Media Thread, page-12505

Anyone selling today hasn't read the results of a study which was posted yesterday by Toronumerouno

BACKGROUND:

Chimeric antigen receptor (CAR) T cells targeting the B-cell antigen CD19 are standard therapy for relapsed or refractory B-cell lymphoma and leukemia. CAR T cell therapy in solid tumors is limited due to an immunosuppressive tumor microenvironment and a lack of tumor-restricted antigens. We recently engineered an oncolytic virus (CF33) with high solid tumor affinity and specificity to deliver a nonsignaling truncated CD19 antigen (CD19t), allowing targeting by CD19-CAR T cells. Here, we tested this combination against pancreatic cancer.

STUDY DESIGN:

We engineered CF33 to express a CD19t (CF33-CD19t) target. Flow cytometry and ELISA were performed to quantify CD19t expression, immune activation, and killing by virus and CD19-CAR T cells against various pancreatic tumor cells. Subcutaneous pancreatic human xenograft tumor models were treated with virus, CAR T cells, or virus+CAR T cells.

RESULTS:

In vitro, CF33-CD19t infection of tumor cells resulted in >90% CD19t cell-surface expression. Coculturing CD19-CAR T cells with infected cells resulted in interleukin-2 and interferon gamma secretion, upregulation of T-cell activation markers, and synergistic cell killing. Combination therapy of virus+CAR T cells caused significant tumor regression (day 13): control (n = 16, 485 ± 20 mm³), virus alone (n = 20, 254 ± 23 mm³, p = 0.0001), CAR T cells alone (n = 18, 466 ± 25 mm³, p = NS), and virus+CAR T cells (n = 16, 128 ± 14 mm³, p < 0.0001 vs control; p = 0.0003 vs virus).

CONCLUSIONS:

Engineered CF33-CD19t effectively infects and expresses CD19t in pancreatic tumors, triggering cell killing and increased immunogenic response by CD19-CAR T cells. Notably, CF33-CD19t can turn cold immunologic tumors hot, enabling solid tumors to be targetable by agents designed against liquid tumor antigens.

https://journals.lww.com/journalacs/abstract/2024/04000/using_oncolytic_virus_to_retask_cd19_chimeric.14.aspx