Recommendations for measuring HIV reservoir size in cure-directed clinical trials.

Therapeutic strategies are being clinically tested either to eradicate latent HIV reservoirs or to achieve virologic control in the absence of antiretroviral therapy. Attaining this goal will require a consensus on how best to measure the numbers of persistently infected cells with the potential to cause viral rebound after antiretroviral-therapy cessation in assessing the results of cure-directed strategies in vivo. Current measurements assess various aspects of the HIV provirus and its functionality and produce divergent results. Here, we provide recommendations from the BEAT-HIV Martin Delaney Collaboratory on which viral measurements should be prioritized in HIV-cure-directed clinical trials.

Early versus deferred antiretroviral therapy for children older than 1 year infected with HIV (PREDICT): a multicentre, randomised, open-label trial.

BACKGROUND: The optimum time to start antiretroviral therapy for children diagnosed with HIV infection after 1 year of age is unknown. We assessed whether antiretroviral therapy could be deferred until CD4 percentages declined to less than 15% without affecting AIDS-free survival. METHODS: In our multicentre, randomised, open-label trial at nine research sites in Thailand and Cambodia, we enrolled children aged 1-12 years who were infected with HIV and had CD4 percentages of 15-24%. Participants were randomly assigned (1:1) by a minimisation scheme to start antiretroviral therapy at study entry (early treatment group) or antiretroviral therapy to start when CD4 percentages declined to less than 15% (deferred treatment group). The primary endpoint was AIDS-free survival (based on US Centers for Disease Control and Prevention category C events) at week 144, assessed with the Kaplan-Meier analysis and the log-rank approach. This study is registered with ClinicalTrials.gov, number NCT00234091. FINDINGS: Between March 28, 2006, and Sept 10, 2008, we enrolled 300 Thai and Cambodian children infected with HIV, with a median age of 6·4 years (IQR 3·9-8·4). 150 children were randomly allocated early antiretroviral therapy (one participant was excluded from analyses after withdrawing before week 0) and 150 children were randomly allocated deferred antiretroviral therapy. Median baseline CD4 percentage was 19% (16-22%). 69 children (46%) in the deferred treatment group started antiretroviral therapy during the study. AIDS-free survival at week 144 in the deferred treatment group was 98·7% (95% CI 94·7-99·7; 148 of 150 patients) compared with 97·9% (93·7-99·3; 146 of 149 patients) in the early treatment group (p=0·6). INTERPRETATION: AIDS-free survival in both treatment groups was high. This low event rate meant that our study was underpowered to detect differences between treatment start times and thus additional follow-up of study participants or future studies are needed to answer this clinical question.

A randomized trial of interleukin-2 during withdrawal of antiretroviral treatment.

In HIV-infected individuals on antiretroviral treatment with viral suppression, structured treatment interruptions are designed to allow exposure to endogenous HIV antigens and to thereby boost HIV-specific immunity. AIDS Clinical Trials Group A5132 was an exploratory 2-arm randomized trial that evaluated two 4-week treatment interruptions in combination with 2 strategies for administering interleukin-2 (IL-2): 2.0 million international units of IL-2 subcutaneously daily during the final 2 weeks of treatment interruption and the first week of treatment reinitiation (arm A), or 4.5 million international units of IL-2 subcutaneously twice a day during the first 5 days of treatment reinitiation (arm B). Twenty-one subjects with HIV-1 RNA <50 copies/mL and CD4+ T cell counts ≥300 (median 615) cells/mm(3) were randomized. The primary endpoint was the viral setpoint measured 11-12 weeks after a third treatment interruption (observed for 7 Arm A and 9 Arm B). The median HIV-1 RNA setpoints were 4.3 and 4.5 log(10) copies/mL for Arm A and Arm B, respectively; there was no evidence of a difference between arms (P = 0.50, rank-sum test, worst rank for unobserved viral setpoint). The current study, the first to evaluate IL-2 during repeated short-term treatment interruptions, revealed no evidence for augmentation of HIV immunity. Viral setpoints were similar to historical controls, emphasizing the need for new strategies to enhance HIV-specific immunity.

