A phase I randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and immunogenicity of a live-attenuated quadrivalent dengue vaccine in flavivirus-naïve and flavivirus-experienced healthy adults.

Dengue (DENV) is a mosquito-borne virus with four serotypes causing substantial morbidity in tropical and subtropical areas worldwide. V181 is an investigational, live, attenuated, quadrivalent dengue vaccine. In this phase 1 double-blind, placebo-controlled study, the safety, tolerability, and immunogenicity of V181 in baseline flavivirus-naïve (BFN) and flavivirus-experienced (BFE) healthy adults were evaluated in two formulations: TV003 and TV005. TV005 contains a 10-fold higher DENV2 level than TV003. Two-hundred adults were randomized 2:2:1 to receive TV003, TV005, or placebo on Days 1 and 180. Immunogenicity against the 4 DENV serotypes was measured using a Virus Reduction Neutralization Test (VRNT60) after each vaccination and out to 1 year after the second dose. There were no discontinuations due to adverse events (AE) or serious vaccine-related AEs in the study. Most common AEs after TV003 or TV005 were headache, rash, fatigue, and myalgia. Tri- or tetravalent vaccine-viremia was detected in 63.9% and 25.6% of BFN TV003 and TV005 participants, respectively, post-dose 1 (PD1). Tri- or tetravalent dengue VRNT60 seropositivity was demonstrated in 92.6% of BFN TV003, 74.2% of BFN TV005, and 100% of BFE TV003 and TV005 participants PD1. Increases in VRNT60 GMTs were observed after the first vaccination with TV003 and TV005 in both flavivirus subgroups for all dengue serotypes, and minimal increases were measured PD2. GMTs in the TV003 and TV005 BFE and BFN groups remained above the respective baselines and placebo through 1-year PD2. These data support further development of V181 as a single-dose vaccine for the prevention of dengue disease.

Immunogenicity and safety of an investigational tetravalent recombinant subunit vaccine for dengue: results of a Phase I randomized clinical trial in flavivirus-naïve adults.

There is an unmet medical need for vaccines to prevent dengue. V180 is an investigational recombinant subunit vaccine that consists of truncated dengue envelope proteins (DEN-80E) for all 4 serotypes. Three dosage levels of the tetravalent DEN-80E antigens were assessed in a randomized, placebo-controlled, Phase I dose-escalation, first-in-human proof-of-principle trial in healthy, flavivirus-naïve adults in Australia (NCT01477580). The 9 V180 formulations that were assessed included either ISCOMATRIX™ adjuvant (2 dosage levels), aluminum-hydroxide adjuvant, or were unadjuvanted, and were compared to phosphate-buffered saline placebo. Volunteers received 3 injections of assigned product on a 0, 1, 2 month schedule, and were followed for safety through 1 year after the last injection. Antibody levels were assessed at 6 time-points: enrollment, 28 days after each injection, and 6 and 12 months Postdose 3 (PD3). Of the 98 randomized participants, 90 (92%) received all 3 injections; 83 (85%) completed 1-year follow-up. Immunogenicity was measured by a qualified Focus Reduction Neutralization Test with a 50% neutralization cutoff (FRNT50). All 6 V180 formulations with ISCOMATRIX™ adjuvant showed robust immunogenicity, while the 1 aluminum-adjuvanted and 2 unadjuvanted formulations were poorly immunogenic. Geometric mean antibody titers generally declined at 6 months and 1 year PD3. All 9 V180 formulations were generally well tolerated. Formulations with ISCOMATRIX™ adjuvant were associated with more adverse events than aluminum-adjuvanted or unadjuvanted formulations.

Effect of body mass index and ertapenem versus cefotetan prophylaxis on surgical site infection in elective colorectal surgery.

BACKGROUND: The effectiveness of prophylactic antibiotics in the prevention of surgical site infection (SSI) after elective colorectal surgery is dependent on many factors, including the body mass index (BMI) of the patient. In this study, the association of BMI and type of antibiotic prophylaxis with SSI was evaluated in patients undergoing elective colorectal surgery. METHOD: A post-hoc analysis was performed using data obtained from a multicenter randomized, double-blind study of 1,002 patients undergoing elective colorectal surgery who received prophylactic administration of ertapenem (1 g) or cefotetan (2 g). Among 650 evaluable patients, the effect of BMI and type of antibiotic prophylaxis on SSI rates was assessed four weeks after surgery. Mechanical bowel preparation was standardized, and no patient received oral antibiotics; intravenous antibiotics were not repeated during or after surgery. RESULTS: The majority of patients had a BMI between 18.5 and 39.9 kg/m2. Regardless of the type of prophylaxis, SSI rates were significantly higher in patients with a BMI > or = 30 kg/m2 than in those with a BMI < 30 kg/m2. However, failure, defined as SSI, was significantly less common after ertapenem than after cefotetan prophylaxis at both BMI < 30 kg/m2 (12.7% vs. 26.4%, respectively; difference -13.7; 95% confidence interval [CI] -21.0, -6.5) and BMI > or = 30 kg/m2 (26.7% vs. 41.9%, respectively; difference -15.3; 95% CI -28.2, -2.0). The most prevalent type of SSI was superficial incisional infection, which was more common with both treatments in patients with a BMI > or = 30 kg/m2; however, the incidence of superficial SSI was lower after ertapenem than cefotetan prophylaxis. CONCLUSION: In patients undergoing elective colorectal surgery, the incidence of SSI, specifically superficial incisional SSI, was higher in patients with a BMI > or = 30 kg/m2, regardless of the prophylactic antibiotic given. Ertapenem prophylaxis was more effective than cefotetan in the prevention of SSI at any BMI.

