The following is a summary of data presented at the American Society for Microbiology's 45th Interscience Conference on Antimicrobial Agents and Chemotherapy in Washington.

• Carrington Laboratories Inc., of Irving, Texas, said its subsidiary, DelSite Biotechnologies Inc., presented preclinical data of its avian influenza vaccine administered using the GelVac nasal powder delivery system, showing that an inactivated influenza nasal powder vaccine demonstrated a strong protective immunity in an animal model against both H5 avian and contemporary influenza virus. Results also show that the GelVac system appears to demonstrate both antigen-sparing and antigen stabilization effects.

• Cubist Pharmaceuticals Inc., of Lexington, Mass., presented results from its Phase III trial of Cubicin (daptomycin for injection) in patients with bloodstream infections (bacteremia) and heart infections (infective endocarditis) caused by both methicillin-susceptible and methicillin-resistant Staphylococcus aureus. Data, initially reported in June, showed the study met its primary endpoints of non-inferiority vs. the standard of care. (See BioWorld Today, June 29, 2005.)

• Dynavax Technologies Corp., of Berkeley, Calif., said a Phase II/III trial showed superiority with its hepatitis B virus vaccine Heplisav over London-based GlaxoSmithKline plc's Engerix-B vaccine. In the primary efficacy endpoint of seroprotection, there was 100 percent protection in the Heplisav-treated group compared to 90.5 percent in the Engerix-B treated group (p=0.034). The company said Heplisav could become the first Toll-like receptor 9 agonist-based product to seek regulatory approval.

• Elusys Therapeutics Inc., of Pine Brook, N.J., said two preclinical studies of ETI-211, a heteropolymer antibody, demonstrated the drug's ability in clearing methicillin-resistant Staphylococcus aureus infections and in providing an immune protection against subsequent infection. Four days after infection, kidney, liver and spleens from animals pre-treated with ETI-211 showed no evidence of live bacteria whereas organs from control animals showed high bacteria counts.

• Gemini Science Inc., of San Diego, a wholly owned subsidiary of Kirin Brewery Co. Ltd., of Tokyo, said it is initiating preclinical studies required to begin clinical testing of a fully human monoclonal antibody to the influenza A M2 protein for protection against and treatment of influenza infection. Preliminary studies using in vitro and in vivo systems demonstrated broad activity against a wide range of human and avian influenza strains, including H5N1.

• Inhibitex Inc., of Alpharetta, Ga., said Phase II data of Aurexis as a first-line treatment, in combination with antibiotics, for serious, life-threatening Staphylococcus aureus bloodstream infections showed positive trends in the composite primary endpoint of mortality, relapse rate and infection-related complications. Aurexis also displayed positive trends in a number of secondary endpoints, including the progression in the severity of sepsis and days in the intensive care unit. The company plans to start additional clinical studies in 2006.

• Oscient Pharmaceuticals Corp., of Waltham, Mass., presented data on the in vitro activity of several products and product candidates against strains of Clostridium difficile, including results of its lead candidate, Ramoplanin, a glycolipodepsipeptide antibiotic. It was shown to be active against all isolates tested, including those strains associated with the recent outbreak of C. difficile and the isolates resistant to other agents.

• PowderMed Ltd., of Oxford, UK, presented results of a Phase I trial showing that its needle-free injection system, a DNA plasmid encoding the H3 hemagglutinin gene for Panama flu, achieved the immune response defined by the Committee for Proprietary Medical Products at the 2 microgram and 4 microgram doses at 56 days. The product also was shown to have a favorable response on three genetically drifted H3 strains of influenza. PowderMed expects to initiate Phase II studies using both bird flu strains and annual flu strains in 2006.

• Rib-X Pharmaceuticals Inc., of New Haven, Conn., started Phase I trials of its first candidate for treating resistant infections. The candidate was derived from the company's Rx-01 program, which uses X-ray crystallography and computational chemistry in designing drugs. Rx-01 antibiotics inhibit the ribosome, a cellular process that catalyzes the chemical steps to produce proteins. They have shown activity against multidrug-resistant Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and Zyvox-resistant enterococci.

• Sangamo BioSciences Inc., of Richmond, Calif., said a preclinical study has demonstrated that cells can be made resistant to HIV infection by treatment with the company's zinc finger DNA-binding protein nucleases designed to specifically disrupt the CCR5 gene. Researchers found that ZFN-modified cells were resistant to HIV infection, while control cells were infected when challenged with the virus. The CCR5 gene is a receptor required for HIV entry into immune cells.

• Tanox Inc., of Houston, said analysis of 24-week data from its Phase II study of TNX-355, an HIV antibody, showed the product met its primary endpoint of mean change in viral reduction load from baseline with statistical significance. TNX-355, combined with an optimized background regimen (OBR), was shown to demonstrate virologic benefit compared to OBR alone, as measured by average area under the curve minus baseline. The 15mg/kg dose arm showed a 0.97 log¹⁰ reduction in viral load by week 24, and the 10mg/kg dose arm was a 1.2 log¹⁰ reduction, compared to a 0.41 log¹⁰ reduction in the placebo arm.

• Targanta Therapeutics Inc., of Montreal, presented posters demonstrating that bacteriophage proteins G1ORF240 and TwORF168 validate the DNA sliding clamp of Staphylococcus aureus for inhibitor screening, with researchers determining that the expression of the two viral proteins inhibit DNA production and cause the bacteria to be destroyed. In a separate poster, researchers identified a class of selective RNA polymerase compounds that exhibit antibacterial properties against S. aureus, acting via the S. aureus RNAP holoenzyme. A member of this class, identified as 2-reidothiophene-3-carboxylate ester, has been shown to selectively inhibit transcription.

• Tibotec Pharmaceuticals Ltd., of Cork, Ireland, said primary 24-week data from the Phase 2b trial of the protease inhibitor TMC114 in treatment-experienced patients showed that 62 percent of patients achieved a reduction in viral load of 1 log10 or more in the highest dose group, compared to 14 percent in the control group. Also, Phase IIb results in HIV-1 patients with non-nucleoside reverse transcriptase inhibitor resistance showed that the viral load reduction in patients receiving TMC125 in combination with an optimized background regimen was significantly greater than in the active control at the 24-week primary endpoint (p<0.05). Both products are in Phase III trials.