Continuing or adding IL-2 in patients treated with antiretroviral therapy (ACTG Protocol A5051, a rollover trial of ACTG Protocol A328).

BACKGROUND: Effective antiretroviral therapy reduces HIV-1 RNA levels, improves CD4 T-cell counts, and lowers the risk of opportunistic infections and malignancies. Interleukin-2 (IL-2) has been shown to increase CD4 T-cell numbers mainly by expanding CD4 cells and by prolonging their half-lives. HIV-infected patients previously enrolled into A328 had been randomized to antiretroviral therapy (ART) alone or ART followed by IL-2. In A5051, 53 patients from A328 who had previously received IL-2 were allowed to continue IL-2 for an additional 80 weeks; 27 patients who had received ART alone received IL-2 for 80 weeks. RESULTS: The patients previously receiving IL-2 continued to have elevated CD4 levels with extended use of IL-2. The prior ART-alone recipients had increases in CD4 levels to comparable levels as the prior IL-2 recipients (median 804 versus 847 cells/mm3 at week 72; 60% versus 9% had >50% increase in A5051 to week 72, p < 0.001). Those who had previously received IL-2 required fewer IL-2 cycles to maintain their CD4 T-cell counts compared to those newly initiating IL-2. The treatments were well tolerated with no significant differences in toxicity or discontinuations between those newly versus previously receiving IL-2. There were few clinical events observed. CONCLUSIONS: Although sustained CD4 T-cell count increases were seen with IL-2 administration as in other studies, the absence of clinical benefit in two recent randomized trials has demonstrated no apparent role for IL-2 as a therapy in HIV disease. TRIAL REGISTRATION: A5051 ClinicalTrials.gov Identifier: NCT00000923.

A randomized therapeutic vaccine trial of canarypox-HIV-pulsed dendritic cells vs. canarypox-HIV alone in HIV-1-infected patients on antiretroviral therapy.

Targeting canarypox (CP)-HIV vaccine to dendritic cells (DCs) elicits anti-HIV-1 immune responses in vitro. We conducted a phase I/II clinical trial to evaluate whether adding DC to a CP-HIV vaccine improved virologic control during analytic treatment interruption (ATI) in HIV-1-infected subjects. Twenty-nine subjects on suppressive antiretroviral therapy were randomized to vaccination with autologous DCs infected with CP-HIV+keyhole limpet hemocyanin (KLH) (arm A, n=14) or CP-HIV+KLH alone (arm B, n=15). The mean viral load (VL) setpoint during ATI did not differ between subjects in arms A and B. A higher percentage of subjects in the DC group had a VL setpoint < 5,000 c/mL during ATI (4/13 or 31% in arm A compared with 0/13 in arm B, p=0.096), but virologic control was transient. Subjects in arm A had a greater increase in KLH lymphoproliferative response than subjects in arm B; however, summed ELISPOT responses to HIV-1 antigens did not differ by treatment arm. We conclude that a DC-CP-HIV vaccine is well-tolerated in HIV-1-infected patients, but does not lower VL setpoint during ATI compared with CP-HIV alone. New methods to enhance the immunogenicity and antiviral efficacy of DC-based vaccines for HIV-1 infection are needed.

A randomized, partially blinded phase 2 trial of antiretroviral therapy, HIV-specific immunizations, and interleukin-2 cycles to promote efficient control of viral replication (ACTG A5024).

Strategies to limit life-long dependence on antiretroviral therapy (ART) are needed. We randomized 81 human immunodeficiency virus (HIV)-infected subjects to 4 interventional arms involving continued ART plus ALVAC vCP1452 (or placebo) with or without interleukin (IL)-2 infusions. Viral load rebound 12 weeks after ART interruption was then analyzed to assess immune control. Fifty-two subjects reached the study end point. ALVAC recipients had 0.5 log(10) lower virologic rebounds (P=.033). IL-2 plus vaccine boosted CD4(+) T cell counts (P<.001) but did not diminish viral rebound. Significant changes were not detected for HIV-specific lymphoproliferative responses in any arm. This exploratory protocol provides useful clinical data for future therapeutic immunization trial design.

