The Effect of Vorinostat on HIV RNA Expression in the Resting CD4+ T Cells of HIV+ Pts on Stable ART

HIV-1 Infection Clinical Trial

Official title: A Phase I/II Investigation of the Effect of Vorinostat (VOR) on HIV RNA Expression in the Resting CD4+ T Cells of HIV-Infected Patients Receiving Stable Antiretroviral Therapy

Status Completed

Clinical Trial Summary

The purpose of this study is to compare HIV RNA expression and infection within resting (CD4)+ cells in HIV-infected patients on stable ART before and after a single exposure to Vorinostat (VOR), after exposure to short intervals of VOR, and after repeated short interval exposure to VOR dosed over several weeks.

Hypotheses:

1. The frequency of resting CD4+ T cell- associated HIV RNA (RCVL) will be increased following single and repeated exposure to VOR when given at appropriate intervals, and

2. That repeated exposure to VOR will reduce the frequency of HIV infection within resting CD4+ T cells (RCI)

Clinical Trial Description

This is a Phase I-II single-center study in participants (ppts) with HIV-1 infection receiving stable ART, with plasma HIV RNA < 50 copies/mL. Baseline ART will be maintained throughout the study. Participants will be screened for study entry, and then undergo an initial leukapheresis evaluation at study entry to obtain resting CD4+ T cells for quantitation of resting CD4+ T cell infection (RCI) and resting CD4+ T cell- associated HIV RNA (RCVL) at a baseline evaluation. All 1st time leukapheresis participants, and others as requested based on prior latent pools determinations will have HIV-1 DNA PCR done. All participants who enter the study will receive VOR at assigned study visits, and undergo repeat leukapheresis to measure the effects of VOR exposure.

Participants with and without an ex vivo response to VOR (baseline leukapheresis [Visit 2.0]) will be evaluated for an in vivo response to the single dose of VOR 400 mg. Participants who completed Step 1 in protocol v3.0 and v5.0 are eligible to enroll directly into Step 2 after being consented to Version 6.0 and completing Step 1, Visits 1 and 2 of this protocol. The leukapheresis at Visit 2 will be optional based on prior ascertainment of baseline parameters. Omission of the leukapheresis at visit 2 will be determined by study PI. Enrollment and completion of required research assays will be completed at this study visit. Enrollment into Step 1 will continue until 12 evaluable participants have successfully completed multiple doses of VOR (Step 3), or until the study-stopping rules are met.

Step 1 includes four visits: screening (visit 1), enrollment and baseline Leukapheresis (Visit 2), single dose administration of VOR (visit 3) and safety follow up (Visit 4). It is estimated that up to 30 eligible participants may be screened and enrolled to provide a total of 12 evaluable participants who complete Step 3. VOR 400 mg will be administered as a single dose at study Visit 3. Each participant will only receive 400 mg VOR at this one time point. An abbreviated pharmacokinetics (PK) as well as a leukapheresis procedure will be part of Visit 3. It is anticipated that Step 1 will occur over a minimum of 8 weeks. All participants must complete Step 1 prior to moving to Step 2. All participants will be assessed after the Visit 3 leukapheresis for an in vivo response to the 400 mg of VOR.

Progression from Step 1 (single dose) to Step 2 (paired doses) will be based on each participant's increase in RCVL following their first dose of 400 mg VOR (Visit 3), compared to that measured at baseline (Visit 2). Progression from Step 2 (paired doses) to Step 3 (multiple doses) will be based on each participant's increase in RCVL following the 3rd dose of 400 mg VOR (Visit 6), compared to that measured at baseline (Visit 2).

The goal of this study is to determine the optimal interval between two doses of VOR (Step 2), and the response of RCI (and secondarily RCLV) to repeated doses at this interval (Step 3).

