Effects of omeprazole on plasma levels of raltegravir.

Raltegravir, a human immunodeficiency virus type 1 (HIV-1) integrase inhibitor, has pH-dependent solubility. Raltegravir plasma concentration increases with omeprazole coadministration in healthy subjects; this is likely secondary to an increase in bioavailability attributable to increased gastric pH. Increased gastric pH has been reported in HIV-1-infected individuals, and the effects of omeprazole in this intended population may be diminished. Further investigation is necessary.

Safety and efficacy of the HIV-1 integrase inhibitor raltegravir (MK-0518) in treatment-experienced patients with multidrug-resistant virus: a phase II randomised controlled trial.

BACKGROUND: Raltegravir (MK-0518) is an HIV-1 integrase inhibitor with potent in-vitro activity against HIV-1 strains including those resistant to currently available antiretroviral drugs. The aim of this study was to assess the safety and efficacy of raltegravir when added to optimised background regimens in HIV-infected patients. METHODS: HIV-infected patients with HIV-1 RNA viral load over 5000 copies per mL, CD4 cell counts over 50 cells per muL, and documented genotypic and phenotypic resistance to at least one nucleoside reverse transcriptase inhibitor, one non-nucleoside reverse transcriptase inhibitor, and one protease inhibitor were randomly assigned to receive raltegravir (200 mg, 400 mg, or 600 mg) or placebo orally twice daily in this multicentre, triple-blind, dose-ranging, randomised study. The primary endpoints were change in viral load from baseline at week 24 and safety. Analyses were done on a modified intention-to-treat basis. This trial is registered with ClinicalTrials.gov, with the number NCT00105157. FINDINGS: 179 patients were eligible for randomisation. 44 patients were randomly assigned to receive 200 mg raltegravir, 45 to receive 400 mg raltegravir, and 45 to receive 600 mg raltegravir; 45 patients were randomly assigned to receive placebo. One patient in the 200 mg group did not receive treatment and was therefore excluded from the analyses. For all groups, the median duration of previous antiretroviral therapy was 9.9 years (range 0.4-17.3 years) and the mean baseline viral load was 4.7 (SD 0.5) log10 copies per mL. Four patients discontinued due to adverse experiences, three (2%) of the 133 patients across all raltegravir groups and one (2%) of the 45 patients on placebo. 41 patients discontinued due to lack of efficacy: 14 (11%) of the 133 patients across all raltegravir groups and 27 (60%) of the 45 patients on placebo. At week 24, mean change in viral load from baseline was -1.80 (95% CI -2.10 to -1.50) log10 copies per mL in the 200 mg group, -1.87 (-2.16 to -1.58) log10 copies per mL in the 400 mg group, -1.84 (-2.10 to -1.58) log10 copies per mL in the 600 mg group, and -0.35 (-0.61 to -0.09) log(10) copies per mL for the placebo group. Raltegravir at all doses showed a safety profile much the same as placebo; there were no dose-related toxicities. INTERPRETATION: In patients with few remaining treatment options, raltegravir at all doses studied provided better viral suppression than placebo when added to an optimised background regimen. The safety profile of raltegravir is comparable with that of placebo at all doses studied.

In vitro susceptibilities of aerobic and facultative gram-negative bacilli isolated from patients with intra-abdominal infections worldwide: the 2002 Study for Monitoring Antimicrobial Resistance Trends (SMART).

BACKGROUND: The Study for Monitoring Antimicrobial Resistance Trends (SMART) was begun in 2002 to monitor international drug-resistance patterns among aerobic and facultative gram-negative bacilli isolated from patients with intra-abdominal infections. METHODS: In 2002, 40 medical centers from 17 countries collected consecutive non-duplicate isolates from intra-abdominal infections for susceptibility testing against 12 antimicrobial agents using the broth microdilution methods recommended by the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards). RESULTS: A total of 3,134 aerobic and facultative gram-negative bacilli were isolated. Enterobacteriaceae accounted for 82% of the total and were most consistently susceptible to amikacin and the carbapenems. Escherichia coli (45%) and Klebsiella spp. (17%) were the most common species. The susceptibility rates of these organisms to the 12 antimicrobial agents differed among geographic regions, with isolates from the Asia/Pacific and Latin American regions usually having the highest rates of resistance. Ampicillin/sulbactam was the agent least frequently active against E. coli (56% susceptible) and Klebsiella spp. (73% susceptible). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically in 7% of E. coli, 13% of Klebsiella spp., and 18% of Enterobacter spp. Producers of ESBL overall had a more antibiotic-resistant profile than non-producers but were usually susceptible to carbapenems. CONCLUSIONS: Antimicrobial resistance rates among gram-negative bacilli isolated from intra-abdominal infections differed among geographic regions. The carbapenems were consistently active in vitro against Enterobacteriaceae worldwide, including ESBL producers.

Long-term efficacy, safety, and tolerability of indinavir-based therapy in protease inhibitor-naive adults with advanced HIV infection.

A double-blind, randomized study of zidovudine-experienced, PI- and lamivudine-naive adults with baseline CD4 cell counts of < or =50 cells/mm3 had demonstrated that the HIV suppression achieved with zidovudine, lamivudine, and indinavir therapy was superior to that achieved with dual-nucleoside or indinavir-only regimens after 24 weeks of therapy. In a 192-week extension of the study, 371 participants received open-label indinavir with or without other antiretroviral drugs. One hundred and eight subjects were originally randomized to receive triple therapy. After 216 weeks, the proportion of subjects with HIV RNA levels of <500 copies/mL were 34%, according to a general estimating equation analysis, 92%, according to an observed data analysis, and 24%, according to an intention-to-treat analysis counting noncompleters as failures; the proportions of subjects with HIV RNA levels of <50 copies/mL were 31%, 85%, and 22%, respectively. Hyperbilirubinemia (experienced by 31% of subjects), nausea (17%), abdominal pain (14%), and nephrolithiasis (13%) were the most common drug-related adverse events during the extension.

