Study of Efficacy and Safety of CTL019 in Pediatric ALL Patients

This is a single arm, open-label, multi-center, phase II study to determine the efficacy and safety of CTL019 in pediatric patients with r/r B-cell ALL.

This was a initially a one cohort, open-label, multi-center, phase II study to determine the efficacy and safety of CTL019 in pediatric patients with r/r B-cell ALL. This main cohort completed enrollment. Two new cohorts were added via an amendment, Cohort 1 for high risk B-cell ALL patients at first relapse, and Cohort 2 for feasibility and safety of CTL019 in high risk B-cell ALL in patients that relapsed \<6 months post allo-HSCT. Due to lack of recruitment, Cohort 1 and Cohort 2 halted recruitment. This decision was not related to any safety issue.

The study had the following sequential phases: Screening, Pre-Treatment (Cell Product Preparation \& Lymphodepleting Chemotherapy), Treatment and Primary Follow-up, Secondary Follow-up (if applicable) and Survival Follow-up. The total duration of the study is 5 years from CTL019 cell infusion.

Efficacy analyses were performed only on the Main Cohort (n=79) who were infused with tisagenlecleucel. However, the data on disposition and demographics presented in this section includes all patients enrolled to the study (98) and all infused patients (80) (Main Cohort + Cohort 1). No patients were enrolled in Cohort 2.

Eligibility Criteria:
Inclusion Criteria:

1. Relapsed or refractory pediatric B-cell ALL
2. Adequate organ function
3. For relapsed patients, documentation of CD19 tumor expression within 3 months of study entry.
4. Bone marrow with ≥ 5% lymphoblasts by morphologic assessment at screening.
5. Life expectancy \> 12 weeks.
6. Karnofsky (age ≥16 years) or Lansky (age \< 16 years) performance status ≥ 50 at screening
7. Signed written informed consent and assent forms
8. Must meet the institutional criteria to undergo leukapheresis or have an acceptable, store leukapheresis product
9. Must have an apheresis product of non-mobilized cells received and accepted by the manufacturing site.
10. Cohort 1 only:

    1. First relapse AND hypodiploid cytogenetics OR
    2. First relapse AND t(17;19) with defined TCF3-HLF fusion OR
    3. First relapse with any cytogenetics provided the relapse occurred ≤ 36 months of initial diagnosis AND MRD at end of reinduction therapy is ≥0.01% by flow cytometry (local assessment)

Exclusion Criteria

1. Isolated extra-medullary disease relapse
2. Patients with concomitant genetic syndrome: such as patients with Fanconi anemia, Kostmann syndrome, Shwachman syndrome or any other known bone marrow failure syndrome. Patients with Down Syndrome will not be excluded.
3. Patients with Burkitt's lymphoma/leukemia (i.e. patients with mature B-cell ALL, leukemia with B-cell \[sIg positive and kappa or lambda restricted positivity\] ALL, with FAB L3 morphology and /or a MYC translocation)
4. Prior malignancy, except carcinoma in situ of the skin or cervix treated with curative intent and with no evidence of active disease
5. Treatment with any prior gene therapy product
6. Has had treatment with any prior anti-CD19/anti-CD3 therapy, or any other anti-CD19 therapy
7. Active or latent hepatitis B or active hepatitis C (test within 8 weeks of screening), or any uncontrolled infection at screening
8. Human Immunodeficiency Virus (HIV) positive test within 8 weeks of screening
9. Presence of grade 2 to 4 acute or extensive chronic graft-versus-host disease (GVHD).
10. Active CNS involvement by malignancy, defined by CNS-3 per NCCN guidelines.
11. Patient has an investigational medicinal product within the last 30 days prior to screening.
12. Pregnant or nursing (lactating) women.
13. Women of child-bearing potential, defined as physiologically capable of becoming pregnant, unless they agree to use highly effective methods of contraception for at least 12 months after the CTL019 infusion and after CAR T-cells are no longer present by qPCR on two consecutive tests
14. Sexually active males must use a condom during intercourse at least 12 months after the CTL019 infusion after CAR T-cells are no longer present by qPCR on two consecutive tests