First in a New Family of Antibiotics Designed to Fight Resistant Bacteria Proves Effective in Clinical Trials

Results presented at international meeting in Toronto

TORONTO, Ont., Sept. 20, 2000 - World experts in the field of infectious diseases, gathered for the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), learned today about important study results on the new antibiotic KETEK(telithromycin).

Data from 10 large-scale international studies conclude that KETEK?, administered once-daily over a period of five days, is effective in the treatment of a wide range of respiratory tract infections including some caused by pathogens resistant to currently available antibiotics.

KETEK? is the first member in a new family of antibiotics called ketolides. KETEK? is designed to be effective on a broad spectrum of bacteria. It inhibits the protein synthesis needed for bacterial reproduction by binding 10 times tighter than macrolides (another family of antibiotics) at two different sites on the bacteria. In vitro data suggest that it has a low propensity to induce bacterial resistance.

"Bacterial resistance to commonly-prescribed antibiotics is a serious problem faced by the medical community. There is a great need for new weapons to combat some of these bacteria and I am very encouraged about the results obtained with telithromycin," said Dr. Gary Garber, Professor and Head, Division of Infectious Diseases, University of Ottawa.

Study results

In phase III clinical trials, the last phase before a product is submitted for regulatory approval, KETEK? (800 mg once a day for five days, except for community-acquired pneumonia which requires a seven to 10 day treatment regimen) was compared to existing antibiotics used in the treatment of respiratory tract infections such as community-acquired pneumonia (CAP), acute bacterial exacerbations of chronic bronchitis (AECB), acute sinusitis and tonsillitis/pharyngitis.

Nearly 2,500 patients were treated with KETEK? while close to 1,800 people received comparator antibiotics. KETEK? was shown to be active against a wide range of bacteria associated with pneumonia and other respiratory tract infections including Streptococcus pneumoniae (which accounts for two thirds of all CAP cases), Streptococcus pyogenes (associated with severe group A streptococcal infections), Staphylococcus aureus (which accounts for about one per cent of all community-acquired pneumonia), Haemophilus influenzae (the second most common cause of bacterial pneumonia) and Moraxella catarrhalis (which can cause respiratory disease and middle ear infections).

KETEK? was also effective against atypical bacteria such as Chlamydia pneumoniae (associated with six to 19 per cent of community-acquired pneumonia), Mycoplasma pneumoniae (bacteria-like organism and the most common pathogen of lung infections in five to 35 year old patients) and Legionella pneumoniae (responsible for one to eight per cent of all community-acquired pneumonia requiring hospitalisation).

Key findings from the various studies were:

  • 94.6 per cent vs. 90.1 per cent cure rate of CAP compared to high dose amoxicillin (1,000 mg three times a day)
  • 88.3 per cent vs. 88.5 per cent cure rate of CAP compared to clarithromycin (500 mg twice a day)
  • 91.1 per cent vs. 94.8 per cent cure rate of CAP compared to trovafloxacin (200 mg once a day)
  • 89.2 per cent vs. 86.3 per cent cure rate of AECB compared to cefuroxime axetil (500 mg twice a day for 10 days)
  • 86.1 per cent vs. 82.1 per cent cure rate of AECB compared to amoxycillin/clavulanic acid (500 mg/125 mg, three times a day for 10 days)
  • 75.8 per cent vs. 74.6 per cent cure rate of sinusitis compared to amoxycillin/clavulanic acid
  • 94.8 per cent vs. 94.1 per cent cure rate of pharyngitis/tonsillitis compared to 20 to 30 doses of penicillin V

Infectious diseases in Canada

In Canada, pneumonia is the second leading cause of death related to respiratory diseases.

In 1997, pneumonia was responsible for 80,300 hospitalisations.

"Even though the medical community and the general public have developed a better understanding of the role of antibiotics, resistance remains an important concern. We are witnessing more and more cases of bacteria resistant to all existing antibiotics. Education on how to better use antibiotics and the development of new agents are key to the safety of the population," said Dr. Donald Low, Chief, Department of Microbiology at Mount Sinai Hospital in Toronto.

Antibiotic resistance

Several studies on bacterial resistance to antibiotics have been conducted in the past decade in Canada. A cross-Canada surveillance of antimicrobial resistance in respiratory tract pathogens, a study published in the Canadian Journal of Infectious Diseases in 1999, looked at the prevalence of resistant Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. It was determined that during the course of the study (September 1994 to December 1996), penicillin-resistant S. pneumoniae cases doubled.

Another study published in 1998 by the Canadian Committee on Antibiotic Resistance concluded that “penicillin-resistant pneumococcal infection is a tangible and increasing risk for children in most areas of Canada".

Aventis Pharma has submitted KETEK? to Health Canada for regulatory review for the treatment of community-acquired pneumonia, acute exacerbation of chronic bronchitis, sinusitis and tonsillitis/pharyngitis.

For more information, please contact:
Sheila McEachen
Cohn & Wolfe
416-924-5700

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Posted: June 2004

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