Armata Pharmaceuticals Introduces Breakthrough AP-SA02 Therapy for Treating S. aureus Bacteremia
Armata Pharmaceuticals has introduced AP-SA02 for the adjunct treatment of complicated Staphylococcus aureus (S. aureus) bacteremia caused by methicillin-sensitive S. aureus (MSSA) or methicillin-resistant S. aureus (MRSA).
AP-SA02 is a fixed multi-phage therapy designed to target S. aureus. The therapy is administered intravenously and is being developed as an additional treatment alongside best available antibiotic therapy (BAT) for patients with complicated S. aureus bloodstream infections. It has also received Qualified Infectious Disease Product (QIDP) and Fast Track designations from the FDA.
The Breakthrough Therapy designation is supported by results from the Phase 1b/2a diSArm study involving adults with complicated S. aureus bacteremia. The randomised, double-blind, placebo-controlled study evaluated the safety, tolerability and efficacy of intravenous AP-SA02 when given alongside BAT. The therapy was administered every six hours for five days and was generally well tolerated, with no serious adverse events attributed to AP-SA02.
Patients who received AP-SA02 alongside BAT showed higher and earlier clinical cure rates than those who received placebo with BAT. At the end-of-study assessment, conducted 28 days after completion of BAT, 100% of patients treated with AP-SA02 maintained a clinical response without relapse, compared with 75% of patients receiving placebo. The AP-SA02 group also showed faster normalisation of C-reactive protein (CRP) and interleukin-10 (IL-10), biomarkers associated with disease severity and complications in S. aureus bacteremia.
S. aureus bacteremia is a serious bloodstream infection that can lead to complications and death. Treatment can be particularly challenging when the infection is caused by MRSA, which is resistant to several commonly used antibiotics. Bacteriophage therapy uses viruses that specifically infect and destroy bacteria and is being investigated as an approach for treating difficult-to-treat bacterial infections.
The FDA’s Breakthrough Therapy designation is intended to accelerate the development and review of medicines for serious or life-threatening conditions where preliminary clinical evidence indicates the potential for substantial improvement over available treatments. The designation also provides increased interaction with the FDA during the clinical development process.
AP-SA02 is being developed as an intravenous treatment administered every six hours for five days. Armata holds the development rights for the therapy and plans to initiate the Phase 3 study in the second half of 2026. The development programme has received partial support through a $28.7 million award from the Department of War, provided through the Medical Technology Enterprise Consortium and managed by the Naval Medical Research Command’s Naval Advanced Medical Development programme.
