AvidBiotics Taps Nature for Two Ways To Fight Lethal Microbes

AvidBiotics Avidocin protein

potential products called Purocin proteins, and a collaboration with DuPont Nutrition & Health (NYSE: [[TICKER: DD]]) on food processing agents. One possible product for DuPont is a spray liquid that could control Salmonella contamination of meat from poultry.

“They’re funding us at a significant level,” Martin says.

AvidBiotics can also apply its protein platform to veterinary medicine—another possible way to bring in revenues from the technology while the company continues work on human therapeutics and prophylactic treatments, Martin says. The company has raised about $25 million to date from individual investors and government research grants, Knighton says. It has 15 employees.

In the arena of C. difficile treatments for people, AvidBiotics would be competing with Lexington, MA-based Cubist Pharmaceuticals (NASDAQ:  [[ticker:CBST]]), which markets a novel antibiotic, fidaxomicin (Dificid) that was approved by the FDA in 2011 for the treatment of diarrhea caused by a C. difficile infection. Fidaxomicin was developed by San Diego, CA-based Optimer Pharmaceuticals, which Cubist acquired last year.

Cubist markets fidaxomicin as a narrow-spectrum antibiotic that wipes out C. difficile with minimal damage to other intestinal microbes. In clinical trials, participants taking fidaxomicin had fewer recurrences of C. difficile infection than those who took the conventional antibiotic vancomycin. Cubist and Optimer reported total revenues of $15.8 million from sales of fidaxomicin in the US and Canada during the fourth quarter of 2013.

Cubist’s drug, however, can promote the development of antibiotic resistance. Doctors are advised to prescribe it only when a patient has a known or strongly suspected C. difficile infection.

AvidBiotics hopes to prove that its Avidocin proteins will not increase the resistance of human gut bacteria to antibiotics. Drug resistance is a mounting problem in healthcare, and especially in hospitals. Bacteria readily acquire genes for antibiotic resistance by a number of means, such as viruses that can shuttle genes from one bacterium to another. In addition, the overuse of antibiotics kills off the bacteria that are vulnerable to the drug, allowing the resistant bacteria to multiply and dominate the microbial population.

Knighton says AvidBiotics’ bactericidal proteins could potentially be used to protect patients not infected with C. difficile from contracting the infection when they’re admitted to a hospital. The protein compounds might also be used as a preventive measure for hospital patients who already carry the dangerous bacteria, to suppress an explosion of the C. difficile population that might occur under the stress of surgery and treatment with antibiotics, Knighton says.

AvidBiotics was awarded a $600,000 grant from the National Institute of Allergic and Infectious Diseases of the National Institutes of Health in late 2012 to help advance its work on antibacterials targeted at C. difficile. The NIH has also supported the company’s work on the development of a second type of drug agent it calls Micasides.

These experimental compounds are designed to duplicate the natural protections of the human innate immune system against cancer cells and infected cells. These stressed cells normally produce proteins called MIC and display them on the cell surface. The MIC proteins are like flags to immune system cells such as natural killer cells, which rush to destroy the abnormal cells because they’re a threat to the host, Martin says.

But some cancer cells and infected cells manage to prevent the MIC proteins from appearing as surface signals. AvidBiotics is developing engineered human MIC proteins that stick to abnormal cells and also bind them to immune system cells that can destroy them.

“It’s a way of capitalizing on what nature has developed and trying to improve on it,” Martin says.

Author: Bernadette Tansey

Bernadette Tansey is a former editor of Xconomy San Francisco. She has covered information technology, biotechnology, business, law, environment, and government as a Bay area journalist. She has written about edtech, mobile apps, social media startups, and life sciences companies for Xconomy, and tracked the adoption of Web tools by small businesses for CNBC. She was a biotechnology reporter for the business section of the San Francisco Chronicle, where she also wrote about software developers and early commercial companies in nanotechnology and synthetic biology.