STROX Biopharmaceuticals, LLC (“STROX” or the “Company”) is an early-stage company engaged in the development of anti-bacterial antibody products for treatment of life-threatening infections. The Company’s lead product is an antibody for treating hospital-acquired Staphylococcus aureus (SA) infections, including those caused by methicillin-resistant SA (MRSA). Unlike conventional antibiotics, this innovative antibody product specifically directs components of the body’s immune system to bind and then kill SA bacteria.
Staphylococcus aureus (SA)
The considerable economic impact of SA on healthcare systems and increasing prevalence of antibiotic-resistant strains of SA provide a huge market opportunity for new modes of treating infections caused by these bacteria. SA infections are acquired both inside and outside of healthcare facilities. Because infection-prone patients congregate in hospitals and other non-ambulatory healthcare facilities, these institutions are dangerous reservoirs of SA. Coupled with the heavy use of multiple antibiotics in these institutions, the vast majority of SA infections have become resistant to several different classes of anti-bacterial drugs.
Hospital-acquired SA infections are a leading cause of disability and death, and have placed a tremendous economic burden on healthcare systems throughout the world. Analysis of 2000-2001 U.S. hospital data showed that inpatients with SA infection as a discharge diagnosis had, on average, three times the length of hospital stay, three times the total charges, and five times the risk of in-hospital death than patients without infection. This translates to roughly an additional 12,000 deaths and $9.5 billion in charges per year. For 2003 the total economic burden from all SA-related inpatient stays in the U.S. increased to $14.5 billion, with the average annual increase estimated at nearly 12%.
For decades, the standard treatment for SA infections has been administration of antibiotics. Heavy use of these drugs, however, has fueled the development of antibiotic resistance in SA, particularly MRSA. The increasing prevalence of SA strains that are impervious to numerous conventional antibiotics has created the need to use other, more exotic, antibiotics such as vancomycin, daptomycin, and linezolid – all of which can have serious side effects and limitations. Frighteningly, SA resistance to each of these “antibiotics of last resort” has been reported, suggesting the possible emergence of a SA superbug invulnerable to all modern antibiotics. Although this scenario has not yet materialized, the recent emergence of a Klebsiella pneumoniae superbug (NDM-1 strain) resistant to all modern antibiotics except the kidney-damaging drug polymyxin E is a chilling harbinger of what is to come.
The last quarter century, however, saw a dramatic reversal in the attitudes of healthcare professionals toward bacterial infections. Driven by the evolving resistance of many bacterial pathogens to antibiotic therapy, the euphoria of the 50’s and 60’s was replaced by a growing concern that microbes were not only regaining the upper hand but might just win the war after all.
Overcoming Immune System Evasion
A major challenge in developing immunologic approaches to managing bacterial infections is that bacteria have evolved mechanisms for avoiding clearance by the immune system. A bacterial infection in a person can be viewed as a battle between these virulence mechanisms -- the bad guys -- and those components of the immune system that function to kill bacteria -- the good guys. In designing its product, STROX carefully considered how SA’s “virulence factor” weapons allow SA to counter antibody-mediated immune system attacks, and developed a strategy for disabling them. In particular, STROX believes that two factors, which act in concert, are critical for allowing SA to escape antibody-based attacks: staphylococcal Protein A (SpA) and the polysaccharide capsule. SpA acts by directly binding and neutralizing the vast majority of circulating antibodies. The polysaccharide capsule acts by covering or “cloaking” most of the components on SA that are targeted by antibodies.
The Company’s lead product, Saurestat™, is an antibody specifically designed to overcome both the neutralizing effects of SpA and the cloaking effects of the polysaccharide capsule. STROX has a robust patent portfolio that covers this technology.
The initial indication planned for Saurestat™ is the treatment of hospital-acquired SA infections such as bacteremia, surgical wound infections, and medical device implant-associated infections. Given the multi-billion dollar economic burden SA infection imposes, premium pricing of this product is expected. Assuming modest estimates of market penetration, the annual U.S. sales of Saurestat™ have the potential to exceed $1 billion (approximately 5% of the estimated annual U.S. economic burden of SA infection), and greater than $2 billion in the global healthcare market. For comparison purposes, 2008 sales of Cubicin® (injectable daptomycin) in the U.S. were $414.7 million. Zyvox® (linezolid) sales were $1.115 billion for the same year. Although there are no antibody products currently on the market specifically for treating SA infections, 2007 sales for the 20 approved therapeutic antibodies for other indications were approximately $25 billion. Eight of these are considered “blockbusters,” each surpassing $1 billion in annual sales.
Copyright 2011 STROX Biopharmaceuticals, LLC. All rights reserved.