In patients with diffuse large B-cell lymphoma the use of the antibody-drug conjugate Polatuzumab vedotin instead of Vincristine in standard therapy, consisting in Rituximab, Cyclophosphamide, Doxorubicin, Vincristine and Prednisone (R-CHOP), improves patients outcomes, as shown by the Polarix clicinal trial: presented during a media preview of the latest American Society of Hematology (ASH) Annual Meeting, it has been recently published on the New England Journal of Medicine.
R-CHOP is the current standard of care for patients with newly diagnosed diffuse large B-Cell lymphoma, but only 60 to 70 percent of patients are cured with R-CHOP: many patients relapse after receiving the treatment and patients with high risk factors are likely to experience poorer outcomes. That’s why researchers added to the standard therapy Polatuzumab vedotin, an antibody-drug conjugate targeting CD79b, which is ubiquitously expressed on the surface of malignant B cells. For this phase III study, coordinated by Memorial Sloan Kettering Cancer Center, 879 patients with previously untreated intermediate and high-risk lymphoma were randomized to receive six cycles of R-CHOP or a R-CHOP where Vincristine was replaced with Polatuzumab vedotin, plus two cycles of Rituximab alone. After a median follow-up of 28 months, the two-year progression-free survival rate was 76.7% for Polatuzumab vedotin combination versus 70.2 percent of R-CHOP. The study found no difference in overall survival and safety profile between treatment arms.
These results, authors say, support the use of the Polatuzumab vedotin combination in the initial treatment of this patients and study coordinator Gilles Salles, chief of the Lymphoma Service at MSK, said: «Diffuse large B-cell lymphoma is one of the most common hematological malignancies and over the last two decades there have been multiple attempts – albeit unsuccessful – to improve the cure rate of this disease either through modified dose, schedule of R-CHOP or by adding targeted agents to this regimen. This study shows that R-CHP in combination with Polatuzumab vedotin significantly improves progression-free survival rates for patients with diffuse large B-cell lymphoma and results in a sizable reduction in the relapse risk after successful treatment completion, avoiding the use of salvage therapies that are often unsuccessful and associated with significant toxicity burden». In mid-January Polatuzumab vedotin in combination with Bendamustine and Rituximab has been approved in Italy for reimbursement in relapsing/refractory diffuse large B-cell lymphoma patients not suitable for transplantation.