Marker Therapeutics Inc (MRKR)

[Lady_luck]

2693 Adoptive T-Cell Therapy for Acute Lymphoblastic Leukemia Targeting Multiple Tumor Associated Antigens
Program: Oral and Poster Abstracts
Session: 614. Acute Lymphoblastic Leukemia: Therapy, excluding Transplantation: Poster II
Hematology Disease Topics & Pathways:
Biological, ALL, Leukemia, Diseases, Therapies, Pediatric, Technology and Procedures, cell expansion, Study Population, immunotherapy, Lymphoid Malignancies
Sunday, December 2, 2018, 6:00 PM-8:00 PM

Thus far we have treated 8 high risk ALL patients with donor derived TAA T cells post-transplant to prevent disease relapse (Table 1). Infusions were well tolerated with no dose-limiting toxicity, GVHD, CRS or other adverse events. Two patients were not evaluable per study criteria as they received >0.5mg/kg of steroids within 4 weeks of infusion and were replaced. Five of the 6 remaining patients infused remain in CR a median of 11.2 months post-infusion (range 9-22 months). We detected the expansion of tumor-reactive T cells in patient peripheral blood post-infusion against both targeted (WT1, Survivin, PRAME) and non-targeted antigens (SSX2, MAGE-A4, -A1, -A2B, -C1, MART1, AFP and NYESO1) reflecting epitope and antigen spreading. The single patient who relapsed showed no evidence of tumor-directed T cell expansion despite receiving 3 additional infusions at 4 week intervals.
Conclusion: In summary, infusion of donor multi-TAA-specific T cells to patients with ALL post allogeneic HSCT is feasible, safe and as evidenced by expansion and antigen spreading in patients, may contribute to disease control. This strategy may present a promising addition to current immunotherapeutic approaches for prophylaxis for leukemic relapse in HSCT recipients.

https://ash.confex.com/ash/2018/webprogram/Paper115465.html