Polatuzumab Vedotin As a Salvage Treatment in Relapsed or Refractory DLBCL: Single Center Experience

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.4558-4558
• Main Authors: Bin Morya, Marwa, Marei, Mohammed A., Tailor, Imran K., Alrajhi, Abdullah M, Alnakhli, Adel, Alnajjar, Foud, Alnoamani, Mohammed S., Alshehri, Hassan, Motabi, Ibraheem H., AlShehry, Nawal, Alfayez, Mansour
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-150242

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, accounting for approximately 25% of all newly diagnosed patients (Swerdlow et. al. IARC, 2017). It is estimated that 40% of patients are refractory to, or relapse after treatment with chemo-immunotherapy (R-CHOP). Salvage therapy with autologous stem-cell transplantation (ASCT) can cure around 40% of those patients, nevertheless, the prognosis is poor for most patients with R/R DLBCL who are relapsed after, or ineligible for ASCT, and in those with suboptimal response to salvage chemotherapy. Polatuzumab vedotin is a CD79b-targeted antibody-drug conjugate delivering monomethyl auristatin E (MMAE), a microtubule inhibitor. It was granted accelerated approval by the US FDA on June 2019 for treatment of R/R DLBCL after at least two prior therapies, in combination with bendamustine and rituximab. We herein report our experience on the use of polatuzumab in patients with R/R DLBCL. Methods: Retrospective-single center review on the use of polatuzumab vedotin as part of a compassionate program in patients with R/R DLBCL between June 2018 and July 2021. Inclusion criteria for the study were: age ≥ 18 years, R/R DLBCL [both de-novo and transformed lymphoma], 2 or more prior lines of therapy, and treatment with polatuzumab-based therapy for at least 1 cycle. Patients with CNS involvement were excluded. The compassionate use access program provided polatuzumab at a dose of 1.8 mg/kg, administered with or without bendamustine (up to two doses of 90 mg/m2,) and rituximab (375 mg/m2). Treatment was given every 21 days for up to 6 cycles. Results: we identified 3 patients with R/R DLBCL who were treated with polatuzumab-based therapy. The median number of prior therapies was 2 (2 - 5). The median IPI and CNS-IPI score were 2, (1 - 4) and 2, (2 - 5), respectively (Baseline characteristics are summarized in Table). The median number of Pola-BR cycles received was 3 (2 - 6). One patient completed 6 cycles of polatuzumab with bendamustine and rituximab and achieved partial response. The other two patients were taken of treatment at the time of progression on cycles number 1 and 3. Treatment options were limited after polatuzumab-based therapy. The patient who achieved partial response after 6 cycles of Pola-BR maintained that response for 11 months without additional treatment and died due to COVID-19 associated pneumonia. One patient been screened for Glofitamab compassionate