Step 2 will be initiated at least 4 weeks after the completion of the Step 1 safety follow up visit (Visit 4). If greater than 60 days elapse between Visit 4 and Visit 5, participants will repeat screening Visit labs to qualify for continued study participation. In Step 2, two paired doses of VOR 400 mg will be administered. The interval between the 2 paired doses can be as short as 48 hours, and as much as 4 days apart from each other, and participants will be assessed via a 3rd leukapheresis for in vivo response to the second of the paired doses of 400 mg VOR. The first three (3) participants will first be assessed for an in-vivo response after the 2nd dose of the paired doses given 48 hours (2 days) apart. Subsequent participants will be assessed for responses to paired doses separated by 48 hours, or the interval may be lengthened to as much 96 hours (4 days), as dictated by the accumulated responses observed in subsequent participants.

If at least 2 of the 3 participants with 48-hour intervals respond (defined as a significant within-subject increase in cell-associated HIV RNA, see Fig 3), then 3 subsequent participants will receive 48-hour intervals. If 2 of these 3 respond 4 of 6 total), then 3 additional participants will receive 48-hour intervals. If among the first 6 evaluable participants receiving 48-hour intervals there are 3 non-responders, then subsequent participants will receive 72-hour intervals. Participants receiving 72-hour intervals will then be assessed in the same way as those receiving 48-hour intervals, to either continue additional participants at 72-hour intervals or to increase to 96-hour intervals. Step 2 will enroll until a total of 12 evaluable subjects with a measureable increase in cell-associated HIV RNA are obtained, and these volunteers have advanced to Step 3.

Our preliminary results from version 5.0 are consistent with the hypothesis that the complex cellular effects of HDAC inhibitor exposure require more than 24 hours to resolve. We observed what appears to be an antagonistic effect where a VOR dose blunts the effect of the next dose when two doses are given within 24 hours of each other. The purpose of Step 2 is to establish the optimal dosing interval in which a response to Vorinostat is sustained. Step 2 will study dosing intervals; starting with a 48-hour interval and moving to longer intervals between doses depending on the effect observed with the ultimate goal to determine the shortest interval that yields an optimal effect of VOR.

If a participant fails to respond in their initial Step 2 dosing interval, they can be eligible to repeat Step 2. They can re-enter or repeat Step 2 one time only. They will only re-enter Step 2 to test a longer dosing interval. Again, if > 60 days elapses between the final safety visit of step 2 (Visit 7) and their re-entry to Step 2, they will re-screen (visit 1 only) to qualify to continue in the study.

After a period of at least 6 weeks, to allow data analysis, participants who demonstrate an in vivo response to the 2nd of the paired dose of VOR will proceed to Step 3 and receive 10 doses of VOR 400 mg administered at the same interval at which cell-associated HIV-RNA induction was observed in Step 2. If greater than 60 days elapse between Visit 7 and Visit 8, participants will repeat the screening visit labs to qualify for continued participation in the study. At the completion of 10 doses, participants will then be assessed via a 4th and final leukapheresis for in vivo response to the serial dosing of VOR.

It is anticipated that Step 3 will occur over a minimum of 4 weeks; however this may vary among participants based on their Step 2 dosing interval stage. Accumulated blood volumes and the timing between leukapheresis procedures will determine the length of time between each stepsParticipants completing this protocol (version 6.0), who respond initially in Step 2 will receive a total of 5200 mg of Vorinostat. Participant completing the study, who repeat Step 2, will receive a total of 6000 mg of Vorinostat. For reference, participants who completed the previous version (5.0) received a total of 10,000 mg of Vorinostat without clear evidence of any durable drug-associated toxicity thus far.

The change in the frequency of HIV-1 infection per million resting CD4 + cells will be measured after repeated short interval dosing with VOR in Step 3. This 4th leukapheresis (Visit 12) will be compared to the baseline leukapheresis done at Visit 2. If the VOR 400 mg dosing in Step 3 is interrupted due to toxicity or intolerance, then the leukapheresis will be performed as soon as possible after the VOR interruption. This is justified as if a depletion of resting cell infection can occur; new resting cell infection is unlikely to occur in the presence of ART. Test dosing in this Step will continue until the study's stopping (lack of response in five) or toxicity rules are met. ;

Study Design

Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• HIV-1 Infection

• NCT number: NCT01319383
• Study type: Interventional
• Source: University of North Carolina, Chapel Hill
• Status: Completed
• Phase: Phase 1/Phase 2
• Start date: March 2011
• Completion date: April 2016