KEY TAKEAWAYS
- The phase I/II trial aimed to present updated safety and effectiveness data of PRIMCAR MC-1-50 CAR-T cells in r/r B-ALL pts.
- PRIMCAR CAR T cells were given to pts at prescribed doses after preconditioning with fludarabine and cyclophosphamide. Toxicity and cytokine release syndrome were graded using CTCAE and ASTCT criteria, respectively.
- The study found very low doses of PRIMCAR CAR T cells were safe and effective in r/r B-ALL, suggesting potential for outpatient use.
CD19 chimeric antigen receptor (CD19 CAR T) cell therapy has shown promising results in relapsed/refractory(r/r) B-cell acute lymphoblastic leukemia(B-ALL), but life-threatening side effects and disease relapse limit its widespread use.
Researchers aimed to present updated safety and effectiveness data of PrimeCAR platform (PRIMCAR) MC-1-50 CAR-T cells in R/R B-ALL.
The study produced MC-1-50 CAR T cells using the PRIMCAR platform, shortening manufacturing to approximately 2 days. Patients(pts) received a single dose of MC-1-50 at varying doses (Level 1: 1×105 CAR+/kg, Level 2: 2×105 CAR+/kg, Level 3: 3×105 CAR+/kg, Level 4: 5×105 CAR+/kg). Before treatment, pts underwent a 3-day preconditioning regimen with fludarabine (25-30 mg/m2) and cyclophosphamide (200-300 mg/m2). Toxicity was assessed using CTCAE, and CRS and ICANS were evaluated using ASTCT criteria.
About 19 pts with r/r B-ALL were treated. There were no dose-limiting toxicities (DLTs) reported. CRS was observed in 18 pts (94.7%), with 10 (52.6%) at grade 1, 7 (36.8%) at grade 2, and 1 (5.3%) at grade 3; no CRS of grade 4 or higher occurred. ICANS occurred in three pts(15.8%), with 2 (10.5%) at grade 1 and 1 (5.3%) at grade 2; no ICANS of grade 3 or higher occurred. All pts achieved complete remission (CR/CRi) within the first month, with no detectable minimal residual disease (MRD) in the bone marrow. Pts received no other anti-tumor therapy until relapse confirmation. The median duration of response (DOR) was not reached. About 6 pts experienced relapse, 4 becoming CD19 negative and 2 having CD19 gene mutations at relapse. All pts across the 4 dose levels exhibited good CAR-T expansion and long persistence features. Only 3 pts experienced CAR-T loss.
The study found very low doses of PRIMCAR CAR T cells were safe and effective in r/r B-ALL, suggesting potential for outpatient use.
Source: https://ascopubs.org/doi/abs/10.1200/JCO.2023.41.16_suppl.7026#:~:text=
Clinical Trial: https://www.clinicaltrials.gov/study/NCT04271410
Zhi Yang, Shiqi Li, Yu Li, Lin Liu, Zhongtao Yuan, Yingzi Zhang, Le Luo, Lihua Zhang, Yingnian Chen, Qianzhen Zhang, Junjie Shen, Yunyan Li, Linling Wang, Meiling Wang, Wei Zhu, Xiao He, Youcheng Wang, Yancheng Dong, Sanbin Wang, and Cheng Qian. DOI: 10.1200/JCO.2023.41.16_suppl.7026 Journal of Clinical Oncology 41, no. 16_suppl (June 01, 2023) 7026-7026.
