Positive results from Affinium Pharmaceuticals' Phase 2a clinical trial of AFN-1252 in ABSSSI

Mar 21 2013

Affinium Pharmaceuticals announced today that its Phase 2a clinical trial evaluating oral AFN-1252 in acute bacterial skin & skin structure infections (ABSSSI) demonstrated excellent efficacy and safety data, marking a significant proof-of-concept milestone for Affinium's first-in-class, novel antibiotic targeted against bacterial fatty acid biosynthesis inhibition (FabI inhibitors).

Barry Hafkin , MD, Chief Medical Officer of Affinium Pharmaceuticals stated, "This clinical study in 103 patients from 18 centers in the USA and Canada confirms excellent efficacy, safety and tolerability of 200 mg of oral AFN-1252 dosed twice daily for 5-14 days in patients with acute bacterial skin and skin structure infections (ABSSSI) due to Staphylococcus". Patients were recruited from outpatient or emergency room settings.   The enrolled patients had a variety of skin infections of ≥ 75 cm² in size, including severe abscesses (38%), cellulitis (27%), and wound infections (35%).  Investigators had the option of adding a second antibiotic to cover other potential pathogens or admitting the patient into the hospital. The vast majority of the patients were treated with oral AFN-1252 as monotherapy in the outpatient setting based on the suspicion of staphylococci from the clinical presentation and pretreatment Gram stain.  This study fully utilized recent FDA guidances for clinical trials in ABSSSI, including both entry and efficacy criteria.

Key results from the study include:

• Day 3 Improvement was achieved in 94% of patients in the clinically evaluable (CE) and microbiologically-evaluable (ME) populations.
• Overall cure, defined as resolution of lesion at short term follow-up, was seen in 93% of patients.
• Treatment emergent adverse events (TEAEs) related to study drug occurred in 67% of patients, of which 90% were mild or moderate. The most common TEAEs were headache, nausea and vomiting. Only 4 patients withdrew due to drug-related TEAEs.
• Of the 103 ITT patients who received drug, 87 patients had evidence of Staphylococcus at baseline (MITT), 88 were clinically evaluable at end of treatment (test of cure) and 76 were microbiologically evaluable.
• Consistent with the growing incidence of MRSA in the community, almost 50% of the S. aureus isolates were methicillin-resistant (MRSA).

"It's very exciting to have an oral formulation of a new mechanism of action antibiotic that has such high potency against MRSA and a safety profile which is promising, particularly for longer term therapy," stated Dr. Vance Fowler , Professor of Medicine at Duke University Medical Center.

Dr. Robert Daum , Professor of Pediatrics and Head of the MRSA Research Center at the University of Chicago indicated that "an antibiotic that preserves gut flora and minimizes the risk of C. difficile overgrowth would bring important advantages to treatment of skin infections in both the hospital and community.  The potential of AFN-1252 to provide these benefits is groundbreaking and should be pursued in greater detail."

"These data support the use of oral AFN-1252 as safe and rapid treatment of serious staphylococcal infections, including MRSA," stated Dr. Ed Mascioli , newly appointed CEO of Affinium. "We are eagerly pursuing the continued development of the oral formulation, as well as conducting Phase 1 studies for the intravenous formulation this year."