LaQuisa C. Hill, MD, on Relapsed or Refractory T-ALL: New Data on CD5 CAR T Cells
2023 ASCO Annual Meeting
LaQuisa C. Hill, MD, of Baylor College of Medicine, Houston Methodist Hospital, discusses study findings showing that CD5 chimeric antigen receptor (CAR) T cells may induce clinical responses in heavily treated patients with relapsed or refractory T-cell acute lymphoblastic leukemia. Manufacturing CD5 CAR T cells with tyrosine kinase inhibitors seemed to improve their potency and antitumor activity (Abstract 7002).
Transcript
Disclaimer: This video transcript has not been proofread or edited and may contain errors.
LaQuisa C. Hill, MD:
The purpose of this study was a phase one clinical trial that was a dose escalation study using autologous CD5 CAR T for treatment of patients with relapse/ refractory T-cell ALL. In the initial cohort, we used our standard manufacturing practice that was overall very well-tolerated. However, in the eight patients initially treated, there were minimal responses seen with only one patient achieving a MRD positive remission.
We subsequently analyzed the cell products and determined that the CAR T cells had a significantly exhausted phenotype as a result of chronic CAR signaling. Therefore, we implemented a manufacturing change to include the use of TKI inhibitors dasatinib and ibrutinib in order to inhibit the chronic CAR signaling and saw a significant improvement in the naive T-cell repertoire and significant reduction in the number of exhausted T-cells in the final product. In the next cohort, we treated a total of seven patients, all manufactured using the TKI inhibition. And amongst those patients there was a total of four MRD negative remissions achieved out of seven patients treated.
The CAR T cell was well-tolerated in terms of CRS and ICANS. No grade-three events occurred. However, there was an increased risk of, or observation of, EBV reactivation with two patients developing PTLD. Currently it is unclear of the direct relationship to the CD5 CAR T cells manufactured with TKI. However, we plan to continue vigilant monitoring for this unexpected side effect and have instituted mitigation plans utilizing prophylactic rituximab as well as ensuring that patients have EBV-specific virus T cells available in the event that EBV reactivation occurs.
Moving forward, we will continue to try and optimize the CAR T cell product both for efficacy and safety and are looking into alternative immune effector subsets, such as virus-specific T cells as the immune factor cell of choice, as well as considering use of third-party or off-the-shelf T cells from healthy donors.
The ASCO Post Staff
Smitha Krishnamurthi, MD, of the Cleveland Clinic, and Deb Schrag, MD, MPH, of Memorial Sloan Kettering Cancer Center, discuss phase III findings from the PROSPECT trial, which showed FOLFOX chemotherapy with selective use of radiation therapy and sensitizing fluoropyrimidine (5FUCRT) is noninferior to 5FUCRT for the neoadjuvant treatment of patients with locally advanced rectal cancer, prior to low anterior resection with total mesorectal excision (Abstract LBA2).
The ASCO Post Staff
Amer Methqal Zeidan, MBBS, MHS, of Yale University and Yale Cancer Center, discusses phase III findings on the first-in-class telomerase inhibitor imetelstat, which was given to patients with heavily transfusion-dependent non-del(5q) lower-risk myelodysplastic syndromes that are resistant to erythropoiesis-stimulating agents. Imetelstat resulted in a significant and sustained red blood cell (RBC) transfusion independence in 40% of these heavily transfused patients. The response was also durable and accompanied by an impressive median hemoglobin rise of 3.6 g/dL, and seen in patients with and without ring sideroblasts. Importantly, reduced variant allele frequency was observed in the most commonly mutated myeloid genes which correlated with duration of transfusion independence and hemoglobin rise, therefore suggesting a disease-modifying potential of this agent (Abstract 7004).
The ASCO Post Staff
Tycel J. Phillips, MD, of City of Hope National Medical Center, and Emanuele Zucca, MD, of the Oncology Institute of Southern Switzerland and the International Extranodal Lymphoma Study Group, discuss findings from the largest prospective study of patients with primary mediastinal B-cell lymphoma. The trial data support omitting radiotherapy in patients who achieve complete metabolic response after immunochemotherapy (Abstract LBA7505).
The ASCO Post Staff
Georgina V. Long, MD, PhD, of Melanoma Institute Australia and The University of Sydney, discusses new data showing that patients with resected stage IIB/C melanoma who were treated with adjuvant nivolumab had prolonged recurrence-free survival compared with placebo across all biomarker subgroups. The baseline biomarkers most predictive of prolonged recurrence-free survival with nivolumab were high interferon gamma score, high tumor mutational burden, CD8 T-cell infiltration, and low C-reactive protein (Abstract 9504).
The ASCO Post Staff
Guillermo Garcia-Manero, MD, of The University of Texas MD Anderson Cancer Center, discusses phase III findings from the COMMANDS trial. Compared with epoetin alfa, luspatercept improved red blood cell transfusion independence and erythroid response, as well as the duration of response in erythropoiesis-stimulating agent–naive, transfusion-dependent patients with lower‐risk myelodysplastic syndromes (Abstract 7003).
