARIX (NCT03274492) study.
This randomized, double-blind, placebo-controlled trial of 879 patients with previously untreated diffuse large B-cell lymphoma, who also had to have an International Prognostic Index (IPI) score of 2-5, compared the use of combination polatuzumab vedotin-piiq (Polivy) in addition to rituximab (Rituxan), cyclophosphamide, doxorubicin hydrochloride (hydroxydaunomycin), and prednisone (R-CHP) with standard of care R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate [Oncovin], and prednisone).
The results of this trial demonstrated a statistically significant number of patients had progression-free survival (PFS) at 2 years for patients given the antibody-drug conjugate compared with R-CHOP at 76.7% (95% CI, 72.7%-80.8%) vs 70.2% (95% CI, 65.8%-74.6%), respectively (HR 0.73; 95% CI, 0.57-0.95, P = .02).
Overall survival and toxicities remained similar in both arms, but these data were enough to secure an FDA approval in April 2023 for this combination for patients with high-grade DLBCL. Budde discusses the design of this trial that led to the FDA approval and what role polatuzumab plays in this treatment combination.
0:08 | So, POLARIX is a phase 3 study that [randomly assigned] around 1000 patients to either the standard of care using R-CHOP or [randomly assigned] patients to the group that are using using R-CHP-pola, meaning they were replacing vincristine with polatuzumab. And polatuzumab, as we know, it's a targeted chemotherapy; an antibody-drug conjugate that is targeting CD79b, which is a protein commonly expressed in B-cell lymphoma.
0:45 | So, these patients were [randomly assigned] to these 2 groups, also based on their IPI score…based on either if they were a 2 or 3-5. So, any patient with IPI 1 will not be in involved in this study. The age is also capped between 18 to 80 [years of age], in a 1:1 randomization. So, these patients received a total of 6 cycles [of treatment] in either arm, followed by 2 cycles of rituximab at the end of the chemotherapy treatment. The primary end point for this randomization study was really to look at the PFS.