Title

Safety Study of a Dual Anti-HIV Gene Transfer Construct to Treat HIV-1 Infection
An Adaptive Phase I/II Study of the Safety of CD4+ T Lymphocytes and CD34+ Hematopoietic Stem/Progenitor Cells Transduced With LVsh5/C46, a Dual Anti-HIV Gene Transfer Construct, With and Without Conditioning With Busulfan in HIV-1 Infected Adults Previously Exposed to ART
  • Phase

    Phase 1/Phase 2
  • Study Type

    Interventional
  • Study Participants

    13
This is an early phase research study looking at whether an experimental gene transfer, LVsh5/C46 (also known as Cal-1), is safe and if it can protect the immune system from the effects of HIV without the use of antiretroviral drugs.

Cal-1 is an experimental gene transfer agent designed to inhibit HIV infection through 2 active parts:

Removing a protein named CCR5 from bone marrow and white blood cells
Producing a protein named C46 on bone marrow and white blood cells
It is estimated that 33 million individuals are currently infected with HIV. HIV/AIDS is a disease that impairs immune function, primarily by decreasing CD4+ T lymphocytes. The progression can be contained by daily dosing with antiretroviral therapy (ART) but there are side effects that can be treatment limiting, and the development of HIV drug resistance can force the physician to modify the ART regimen. There are no effective vaccines currently available for HIV.

LVsh5/C46 (also known as Cal-1) is a dual therapeutic, self-inactivating lentiviral vector that encodes for both a short hairpin RNA against the HIV-1 co-receptor CCR5 (sh5) and a HIV-1 fusion inhibitor, C46 and inhibits two processes required for HIV-1 infection:

Binding of the virus to the cellular CCR5 co-receptor and
Fusion of the virus with the host cell

The rationale is that Cal-1 introduced into hematopoietic progenitor/stem cells (HSPC) and mature CD4+ T lymphocytes will protect these cells and their progeny cells from HIV-1 infection and its pathogenic sequelae. This may provide a continuous means of controlling HIV-1 after a single or infrequent dose(s), thereby decreasing or delaying (partially or completely) the need for antiretroviral drug therapy.
Study Started
Apr 30
2013
Primary Completion
Sep 30
2017
Study Completion
Nov 30
2017
Results Posted
Aug 06
2020
Last Update
Aug 06
2020

Drug Busulfan

Intravenous busulfan

  • Other names: Busulfex

Biological Cal-1 modified HSPC

Hematopoietic progenitor/stem cells (HSPC) modified with LVsh5/C46 (Cal-1)

  • Other names: LVsh5/C46 modified HSPC

Biological Cal-1 modified CD4+ T lymphocytes

CD4+ T lymphocytes modified with LVsh5/C46 (Cal-1)

  • Other names: LVsh5/C46 modified CD4+ T lymphocytes

No busulfan pre-conditioning Experimental

Cal-1 modified HSPC and Cal-1 modified CD4+ T lymphocytes without busulfan preconditioning

1 x 4mg/kg busulfan preconditioning Experimental

Cal-1 modified HSPC and Cal-1 modified CD4+ T lymphocytes, with single 4mg/kg busulfan dose administered as pre-conditioning for transplant

2 x 4mg/kg busulfan pre-conditioning Experimental

Cal-1 modified HSPC and Cal-1 modified CD4+ T lymphocytes, with two 4mg/kg busulfan doses administered as pre-conditioning for transplant

Criteria

Inclusion Criteria:

Prior to any study-related procedures, signed informed consent indicating that they understand the purpose, risks and procedures required for the study and are willing to participate in the study
Individuals aged 18 to 65 years of age (inclusive) at time of consent
Documented HIV-1 infection ≥ 6 months prior to Screening 1
Previous treatment with antiretroviral agents that had a demonstrated suppressive effect (defined as plasma HIV RNA ≤ 50 copies/ml)
A documented viable ART regimen option, as determined by the Investigator, taking into account prior ART experience and HIV geno/phenotyping analyses

Not taking antiretroviral therapy for ≥ 6 weeks prior to Screening 1, for one or more of the following reasons:

i) Concerns over short-term or long-term toxicities associated with antiretroviral agents, or ii) Treatment fatigue from the daily regimen of life-long therapy

