Polatuzumab Vedotin in the Treatment of NHL - News from the 25th EHA Congress

Polatuzumab Vedotin in the Treatment of NHL

Polatuzumab vedotin (Pola) is a conjugate of a cytostatic agent with antimicrotubule activity (MMAE) and a monoclonal antibody against the CD79b antigen. This antigen is present on the surface of malignant lymphocytes (expressed by 95% of DLBCL). After binding of the antibody to the CD79b antigen, the antimicrotubule agent enters the cancer cells, causing their apoptosis.

In the Czech Republic, it is approved for the treatment of R/R DLBCL in combination with rituximab and bendamustine (Pola-BR).

News from the 25th EHA Congress

Ongoing POLARGO Study

Sancho et al. presented a multicentric open-label randomized phase III clinical study POLARGO, aimed at comparing the safety and efficacy of rituximab/gemcitabine/oxaliplatin (R-GEMOX) with the Pola-R-GEMOX regimen. The study includes patients with R/R DLBCL who have not undergone allogeneic HSCT.

The primary outcome of the study will be overall survival (OS). Key secondary outcomes will include the proportion of patients with complete remission (CR) and the objective response rate (ORR). The study is currently open and enrolling patients.

Polatuzumab Vedotin in Real-World Clinical Practice - Experiences from Greece

Dimou et al. presented results of data analysis of patients with R/R DLBCL who were treated with polatuzumab vedotin under a Greek compassionate use program. Patients received Pola in combination with Pola-BR or Pola-R, with the latter used if response to Pola-BR lasted less than 12 months. All had undergone at least 2 lines of therapy before enrollment.

The analysis included 46 adult patients who received Pola under compassionate use between October 2018 and January 2020. 30 patients discontinued treatment, and 16 are continuing it. Among the 30 who discontinued, the median follow-up duration was 3 months. The median number of Pola cycles was 3. The response rate (RR) was 50% (complete remission 17.6%, partial remission 32.4%). Five of the responding patients had undergone ≥ 4 lines of therapy prior to Pola. The median progression-free survival (PFS) was 4 months, and the median OS was 6.5 months.

Polatuzumab Vedotin in the Treatment of R/R Follicular Lymphoma - Interim Analysis Results

Data from in vitro studies suggest that Pola, venetoclax (Ven), and obinutuzumab (Obi) might have a significant antitumor effect in patients with relapsed/refractory follicular lymphoma (R/R FL). A currently ongoing multicentric open-label single-arm phase Ib/II clinical study is including patients with R/R FL who had undergone at least 1 cycle of immunochemotherapy containing an anti-CD20 antibody. In the induction phase, patients received 6 cycles of Pola, Obi, and Ven every 21 days. Patients with complete or partial remission or stable disease continued with Obi (24 months) and Ven (8 months) in the maintenance phase.

Yuen et al. presented interim analysis results as of November 13, 2019. By the analysis date, 71 patients were included in the study, with a median age of 63 years. The most common non-hematological adverse events (AEs) were infections, diarrhea, nausea, and fatigue. Grade 3/4 AEs occurred in 59% of patients, most commonly neutropenia. Preliminary efficacy analysis was conducted on 15 patients, with a response rate assessed according to modified Lugano criteria reaching 87%, and complete remission in 60%.

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Sources:
1. Sancho J.-M., Haioun C., Matasar M. et al. POLARGO: randomized phase III study of polatuzumab vedotin plus rituximab, gemcitabine, and oxaliplatin (R-GEMOX) in relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). EHA 2020 Jun 12: PB2235.
2. Dimou M., Papageorgiou S., Stavroyianni N. et al. Polatuzumab-vedotin in combination with rituximab/bendamustine in a Greek multicenter cohort of relapsed/refractory aggressive B-cell-non-Hodgkin lymphoma patients: real-life data on efficacy & safety. EHA 2020 Jun 12: EP1242.
3. Yuen S. Arthur C., Phillips T. et al. Polatuzumab vedotin + obinutuzumab + venetoclax in patients with relapsed/refractory follicular lymphoma: interim analysis of a phase Ib/II trial. EHA 2020 Jun 12: EP1162.