New anti-infective drug aims to fight drug-resistant bacteria at source

Nov 29 2007

Deadly methicillin-resistant Staphylococcus aureus - MRSA - a bacterium that responds poorly to conventional antibiotic treatment, infects 90,000 Americans per year and causes 19,000 deaths, most in hospital settings.

Infections have recently been reported outside of hospital settings at an increasing rate, which has alarmed public health officials. Approximately 14% of MRSA-related illnesses occur in community settings.

While the infection and mortality figures for S. aureus are frightening, the “bug” is a lot more prevalent that one would think. S. aureus colonizes, without infecting, about 30% of human beings. S. aureus colonization exists unnoticed, primarily in the nose and on the skin. Individuals who suffer wounds, or whose immune systems are compromised by illness, are susceptible to conditions as mild as a boil or as life-threatening as systemic infection.

Emeryville, California-based NovaBay Pharmaceuticals, Inc. has announced results from a Phase I clinical trial with NVC-422, a new compound with potent activity against numerous pathogens, including MRSA. NVC-422, whose trade name is AgaNase™, is unique in that it is an anti-infective, but technically not an antibiotic.

Nasal colonization by Staphylococci is an important risk factor that predisposes carriers to nosocomial (hospital) infections. NovaBay hopes that by greatly reducing this layer of colonizing bacteria, hospital patients will be less likely to experience serious MRSA infections.

NVC-422 rapidly destroys a range of pathogens that includes Gram-positive and Gram-negative bacteria, yeasts, and viruses. Because it kills pathogens on contact and not through typical antibiotic mechanisms, it is believed that bacteria and viruses are unlikely to develop resistance to NVC-422 treatment. This “non-antibiotic” strategy is critical for maintaining the efficacy of antibiotic therapies for life-threatening infections.

The recently completed Phase I trial demonstrated that topical application of NVC-422 to the lower nasal passages, or nostrils, is safe and well tolerated. Moreover, researchers could not detect any trace of NVC-422 in the blood.

The clinical study tested safety and tolerability following repeated applications of AgaNase at two drug concentrations, 0.1% and 0.3%, applied by spray or swab to the nostrils. Ninety-six subjects were enrolled and completed the study. Adverse events were local, mild and transitory and did not appear to increase with dosage.

Based on these results, NovaBay has begun a second Phase I trial to test the safety of NVC-422 at a higher dose. Results from this study should become available by early 2008. In parallel with the second Phase I study, NovaBay expects to begin a Phase IIa study by January 2008, in healthy volunteers who harbor S. aureus in their nasal passages.

“NVC-422 could become a critical option in the ongoing battle against drug-resistant infections, including MRSA,” said Dr. Ron Najafi, NovaBay's President and Chief Executive Officer. “We intend to move forward with additional safety and efficacy trials in volunteers and patients at risk of infection.”

The target market for NVC-422 is hospital-associated infections, particularly those occurring in surgical wounds. Surgical site infection significantly lengthens hospital stays and may result in death. Hospital-associated MRSA infections cost the U.S. healthcare system tens of billions of dollars per year and are rapidly rising in frequency.

NovaBay has entered into a licensing and research collaboration agreement with an affiliate of Alcon, Inc. for the use of compounds similar to NVC-422 in eye, ear and sinus infections, and in contact lens solutions.