Plasma HIV-1 viral RNA ≥ 5,000 copies/mL and ≤ 100,000 copies/ml at Screening 1 and Screening 2
CD4+ T lymphocyte count ≥ 500 cells/µl at Screening 1 and Screening 2

Exclusion Criteria:

Abnormal hematology at Screening 1: Absolute neutrophil count (ANC) < 1.5 x 109/L, Platelet count < 100 x 109/L, Hemoglobin < 10 g/dL
Abnormal biochemistry at Screening 1: Alanine aminotransferase (ALT) > 2.5 x Upper Limit of Normal (ULN), Total bilirubin > 1.5 x ULN, Serum creatinine > 1.5 x ULN
Detection of any CXCR4-tropic HIV-1 at Screening 1
Evidence of co-infection with hepatitis B virus, hepatitis C virus, West Nile Virus, or HTLV-1 as detected at Screening 2
Evidence of active TB infection determined by positive QuantiFERON®-TB Gold/IGRA test result and clinical confirmation at Screening 2
ART or other antiretroviral therapy within 6 weeks of Screening 1 or any time during the pre-infusion period
Documented history of CD4+ T lymphocyte count < 250 cells/µl
Any previous or current AIDS-defining illnesses (CDC Category C), including AIDS-related dementia, with the exception of Kaposi's sarcoma confined to the skin
History of malignancy or systemic chemotherapy within the last 5 years (i.e., subjects with prior malignancy must be disease-free for 5 years), except curatively-treated basal cell carcinoma, cutaneous squamous cell carcinoma, or cervical or anal intra-epithelial neoplasia
History of steroid-dependent asthma in the past 5 years
History of seizure
Any clinical history of hematologic diseases including leukemia, myelodysplasia, myeloproliferative disease, thromboembolic disease, sickle cell disorder, thrombocytopenia or leukopenia
Class II-IV heart failure, according to the New York Heart Association classification
Inadequate venous access for apheresis, as assessed at Screening 1
Current or planned systemic immunosuppressive or immunomodulatory medication
Taking warfarin, aspirin or any medication that is likely to affect platelet function or other aspects of blood coagulation, and unable to safely cease this medication for a period of 1 week prior, during, and 1 week after administration of G-CSF (a total period of 19 days)
Participation in any study involving any investigational drug or medical device within 30 days prior to Screening 1
Receipt of a vaccine for HIV-1 or any gene transfer product at any time
Prior treatment with recombinant G-CSF or busulfan or other stem-cell mobilizing or modulating agent within the previous 12 months
Known hypersensitivity to busulfan, G-CSF (Neupogen™) or E. coli-derived proteins
Subjects who will not accept transfusions of blood products
Pregnant or breast-feeding at any time between Screening 1 and Baseline (infusion)
History of alcohol or drug abuse within the 12 months prior to Screening 1
Inability to understand and provide informed consent

Summary

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

All Events

Event Type Organ System Event Term Cohort 1 (CSL202 With No Busulfan) Cohort 2 (CSL202 With 1 Busulfan Dose) Cohort 3 (CSL202 With 2 Busulfan Doses)

Total Area Under the Curve (AUC) for Busulfan

Cohort 3: Total AUC = first dose AUC value + second dose AUC value

Cohort 2 (CSL202 With 1 Busulfan Dose)

6521.5
micromolar*min (Mean)
Full Range: 5863.0 to 7259.0

Cohort 3 (CSL202 With 2 Busulfan Doses)

8296.8
micromolar*min (Mean)
Full Range: 7893.0 to 8601.0

Number of Participants With Severe and Life-threatening Adverse Events (AEs)

Cohort 1 (CSL202 With No Busulfan)

Life-threatening

Severe

Cohort 2 (CSL202 With 1 Busulfan Dose)

Life-threatening

Severe

Cohort 3 (CSL202 With 2 Busulfan Doses)

Life-threatening

Severe

Number of Participants With Severe or Life-threatening AEs Related to CSL202

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

Number of Participants With the Presence of Replication-competent Retrovirus

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

Number of Participants With Predominant Integration Site Analysis

Vector Integration Site Analysis performed only when Cal-1 Marking is >= 1%.

