BAL8557 is the water-soluble prodrug of a novel antifungal triazole, BAL4815. BAL4815 is active against a broad spectrum of major opportunistic and pathogenic fungi, including strains that are resistant to other azoles. Cohorts of healthy male subjects received single-ascending oral (p.o.) doses of BAL8557 that were equivalent to 100, 200, or 400 mg of BAL4815 or single-ascending, 1-h constant-rate intravenous (i.v.) infusions of BAL8557 which were equivalent to 50, 100, or 200 mg of BAL4815. In each cohort, six subjects were randomly assigned to receive active drug and two subjects were assigned to receive the placebo. All doses were well tolerated, and no severe or serious adverse events occurred. Maximum plasma concentrations of BAL4815 were observed 1.

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.

Ceftobiprole is the first broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) to be assessed in late-stage clinical trials. As a pivotal step in the clinical development of ceftobiprole, a multicenter, global, randomized, double-blind trial was conducted to compare the efficacy of ceftobiprole to that of vancomycin in patients with complicated skin and skin structure infections (cSSSIs) caused by gram-positive bacteria. The primary objective was to assess noninferiority on the basis of the cure rates 7 to 14 days after the completion of therapy in patients administered ceftobiprole 500 mg every 12 h or vancomycin 1 g every 12 h. Of 784 patients randomized, 282 receiving ceftobiprole and 277 receiving vancomycin were clinically evaluable. Of these patients, 93.3% treated with ceftobiprole and 93.5% treated with vancomycin were cured (95% confidence interval of difference, ؊4.4%, 3.9%). The cure rates for patients with MRSA infections were 91.8% (56/61) with ceftobiprole treatment and 90.0% (54/60) with vancomycin treatment (95% confidence interval of difference, ؊8.4%, 12.1%). At least one adverse event (AE) was reported by 52% of the ceftobiprole-treated patients and 51% of the vancomycin-treated patients. The most common AEs reported by the ceftobiprole-treated patients were nausea (14%) and taste disturbance (8%). Discontinuation of the study drug because of treatment-emergent AEs occurred in 4% (n ‫؍‬ 17) of the ceftobiprole-treated patients and 6% (n ‫؍‬ 22) of the vancomycin-treated patients. The results of this trial support the use of ceftobiprole as an effective and well-tolerated treatment option for patients with cSSSIs caused by a spectrum of gram-positive bacteria.Complicated skin and skin structure infections (cSSSIs) in hospitalized patients are often caused by gram-positive bacteria (28). Because Staphylococcus aureus and Streptococcus pyogenes are the leading causes of cSSSIs, guidelines for the treatment of cSSSIs consistently recommend empirical antimicrobial therapy that provides activity against these bacteria.Over the last 20 years, the prevalence of methicillin-resistant S. aureus (MRSA) as a cause of cSSSIs has been increasing worldwide (15,18,19). Recent experience suggests that MRSA is now responsible for nearly 60% of purulent skin and soft tissue infections in patients presenting to emergency rooms in the United States (23). Community-origin MRSA with apparently enhanced virulence has emerged as the leading cause of serious skin infections arising in the community (23). The increasing importance of MRSA as a cause of cSSSIs has driven the need for the development of new agents with reliable activity against this pathogen. In particular, the development of a cephalosporin with a broad spectrum of activity that includes MRSA and that can be used to treat a range of serious polymicrobial infections began several years ago and has progressed to the point where one such agent, ceftobiprole, is now in late-stage clinical trials.Ceftobiprole, ...

BAL8557 is the water-soluble prodrug of BAL4815, a new broad-spectrum antifungal. Healthy male subjects were randomly assigned to four treatment cohorts to receive multiple oral doses or multiple 1-h constant-rate intravenous infusions of BAL8557. Loading doses of BAL8557 were equivalent to 100 mg (followed by oncedaily maintenance doses of 50 mg) or 200 mg (followed by once-daily maintenance doses of 100 mg) of BAL4815. In each cohort, six subjects received active drug and two subjects received the placebo. Study duration was 21 days (oral) and 14 days (intravenous). All adverse events reported were mild or moderate, except one severe rhinitis event which was not related to trial medication. After both routes of administration, maximum drug concentration observed in plasma (C max ) and area under the concentration-time curve (AUC) values of BAL4815 increased proportionally to the administered dose. AUC values reflected a fourfold to fivefold accumulation of active drug in plasma during once-daily dosing, which is in line with the long elimination half-life of BAL4815 determined after the last administration (mean, 84.5 to 117 h). At steady state, the volume of distribution was large and amounted to 308 to 542 liters. Systemic clearance reached only 2.4 to 4.1 liter/h. At the levels obtained in the present study, C max values of 2.56 and 2.55 g/ml after oral and intravenous administrations, respectively, there was no indication of CYP3A4 induction or inhibition (as revealed by the urinary 6-␤-hydroxycortisol/cortisol test). Based on AUC values after oral and intravenous administration, an excellent oral bioavailability can be predicted for BAL4815. Once-daily oral dosing of 50-or 100-mg equivalents of BAL8557 were recently demonstrated to be efficacious in a phase 2 study conducted with patients with esophageal candidiasis. These doses (preceded by adequate loading dose[s]) will be further explored in the treatment of systemic mycoses.The frequency of severe systemic mycoses has steadily increased during the last years, and resistance to currently prescribed antifungals is growing rapidly (8,10,17). Therefore, there is an urgent need for new potent and safe antifungals which can be administered orally as well as intravenously (6, 9, 18).The water-soluble triazole prodrug BAL8557 (for chemical structure, see reference 15) is suitable for oral and intravenous administration. In plasma, it is rapidly and almost quantitatively (Ͼ99%) converted by esterases to BAL8728 (prodrug cleavage product) and to BAL4815 (active drug) (2). Area under the concentration-time curve (AUC) values of BAL8728 were low and amounted to approximately 1% of the corresponding AUCs of BAL4815 (15). BAL4815 is a potent inhibitor of ergosterol biosynthesis and shows in vitro broad-spectrum activity against all major opportunistic fungi and the true pathogenic fungi. In rat and murine models, BAL4815 was highly effective against systemic candidiasis and aspergillosis First pharmacokinetic data of BAL4815 in human were obtained in a single-ascen...

Eighty-one clinical isolates of Helicobacter pylorishowed no resistance to rifampin (MIC range, 0.032 to 2 μg/ml; MIC at which 50% of isolates are inhibited [MIC50], 0.25 μg/ml). The MIC50 of rifabutin was 0.008 μg/ml (n = 16). All resistant laboratory mutants of H. pylori ATCC 43504 showed amino acid exchanges in codons 524 to 545 or codon 585 of the rpoB gene, corresponding to the gene sequences from Mycobacterium tuberculosis andEscherichia coli.