PD-1 Blockade for Diffuse Large B-Cell Lymphoma after Autologous Stem Cell Transplantation

• Published in: Blood 2018-11, Vol.132 (Supplement 1), p.706-706
• Main Authors: Chen, Yi-Bin, Armand, Philippe, Redd, Robert A., Bsat, Jad, Merryman, Reid W, Coleman, Kimberly, Herrera, Alex F., Dahi, Parastoo B., Nieto, Yago, LaCasce, Ann S., Fisher, David C., Ng, Samuel Y., Odejide, Oreofe O., Freedman, Arnold S., Kim, Austin I, Crombie, Jennifer L, Jacobson, Caron A., Jacobsen, Eric D, Wong, Jeffrey L, Patel, Sanjay S, Ritz, Jerome, Rodig, Scott J, Shipp, Margaret A., Joyce, Robin M.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-114914

Background: The leading cause of death after high-dose chemotherapy and autologous stem cell transplantation (ASCT) for relapsed / refractory (R/R) diffuse large B-cell lymphoma (DLBCL) remains disease relapse. Except for specific subsets, DLBCL appears to have relatively low susceptibility to single-agent PD-1 blockade. However, administering PD-1 blockade early after ASCT could leverage the remodeling immune landscape and minimal residual disease state to increase the therapeutic effect of PD-1 blockade and decrease the relapse rate after ASCT. A prior study with pidilizumab showed encouraging results in this setting (Armand et al. JCO 2013;31:4199-206), but the specificity of that antibody is still under investigation. We therefore conducted a phase 2 multi-center single-arm study of the anti-PD-1 monoclonal antibody pembrolizumab (pembro) in patients with chemosensitive DLBCL after ASCT. Another arm of this study enrolled pts with R/R classical Hodgkin lymphoma and will be presented separately. Methods: Patients ≥ 18y with R/R DLBCL who had received no more than 3 lines of prior therapy and had undergone ASCT with chemosensitive disease were enrolled on this study. In addition to meeting standard eligibility criteria for pembro treatment, pts had to have recovered from ASCT toxicities and had to begin study treatment within 60 days of stem cell infusion, with a goal of starting treatment within 21 days of hospital discharge. All patients received pembro 200mg IV every 3 weeks for 8 cycles. PET-CT scans were obtained at post-ASCT baseline, after 3 and 7 cycles, then at 12 and 18 months post-ASCT. The primary endpoint was the progression-free survival rate (PFS) at 18 months after ASCT, assessed using the International Harmonization Project 2007 criteria, with the approach considered promising if 22 patients were alive and in remission at 18 months. Results: 31 pts were enrolled and 2 withdrew consent before starting treatment. Among the 29 eligible pts, median age was 57 (22-76). Prior to ASCT, 18 (62%) were in CR and 11 (38%) were in PR. At study baseline (post-ASCT), 25 (86%) were in CR. 18 pts (62%) completed all 8 cycles of pembro per protocol. 11 pts (38%) stopped pembro early for pt choice (n=1, after febrile neutropenia), toxicity (n=6, including 3 pts with gr3 pneumonitis, 1 with g3 hepatitis, 1 with gr4 aplastic anemia) or progressive disease (n=4). 23 pts (79%) experienced a total of 57 gr3 or higher adverse events (AEs). The most common gr4 A