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.
Related Videos
The ASCO Post Staff
Bobbie J. Rimel, MD, of Cedars-Sinai Medical Center, and Mansoor R. Mirza, MD, of Denmark’s Rigshospitalet and Copenhagen University Hospital, discuss new findings on dostarlimab-gxly plus carboplatin/paclitaxel, which improved progression-free survival while maintaining health-related quality of life, further supporting its use as a standard of care in primary advanced or recurrent endometrial cancer (Abstract 5504).
The ASCO Post Staff
Cathy Eng, MD, of Vanderbilt-Ingram Cancer Center, and Thejus Jayakrishnan, MD, of the Cleveland Clinic Taussig Cancer Institute, discuss significant differences in the citrate cycle, a core pathway of cellular metabolism associated with colorectal cancer. Metabolomic differences impacted by environmental exposures (arginine biosynthesis and dietary red meat) were also noted, suggesting possible links with younger age of onset in this disease (Abstract 3510).
The ASCO Post Staff
Lisa A. Carey, MD, of the University of North Carolina at Chapel Hill, and Javier Cortes, MD, PhD, of the International Breast Cancer Center and Universidad Europea de Madrid, discuss phase II findings showing that one in three patients with HER2-positive early breast cancer may safely omit chemotherapy. Among the chemotherapy-free patients treated with trastuzumab and pertuzumab, the 3-year invasive disease–free survival was 98.8%, with no distant metastases (Abstract LBA506).
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
Narjust Florez, MD, of Dana-Farber Cancer Institute, and Roy S. Herbst, MD, PhD, of Yale Cancer Center, discuss new phase III findings on osimertinib, a third-generation, central nervous system EGFR-TKI, which demonstrated an unprecedented overall survival benefit for patients with EGFR-mutated, stage IB–IIIA non–small cell lung cancer after complete tumor resection, with or without adjuvant chemotherapy (Abstract LBA3).
