TRAC and Power3 (SPPL3) Genes Knock-out Allogeneic CD19-targeting CAR-T Cell Therapy in r/r B-NHL

Overview

ATHENA chimeric antigen receptor (CAR)-T, a CD19-directed CAR-T cell immunotherapy comprised of allogeneic T cells prepared for the treatment of relapsed or refractory (r/r) B-cell non-Hodgkin's lymphoma (NHL). The cells are from healthy adult volunteer donors that are knocked out of TRAC and Power3 (SPPL3) genes ex vivo using CRISPR-Cas9 gene editing components. In this study, a second-generation anti-CD19 CAR prototype was constructed, bearing murine FMC63 single-chain variant fragment (scFv) together with intracellular CD28 co-stimulatory and CD3ζ signaling domains linked by a CD28 sequence comprising the hinge and transmembrane domains.

This is a single center, prospective, open-label, single-arm, phase 1/2 study. A total of around 30 patients with r/r B-cell NHL will be enrolled in the study and receive allogeneic CD19-CAR-T cell infusion. Phase 1 (n=6 to 18) is a dose escalation part, and phase 2 (n=10 to 12) is a expansion cohort part. The primary objective of this study was to evaluate the safety and efficacy of ATHENA CAR-T cell therapy in patients with r/r B-cell NHL.

Description

Phase 1 (dose escalation)

In phase 1, 6-18 subjects will be enrolled. Subjects will receive 3 doses of ATHENA CAR-T cell therapy ( 1× 10^6 cells/kg、3× 10^6 cells/kg、1 × 10^7 cells/kg) increases from low dose to high dose according to the "3 + 3" principle:

Three (3) subjects are enrolled in a cohort corresponding to a dose level. If 1 subject in a cohort of 3 subjects experiences a dose-limiting toxicity (DLT), 3 additional subjects will be enrolled at the current dose level. For safety purposes, the administration of ATHENA CAR T will be staggered by 28 days between the first two subjects in each cohort. And for each of the remaining cohorts, the administration of ATHENA CAR-T will be staggered by 28 days before enter into the next cohort.

Phase 2 (expansion cohort)

In phase 2, 10 to 12 subjects will be enrolled and receive ATHENA CAR-T cell infusion at dose of recommended phase 2 dose (RP2D), which will be determined based on the maximum tolerated dose (MTD), occurrence of DLT, the obtained efficacy results, pharmacokinetics/pharmacodynamics and other data according to the phase 1.

Objectives

The primary objectives of the phase 1 were to evaluate the tolerability and safety of ATHENA CAR-T in patients with r/r B-cell NHL, and determine RP2D. The primary purpose of the phase 2 study was to evaluate the efficacy of ATHENA CAR-T in the above population.

Eligibility

Inclusion Criteria:

1. Age 18-70 (inclusive).
2. Subjects who meet the following requirements:

   2.1 Histologically confirmed refractory/relapsed B cell NHL, including the following types defined by WHO 2016:

   • Diffuse large B-cell lymphoma (DLBCL) not otherwise specified;
   • Primary mediastinal (thymic) large B-cell lymphoma (PMBCL);
   • Transformed follicular lymphoma (TFL);
   • High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBCL);
   • Follicular lymphoma (FL);
   • Mantle cell lymphoma (MCL) (pathologically confirmed, with documentation of monoclonal B cells that have a chromosome translocation t(11;14)(q13;q32) and/or overexpress cyclin D1);
   • Marginal zone lymphoma (MZL), including nodal or splenic marginal zone B-cell lymphoma and mucosa-associated lymphoid tissue (MALT) lymphoma.

     2.2 Relapsed disease is defined as disease progression (PD) after achieving disease
     remission (including CR and PR) with the latest standard regimen.
     2.3 Refractory disease is defined as no CR to first-line therapy:
       -  Evaluation of PD (never reached response or SD) after standard first-line
          treatment, or
       -  SD as best response after at least 4 cycles of first-line therapy (eg,4 cycles
          of R-CHOP), or
       -  PR as best response after at least 6 cycles and biopsy-proven residual disease
          or disease progression ≤ 6 months of therapy, or
       -  Refractory post-autologous stem cell transplant (ASCT) i. Disease progression
          or relapsed less than or equal to 12 months of ASCT (must have biopsy proven
          recurrence in relapsed individuals) ii. If salvage therapy is given post-ASCT,
          the individual must have had no response to or relapsed after the last line of
          therapy.
     2.4 Individuals who are intolerant to standard treatment can also be included in the
     study in the investigator's judgment.

3. Individuals must have received adequate prior therapy:

3.1 For MCL, prior therapy must have included:

• Anthracycline or bendamustine-containing chemotherapy and
• Anti-CD20 monoclonal antibody (unless investigator determines that tumor is CD20-negative) and
• Bruton's tyrosine kinase inhibitor (BTKi).

3.2 For other types, prior therapy must have included:

• Anti-CD20 monoclonal antibody (unless investigator determines that tumor is CD20-negative) and
• Anthracycline containing chemotherapy regimen.