Clinical efficacy of raltegravir against B and non-B subtype HIV-1 in phase III clinical studies.

OBJECTIVE: We evaluated the long-term efficacy of raltegravir according to HIV-1 subtype (B and non-B) using data from three phase III studies in treatment-experienced (BENCHMRK-1 and 2) and treatment-naive (STARTMRK) HIV-infected patients. METHODS: HIV-1 subtypes were identified from baseline plasma specimens using genotypic data of the PhenoSense GT test (Monogram Biosciences, South San Francisco, California, USA). Non-B subtypes were combined for the current analyses due to small numbers of each specific subtype. An observed failure approach was used (only discontinuations due to lack of efficacy were treated as failures). Resistance evaluation was performed in patients with documented virologic failure. RESULTS: Seven hundred and forty-three patients received raltegravir and 519 received comparator (efavirenz in STARTMRK; optimized background therapy in BENCHMRK). Non-B subtype virus (A, A/C, A/D, A/G, A1, AE, AG, B/G, BF, C, D, D/F, F, F1, G, and complex) was isolated at baseline in 98 (13%) raltegravir recipients and 62 (12%) comparator recipients. Subtypes AE and C were most common, isolated in 41 and 43 patients, respectively. The proportion of raltegravir recipients achieving HIV RNA less than 50 copies/ml was similar between non-B and B subtypes (STARTMRK: 94.5 vs. 88.7%; BENCHMRK-1 and 2: 66.7 vs. 60.7%); change in CD4 cell count also was similar between non-B and B subtypes (STARTMRK: 243 vs. 221 cells/µl; BENCHMRK-1 and 2: 121 vs. 144 cells/µl). Phenotypic resistance to raltegravir in non-B virus was associated with integrase mutations observed previously in subtype B virus. CONCLUSION: In phase III studies in treatment-naive and treatment-experienced patients, raltegravir showed comparable and potent clinical efficacy against B and non-B HIV-1 subtypes.

Long-term efficacy and safety of the HIV integrase inhibitor raltegravir in patients with limited treatment options in a Phase II study.

BACKGROUND: Raltegravir in combination therapy has demonstrated potent suppression of HIV-1 with a favorable safety profile. This report provides 96-week efficacy and safety data from Protocol 005, a Phase II study. METHODS: HIV-infected patients with very limited treatment options and failing antiretroviral therapy were randomized to raltegravir 200, 400, or 600 mg or placebo b.i.d., plus optimized background therapy for >or=24 weeks; all patients were then offered open-label raltegravir 400 mg b.i.d. Efficacy measurements included changes in viral load and CD4 count from baseline and percent of patients with HIV-1 RNA <400 and <50 copies/mL. RESULTS: One hundred and thirty-three patients received raltegravir and 45 received placebo. No dose-dependent differentiation in the safety or antiviral activity of raltegravir was observed during the double-blind phase. For the combined raltegravir groups, mean change in viral load from baseline was -1.60 log10 copies/mL at week 48 and -1.38 log10 copies/mL at week 96 (observed failure approach). At week 48, HIV-1 RNA levels were <400 copies/mL in 68% of raltegravir recipients and <50 copies/mL in 55%; these levels were maintained in 55% and 48% of raltegravir recipients, respectively, at week 96 (noncompleter = failure). There were few discontinuations of raltegravir (4%) due to adverse events. CONCLUSIONS: In patients with limited treatment options, raltegravir with OBT had a potent and sustained antiretroviral effect and was generally well tolerated through 96 weeks.

In vitro susceptibilities of aerobic and facultative Gram-negative bacilli isolated from patients with intra-abdominal infections worldwide: the 2003 Study for Monitoring Antimicrobial Resistance Trends (SMART).

OBJECTIVES: The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance programme was begun in 2002 to monitor antimicrobial resistance trends among aerobic and facultative Gram-negative bacilli (GNB) isolated from intra-abdominal infections worldwide. METHODS: In 2003, 74 medical centres from 23 countries collected isolates for testing. Antimicrobial susceptibility testing was performed using broth microdilution according to the NCCLS guidelines for MIC testing. RESULTS: A total of 5658 aerobic and facultative GNB were isolated from intra-abdominal infections. Enterobacteriaceae composed 84% of the total isolates. Among the agents tested, the carbapenems were the most consistently active against the Enterobacteriaceae. E. coli was the most common isolate (46%), and the susceptibility rate to the quinolone (70-90% susceptible), cephalosporin (80-97% susceptible), aminoglycoside (77-100% susceptible) and carbapenem (99-100% susceptible) agents tested varied among geographic regions, with isolates from the Asia/Pacific region generally being the most resistant. Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically in 9% of E. coli, 14% of Klebsiella spp., and 14% of Enterobacter spp. worldwide. ESBL producers generally had a more antibiotic-resistant profile than non-ESBL producers. CONCLUSIONS: Antimicrobial resistance among GNB isolated from intra-abdominal infections is a problem worldwide, especially in the Asia/Pacific region. The carbapenems ertapenem, meropenem and imipenem are highly active in vitro against Enterobacteriaceae isolated from intra-abdominal sites, including organisms that produce ESBLs.