New Antibiotic Performs Well Against Vancomycin for Treatment of ABSSSIs

Topline results of a recent phase 3 multicenter, randomized, double-blind clinical trial (REVIVE-1) comparing the safety and efficacy of the new antibiotic iclaprim versus vancomycin for the treatment of acute bacterial skin and skin structure infections (ABSSSIs), have revealed that “iclaprim achieved the primary endpoint of non-inferiority (NI) (10% margin) compared to vancomycin at the early time point (ETP), 48 to 72 hours after the start of administration of the study drug, in the intent-to-treat (ITT) patient population,” according to a press release from Motif Bio plc, the biopharmaceutical company that developed iclaprim. In addition, “Iclaprim achieved NI (10% margin) at the test of cure (TOC) endpoint, 7 to 14 days after study drug discontinuation, in the ITT patient population.”

A total of 600 patients were enrolled in the study, following the inclusion criteria that patients were 18 years of age or older, had a “bacterial infection of the skin with a lesion size area of at least 75 cm2,” “a major cutaneous abscess, cellulitis/erysipelas, and/or wound infections,” and “the presence of purulent or seropurulent drainage or at least three signs and symptoms of infection (discharge, erythema, swelling, warmth, or pain).”

Each patient received either an 80mg intravenous dose of iclaprim or a 15mg/kg intravenous dose of vancomycin every 12 hours for a period of 5 to 14 days. They were then evaluated “daily up to ETP,” and then, “every 48-72 hours through the end of treatment.” In addition, the patients were evaluated at the TOC visit (which occurred 7 to 14 days post-EOT) and again at a Late Follow-Up visit, approximately 28 to 32 days after the first dose.

Although iclaprim performed just as effectively as vancomycin, according to Fierce Biotech contributor Nick Paul, the biopharma company is aimed at positioning it as the safer option of the two. Safety data has yet to be released; however, according to Motif Bio, preliminary results look promising.

The company is now focused on a second phase 3 trial (REVIVE-2) which will follow the same design, but will enroll patients at different sites. If successful, Motif Bio with file a new drug application (NDA). Because the US Food and Drug Administration has already granted iclaprim Fast Track designation as well as a Qualified Infectious Disease Product for the treatment of ABSSIs and hospital-acquired bacterial pneumonia, following the submission of the NDA, the drug is available Priority Review.

"Following the positive outcome in this clinical trial, the differentiated mechanism, potency, spectrum, safety and efficacy of iclaprim, if approved, could provide a valuable new antibiotic treatment option that is urgently needed to offset the rising problem of bacterial resistance,” said William D. O'Riordan M.D., FACEP, Chief Medical Officer of eStudySite in the press release.

Multidrug resistant infections, such as ABSSSI, are serious and potentially life-threatening. These infections are typically caused by methicillin-resistant Staphylococcus aureus (MRSA). According to the latest data from the Centers for Disease Control and Prevention (CDC), 2 in 100 individuals carry MRSA. Iclaprim is a novel diaminopyrimidine with potent activity on trimethoprim sensitive and resistant bacteria, such as MRSA.