Targanta Announces Highlights of Oritavancin Data to Be Presented at the 18th ECCMID
Saturday April 19, 1:00 am ET
Presentations Highlight Candidate Antibiotic's In Vivo and In Vitro Activity
BARCELONA, Spain--(BUSINESS WIRE)--Targanta Therapeutics Corporation (NASDAQ: TARG - News) today announced the presentation of data further detailing the in vivo and in vitro activity of its lead intravenous antibiotic candidate, oritavancin, at the 18th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) taking place in Barcelona, Spain, April 19th through the 22nd. Oritavancin is currently awaiting U.S. regulatory approval for the treatment of complicated skin and skin structure infections (cSSSI) caused by gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, or MRSA.
Thomas Parr, Jr., Ph.D., Targanta’s Chief Scientific Officer commented on the Company’s presence at the meeting: “We are delighted that oritavancin is the focus of so many poster and oral presentations at this important European infectious disease conference. We believe it could not come at a better time, as we prepare for a mid-2008 Marketing Authorization Application (MAA) submission seeking approval of oritavancin in the European Union for the treatment of complicated skin and soft tissue infections, the European term for cSSSI. We would like to thank our international collaborators and commend the Targanta researchers for their contributions to the impressive body of work being presented at ECCMID this year.”
Highlights of the presentations focused on oritavancin follow.
Oritavancin Active Against Small Colony Variants (SCVs)
Persistence of S. aureus infection has been associated with the presence of SCVs in a variety of clinical situations including cystic fibrosis, osteomyelitis, and device-associated infections. These SCVs are thought to be protected from the effects of antibiotics due to their intracellular location. Two posters are being presented at ECCMID that suggest oritavancin’s potential utility in the eradication of these persistent infections.
Poster 1058 (P-1058) concludes that when used at high concentrations, oritavancin shows the most rapid and substantial effect of the agents studied (gentamicin, rifampicin, vancomycin, moxifloxacin, linezolid and tigecycline) against an SCV strain that was isolated from a cystic fibrosis patient in a human airway model, while P-1059 concludes that the combination of oritavancin with either moxifloxacin or rifampicin may prove useful for eradicating intracellular SCVs; indeed, the oritavancin-rifampicin combination was the only combination tested that eradicated the infecting strain from the human cell line.
Data Support Study of Short-Course Oritavancin for cSSSI
Targanta is currently testing a single/infrequent dosing regimen for oritavancin in the treatment of cSSSI in a Phase 2 clinical trial. In an oral presentation (O-152), pharmacokinetic and pharmacodynamic data will be presented that provided the basis for this trial. Due to oritavancin’s long half life and demonstrated concentration-dependent bactericidal activity, the approach presented here proved useful in selecting the dosing regimen for the study. Further, the speaker postulates that front-loaded regimens are likely to result in improved response rates for patients with cSSSI relative to other antibiotic regimens previously studied. Targanta believes, if clinical development of oritavancin with a single/infrequent dosing regimen is successful, that oritavancin could play a role in changing the treatment paradigm for cSSSI as a result of possible patient convenience and pharmacoeconomic benefits through shorter hospital stays and reduced use of hospital resources.
Broad, Rapid and Potent In Vitro Activity Demonstrated
Six posters are being presented today at ECCMID detailing oritavancin’s activity in vitro against a variety of strains of susceptible and resistant gram-positive bacteria:
Data from the study summarized in P-537 suggest that oritavancin activity is differentiated from other glycopeptide antibiotics, such as vancomycin, due to its ability to rapidly kill MRSA by affecting the coordination of cell division, and vancomycin-resistant Enterococcus faecalis (VRE) by breaking down the cell wall.
P-538 and P-539 conclude that oritavancin maintains potent in vitro activity against clinical European bacterial isolates including: strains of staphylococci resistant to oxacillin or multiple drugs, coagulase-negative staphylococci non-susceptible to linezolid and daptomycin; both vancomycin-susceptible and –resistant enterococci (VSE and VRE) whether E. faecalis or E. faecium; and against all streptococci, regardless of penicillin, macrolide or multi-drug resistance phenotypes.
In the study summarized in P-584, researchers demonstrated oritavancin activity against S. aureus that showed hetero-vancomycin-intermediate resistance (hVISA); hVISA isolates are thought to be the precursors of VISA strains and associated with failure in treatment with vancomycin.
P-544 concludes that under the conditions tested, which mimicked physiologically relevant antibiotic concentrations for oritavancin and the comparators (vancomycin, teicoplanin, linezolid and daptomycin), oritavancin was the only antibacterial agent tested that displayed concentration-dependent killing of all tested strains of MRSA, VRSA and hVISA in vitro. Furthermore, oritavancin cell eradication activity was rapid, killing at least 99.9% of viable cells of the tested strains within 6 hours.
Poster 597 details oritavancin’s activity against biofilms of Staphylococcus epidermidis , as well as biofilms of VSE and VRE, which are prominent in infections of indwelling devices and infective endocarditis and thought to be a major cause of relapse.
About Oritavancin
Oritavancin is a novel semi-synthetic lipoglycopeptide antibiotic candidate with potent bactericidal (killing) activity against a broad spectrum of gram-positive bacteria. The product candidate has been tested in over 2,100 individuals and has completed two Phase 3 studies for the treatment of complicated skin and skin structure infections (cSSSI) in which the primary endpoints were met. Targanta submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in February 2008 seeking to commercialize oritavancin for the treatment of cSSSI and believes oritavancin's properties may give it distinct advantages in the treatment of patients with serious gram-positive skin infections, if approved.
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