Polyethylene glycol versus sodium phosphate mechanical bowel preparation in elective colorectal surgery.

BACKGROUND: The type of mechanical bowel preparation (MBP) used before elective colorectal surgery remains controversial. METHODS: This post hoc analysis of a prospective randomized controlled antibiotic prophylaxis trial (ertapenem vs. cefotetan) evaluated the effect of polyethylene glycol (PEG) and sodium phosphate (SP) MBPs on the rates of postoperative surgical site infections (SSI). RESULTS: Good to excellent MBPs were observed in 281 of 303 (93%) evaluable patients for the PEG and 336 of 367 (92%) for the SP types. A higher rate of SSI was observed in the PEG (34%) than SP (24%) group (difference, 10%; 95% confidence interval, 3.4-17.2). The MBP type was a significant risk factor for SSI, with SP favored over PEG (odds ratio, .6; 95% confidence interval, .43-.85) in univariate analysis; multivariate analysis favored SP, but was not significant (odds ratio, .69; 95% confidence interval, .46-1.02). SSI was lowest with SP and ertapenem (19%) and highest with PEG and cefotetan (44%). CONCLUSIONS: SP, coupled with ertapenem antibiotic prophylaxis, may improve outcomes and reduce SSIs in patients undergoing elective colorectal surgery when compared with PEG coupled with cefotetan antibiotic prophylaxis.

Ertapenem versus cefotetan prophylaxis in elective colorectal surgery.

BACKGROUND: Ertapenem, a long-acting carbapenem, may be an alternative to the recommended prophylactic antibiotic cefotetan. METHODS: In this randomized, double-blind trial, we assessed the efficacy and safety of antibiotic prophylaxis with ertapenem, as compared with cefotetan, in patients undergoing elective colorectal surgery. A successful outcome was defined as the absence of surgical-site infection, anastomotic leakage, or antibiotic use 4 weeks postoperatively. All adverse events were collected until 14 days after the administration of antibiotic prophylaxis. RESULTS: Of the 1002 patients randomly assigned to study groups, 901 (451 in the ertapenem group and 450 in the cefotetan group) qualified for the modified intention-to-treat analysis, and 672 (338 in the ertapenem group and 334 in the cefotetan group) were included in the per-protocol analysis. After adjustment for strata, in the modified intention-to-treat analysis, the rate of overall prophylactic failure was 40.2% in the ertapenem group and 50.9% in the cefotetan group (absolute difference, -10.7%; 95% confidence interval [CI], -17.1 to -4.2); in the per-protocol analysis, the failure rate was 28.0% in the ertapenem group and 42.8% in the cefotetan group (absolute difference, -14.8%; 95% CI, -21.9 to -7.5). Both analyses fulfilled statistical criteria for the superiority of ertapenem. In the modified intention-to-treat analysis, the most common reason for failure of prophylaxis in both groups was surgical-site infection: 17.1% in the ertapenem group and 26.2% in the cefotetan group (absolute difference, -9.1; 95% CI, -14.4 to -3.7). In the treated population, the overall incidence of Clostridium difficile infection was 1.7% in the ertapenem group and 0.6% in the cefotetan group (P=0.22). CONCLUSIONS: Ertapenem is more effective than cefotetan in the prevention of surgical-site infection in patients undergoing elective colorectal surgery but may be associated with an increase in C. difficile infection. (ClinicalTrials.gov number, NCT00090272 [ClinicalTrials.gov].).

Effects of ritonavir on indinavir pharmacokinetics in cerebrospinal fluid and plasma.

