Colleen E. Annesley, MD, on Working to Mitigate Inferior Cell Persistence With Manufactured T-APCs
The medical Director and interim co-Chief Medical Officer at Seattle Children's Therapeutics discussed complete data from the PLAT-03 feasibility trial assessing SCRI-CAR19 and CD19t T-APCs in B-ALL.
“So, the major aims of the PLAT-03 study were to look at the feasibility of being able to manufacture these patient-derived products, from stored leftover apheresis products for patients and deliver T APCs to patients after their CAR T-cell infusion. And then the other thing was to look at safety to see, how well were these products tolerated in patients? We had some preliminary data on this several years ago presented at ASH... but now the trial is complete.”
The use of CD19t T-APCs (manufactured T cells with CD19 tag antigen presenting cells) in patients treated with SCRI-CAR19 for relapsed, refractory CD19+ B-cell acute lymphocytic leukemia (B-ALL) likely to have inferior persistence and thus higher risk of relapse was well tolerated and appeared to enhance cell persistence.
These data, from the PLAT-03 (NCT03186118) pilot study, were presented in a poster at the 2023 American Society of Hematology (ASH) Annual Meeting & Exposition, held December 9-12, in San Diego, California by Colleen E. Annesley, MD, Medical Director and interim co-Chief Medical Officer, Seattle Children's Therapeutics, and Associate Professor, Department of Pediatrics, University of Washington School of Medicine.
CGTLive spoke with Annesley to learn more about PLAT-03 and the updated data from it. She discussed the factors that led to inferior persistence, including low antigen burden, and the trend of improved persistence seen. She shared that more research into T-APCs is warranted based off of the data seen in PLAT-03 and necessary to see a possible clear improvement in leukemia-free survival considering patients who received T-APCs were not similar at baseline to those who did not.
Click here to read more coverage of the ASH 2023 meeting.
REFERENCE
Annesley C, Seidel K, Wu QV, et al. A phase 2 trial of SCRI-CAR19 demonstrates favorable leukemia-free survival (LFS), with a pilot study of CD19-expressing T-cell antigen presenting cells (CD19t T-APCs) demonstrating safety and tolerability. Presented at: 2023 ASH Annual Meeting & Exposition, December 9-12; San Diego, California. Abstract 3467
Conservative Management Following Treatment With DMD Gene Therapy Elevidys
May 19th 2025Ben Samelson-Jones, MD, PhD, the associate director of clinical in vivo gene therapy at Children’s Hospital of Philadelphia discussed a case he presented at the American Society of Gene and Cell Therapy’s 2025 meeting.
