Designation for adjunct treatment of complicated bacteremia caused by methicillin-sensitive S. aureus ("MSSA") or methicillin-resistant S. aureus ("MRSA"). Breakthrough Therapy designation is intended to expedite the review of medicines that treat a serious or life-threatening condition and have shown preliminary clinical evidence indicating the potential for substantial improvement over available therapies.

"The decision by the FDA to grant Breakthrough Therapy designation to AP-SA02, in addition to Qualified Infectious Disease Product ("QIDP") and Fast Track designations, recognizes the urgent need for new treatment options for patients with complicated S. aureus bacteremia ("SAB"), including MRSA, where many outcomes remain poor despite current standard-of-care," said Dr. Deborah Birx, Chief Executive Officer of Armata. "Based on the Phase 2 clinical trial data, we believe AP-SA02 has the potential to represent an important advancement in the treatment of complicated SAB, a serious bloodstream infection that continues to be associated with significant relapse rate, morbidity and mortality. If ultimately confirmed in Phase 3 and approved, AP-SA02 has the potential to become the first antibacterial therapy approved based on superiority to current standard-of-care treatment in this patient population. We are grateful for the FDA's enhanced engagement and are committed to working closely with the Agency to efficiently advance the development and review of AP-SA02, with the goal of bringing this potential new treatment option to patients as quickly as possible."

Critically, the Breakthrough Therapy designation is supported by data from the successful Phase 1b/2a diSArm study in adults with complicated SAB. Armata's proprietary purification process yielded the production of a high-purity, high-titer AP-SA02 drug product formulation enabling repetitive dose intravenous administration every six hours for five days. This dosing regimen was well tolerated with no serious adverse events attributed to AP-SA02, and, when added to best available antibiotic therapy ("BAT") demonstrated higher and earlier clinical cure rates than placebo plus BAT. At the end-of-study assessment, 28 days after completion of BAT, 100% of patients treated with AP-SA02 maintained clinical response without relapse, compared with 75% of patients receiving placebo. Patients treated with AP-SA02 also demonstrated favorable trends across multiple measures of disease resolution, including more rapid normalization of C-reactive protein (CRP) and Interleukin-10 (IL-10), biomarkers associated with mortality risk and complications in SAB.