Contracts Support Clinical Trials On Antibiotic-Resistant, Community-Acquired Staph Infections

Finding ways to effectively treat bacterial infections with antibiotics that minimize the development of drug resistance is a key goal of antimicrobial resistance research.

NIAID announced the award of two new five-year contracts to study whether selected oral, off-patent antibiotics can effectively treat uncomplicated cases of skin and soft tissue infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) bacteria. If so, doctors could use those antibiotics first in an effort to dampen the development of resistance to such last-resort antibiotics as vancomycin.

S. aureus bacteria are the most common cause of skin and soft tissue infections in the United States; strains resistant to the antibiotic methicillin have increased and are now common in hospitals and long-term care facilities. The emergence of CA-MRSA in the 1990s caused great concern to health professionals because, unlike hospital-acquired infections, CA-MRSA affects otherwise healthy people who have not recently been hospitalized or exposed to other medical facilities. CA-MRSA illnesses range from minor skin and soft tissue infections to serious or even lethal infections. The best ways to treat CA-MRSA have not yet been determined.

Hospital-acquired MRSA infections generally respond only to a few antibiotics such as vancomycin and linezolid. Lab tests suggest that CA-MRSA bacteria are susceptible to more antibiotics than hospital-acquired MRSA strains, but the clinical efficacy of these antibiotics in treating CA-MRSA has not been proven.

The newly awarded contracts will support multisite, Phase II/III clinical trials to determine better ways to treat skin and soft tissue infection caused by CA-MRSA with the aim of preserving the efficacy of final-option drugs such as vancomycin and linezolid by reducing their frequency of use. Because the antibiotics used in the trial, which include clindamycin and trimethoprim/sulfamethoxazole, are no longer under patent, pharmaceutical companies have no incentive to conduct clinical trials using them. By supporting clinical trials of off-patent antibiotics, NIAID plays a key role in ensuring that the value of these drugs is fully realized.

One study will be led by University of California, Los Angeles, researchers David A. Talan, M.D., and Gregory J. Moran, M.D. The second contract was awarded to the University of California, San Francisco, where Henry F. Chambers, M.D., will lead the study. Each trial is designed to enroll up to 1,200 people. Together, the two contracts will total up to $19 million over five years.