M. Michelle Berrey

Nucleotide polymerase inhibitor sofosbuvir plus ribavirin for hepatitis C.

BACKGROUND The standard treatment for hepatitis C virus (HCV) infection is interferon, which is administered subcutaneously and can have troublesome side effects. We evaluated sofosbuvir, an oral nucleotide inhibitor of HCV polymerase, in interferon-sparing and interferon-free regimens for the treatment of HCV infection. METHODS We provided open-label treatment to eight groups of patients. A total of 40 previously untreated patients with HCV genotype 2 or 3 infection were randomly assigned to four groups; all four groups received sofosbuvir (at a dose of 400 mg once daily) plus ribavirin for 12 weeks. Three of these groups also received peginterferon alfa-2a for 4, 8, or 12 weeks. Two additional groups of previously untreated patients with HCV genotype 2 or 3 infection received sofosbuvir monotherapy for 12 weeks or sofosbuvir plus peginterferon alfa-2a and ribavirin for 8 weeks. Two groups of patients with HCV genotype 1 infection received sofosbuvir and ribavirin for 12 weeks: 10 patients with no response to prior treatment and 25 with no previous treatment. We report the rate of sustained virologic response 24 weeks after therapy. RESULTS Of the 40 patients who underwent randomization, all 10 (100%) who received sofosbuvir plus ribavirin without interferon and all 30 (100%) who received sofosbuvir plus ribavirin for 12 weeks and interferon for 4, 8, or 12 weeks had a sustained virologic response at 24 weeks. For the other patients with HCV genotype 2 or 3 infection, all 10 (100%) who received sofosbuvir plus peginterferon alfa-2a and ribavirin for 8 weeks had a sustained virologic response at 24 weeks, as did 6 of 10 (60%) who received sofosbuvir monotherapy. Among patients with HCV genotype 1 infection, 21 of 25 previously untreated patients (84%) and 1 of 10 with no response to previous therapy (10%) had a sustained virologic response at 24 weeks. The most common adverse events were headache, fatigue, insomnia, nausea, rash, and anemia. CONCLUSIONS Sofosbuvir plus ribavirin for 12 weeks may be effective in previously untreated patients with HCV genotype 1, 2, or 3 infection. (Funded by Pharmasset and Gilead Sciences; ClinicalTrials.gov number, NCT01260350.).

Effect of interleukin-2 on the pool of latently infected, resting CD4+ T cells in HIV-1-infected patients receiving highly active anti-retroviral therapy

The size of the pool of resting CD4+ T cells containing replication-competent HIV in the blood of patients receiving intermittent interleukin (IL)-2 plus highly active anti-retroviral therapy (HAART) was significantly lower than that of patients receiving HAART alone. Virus could not be isolated from the peripheral blood CD4+ T cells in three patients receiving IL-2 plus HAART, despite the fact that large numbers of resting CD4+ T cells were cultured. Lymph node biopsies were done in two of these three patients and virus could not be isolated. These results indicate that the intermittent administration of IL-2 with continuous HAART may lead to a substantial reduction in the pool of resting CD4+ T cells that contain replication-competent HIV.

Phase 1 Evaluation of the Respiratory Syncytial Virus–Specific Monoclonal Antibody Palivizumab in Recipients of Hematopoietic Stem Cell Transplants

Intravenous palivizumab (15 mg/kg) was investigated in 2 phase 1 studies among recipients of hematopoietic stem cell transplants (HSCTs). Study 1 included 6 HSCT patients without active respiratory syncytial virus (RSV) infection. Study 2 included 15 HSCT patients with RSV upper respiratory tract infection (URTI; n=3) or RSV interstitial pneumonia (IP; n=12), all of whom also received aerosolized ribavirin. Peak serum concentrations of palivizumab in the 2 studies were similar. The mean serum half-life was 22.4 days in study 1, which mainly included autologous HSCT recipients, and 10.7 days in study 2, which mainly included allogeneic HSCT recipients. No antibodies to palivizumab were detected in study 1. No adverse events were attributed to palivizumab in the 2 studies. In study 2, all 3 patients with RSV URTI recovered without progression to lower respiratory tract disease, and 10 (83%) of the 12 patients with RSV IP survived the 28-day study period. Thus, palivizumab appears to be safe and well tolerated in HSCT recipients.