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

Mean Cell Dose for CD4+ Cells (Ttn)

Cohort 1 (CSL202 With No Busulfan)

16.94
Number (10^8 cells) (Mean)
Full Range: 14.61 to 20.62

Cohort 2 (CSL202 With 1 Busulfan Dose)

81.855
Number (10^8 cells) (Mean)
Full Range: 38.94 to 138.68

Cohort 3 (CSL202 With 2 Busulfan Doses)

49.553
Number (10^8 cells) (Mean)
Full Range: 20.7 to 79.29

Mean Cell Dose for CD34+ Cells (HSPCtn)

Cohort 1 (CSL202 With No Busulfan)

2.1
Number (10^6 cells/kg body weight) (Mean)
Full Range: 0.35 to 5.0

Cohort 2 (CSL202 With 1 Busulfan Dose)

2.4
Number (10^6 cells/kg body weight) (Mean)
Full Range: 1.0 to 4.0

Cohort 3 (CSL202 With 2 Busulfan Doses)

10.6
Number (10^6 cells/kg body weight) (Mean)
Full Range: 7.4 to 12.5

Percent Transduction Efficiency of CD4+ Cells (Ttn) and CD34+ Cells (HSPCtn) of Final Cell Product

Cohort 1 (CSL202 With No Busulfan)

CD34+ Cells (HSPCtn)

58.6
Percent transduction efficiency (Mean)
Full Range: 51.0 to 77.0

CD4+ Cells (Ttn)

41.0
Percent transduction efficiency (Mean)
Full Range: 21.0 to 60.0

Cohort 2 (CSL202 With 1 Busulfan Dose)

CD34+ Cells (HSPCtn)

26.3
Percent transduction efficiency (Mean)
Full Range: 12.0 to 53.0

CD4+ Cells (Ttn)

29.2
Percent transduction efficiency (Mean)
Full Range: 13.0 to 39.0

Cohort 3 (CSL202 With 2 Busulfan Doses)

CD34+ Cells (HSPCtn)

31.3
Percent transduction efficiency (Mean)
Full Range: 21.0 to 49.0

CD4+ Cells (Ttn)

66.8
Percent transduction efficiency (Mean)
Full Range: 39.0 to 84.0

Cal-1 C46 Expression in Peripheral Blood

C46 relative expression will be analyzed by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and normalized to the expression of β2-microglobulin (β2M) mRNA

Cohort 1 (CSL202 With No Busulfan)

Peak marking

Week 48

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

1.0496
units of relative expression (Mean)
Full Range: 0.0 to 2.9977

Week 48

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

2.1701
units of relative expression (Mean)
Full Range: 0.0 to 6.48

Week 48

Number of Participants With HIV-1 Tropism Shift

Shift from R5 to X4 or dual/mixed tropism

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

Cal-1 sh5 Expression in Peripheral Blood

sh5 relative expression will be analyzed by RT-qPCR and normalized to the expression of RNU38B microRNA

Cohort 1 (CSL202 With No Busulfan)

Peak marking

Week 48

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

0.2027
units of relative expression (Mean)
Full Range: 0.0 to 0.6489

Week 48

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

1.6933
units of relative expression (Mean)
Full Range: 0.193 to 4.6736

Week 48

Percent Cal-1 Marking in Peripheral Blood

Cohort 1 (CSL202 With No Busulfan)

Peak marking

0.35
percent Cal-1 marking (Mean)
Full Range: 0.0 to 1.16

Week 48

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

0.765
percent Cal-1 marking (Mean)
Full Range: 0.61 to 0.89

Week 48

0.1275
percent Cal-1 marking (Mean)
Full Range: 0.0 to 0.38

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

3.12
percent Cal-1 marking (Mean)
Full Range: 0.18 to 7.46

Week 48

0.1275
percent Cal-1 marking (Mean)
Full Range: 0.0 to 0.49

Cal-1 Marking in Gut-associated Lymphoid Tissue (GALT) (10-15 cm)

Samples were collected via endoscopic biopsy from the sigmoid colon: 10-15 cm from the anal margin

Cohort 1 (CSL202 With No Busulfan)

Peak marking

0.8121
copies/cell (Mean)
Full Range: 0.0 to 2.7054

Week 48

0.8121
copies/cell (Mean)
Full Range: 0.0 to 2.7054

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

0.0007
copies/cell (Mean)
Full Range: 0.0 to 0.0019

Week 48

0.0004
copies/cell (Mean)
Full Range: 0.0 to 0.001

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

0.0022
copies/cell (Mean)
Full Range: 0.0006 to 0.006

Week 48

0.0001
copies/cell (Mean)
Full Range: 0.0 to 0.0004

Cal-1 Marking in GALT (25-35 cm)