Evidence that intermittent structured treatment interruption, but not immunization with ALVAC-HIV vCP1452, promotes host control of HIV replication: the results of AIDS Clinical Trials Group 5068.

BACKGROUND: The ability to control human immunodeficiency virus (HIV) replication in vivo in the absence of antiretroviral therapy (ART) is a measure of the efficiency of antiviral immunity. In a study of patients with chronic, ART-suppressed HIV infection, AIDS Clinical Trials Group 5068 investigated the effects of immunization with an exogenous HIV vaccine and pulse exposure to the subject's unique viral epitopes, by means of structured treatment interruptions (STIs), on the dynamics of viral rebound during a subsequent analytical treatment interruption (ATI). METHODS: Ninety-seven subjects receiving stable ART with an HIV-1 RNA load <50 copies/mL and CD4(+) T lymphocyte count >400 cells/mm(3) were randomized to undergo continued ART, STIs, ALVAC-HIV vCP1452 immunization, or STIs and ALVAC-HIV vCP1452 immunization. RESULTS: Subjects in the 2 STI arms had a significantly longer median doubling time in the period of the initial rise of viral load, a significantly lower median peak viral load, a significantly lower median end-of-ATI viral load set point, and a greater proportion of subjects with an end-of-ATI viral load set point <1,000 copies/mL, compared with the subjects in the 2 arms without STIs. With an immunization schedule of 3 sets of 3 weekly injections, ALVAC-HIV vCP1452 did not affect viral load measures. CONCLUSIONS: In this randomized, controlled study of intermittent STI as a therapeutic autoimmunization strategy, evidence of enhanced immunologic control of HIV replication was demonstrated.

Activity, safety, and immunological effects of hydroxyurea added to didanosine in antiretroviral-naive and experienced HIV type 1-infected subjects: a randomized, placebo-controlled trial, ACTG 307.

We performed a 24-week, placebo-controlled, comparative trial of hydroxyurea (HU) monotherapy, didanosine(ddI) monotherapy, and the combination of ddI plus HU administered as 1000 mg qd or 1500 mg qd in antiretroviral-naive and experienced subjects with CD4+ lymphocyte counts of 200-700 cells/mm3. Enrollment included 134 subjects. HU enhanced the antiviral activity of ddI by 1.0 log10 copies/ml after 8 weeks of therapy, with sustained responses over 24 weeks. HU alone over 4 weeks had no effect. Lamivudine resistance had little impact on antiretroviral activity when examined across treatment arms. Increases in absolute CD4+ T cell counts, but not CD4+ T cell percentages, were less in subjects who received HU compared to ddI monotherapy, and lymphoproliferative responses to antigenic and mitogenic stimuli were not altered. Subjects who received HU 1500 mg were more likely to experience dose-limiting hematological toxicities compared to those who received 1000 mg, without any additional antiviral benefit. HU may continue to have a role as a component of HIV therapy.

Granulocyte-macrophage colony-stimulating factor induces modest increases in plasma human immunodeficiency virus (HIV) type 1 RNA levels and CD4+ lymphocyte counts in patients with uncontrolled HIV infection.

BACKGROUND: Studies have reported that plasma human immunodeficiency virus type 1 (HIV-1) RNA levels and CD4+ lymphocyte counts in HIV-infected patients improved after treatment with granulocyte-macrophage colony-stimulating factor (GM-CSF). METHODS: In AIDS Clinical Trials Group Protocol 5041, 116 patients were enrolled in a double-blind, randomized, placebo-controlled clinical trial of 16 weeks of 250 microg of GM-CSF administered subcutaneously 3 times/week, followed by open-label treatment for an additional 32 weeks. Patients had stable baseline plasma HIV-1 RNA levels of > or =1500 copies/mL and received constant antiretroviral regimens through at least the first 16 weeks of the study. RESULTS: After 16 weeks, the GM-CSF group tended to have greater, though clinically insignificant, increases in plasma HIV-1 RNA levels, compared with the placebo group (median change, +0.048 vs. -0.103 log copies/mL; P=.036, in a post hoc analysis). There were trends toward progressive modest increases in CD4+ lymphocyte counts with GM-CSF treatment at 16 weeks (median change, +14 vs. -6 cells/mm3; P=.06) and beyond. CONCLUSIONS: GM-CSF does not have an antiviral effect in patients with ongoing HIV replication but may increase CD4+ lymphocyte counts.

