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| |  Sparfloxacin Offers Impressive Activity Against Gram-Positive Organisms NEW ORLEANS, Sept. 16, 1996 -- Data presented today at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) demonstrate that sparfloxacin, an investigational oral antibiotic, is highly active against stubborn Gram-positive pathogens that cause many common respiratory tract infections, including penicillin-resistant Streptococcus pneumoniae. This Phase III data indicates that sparfloxacin, the first in a new generation of fluoroquinolones, may be useful in the treatment of community-acquired pneumonia (CAP), acute maxillary sinusitis (AMS) and acute bacterial exacerbations of chronic bronchitis (ABECB), conditions that affect nearly 50 million Americans annually and account for the majority of antibiotics used in communities. Respiratory tract infections, increasingly caused by drug-resistant Streptococcus pneumoniae, are among the leading causes of illness and death among the elderly, patients with underlying medical conditions and children. Further, pneumococcal resistance to penicillin, cephalosporins and macrolides has spread worldwide and is rapidly increasing, posing a threat to the treatment of these common respiratory infections. "Sparfloxacin will become available at a time when Gram-positive bacteria have re-emerged as a major problem compounded by growing resistance to currently available antibiotics," said Benjamin A. Lipsky, M.D., Associate Professor at the University of Washington and Hospital Epidemiologist at the VA Puget Sound Health Care System in Seattle and an investigator in the Surveillance Program of Antimicrobial Resistance (SPAR) Multicenter Study Group. "With its high level of activity and broad coverage of respiratory pathogens, sparfloxacin is one of few oral agents to demonstrate clinical efficacy in the treatment of adult respiratory infections caused by penicillin-resistant pneumococci." Clinical studies indicate that sparfloxacin -- a once-a-day broad-spectrum antibiotic that differs in structure and mechanism of action from other commonly used antibiotics -- is active against most pathogens that are resistant to penicillins, cephalosporins and carbapenems. Additionally, the agent demonstrates expanded activity against Gram-negative (e.g. Moraxella catarrhalis and Haemophilus influenzae) and Gram-positive (Streptococcus pneumoniae and Staphylococcus aureus) pathogens and effectiveness against atypical organisms, such as chlamydia, mycoplasma and legionella. Sparfloxacin Effective Against Other Agents in Treating CAP Two new studies from the SPAR Multicenter Study Group demonstrate the effectiveness of sparfloxacin compared with other agents commonly used to treat CAP. In a double-blind, randomized, multicenter study, 428 patients with CAP received 10 days of either 200 mg of sparfloxacin once daily (following a single 400 mg loading dose), or 500 mg of erythromycin every six hours. Among clinically evaluable patients, the clinical response rate was 86.4 percent for patients treated with the usual dose of sparfloxacin, compared with 80.7 percent for the high-dose erythromycin group. However, sparfloxacin was statistically superior for its bacteriologic response rate of 91.7 percent versus 75.9 percent for erythromycin. Data also revealed sparfloxacin's effectiveness against strains of S. pneumoniae that are resistant to penicillin as well as infections caused by atypical organisms. Results from a second study of 330 patients diagnosed with CAP indicated that patients receiving sparfloxacin demonstrated a statistically superior bacteriologic response over cefaclor. The patient bacteriologic responses in this population were 89 percent for sparfloxacin and 79 percent for cefaclor. "The advantage of sparfloxacin is its effectiveness against virtually all common respiratory pathogens, particularly the stubborn drug-resistant Streptococcus pneumoniae, which is a major contributor to CAP," commented George Bensch, M.D., Director of Allergy and Immunology at the San Joaquin Teaching Hospital in Stockton, Calif. "Sparfloxacin represents an advancement in the quinolone class of antibiotics because it enhances the Gram-positive coverage of respiratory pathogens and fills a gap seen with currently available agents." Community-acquired pneumonia strikes approximately four million Americans each year and hospitalizes about 600,000 with an annual cost of $23 billion. Approximately 500,000 cases of CAP each year are the result of infection with S. pneumoniae. AMS Effectively Treated with Sparfloxacin A double-blind, multicenter study of 504 patients with acute maxillary sinusitis (AMS) demonstrates sparfloxacin's effectiveness in treating AMS, an inflammation of the mucus membranes caused by a secondary bacterial infection. On average, 42 percent of all AMS cases are attributed to infection with S. pneumoniae. Subjects were randomly assigned to receive either 200 mg of sparfloxacin (following a single 400 mg loading dose) for 10 days, or 500 mg of clarithromycin every 12 hours for 14 days. Results demonstrated similar clinical response rates for the two groups (83.1 percent for sparfloxacin, 83.4 percent for clarithromycin), even though the duration of therapy was four days less for sparfloxacin. Additional data revealed a clinical recurrence rate of 9.7 percent for sparfloxacin versus 14 percent for clarithromycin. "This comparative study provides valuable information about treating acute maxillary sinusitis, a condition which affects 30 million Americans each year," said Dr. Bensch. "The reduction in the duration of treatment demonstrated with sparfloxacin represents a potential cost-savings for the patient afflicted with this condition." Study Shows Promising Results of Sparfloxacin for Chronic Bronchitis A study of 798 patients by the SPAR Multicenter Study Group investigated the efficacy of treating ABECB with sparfloxacin versus ofloxacin. Patients were randomized to receive 200 mg of sparfloxacin (following a single 400 mg loading dose) once-a-day, or 400 mg of ofloxacin every 12 hours, each for 10 days. Results demonstrated comparable overall response rates for both groups of patients (85.4 percent and 88.8 percent for sparfloxacin and ofloxacin, respectively). The sparfloxacin group had the advantage of once-daily dosing. "New antibiotics are desperately needed to deal with the growing incidence of drug-resistant infections," added Dr. Lipsky. "As clinicians, we welcome new agents and view them as valuable weapons in our battle against microbial drug resistance." An overview of six Phase III trials comparing patients receiving sparfloxacin to patients receiving one of several other agents (erythromycin, cefaclor, ofloxacin, clarithromycin or ciprofloxacin) revealed no clinically important differences in safety profiles. The most frequently reported side effects of sparfloxacin were photosensitivity reaction, diarrhea, nausea, headache, dizziness, insomnia, abdominal pain and gas. Photosensitivity (almost always mild to moderate) was statistically more frequent with sparfloxacin, while gastrointestinal disturbances were significantly more common with other agents. Sparfloxacin exerts its antibacterial activity by inhibiting DNA gyrase, a bacterial topoisomerase. DNA gyrase is an essential enzyme which controls DNA topology and assists in DNA replication, deactivation and transcription. Sparfloxacin is being developed by Rhone-Poulenc Rorer, Inc. (NYSE: RPR), a global pharmaceutical company. The company filed a New Drug Application (NDA) for the product with the U.S. Food and Drug Administration (FDA) in December of 1995.
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