The following is a summary of “Phase II Study: Zanubrutinib Plus Obinutuzumab vs. Obinutuzumab Alone in Relapsed/Refractory Follicular Lymphoma (ROSEWOOD),” published in the November 2023 issue of Oncology by Zinzani, et al.

For a ROSEWOOD study, researchers sought to evaluate the efficacy and safety of zanubrutinib plus obinutuzumab (ZO) compared to obinutuzumab alone (O) in patients with relapsed/refractory follicular lymphoma (FL). The study was designed following positive findings in a phase Ib study, focusing on overall response rate (ORR) as the primary endpoint.

Patients with relapsed/refractory FL who had received at least two prior lines of therapy, including an anti-CD20 antibody and an alkylating agent, were randomized 2:1 to receive either ZO or O. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival, and safety assessments.

In the randomized study involving 217 patients (ZO, 145; O, 72), with a median follow-up of 20.2 months, the combination of zanubrutinib plus obinutuzumab (ZO) demonstrated significant efficacy compared to obinutuzumab alone (O). The primary endpoint, the overall response rate (ORR) by independent central review (ICR), was 69% for ZO, surpassing the 46% observed with O (P = .001). ZO also exhibited a higher complete response rate of 39% compared to 19% for O. The 18-month duration of response (DOR) rate favored ZO at 69%, while O showed 42%. Median progression-free survival (PFS) significantly extended to 28.0 months for ZO compared to 10.4 months for O (hazard ratio, 0.50; 95% CI, 0.33 to 0.75; P < .001). The most prevalent adverse events with ZO included thrombocytopenia, neutropenia, diarrhea, and fatigue. Incidences of atrial fibrillation and major hemorrhage were reported at 3% and 1%, respectively. The findings supported the ZO combination’s favorable efficacy and manageable safety profile in patients with relapsed/refractory follicular lymphoma.

The ZO combination demonstrated superior efficacy, meaningful activity, and a manageable safety profile in patients with relapsed/refractory FL. The study suggested that ZO could be a potential combination therapy for the patient population, offering a favorable benefit-risk profile compared to obinutuzumab alone.

Source: ascopubs.org/doi/full/10.1200/JCO.23.00775