Age-related immune dysfunction in health and in human immunodeficiency virus (HIV) disease: association of age and HIV infection with naive CD8+ cell depletion, reduced expression of CD28 on CD8+ cells, and reduced thymic volumes.

Older age is a strong predictor of accelerated human immunodeficiency virus (HIV) disease progression. We investigated the possible immunologic basis of this interaction by comparing older (>/=45 years) and younger (

A study of the immunology, virology, and safety of prednisone in HIV-1-infected subjects with CD4 cell counts of 200 to 700 mm(-3).

Adult Clinical Trials Group Study 349 examined the immunology, virology, and safety of 40 mg/d prednisone as an adjunct to antiretroviral therapy in 24 HIV-infected subjects with >200 CD4+ T cells/mm in a randomized placebo-controlled trial. After 8 weeks, median lymphocyte and CD4+ cell numbers increased >40% above baseline values (p =.08). No effect was observed on markers of cell activation or apoptosis, although the proportion of CD28+ CD8+ T cells increased (p =.006). Prednisone inhibited monocyte TNFalpha production without affecting T-cell responses to antigens or mitogens. Two subjects assigned to prednisone were subsequently found to have asymptomatic osteonecrosis of the hip. Many questions remain regarding the role of activation-induced sequestration and apoptosis as causes of progressive CD4+ T-cell loss in AIDS. The potential role of corticosteroids as tools to examine this question will be limited by concerns regarding their toxicity; however, further studies of other agents to limit cellular activation in AIDS are warranted.

Effect of etanercept (Enbrel) on interleukin 6, tumor necrosis factor alpha, and markers of immune activation in HIV-infected subjects receiving interleukin 2.

The effect of etanercept, a soluble p75 tumor necrosis factor (TNF) receptor:Fc fusion protein (Enbrel; Immunex, Seattle, WA) on plasma cytokines was evaluated in 11 HIV-infected subjects receiving highly active antiretroviral therapy (HAART) for 28 weeks with or without subcutaneous or intravenous recombinant human interleukin 2 (rhIL-2). Plasma IL-6 and C-reactive protein (CRP) levels increased after rhIL-2 treatment. Etanercept pretreatment attenuated these increases. Median plasma IL-6 levels were 20.29 pg/ml 4 days after rhIL-2 and 7.87 pg/ml 4 days after etanercept and rhIL-2 (p = 0.22); median CRP levels were 78.73 and 46.16 microg/ml, respectively (p = 0.03). An effect on TNF bioactivity could not be assessed as all measurements were below limits of detection. No significant changes were seen in temperature or plasma levels of IL-4, IL-10, IL-12, interferon gamma, or HIV-1 RNA levels. All subjects had undetectable or low-level HIV-1 RNA levels before etanercept dosing. One subject died; however, her death was thought to be unrelated to etanercept. Pretreatment with etanercept may blunt activation of IL-6 and CRP expression induced by rhIL-2. The safety and utility of etanercept in HIV-infected persons should be explored further.

Early extubation of neonates and young infants after cardiac surgery.

Surgical intervention for many patients born with congenital heart disease has become routine in the first few months of life. Early extubation after cardiac surgery in neonates and young infants is feasible for many of these patients. This approach simplifies postoperative management, eliminates some of the complications related to postoperative care, shortens intensive care and hospital stays, reduces cost, and provides for a more efficient and positive convalescence for these young patients and their families. Management protocols for early extubation are described, and the outcomes reviewed. Copyright 1998 by W.B. Saunders Company