Dose Escalation Study of Cyclophosphamide in HIV-Infected Subjects on HAART Receiving SB-728-T

Study Overview
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Brief Summary
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The purpose of the study is to evaluate the safety, tolerability and effect on HIV viral load, of escalating doses of cyclophosphamide administered 1 day prior to SB-728-T infusion.

Detailed Description
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The objectives of the study are to augment HIV-specific T-cells and to reverse or decrease the progressive destruction of CD4+ T-cells that leads to clinical AIDS. Levels of engraftment vary from negligible to about 10% of the CD4+ T-cells in the vascular compartment. Preliminary analyses of HAART TI suggest that an anti-HIV effect may correlate with the level of SB-728-T engraftment. Concurrently, non-myeloablative lymphodepletion with cyclophosphamide has been demonstrated to enhance engraftment of adoptively transferred T-cells through a variety of mechanisms. The study is being undertaken to increase SB-728-T engraftment through the administration of low non-myeloablative doses of cyclophosphamide.

Official Title
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A Phase I, Open-Label Study to Assess the Effect of Escalating Doses of Cyclophosphamide on the Engraftment of SB-728-T in Aviremic HIV-Infected Subjects on HAART

Conditions
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HIV

Intervention / Treatment
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* Genetic: SB-728-T
* Genetic: SB-728-T
* Genetic: SB-728-T
* Genetic: SB-728-T
* Genetic: SB-728-T


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female, 18 years of age or older with documented HIV diagnosis within 10 years of screening. Must be willing to comply with study-mandated evaluations; including discontinuation of current antiretroviral therapy during the treatment interruption. Must have received at least 6 months of continuous HAART therapy and have had undetectable VLs for the preceding 3 months. On stable antiretroviral medication (no changes to treatment within 4 weeks of screening. CD4+ T-cell count ≥500 cells/µL. Undetectable HIV-1 RNA obtained at screening. ANC ≥2500/µL Platelet count ≥200,000/µL Exclusion Criteria: Acute or chronic hepatitis B or hepatitis C infection. Active or recent (in prior 6 months) AIDS defining complication. Any cancer or malignancy within the past 5 years, with the exception of successfully treated basal cell or squamous cell carcinoma of the skin or low grade (0 or 1) anal or cervical dysplasia. Current diagnosis of NYHA grade 3 or 4 CHF, uncontrolled angina or arrhythmias. History or any features on physical examination indicative of a bleeding diathesis. Received HIV experimental vaccine within 6 months prior to screening, or any previous gene therapy using an integrating vector. Use of chronic corticosteroids, hydroxyurea, or immunomodulating agents within 30 days prior to screening. Use of Aspirin, dipyridamole, warfarin or any other medication that is likely to affect platelet function or other aspects of blood coagulation during the 2 week period prior to leukapheresis. Currently participating in another clinical trial or participation in such a trial within 30 days prior to screening visit. Subjects who are currently taking maraviroc or have received maraviroc within 6 months prior to screening.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1 - IV cyclophosphamide 200 mg<br> | Genetic: SB-728-T<br>* Infusion will be 5 to 30 billion ZFN modified CD4+ T cells 1 day following IV cyclophosphamide 200 mg<br>* Other names: cyclophosphamide;|
| Experimental: Cohort 2 - IV cyclophosphamide 0.5 g/m2<br> | Genetic: SB-728-T<br>* Infusion will be 5 to 30 billion ZFN modified CD4+ T cells up to 3 days following IV cyclophosphamide 0.5 g/m2<br>* Other names: cyclophosphamide;|
| Experimental: Cohort 3 - IV cyclophosphamide 1.0 g/m2<br> | Genetic: SB-728-T<br>* Infusion will be 5 to 30 billion ZFN modified CD4+ T cells up to 3 days following IV cyclophosphamide 1.0 g/m2<br>* Other names: cyclophosphamide;|
| Experimental: Cohort 4 - IV cyclophosphamide 2.0 g/m2<br> | Genetic: SB-728-T<br>* Infusion will be 5 to 30 billion ZFN modified CD4+ T cells up to 3 days following IV cyclophosphamide 2.0 g/m2<br>* Other names: cyclophosphamide;|
| Experimental: Cohort 5 - IV cyclophosphamide 1.5 g/m2<br> | Genetic: SB-728-T<br>* Infusion will be 5 to 30 billion ZFN modified CD4+ T cells up to 3 days following IV cyclophosphamide 1.5 g/m2<br>* Other names: cyclophosphamide;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment-emergent Adverse Events | Number of Participants with Treatment related Adverse Events in subjects who received any portion of the SB-728-T infusion | 28 days after the SB-728-T infusion of the last subject in each Cohort and up to 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of Escalating Doses of Cyclophosphamide on SB-728-T Engraftment as Measured by CCR5 Modified CD4 Cells in Blood. | Effect of repeat doses of SB-728-T on engraftment following cyclophosphamide conditioning as measured by CCR5 Modified CD4 Cells in blood at Month 12. | Up to 12 months after the last SB-728-T infusion | 
| Effect of SB-728-T on Plasma HIV-1 RNA Levels Following HAART Interruption | Effect of SB-728-T on plasma HIV-1 RNA levels following HAART interruption. The unit is log copies/mL, except for the Cohort 1, the unit is  copies/mL. Cohort 1 mean and SD are 0. All 3 subjects had NO HIV-1 RNA DETECTED. | Up to 12 months after the last SB-728-T infusion | 
| Change From Baseline to Month 12 in CD4+ T-cell Counts in Peripheral Blood After Repeat Treatments With SB-728-T. (i.e. Month 12 Value - Baseline Value) | Change from baseline to month 12 in CD4+ T-cell counts in peripheral blood after repeat treatments with SB-728-T. (i.e. month 12 value - baseline value) | Up to 12 months after the last SB-728-T infusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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autologous cell therapy, cyclophosphamide, HIV