Tisagenlecleucel utilisation and outcomes across refractory, first relapse and multiply relapsed B-cell acute lymphoblastic leukemia: a retrospective analysis of real-world patterns

• Authors: Valentin Barsan, Stanford University; Yimei Li, University of Pennsylvania; Snehit Prabhu, Stanford University; Christina Baggott, Stanford University; Khanh Nguyen, Stanford University; Holly Pacenta, University of Texas, Southwestern; Christine L. Phillips, University of Cincinnati; Jenna Rossoff, Ann and Robert H. Lurie Children's Hospital of Chicago; Heather Stefanski, University of Minnesota; Julie-An Talano, Medical College of Wisconsin; Amy Moskop, Medical College of Wisconsin; Susanne Baumeister, Boston Children's Hospital; Michael R. Verneris, University of Colorado, Anschutz; Gary Douglas Myers, Children's Mercy Hospital; Nicole A. Karras, City of Hope National Medical Center; Stacy Cooper, Johns Hopkins University; Muna Qayed, Emory University; Michelle Hermiston, University of California, San Francisco; Prakash Satwani, Columbia University; Christa Krupski, University of Cincinnati; Amy Keating, University of Colorado, Anschutz; Vanessa Fabrizio, University of Colorado, Anschutz; Vasant Chinnabhandar, University of Minnesota; Michael Kunicki, Stanford University; Kevin J. Curran, Memorial Sloan Kettering Cancer Center; Crystal L. Mackall, Stanford University; Theodore W. Laetsch, University of Pennsylvania; Liora M. Schultz, Stanford University
• Journal Title: EClinicalMedicine
• Volume: Volume 65
• Publisher: Elsevier | 2023-10-26, Pages 102268-None
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.eclinm.2023.102268
• Subjects: Health Sciences, Oncology; Health Sciences, Immunology
• Keywords: Immunotherapy; CAR T cells; Tisagenlecleucel; First relapse; Pediatric oncology; Real-world analysis; Commercial CAR; CD19 CAR T cells

Abstract

Background Tisagenlecleucel was approved by the Food and Drug Administration (FDA) in 2017 for refractory B-cell acute lymphoblastic leukemia (B-ALL) and B-ALL in ≥2nd relapse. Outcomes of patients receiving commercial tisagenlecleucel upon 1st relapse have yet to be established. We aimed to report real-world tisagenlecleucel utilisation patterns and outcomes across indications, specifically including patients treated in 1st relapse, an indication omitted from formal FDA approval. Methods We conducted a retrospective analysis of real-world tisagenlecleucel utilisation patterns across 185 children and young adults treated between August 30, 2017 and March 6, 2020 from centres participating in the Pediatric Real-World CAR Consortium (PRWCC), within the United States. We described definitions of refractory B-ALL used in the real-world setting and categorised patients by reported Chimeric Antigen Receptor (CAR) T-cell indication, including refractory, 1st relapse and ≥2nd relapse B-ALL. We analysed baseline patient characteristics and post-tisagenlecleucel outcomes across defined cohorts. Findings Thirty-six percent (n = 67) of our cohort received tisagenlecleucel following 1st relapse. Of 66 evaluable patients, 56 (85%, 95% CI 74–92%) achieved morphologic complete response. Overall-survival (OS) and event-free survival (EFS) at 1-year were 69%, (95% CI 58–82%) and 49%, (95% CI 37–64%), respectively, with survival outcomes statistically comparable to remaining patients (OS; p = 0.14, EFS; p = 0.39). Notably, toxicity was increased in this cohort, warranting further study. Interestingly, of 30 patients treated for upfront refractory disease, 23 (77%, 95% CI 58–90%) had flow cytometry and/or next-generation sequencing (NGS) minimum residual disease (MRD)-only disease at the end of induction, not meeting the historic morphologic definition of refractory. Interpretation Our findings suggested that tisagenlecleucel response and survival rates overlap across patients treated with upfront refractory B-ALL, B-ALL ≥2nd relapse and B-ALL in 1st relapse. We additionally highlighted that definitions of refractory B-ALL are evolving beyond morphologic measures of residual disease.