Therapeutic control of human immunodeficiency virus type 1 (HIV-1) in peripheral compartments does not assure control in the central nervous system. Inadequate drug penetration may provide a sanctuary from which resistant virus can emerge or allow development of psychomotor abnormalities. To characterize the effect of ritonavir on indinavir disposition into cerebrospinal fluid, seven HIV-infected adults underwent intensive sampling at steady-state while receiving twice-daily indinavir (800 mg) and ritonavir (100 mg). Serial cerebrospinal fluid and plasma samples were obtained at 10 time points from each subject. Free indinavir accounted for 98.6% of drug in cerebrospinal fluid and 55.9% in plasma. Mean cerebrospinal fluid C(max), C(min), and area under the concentration-time curve from 0 to 12 h (AUC(0-12)) values for free indinavir were 735 nM, 280 nM, and 6502 nM h(-1), respectively, and the free levels exceeded 100 nM in every sample. The cerebrospinal fluid/plasma AUC(0-12) ratio for free indinavir was 17.5% +/- 6.4%. This ratio was remarkably similar to results obtained in a previous study in which subjects received indinavir without ritonavir, indicating that ritonavir did not have a substantial direct effect on the barrier to indinavir penetration into cerebrospinal fluid. Low-dose ritonavir increases cerebrospinal fluid indinavir concentrations substantially more than 800 mg of indinavir given thrice daily without concomitant ritonavir, despite a lower total daily indinavir dose.

Open-label study of a twice-daily indinavir 800-mg/ritonavir 200-mg regimen in HIV-infected adults failing a protease inhibitor regimen.

There is no standard treatment of HIV-infected patients who fail protease inhibitor (PI)-containing antiretroviral therapy. This open-label, noncomparative 24-week study with a 24-week extension evaluated the efficacy, safety, and tolerability of twice-daily indinavir/ritonavir 800/200 mg plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) in this population. Presented here are the results of the 24-week study. Patients were HIV-infected adults who had prior viral RNA (vRNA) suppression (<400 copies/mL), subsequent failure (> or =400 and < or =100,000 copies/mL) on antiretroviral therapy, and at least one new NRTI available for treatment. The proportions of patients achieving plasma vRNA <400 and <50 copies/mL were analyzed with data as observed (DAO) and intention-to-treat (ITT) models using generalized estimating equations (GEE) or counting noncompleters as failures (NC = F). Mean changes from baseline in vRNA and CD4 cell count were evaluated using DAO and an ITT mixed-model approach. Sixty-three patients (87% male) with a mean age of 42 years and mean baseline vRNA and CD4 cell counts of 3.8 log(10) copies/mL and 360 cells/mm(3), respectively, were enrolled. The proportion (95% confidence interval) of patients achieving vRNA <400 and <50 copies/mL at week 24 were 76% (61%, 87%) and 50% (35%, 65%) for DAO, 64% (50%, 75%) and 43% (30%, 56%) for GEE, and 56% (43%, 68%) and 37% (25%, 50%) for NC = F, respectively. At Week 24, baseline vRNA decreased by >1.0 log(10) copies/mL and CD4 cell counts increased by approximately 90 cells/mm(3). Three patients (5%) experienced serious drug-related adverse events. Seven patients (11%) discontinued treatment due to clinical or laboratory adverse events. In this study, the enhanced, twice-daily regimen of indinavir/ritonavir 800/200 mg plus 2 NRTIs provided suppression of HIV in many patients who had failed a PI-containing regimen and was generally well tolerated.

Open-label study of a twice-daily indinavir 800-mg/ritonavir 100-mg regimen in protease inhibitor-naive HIV-infected adults.

Low-dose ritonavir can boost plasma levels of indinavir, thereby enhancing its antiretroviral activity despite less frequent dosing. In this open-label, noncomparative, 24-week trial with a 24-week extension phase, HIV-infected protease inhibitor (PI)- and lamivudine-naive adults received indinavir/ritonavir 800 mg/100 mg plus stavudine and lamivudine every 12 hours. The proportions of patients achieving plasma HIV RNA (vRNA) <400 and <50 copies/mL were analyzed with data as observed (DAO) and intention-to-treat models using generalized estimating equations (GEE) or counting noncompleters as failures (NC = F). Eighty-nine patients (80% men) with a median age of 36 years and mean baseline vRNA levels and CD4 counts of 5.01 log(10) copies/mL and 269 cells/mm(3) were enrolled. The proportions (95% confidence interval [CI]) of patients achieving vRNA <400 copies/mL were 93% (84%, 98%), 78% (67%, 86%), and 68% (57%, 78%) at week 24 for DAO, GEE, and NC = F analyses, respectively; the corresponding results at week 48 were 95% (84%, 99%), 65% (53%, 76%), and 45% (35%, 57%). Most patients with vRNA <400 had <50 copies/mL. At week 48, baseline vRNA decreased by >2 log(10) copies/mL and CD4 counts increased by approximately 200 cells/mm(3). Five patients (6%) experienced serious drug-related adverse experiences. Twenty patients (23%) discontinued therapy due to adverse experiences. In this study, twice-daily indinavir 800 mg/ritonavir 100 mg with two nucleoside reverse transcriptase inhibitors provided potent viral suppression and immunologic reconstitution in many PI-naive patients.