Sanofi-Aventis’ antibiotic Ketek (telithromycin) could find itself propelled into a new, potentially very lucrative market, after new research headed by the Imperial College London suggested it may prove successful in treating serious asthma attacks.
The research, published in the New England Journal of Medicine on 12 April, found that giving once-daily Ketek in combination with standard care within 24 hours of an acute attack - and for 10 days thereafter - cut recovery time by three days, reduced symptom scores (by 40% versus 26% in the placebo group) and improved lung function across four different measures.
The researchers have yet to put a finger on the mechanism of action as, traditionally, antibiotics have not proved to be successful in treating asthma attacks. Most are linked to viruses, but the study investigators found that over 60% of the 280 patients enrolled in the study scored a positive result for the atypical bacteria Chlamydophilia pneumoniae and/or Mycoplasma pneumoniae, which are believed to heighten the severity of an attack.
However, the paper states that there was no link between bacteriologic status and response to treatment, and the researchers suggest that Ketek’s anti-inflammatory properties may also have had a role to play in producing the benefits seen.
There have only been two previous placebo-controlled trials of an antibiotic in asthma, both of which threw up negative results. However, say the researchers, both studies were very small, the large majority of patients had no bacterial infection and the compounds used were ineffective against atypical bacteria.
Ketek is a ketolide antibiotic and is approved for treating sinusitis, acute exacerbations of chronic bronchitis and pneumonia. It was originally filed with the FDA in 2000, and was deemed approvable in June 2001, although the firm was asked to conduct an additional safety study after concerns over liver toxicity, abnormal heart rhythm and visual disturbances. It was finally approved in April 2004, but the labelling mentions liver toxicity as a potential side effect.
Ketek, which pulled in just $47 million in third quarter sales in 2005 for Sanofi-Aventis (the compound’s full-year revenues were not published), was recently thrust into the spotlight again over links to liver injury after three cases were spotted in patients given the drug, one of whom died. The Office of Drug Safety in June 2005 deemed that there was no new information to change the product’s labelling, but Europe has clamped down on its use as a precautionary measure while it conducts a full risk:benefit analysis.