Effect of Combination Antiretroviral Therapy on T-Cell Immunity in Acute Human Immunodeficiency Virus Type 1 Infection

T-cell responses were evaluated prospectively in 41 patients with acute human immunodeficiency virus type 1 (HIV-1) infection (30 untreated and 11 receiving zidovudine, lamivudine, and indinavir) and in 38 uninfected adults. By 6-12 months, treated patients had significantly greater median Candida and tetanus lymphoproliferative responses (stimulation index [SI], 76 and 55, respectively) than did untreated patients (SI, 7 and 6, P=.02 and.001, respectively), and the responses of treated patients surpassed those of uninfected adults (SI, 19 and 32, P= .002 and .101, respectively). Unlike the patients in the untreated group, the patients in the treated group mounted a 6-fold increased HIV-1 p24 response (SI increase, 1.0 to 5.7, P= .01) within 3 months. HIV-1-specific cytotoxicity remained detectable in most treated patients. Thus, combination therapy administered within 3-4 months of infection was associated with improved T-cell memory responses that were distinct from those of untreated patients. The amplified HIV-1-specific T-cell responses may help maintain cytotoxic activities.

Treatment of primary human immunodeficiency virus type 1 infection with potent antiretroviral therapy reduces frequency of rapid progression to AIDS

Immunologic data supporting immediate antiretroviral therapy in primary human immunodeficiency virus type 1 (HIV-1) infection are emerging; however, clinical benefit has not been demonstrated. The clinical and virologic course of 47 patients who were enrolled from September 1993 through June 1996 and who were not initially treated with potent therapy was compared with the course of 20 patients who immediately began therapy with zidovudine, lamivudine, and indinavir. Demographic and baseline laboratory data were comparable. During 78 weeks of follow-up, the early-treatment cohort showed a reduced frequency of opportunistic infections (5% vs. 21.3%; relative risk, 0.11; P=.02), less frequent progression to AIDS (13% vs. 0%), and significantly less frequent nonopportunistic mucocutaneous disorders and respiratory infections (P<.01). Plasma HIV-1 RNA levels were <50 copies/mL in all patients who continued therapy; however, after 9--12 months, HIV-1 remained detectable in latently infected CD4(+) T cells and in lymph node mononuclear cells. Combination antiretroviral therapy during primary HIV-1 infection demonstrated a decreased frequency of minor opportunistic infections, mucocutaneous disorders, and respiratory infections and reduced progression to AIDS.

Role for HLA class II molecules in HIV-1 suppression and cellular immunity following antiretroviral treatment

HIV-1-infected patients treated early with combination antiretrovirals respond favorably, but not all maintain viral suppression and improved HIV-specific Th function. To understand if genetic factors contribute to this variation, we prospectively evaluated over 18 months 21 early-treated patients stratified by alleles of class II haplotypes. All seven subjects with the DRB1*13-DQB1*06 haplotype, but only 21% of other subjects, maintained virus suppression at every posttreatment measurement. Following HIV-1 p24 antigen stimulation, PBMCs from patients with this haplotype demonstrated higher mean lymphoproliferation and IFN-gamma secretion than did cells from patients with other haplotypes. Two DRB1*13-restricted Gag epitope regions were identified, a promiscuous one that bound its putative restriction element with nanomolar affinity, and another that mapped to a highly conserved region. These findings suggest that class II molecules, particularly the DRB1*13 haplotype, have an important impact on virologic and immunologic responses. The advantage of the haplotype may relate to selection of key HIV-1 Th1 epitopes in highly conserved regions with avid binding to class II molecules. Eliciting responses to the promiscuous epitope region may be beneficial in vaccine strategies.

Concordance between HIV source partner identification and molecular confirmation in acute retroviral syndrome.

&NA; Most HIV‐1 transmission studies use self‐reported history to define the source contact. To evaluate the reliability of epidemiologic source partner reporting, heteroduplex mobility assays (HMAs) were performed comparing the different viral strains present in the partners. Partners were typed for human leukocyte antigen (HLA) to evaluate the degree of shared alleles. Of 11 couples evaluated, HMA analysis confirmed nine transmissions (including 1 oral‐genital transmission), indicated probable transmission in 1 couple, and suggested an alternative source partner in another. Nine source partners transmitted a major variant. Four source partners knew their HIV status. Previous HIV monitoring was reported by 5 of the 6 confirmed source partners who were unaware of their HIV status at the time of transmission. We also evaluated potential “sharing of HLA alleles” as a risk factor for HIV‐1 acquisition; partners were not found to have a higher degree of shared HLA alleles. Lack of awareness about infection status as a consequence of infrequent testing plays a major role in the secondary transmission of HIV. These findings re‐emphasize the importance of using safe sex practices at all times.

Antiretroviral Therapy in Primary HIV

Initiation of antiretroviral therapy during primary HIV-1 infection may well redefine the course of the disease by controlling the burst of viral replication and subsequent immune dysfunction. At present, treatment of acute primary HIV-1 should remain largely in the domain of clinical investigation. There are significant problems in providing constant vigilance to medication and subsequent viral suppression. Only clinical trials can define the relative benefit of initiating antiretrovirals during this stage of infection.