Evaluating polatuzumab vedotin and pinatuzumab vedotin for relapsed or refractory NHL

This study evaluated the safety and effectiveness of rituximab (Rituxan) combined with either polatuzumab vedotin (pola) or pinatuzumab vedotin (pina) for patients with non-Hodgkin’s lymphoma (NHL) that has come back or stopped responding to treatment. This study concluded that pola was associated with better treatment responses compared to pina.

Treatment remains challenging for high-risk patients with relapsed or unresponsive NHL. One of the goals of developing new treatments is to improve treatment response. This can help reduce the chances of disease relapse and progression (tumor growth or spread).

Antibody-drug conjugates (ADCs) are a new treatment that may help. This treatment directly delivers anti-cancer drugs to tumors, leading to cancer cell death. Pola and pina are two new ADCs for the treatment of relapsed or refractory NHL. The safety and effectiveness of these agents remain under investigation.

This study involved 81 patients with diffuse large B cell lymphoma (DLBCL) and 41 patients with follicular (FL). Patients received rituximab with either pola (R-pola) or pina (R-pina). They were followed-up for up to 1 year after treatment.

In the DLBCL group, more patients treated with R-pina responded to treatment compared to R-pola (60% vs. 54%). Slightly more patients treated with R-pina had a complete disappearance of all signs of cancer compared to R-pola (26% vs. 21%).

In the FL group, more patients treated with R-pola responded to treatment compared to R-pina (70% vs. 62%). More patients treated with R-pola also had a complete disappearance of all signs of cancer compared to R-pina (45% vs. 5%).

On average, patients in the DLBCL group treated with R-pola did not have tumor growth or spread for significantly longer than patients treated with R-pina (13.4 months vs. 6.2 months). For the FL group, patients treated with R-pola also did not have tumor growth or spread for longer than patients treated with R-pina (9.4 months vs. 6.5 months).

In the DLBCL group, 79% (R-pina) and 77% (R-pola) had serious side effects. The most common was severe low white blood cell count (29% vs. 23%). 10% of patients treated with R-pina also reported high blood sugar levels. In the FL group, 62% (R-pina) and 50% (R-pola) had serious side effects. The most common was severe low white blood cell count (29% vs. 15%). 10% of patients treated with R-pola also reported severe diarrhea.

This study concluded that patients with relapsed or unresponsive NHL responded better to polatuzumab vedotin than to pinatuzumab vedotin. This was due mostly to the longer duration of response and lower side effects.

This study was funded by F Hoffmann-La Roche, the manufacturer of the study treatments. Also, this was a phase 2 study. More studies are needed to confirm the roles of polatuzumab vedotin and pinatuzumab vedotin in the treatment of patients with relapsed or unresponsive NHL.