Clinical Trials and Medical Case Reports
Map4k1 Disruption Reprograms Cd8+ T Cells Toward a Stem-Like Memory Phenotype, Enhances Car-T Cell Persistence and Antileukemic Efficacy in a First-In-Human B-Cell Acute Lymphoblastic Leukemia Trial, and Explores Immune Dysfunction, Neuroinflammatory Signatures, and Precision Immunotherapeutic Opportunities in Neurodivergent Patients
Abstract
Camilo Fernández Bravo
Background Chimeric Antigen Receptor (CAR) T-cell therapy targeting CD19 yields profound initial responses in relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL). However, sustained disease-free survival is severely limited by accelerated T-cell exhaustion and premature structural clearance in vivo. Mitogen-Activated Protein Kinase Kinase Kinase Kinase 1 (MAP4K1), or Hematopoietic Progenitor Kinase 1 (HPK1), operates as a key cell-intrinsic negative regulator that disassembles the proximal T-cell receptor (TCR) signalosome.
Methods In this investigator-initiated, open-label, Phase I dose-escalation clinical trial, we evaluated the safety, production feasibility, pharmacokinetic profile, and therapeutic efficacy of multiplex-engineered anti-CD19 CAR T-cells subjected to targeted CRISPR-Cas9-mediated MAP4K1 disruption (MAP4K1-KO-CAR-T19). Fifteen adult patients with highly advanced R/R B-ALL were enrolled across three ascending target dose cohorts (0.5 \times 10^6, 1.0 \times 10^6, and 2.0 \times 10^6\text{ CAR}^+\text{ cells/kg}). A pre-specified exploratory sub-cohort integrated four patients with documented neurodivergent conditions (Autism Spectrum Disorder [ASD], Attention-Deficit/Hyperactivity Disorder [ADHD]) to systematically isolate interactions involving baseline microglial activation, cerebrospinal fluid (CSF) cytokinemia, and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) kinetics.
Results CRISPR-Cas9 ribonucleoprotein delivery achieved a mean MAP4K1 indel frequency of 88.4\% \pm 4.2\%. Disruption of MAP4K1 consistently prevented the inhibitory phosphorylation of SLP-76 (\text{Ser}^{376}) and LAT (\text{Thr}^{155}), driving a profound cellular transition toward a stem-like memory phenotype (\text{T}_{\text{SCM}}:\text{CD45RA}^+\ text{CD62L}^+\text{CCR7}^+\text{CD95}^+) comprising 42.6\% \pm 5.1\% of the final drug product. Over a median clinical observation window of 18.4 months, the objective response rate (ORR) stood at 93.3\%, with 86.7\% (n=13/15) achieving a deep minimal residual disease-negative complete remission (MRD− CR). Cellular persistence was significantly prolonged, maintaining stable B-cell aplasia beyond 12 months in 80.0\% of responders. Cytokine Release Syndrome (CRS) occurred in 80.0\% of participants, with severe presentations (Grade \ge 3) limited to 13.3\%. Total ICANS incidence reached 33.3\%. Neurodivergent patients exhibited elevated baseline CSF levels of IL-6 (8.4 \pm 1.6\text{ pg/mL} vs. 1.9 \pm 0.4\text{ pg/mL}) and soluble TREM2 (28.4 \pm 3.1\text{ ng/mL} vs. 12.1 \pm 1.8\text{ ng/mL}), accelerating the onset of initial neurotoxic manifestations (Day 4 \pm 1 vs. Day 7 \pm 2). However, maximum ICANS severity, peak neuroinflammatory markers, and neuroimaging indicators did not escalate, resolving completely with targeted, protocol-driven interventions.
Conclusions Genome-wide disruption of the MAP4K1 locus successfully redirects CAR T-cell differentiation toward an elite \text{T}_{\ text{SCM}} configuration, providing enhanced persistence and robust antileukemic efficacy in advanced R/R B-ALL. Furthermore, our findings establish that baseline neuroimmune variations in neurodivergent