Cardiac surgery patients receiving XF-73 nasal gel exhibited a valuable, sustained nasal reduction of Staphylococcus aureus

Update on secondary endpoint analysis from recent positive Phase 2b trial

Cardiac surgery patients receiving XF-73 nasal gel exhibited a valuable,

sustained nasal reduction of Staphylococcus aureus

Brighton, United Kingdom, 2^nd August 2021 – Destiny Pharma plc (AIM: DEST), a clinical stage innovative biotechnology company focused on the development of novel medicines that can prevent life threatening infections is pleased to announce additional, strong data from its recent Phase 2b clinical trial.  In March 2021, the Company announced that this study had met its primary endpoint, demonstrating a highly significant reduction of 2.5 log (>99%) in nasal Staphylococcus aureus immediately prior to surgery compared to placebo (p<0.0001) after just 24 hours of XF-73 nasal gel dosing. The placebo-treated patients showed only a 0.4 log reduction in bacterial load immediately before surgery. All patients in the study also received antibiotic dosing as standard of care.

Today’s additional data shows that XF-73 dosed patients can also benefit from a sustained bacterial reduction at the three post-surgical sample time points after wound closure of 1 hour, 2 and 6 days demonstrating 2.5 log, 2.4 log and 2.8 log reductions, respectively, and sustaining the drop of over 99% in S. aureus nasal burden.  The placebo treated patients reported 0.4 log, 1.5 log and 2.5 log reductions at the same time points. The bacterial reductions in XF-73 treated patients were shown to be highly statistically significant over placebo at the 1 hour and 2 days post-surgery timepoints (p<0.0001 and p<0.003, respectively). As a result of the antibiotic dosing used as standard of care, the 6-day time point reduction in the placebo group were equivalent to the XF-73 arm which was expected as it is known (*Wilson et al, 1977) that pre- and post-surgical systemic anti-staphylococcal antibiotic dosing elicits a slow, gradual reduction in nasal bacterial carriage.

This sustained nasal microbiological effect in the period of greatest risk (pre-surgery to wound healing) of XF-73 in patients is a desirable attribute for the reduction in the risk of acquiring a post-surgical, staphylococcal infection. Today’s new data demonstrates that XF-73 nasal gel has the potential to keep patients at a significantly low S. aureus nasal burden during the period of highest infection risk which runs from 1 hour prior to incision, during surgery itself, to the start of wound healing and out to at least 6 days post-surgery.

Neil Clark, CEO of Destiny Pharma, said: “We are very pleased to announce this additional, positive data from the successful Phase 2b study of XF-73 as a novel drug to reduce the incidence of post-surgical infections such as MRSA. We are having discussions with regulators in US and Europe to enable us to design the required Phase 3 clinical study and will announce further updates later in 2021. XF-73 has great potential to provide a safe, fast acting medicine that kills S. aureus in the nose prior to surgery thereby reducing patient infections whilst not generating bacterial resistance. There is a clear clinical need for such a new medicine that helps prevent post-surgical infections and there is a significant commercial opportunity.”

Scientific Advisory Board member, Professor Richard Proctor (Professor Emeritus of Departments of Medical Microbiology & Medicine at University of Wisconsin School of Medicine, Wisconsin, US), said: “This new clinical data from the Phase 2b trial wherein XF-73 produces a sustained reduction in nasal burden of S. aureus out to at least 6 days is an important observation for several reasons.  First, nasal S. aureus burden directly correlates with the incidence of post-surgical wound infections.  Second, reduction in S. aureus nasal colonization is associated with decreased numbers of all staphylococcal infections.”

*Wilson et al., In vivo effects of josamycin, erythromycin, and placebo therapy on nasal carriage of Staphylococcus aureus. Antimicrobial Agents and Chemotherapy,1977, 3: p. 407-10)

For further information, please contact:

Destiny Pharma plc

Neil Clark, CEO

Shaun Claydon, CFO

pressoffice@destinypharma.com

+44 (0)1273 704 440