Novel Antibiotic Sulopenem Misses Primary End Point in cIAI Trial

Results showed that sulopenem failed to demonstrate non-inferiority to ertapenem (difference of 4.7%; 95% CI: -10.3, 1.0); 85.5% of patients in the sulopenem arm had a clinical response vs 90.2% of the ertapenem group.

Iterum Therapeutics announced topline results from the phase 3 SURE 3 trial of sulopenem for the treatment of complicated intra-abdominal infections (cIAI).

The SURE 3 trial was a randomized, double-blind, multicenter study that compared the efficacy and safety of sulopenem to ertapenem in adult patients with cIAI (N=674). Patients were randomized to receive either intravenous (IV) sulopenem once daily for at least 5 days followed by oral sulopenem/probenecid twice daily to complete 7 to 10 total days of treatment, or IV ertapenem once daily for at least 5 days followed by oral ciprofloxacin twice daily with oral metronidazole 4 times daily or, for patients with ciprofloxacin-resistant organism at baseline, amoxicillin-clavulanate twice daily. The primary end point of the study was clinical response on Day 28 in the micro-MITT population.

Results showed that the trial failed to demonstrate non-inferiority to ertapenem (difference of 4.7%; 95% CI: -10.3, 1.0); 85.5% of patients in the sulopenem arm had a clinical response vs 90.2% of the ertapenem group. Based on Food and Drug Administration (FDA) guidance, non-inferiority required that the lower limit of the difference in the outcome rates be >-10%. With regard to safety, the most common treatment-emergent adverse reaction was diarrhea.

“While the difference in the primary outcome is 1 patient shy of the target of -10%, imputing an outcome for the patients with missing data and the secondary supporting analyses, both at the end of treatment as well as the test of cure, provide support for the potential of sulopenem in the treatment of multidrug resistant infections,” said Michael Dunne, MD, Chief Scientific Officer at Iterum Therapeutics. “Over 10% of the patients in this study had a gram-negative pathogen that was resistant to both quinolones and β-lactams, the 2 classes of oral agents that are most commonly used for step down therapy for this indication.”

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The Food and Drug Administration previously granted Special Protocol Agreements (SPA) and Qualified Infectious Disease Product (QIDP) designations for oral and IV sulopenem. The Company is currently evaluating sulopenem in three pivotal phase 3 trials for uncomplicated urinary tract infections, complicated urinary tract infections and complicated intra-abdominal infections. “If we obtain positive results in Q1 2020 from our phase 3 complicated and uncomplicated urinary tract trials, we believe that the overall safety and efficacy results from this cIAI trial would be supportive in an FDA filing for oral and IV sulopenem and that sulopenem’s market potential remains robust,” said Corey Fishman, Chief Executive Officer of Iterum Therapeutics.

Sulopenem is a novel penem antibiotic that has shown in vitro activity against a wide variety of gram-negative, gram-positive and anaerobic bacteria resistant to other antibiotics.

For more information visit iterumtx.com.