     3.3 For individual with transformed FL must have relapse or refractory disease after
     transformation to DLBCL.

4. At least 1 measurable lesion: lymph node site with a long axis >1.5cm, extranodal

     site with a long axis >1.0cm (according to Lugano2014). Lesions that have been
     previously irradiated will be considered measurable only if progression has been
     documented following completion of radiation therapy.

5. CD19 positive (detected by immunohistochemistry [IHC]).

6. Toxicities due to prior therapy must be stable and recovered to ≤ Grade 1 (except

     for hematological toxicities and clinically non-significant toxicities such as
     alopecia).

7. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.

8. Absolute neutrophil count (ANC) ≥ 1 x 10^9/L, Platelet count ≥50 x 10^9/L,

     hemoglobin (Hgb) ≥ 80g/L (hemocytopenia caused by lymphoma invasion of bone marrow
     is not subject to conditions above).

9. Adequate renal, hepatic, pulmonary and cardiac function defined as:

     9.1 Serum creatinine≤1.5 upper limit of normal (ULN) or creatinine clearance (as
     estimated by Cockcroft Gault) ≥ 60 mL/min.
     9.2 Serum alanine aminotransferase / aspartate aminotransferase (ALT/AST) ≤ 3 upper
     limit of normal (ULN); Total bilirubin ≤ 1.5 ULN, except in subjects with 3)
     Gilbert's syndrome.
     9.3 Cardiac ejection fraction ≥ 50%, no evidence of pericardial effusion as
     determined by an echocardiogram (ECHO), and no clinically significant
     electrocardiogram (ECG) findings.
     9.4 Coagulation Function: International Normalized Ratio (INR) ≤ 1.5 times the upper
     limit of normal (ULN), and Activated Partial Thromboplastin Time (APTT) ≤ 1.5 times
     ULN.
     9.5 Baseline oxygen saturation >91% on room air.

10. Subjects of both genders who are willing to practice birth control from the time of

     consent through 6 months after the completion of conditioning chemotherapy. Females
     of childbearing potential must have a negative serum or urine pregnancy test
     (females who have undergone surgical sterilization or who have been postmenopausal
     for at least 2 years are not considered to be of childbearing potential).

11. Voluntarily participate in this clinical trial and sign an informed consent form.

Exclusion Criteria:

1. Expected survival time < 3 months per Principal Investigator's opinion.
2. History of malignancy other than nonmelanoma skin cancer or carcinoma in situ (e.g. cervix, bladder, breast) or follicular lymphoma unless disease free for at least 3 years.
3. Autologous stem cell transplant with therapeutic intent within 3 months of planned ATHENA CAR-T infusion.
4. History of allogeneic stem cell transplantation.
5. Prior CD19 targeted therapy.
6. Patients who have used any of the following agents or treatments within a specific period of time:

   6.1 Received any chemotherapy drugs or small molecule targeted drugs within 2 weeks prior to lymphodepletion;

   6.2 Received any monoclonal antibodies, antibody drug conjugates (ADCs), or bispecific antibodies within 3 weeks prior to lymphodepletion;

   6.3 Received radiotherapy within 6 weeks prior to lymphodepletion. However, if disease progressed at the site of radiotherapy, or if there are positive lesions detected by PET-CT at non-radiotherapy sites, enrollment is allowed.

7. Prior CAR-T therapy or other genetically modified T cell therapy.
8. Subjects with detectable cerebrospinal fluid malignant cells, or brain metastases, or with a history of central nervous system (CNS) lymphoma or primary CNS lymphoma.
9. History of severe, immediate hypersensitivity reaction attributed to lymphodepletion drugs or any component of ATHENA CAR-T.
10. Presence or suspicion of fungal, bacterial, viral, or other infection that is uncontrolled or requiring intravenous (IV) antimicrobials for management.
11. Uncontrolled or active infectious diseases, such as human immunodeficiency virus (HIV) infection, acute or chronic active hepatitis B or C, epstein-barr virus (EBV), and cytomegalovirus (CMV) infection.
12. History or presence of central nervous system (CNS) disorder such as seizure disorder, cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, or any autoimmune disease with CNS involvement.
13. Subjects with cardiac atrial or cardiac ventricular lymphoma involvement.
14. History of myocardial infarction, cardiac angioplasty or stenting, unstable angina, or other clinically significant cardiac disease within 12 months of enrollment.
15. Expected or possible requirement for urgent therapy within 6 weeks due to ongoing or impending oncologic emergency (eg, tumor mass effect, tumor lysis syndrome).
16. Primary immunodeficiency.
17. History of autoimmune disease (e.g. Crohn's, rheumatoid arthritis, systemic lupus) resulting in end organ injury or requiring systemic immunosuppression/systemic disease modifying agents within the last 2 years.
18. History of symptomatic deep vein thrombosis or pulmonary embolism requiring systemic anticoagulation within 6 months of enrollment.
19. Any medical condition likely to interfere with assessment of safety or efficacy of study treatment.
20. History of severe immediate hypersensitivity reaction to any of the agents used in this study.
21. Vaccine ≤ 6 weeks prior to planned start of conditioning regimen.
22. In the investigator's judgment, the subject is unlikely to complete all protocol-required study visits or procedures, including follow-up visits, or comply with the study requirements for participation.