Samples were collected via endoscopic biopsy from the sigmoid colon: 25-35 cm from the anal margin

Cohort 1 (CSL202 With No Busulfan)

Peak marking

0.0255
copies/cell (Mean)
Full Range: 0.0 to 0.0677

Week 48

0.0255
copies/cell (Mean)
Full Range: 0.0 to 0.0677

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

0.0003
copies/cell (Mean)
Full Range: 0.0 to 0.0011

Week 48

0.0003
copies/cell (Mean)
Full Range: 0.0 to 0.0011

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

0.0068
copies/cell (Mean)
Full Range: 0.002 to 0.0186

Week 48

0.0055
copies/cell (Mean)
Full Range: 0.0 to 0.0186

Cal-1 Marking in Bone Marrow

Cohort 1 (CSL202 With No Busulfan)

Peak marking

0.0007
copies/cell (Mean)
Full Range: 0.0 to 0.0026

Week 48

0.0007
copies/cell (Mean)
Full Range: 0.0 to 0.0026

Cohort 2 (CSL202 With 1 Busulfan Dose)

Peak marking

0.0539
copies/cell (Mean)
Full Range: 0.0005 to 0.2027

Week 48

0.0015
copies/cell (Mean)
Full Range: 0.0005 to 0.0044

Cohort 3 (CSL202 With 2 Busulfan Doses)

Peak marking

0.0021
copies/cell (Mean)
Full Range: 0.0009 to 0.003

Week 48

0.0009
copies/cell (Mean)
Full Range: 0.0003 to 0.0025

HIV Viral Load at Baseline Screening and Week 48 or at Anti-retroviral Therapy (ART) Re-commencement

Cohort 1 (CSL202 With No Busulfan)

Baseline screening

4.59
Log10 (copies/mL) (Mean)
Full Range: 4.06 to 4.87

Week 48 or at ART re-commencement

4.56
Log10 (copies/mL) (Mean)
Full Range: 4.0 to 4.93

Cohort 2 (CSL202 With 1 Busulfan Dose)

Baseline screening

4.51
Log10 (copies/mL) (Mean)
Full Range: 3.98 to 4.82

Week 48 or at ART re-commencement

4.7
Log10 (copies/mL) (Mean)
Full Range: 3.88 to 4.96

Cohort 3 (CSL202 With 2 Busulfan Doses)

Baseline screening

4.28
Log10 (copies/mL) (Mean)
Full Range: 3.45 to 4.62

Week 48 or at ART re-commencement

4.61
Log10 (copies/mL) (Mean)
Full Range: 4.2 to 4.95

CD4+ Count at Baseline Screening and Week 48 or at ART Re-commencement

Cohort 1 (CSL202 With No Busulfan)

Baseline screening

680.75
CD4+ cells/cubic mm (Mean)
Full Range: 522.5 to 809.5

Week 48 or at ART re-commencement

553.3
CD4+ cells/cubic mm (Mean)
Full Range: 450.0 to 759.0

Cohort 2 (CSL202 With 1 Busulfan Dose)

Baseline screening

575.13
CD4+ cells/cubic mm (Mean)
Full Range: 537.0 to 677.5

Week 48 or at ART re-commencement

383.5
CD4+ cells/cubic mm (Mean)
Full Range: 274.0 to 549.0

Cohort 3 (CSL202 With 2 Busulfan Doses)

Baseline screening

668.63
CD4+ cells/cubic mm (Mean)
Full Range: 529.0 to 878.0

Week 48 or at ART re-commencement

245.5
CD4+ cells/cubic mm (Mean)
Full Range: 152.0 to 385.0

Total

13
Participants

Age, Continuous

46.2
years (Mean)
Standard Deviation: 9.2

Age, Categorical

Race (NIH/OMB)

Region of Enrollment

Sex: Female, Male

Overall Study

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)

Drop/Withdrawal Reasons

Cohort 1 (CSL202 With No Busulfan)

Cohort 2 (CSL202 With 1 Busulfan Dose)

Cohort 3 (CSL202 With 2 Busulfan Doses)