CARS in Childhood Malignancies

(Vortragsslides all 3 Presentations)


Stephan Grupp, MD, PhD, Children's Hospital of Philadelphia, USA 

US indications for ALLCART (tisa-cel): Refractory or 2nd relapse and 25 yo or less


CYTOKINE RELEASE SYNDROME (CRS): • CRS is related to T cell expansion and may be necessary for efficacy • Symptoms typically occur 1-14 days after CTL019 cell infusion in ALL • Severity scales with disease burden

SEVERE CRS: High ferritin levels suggest Macrophage Activation Syndrome (MAS/HLH); 

CRS ASSOCIATED WITH IFNy AND IL-6: Toci is now the only indicated CRS treatment 

EARLY/PRE-EMPTIVE CRS TREATMENT: • "Early toci" trial testing tocilizumab pre-emptive therapy N =70 • High disease burden (>=40% blasts) only N=15 • Single-dose toci given at the time of sustained fever (true CRS onset) to pre-empt grade 4 CRS • Followed by standard CRS management for both high and low tumor burden cohorts. see the paper "Risk-Adapted Preemptive Tocilizumab to Prevent Severe Cytokine Release Syndrome After CTL019 for Pediatric B-Cell Acute Lymphoblastic Leukemia: A Prospective Clinical Trial."

TRENDS IN INPATIENT/ICU ADMISSION FROM 2012-2019: see the paper "Risk-Adapted Preemptive Tocilizumab Decreases Severe Cytokine Release Syndrome (CRS) after CTL019 CD19-Targeted Chimeric Antigen Receptor (CAR) T-Cell Therapy for Pediatric B-Cell Acute Lymphoblastic Leukemia (B-ALL)"

PERSISTENT CAR T: BRIDGE TO SCT OR BRIDGE OVER SCT? • 80-90% of CHOP patients do not go to BMT after CTL019 • Who does? Plan for BMT all along • MRD+ at D28 (rare) • Early B cell recovery ( <6 mo) • BMT vs. reinfusion • 2nd post-CAR remission • ??? MLL rearranged??? • Concern for lineage switch

EXPANDED INDICATIONS IN ALL CNS DISEASE CONTROL: • 12 patients w / prior CNS3 status • These pts ranged from 1st to 6th relapse pre-CTL019 (1st CNS relapse=l, 2nd= 6, 3rd= 3, 4+= 2) • 4 pts were CNS2 on d-1, all CNS 1 on D28 • ~2% CTL019 patients have experienced CNS relapse • 1 pt with Ph+ disease and 6 prior CNS relapses remains in CR at 4 years • 98% of all pts have CTL019 in CSF • 9/9 pts in CR at 1 yr have CTL019 in CSF (2177 to 15,727 copies/ug genomic DNA).

SHOTS ON GOAL BEYOND BALL/NHL: • Multiple myeloma - BCMA CAR • AML - CD123, CD33 • ALL - CD22, potential combined therapies • CD19/22 combo to reduce relapse risk (CD19 escape) • All these are hematologic malignancies • Solid tumor CARs are not there yet • Problems with trafficking and evasion.


Adapter CAR-T cells: Implications for childhood cancer

Patrick Schlegel, University of Sydney, Children's Medical Research Institute, Westmead Children's Hospital

Adapter CART cell design: see this paper for more information 

AdCAR advantages over conventional CARs: One CAR for all adapter molecule formats; Efficacy: No limitation in cell number; Combinatorial & sequential targeting; Treatment in cycles (physiologic recruitment and engagement of CAR T cells); Promising target antigens in childhood cancer; 

The problem with CAR-T cell target antigens: • Co-expressed on healthy cells • Variable expression levels • Fraction of cancers only express target antigen • Fraction of cancer cells only positive • Evolutionary loss of target antigen;

Solution: • Find best antigens • Distribute toxicity • Multiple synchronic targeting

Clinically used target antigens: 

  • CD-19 (blinatumomab): - Highly co-expressed on 8-lineage cells - Low expression on plasma cells - Very low expression on neurons - Clean target antigen - Long-term targeting possible under substitution of B-ce/1 function.
  • CD33 (gemtuzumab/ozagamycin): - Highly co-expressed on hematopoietic progenitor cells - Clean target antigen - Transient targeting only due to dramatic mye/otoxlclty 

How to start?

• start now (what are we waiting for?) • CAR T cell therapy is NOT more dangerous than chemotherapy • utilise the safety mechanism of AdCAR-T to understand cancer-associated targeting beyond B-lineage restricted antigens • dose in carefully as antibody therapy provides only limited information for CAR T cell therapy • generate broad knowledge and understanding for the application of direct CAR T cell therapy (AdCAR-T might be a transitional program for some applications) • once proven safe, generate data on multiple synchronic targeting - pave the way and fast-track the CART cell development.

start in B-lineage derived cancers; start in fluidic cancers & neuroblastoma


CAR NK-cells: The next generation of Cellular Cancer Therapy

May Daher, M.D., Assistant Professor, Department of Stem Cell Transplantation and Cellular Therapy, MD Anderson

Challenges of autologous CAR-T therapy: Autologous CAR-T still has a number of limitations: 

Patients progress or die while waiting (~10-20%) or manufacturing failure (~5-7%); patient-to-patient variability- "Health of T cells"; Costly, complicated manufacturing; Commercial challenges.

Autologous vs allogeneic CAR products 

Before patient diagnosis : Autologous: patient-derived vs Allogeneic: healthy donor-derived

After patient diagnosis: week 1 Apheresis - week 2-4 manufacture - week 4+single treatment vs immediate treatment (Eliminates the manufacturing time and allows true point, -Can scale to much larger numbers with broader Impact for those In need that will never be possible with the need to generate an auto product for each patient.

Allogeneic CAR-T cells: Need for genetic engineering

NK Cells

  • Innate immune system
  • CD56+CD3-
  • Differentiate in the BM
  • No antigen priming
  • Not antigen specific
  • No/low risk of GVH D Recognition takes place through complex array of receptors

T Cells

  • Adaptive immune system
  • CD3+CD4+ or CD3+CD8+
  • Differentiate in the thymus
  • Antigen priming required
  • Antigen specific 
  • Allogeneic T cells induce GVHD
  • Recognize targets through TCR rearrangement

Advantages of N K cells over T cells for CAR therapy:

CAR-T • Autologous Product • Production time • Cost • 1 patient, 1 product • If allogeneic: GVHD risk • Toxicity: cytokine release syndrome; neurotoxicity (50% need ICU care) • CAR-mediated killing

CAR-NK • Allogeneic Product • "Off the shelf" • Potential low cost • Low/absent GVHD • CAR+ NK Receptor mediated

Clinical CAR-NK Transduction & Expansion: 

Can we enhance CAR NK cell function by targeting checkpoints? • Cytokine-lnducible SH2-containing protein • Encoded by the Cish gene • Negative feedback loop to suppress JAK/STAT signaling in both T and NK cells - Ablation of CIS releases a brake on NK cells, increasing their activity. CISH KO CAR19/IL15 NK cells improve tumor control and survival in a non-curative Raji lymphoma mouse model & C/SH KO improves the fitness and cytotoxicity of CAR-NK cells.
• Autologous CAR-T cells have some limitations despite their success • Allogeneic sources of IEC's for CAR therapy are being explored • NK cells are promising alternative vehicles for CAR engineering • A first-in-human clinical trial confirmed the safety and efficacy of CAR19/IL15 cord blood NK cells • Engineered CB-NK cells targeting other antigens are in development • Targeting checkpoints can increase CAR NK activity