Post-surgical Infections

Clinical background

Destiny Pharma’s lead product exeporfinium chloride (XF-73) focuses on addressing the medical and financial cost of infections due to one of the major Gram positive bacteria, Staphylococcus aureus (S. aureus), a leading cause of post-surgical infection across the world. S. aureus is a Gram-positive bacterium and is frequently found in the nose, respiratory tract, and on the skin. Each year, around 500,000 patients in hospitals of the US contract a staphylococcal infection, chiefly by S. aureus. A third of the human population carry the bacteria S. aureus, typically in the nose. S. aureus carriers are at a significantly higher risk of acquiring a post-surgical infection.

The main approach in S. aureus infection prevention has been to treat patients who carry the bacteria prior to surgery to reduce the risk of infection. This has been achieved predominately by the use of an intra-nasal antibiotics (e.g. mupirocin) and antiseptic (e.g. chlorhexidine) body washes. Bode et al. demonstrated that treatment of all S. aureus, (MRSA & all other strains of S. aureus) in higher risk surgeries led to a >60% reduction in post-surgical S. aureus infections. The recognition of the benefit of treatment of all S. aureus represents about a six-fold increase in the patient population benefiting, a figure of >20 million per year in the USA & Europe alone. A number of key surgical guidelines in the US and EU/RoW now recommend preventative treatment of all S. aureus (MRSA & all other S. aureus strains) in patients undergoing at risk surgeries. However, the use of existing preventative treatments are severely limited by the existence of / and fear of generating the emergence of resistance.

Market opportunity

Destiny Pharma has undertaken independent market research of the product profile of XF-73. This study confirmed that XF-73’s target product profile is superior when compared to mupirocin, with the potential to replace mupirocin as the preferred treatment.

The commercial opportunity for XF-73 is over a billion dollars. There is a significant market for a new drug that can assist in the “prevention of post-surgical staphylococcal infections”, particularly in the US. There are approximately 40 million surgeries per year in the US alone, all of which expose patients to the risk of post-surgical infections. Of these patients, Destiny Pharma estimates that 14 million are at a higher risk of infection as a result of the nature of their surgery and the environment in which they are treated. Therefore, including the potential future use of XF-73 within the ICU the company believes markets totalling at least 20 million patients per annum exist in the US alone.

Destiny Pharma believes that there is significant demand for the XF-73 product and have identified the following additional drivers for adoption:

  • Current practice guidelines have identified patient populations that can benefit while highlighting that antibiotic resistance as an issue with current products;
  • US general, acute-care and short-term hospitals with the highest MRSA infections can have 1% of their Medicare reimbursements withheld;
  • The UN General Assembly called for new drugs to tackle antibiotic resistance in September 2016;
  • US hospital administrators incentivised to reduce infection to ensure high ratings in rankings tables;
  • XF-73 has QIDP and Fast Track regulatory status in the US and also benefits from five years of extra US market exclusivity; and
  • XF-73 could be the first drug approved into a new US indication with first to market advantages;

As XF-73 is differentiated from antibiotics due to its superior bacterial resistance profile, it is likely that its use can be widespread, preserving antibiotic use and could potentially be used without the need for bacterial screening. In this respect, XF-73 can be viewed as a preventative drug more akin to vaccines than antibiotics. Through the QIDP status it has the opportunity to become the first drug approved in the US for the new indication “prevention of post‑surgical staphylococcal infections” and may only need to be compared to placebo at Phase 3 as no comparator exists. It could therefore become the benchmark against which all future competitors will be measured. This is a major advantage and will help drive the clinical programme and also the commercialisation of XF-73 in the US.