China Medical System (00867)’s Innovative Drug XF-73 Nasal Gel Achieved Positive Results from its Overseas Phase IIb Clinical Study

Company News

On 29 March 2021, Destiny Pharma, the collaborative partner of China Medical System Holdings Limited (“CMS”), announced positive top-line results from overseas Phase IIb clinical study of the innovative drug XF-73 nasal gel, primarily used for the prevention of post-surgical Staphylococcus aureus infections.

– Primary endpoint achieved with >99% nasal bacterial load reduction (p<0.0001);

Excellent safety profile and no treatment related adverse events.

The study was a multi-centre, double blind, randomized, placebo-controlled study of multiple applications of a single concentration of XF-73 nasal gel to assess the microbiological effect of XF-73 on commensal S. aureus nasal carriage in patients scheduled for surgical procedures deemed to be at high risk of post-operative S. aureus infection.

Clinical Study Results Highlights

1. Met primary endpoint: XF-73 reduced the mean nasal burden of S. aureus in patients undergoing open heart surgery by 2.5 log (CFU/ml) in the 24 hours immediately before surgery in the micro-ITT (Intend to Treat) population, a statistically highly significant result, (p<0.0001). This equates to a 99.5% reduction in S. aureus bacterial nasal carriage which is a very effective reduction by accepted clinical measures.

2. XF-73 showed 2.1 log, (>99%), greater reduction than placebo in the same patient population and this difference in reduction of nasal burden of S. aureus was statistically highly significant (p<0.0001) in both the micro-ITT and per protocol populations. The effect was maintained during surgery, considered the period when the risk for infections is the highest.

3. Initial analysis of secondary endpoints shows a higher reduction of burden of nasal S. aureus in the XF-73 arm compared to placebo arm in the 24 hours before surgery, and this was also observed when the data was analysed by area under the curve (AUC) and percentage of patients reaching a specific log reduction.

4. These positive results were achieved with just four doses of 0.2% (w/w) XF-73 nasal gel in the 24 hours before incision and the start of surgery.

5. There were no treatment related adverse events.

XF-73 has been awarded Qualifying Infectious Disease Product (QIDP) and Fast Track status by the US FDA. Destiny Pharma now plans to discuss possible Phase 3 clinical study designs with regulatory bodies including the US FDA.

About the Product

XF-73 is a synthetic dicationic porphyrin derivative with antibacterial activity. It has a novel mechanism of action which differs from that of any existing families of antimicrobial agents. It acts via a bacterial cell-surface mechanism that affects membrane permeability and integrity, leading to release of intracellular components and bacterial cell death, without lysis. XF-73 is active against all tested S. aureus strains including methicillin-resistant and multi-drug resistant strains, it exhibits rapid bactericidal activity against S. aureus and has a low potential for development of bacterial resistance. The compound patent and use patent have been granted in China.

A third of the human population are carriers of S. aureus, typically in the nose, and are at a significantly higher risk of acquiring a post-surgical infection. China Antimicrobial Resistance Surveillance System also indicates that it ranked first in Gram-positive bacteria. The WHO Surgical Safety Guidelines point out that nasal colonization of S. aureus is a
risk factor for postoperative infection. However, the use of existing preventative treatments is severely limited by the drug resistant bacteria. In contrast, XF-73 has been shown not to generate drug resistant bacteria, and this superior profile makes it ideally suited for widespread use for the prevention of post-surgical infections, fulfilling the unmet clinical needs.

CMS made an equity investment in Destiny Pharma and acquired certain assets’ rights of XF-73 in China or other Asian countries (excluding Japan).

Further information can be found in the Destiny Pharma’s Press Release: