AP-SA02 for Staphylococcal Bacteremia

(diSArm Trial)

No longer recruiting at 29 trial locations

Overseen By Khalid Gafoor, MD

Age: 18+

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: Armata Pharmaceuticals, Inc.

Disqualifiers: Other organisms, Endocarditis, Brain abscess, others

Stay on Your Current Meds You can continue your current medications while participating

Compensation: Varies

Number of Visits: Unknown

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called AP-SA02, an experimental therapy, to combat serious blood infections caused by the bacteria Staphylococcus aureus, often found in hospitals. Researchers aim to determine if adding AP-SA02 to standard antibiotic treatment is safe and effective. Participants will receive either the AP-SA02 treatment or a placebo (an inactive substance) alongside their regular antibiotics. The trial seeks adults who are hospitalized with confirmed Staphylococcus aureus in their blood, with the infection source managed or planned for control. As a Phase 1 trial, the research focuses on understanding how the treatment works in people, offering participants the opportunity to be among the first to receive this new therapy.

Do I have to stop taking my current medications for this trial?

The trial protocol does not specify if you need to stop taking your current medications. However, since the study involves adding a treatment to existing antibiotic therapy, it's likely you can continue your current medications, especially if they are antibiotics for Staphylococcus aureus.

Is there any evidence suggesting that AP-SA02 is likely to be safe for humans?

Research has shown that AP-SA02 appears safe for treating Staphylococcus aureus infections, which can lead to serious health problems. Early results suggest that this treatment, using natural viruses to target bacteria, is well-tolerated by patients. Studies reported that people who received AP-SA02 responded well, indicating effectiveness without significant harm. No major safety issues emerged, which is encouraging for those considering joining this trial. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard antibiotics used to treat staphylococcal bacteremia, AP-SA02 is an anti-staphylococcal bacteriophage, which means it uses viruses that specifically target and destroy Staphylococcus bacteria. This approach is unique because it directly attacks the bacteria without harming the beneficial bacteria in the body, potentially reducing side effects and the risk of antibiotic resistance. Researchers are excited about AP-SA02 because it offers a targeted action against the infection, which could lead to more effective and quicker recovery for patients.

What evidence suggests that AP-SA02 might be an effective treatment for Staphylococcal bacteremia?

In this trial, participants will receive either AP-SA02 or a placebo. Previous studies have shown that AP-SA02 holds promise for treating Staphylococcus aureus bacteremia, a blood infection. Patients who received AP-SA02 often experienced faster improvement in their infections, beginning in about 2.7 days, compared to 9.3 days for those who did not receive it. The treatment also reduced levels of C-reactive protein, a marker of inflammation, and led to quicker negative blood tests, indicating the infection had cleared. All patients treated with AP-SA02 alongside standard antibiotics eliminated their infections without recurrence. These positive results suggest that AP-SA02 could be a valuable addition to current antibiotic treatments for this serious infection. ^{1 2 3 4 6}

Who Is on the Research Team?

Deborah Birx, MD

Principal Investigator

Armata Pharmaceuticals, Inc.

Are You a Good Fit for This Trial?

Adults over 18 with a Staphylococcus aureus (SA) blood infection who are hospitalized can join. They must have their source of SA infection under control or a plan for it, not be pregnant or breastfeeding, and agree to use contraception if they can have children. Those with certain heart infections, brain abscesses, meningitis, allergies to phage products, or other bacterial growth besides SA cannot participate.

Inclusion Criteria

Positive blood culture for Staphylococcus aureus (SA)

Not pregnant or breastfeeding and is not of reproductive potential or agrees to use contraception if of reproductive potential

I am 18 years or older and currently hospitalized.

Exclusion Criteria

Concomitant growth of organisms besides SA

I have an infection in the left side of my heart.

I have or might have a brain infection.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Phase 1b Treatment

Evaluation of safety and tolerability of multiple ascending intravenous doses of AP-SA02 or placebo as an adjunct to best available therapy

12 days

Phase 2a Treatment

Evaluation of efficacy, safety, and tolerability of multiple doses of AP-SA02 or placebo as an adjunct to best available therapy

12 days

Follow-up

Participants are monitored for safety and effectiveness after treatment

28 days

What Are the Treatments Tested in This Trial?

Interventions

• AP-SA02

Trial Overview This study is testing the safety and effectiveness of AP-SA02 given through an IV as an extra treatment alongside the best available antibiotic therapy versus just the antibiotics alone in treating adults with SA bacteremia. It's randomized and double-blind meaning neither participants nor researchers know who gets what treatment until after results are collected.

How Is the Trial Designed?

Group I: AP-SA02 Experimental Treatment 1 Intervention

Anti-staphylococcal bacteriophage

Group II: Placebo Placebo Group 1 Intervention

Inactive isotonic solution

Who Is Running the Clinical Trial?

Armata Pharmaceuticals, Inc.

Lead Sponsor

Trials

13

Recruited

530+

United States Department of Defense

Collaborator

Trials

940

Recruited

339,000+

Published Research Related to This Trial

Staphylococcus aureus bacteremia (SAB) is a serious and often fatal infection, highlighting the importance of prompt diagnosis and management to improve patient outcomes.

Effective management of SAB requires identifying the primary source of infection, which can include various conditions like skin infections or pneumonia, and necessitates collaboration among healthcare specialists for optimal treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical management of Staphylococcus aureus bacteremia. Arientová, S., Holub, M.[2021]

A study of 78 patients with persistent Staphylococcus aureus bacteremia (SAB-P) revealed an increase in frequency and risk factors over time, including higher rates of organ dysfunction and MRSA infections.

Despite the rise in SAB-P cases, the overall case-fatality rates remained unchanged, indicating that while the patient population is evolving, treatment outcomes for survivors are stable, suggesting a need for new treatment strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Persistent Staphylococcus aureus bacteremia: incidence and outcome trends over time. Khatib, R., Johnson, LB., Sharma, M., et al.[2013]

In a study of 100 episodes of Staphylococcus aureus bacteraemia (SAB) involving 98 patients in South Africa, the 90-day mortality rate was alarmingly high at 47%, with most deaths directly linked to the infection.

Factors such as methicillin-resistant S. aureus (MRSA) infection, comorbidities, and non-optimal antibiotic therapy significantly increased the risk of complicated infections and mortality, highlighting the urgent need for better antibiotic management in these cases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The management and outcomes of Staphylococcus aureus bacteraemia at a South African referral hospital: A prospective observational study. Steinhaus, N., Al-Talib, M., Ive, P., et al.[2018]

In a study of 325 cases of Staphylococcus aureus bacteraemia (SAB) in Iceland, appropriate antibiotic treatment was linked to lower relapse rates and no deaths, highlighting the importance of effective therapy.

Despite 53% of antibiotic treatments being deemed inadequate, the overall 30-day mortality rate for SAB significantly decreased from 25.0% to 6.8% over the study period, indicating improvements in patient outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Staphylococcus aureus bacteraemia--Nationwide assessment of treatment adequacy and outcome. Asgeirsson, H., Kristjansson, M., Kristinsson, KG., et al.[2022]

Patients with Staphylococcus aureus bacteremic pneumonia (SABP) showed higher levels of specific antibodies against virulence factors compared to uninfected controls, indicating a potential immune response that could be leveraged for treatment.

Higher antibody levels against certain Staphylococcus aureus antigens, along with increased haemolytic activity of the bacteria, were associated with better clinical outcomes, suggesting that immunotherapy targeting these antigens may improve patient recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Associations of pathogen-specific and host-specific characteristics with disease outcome in patients with Staphylococcus aureus bacteremic pneumonia. Sharma-Kuinkel, BK., Tkaczyk, C., Bonnell, J., et al.[2022]

In a study of 104 adults with Staphylococcus aureus bacteremia (SAB), 45 cases were identified as complicated, with significant associations found for community acquisition, concomitant bacteriuria, and persistent bacteremia.

Specifically, persistent bacteremia was linked to endocarditis, highlighting the importance of monitoring this factor in patients with SAB to identify those at higher risk for serious complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Concomitant Staphylococcus aureus bacteriuria is associated with complicated S. aureus bacteremia. Pulcini, C., Matta, M., Mondain, V., et al.[2009]

In a study of 241 hospitalized adults with Staphylococcus aureus bacteremia (SAB), 32.4% experienced clinical failure, highlighting the serious risks associated with this infection.

Key factors that improved outcomes included timely follow-up blood cultures (with delays over 4 days increasing risk of failure by 6.6 times), early consultation with infectious disease specialists, and the use of β-lactam antibiotics for methicillin-susceptible strains, which significantly reduced the risk of clinical failure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Performance of processes of care and outcomes in patients with Staphylococcus aureus bacteremia. Rosa, R., Wawrzyniak, A., Sfeir, M., et al.[2016]

In a study of 490 patients with Staphylococcus aureus bacteremia (SAB), the 90-day all-cause mortality rate was found to be 33%, with 60% of these deaths attributed to the infection itself, primarily occurring within the first 30 days after diagnosis.

Key risk factors for infection-related mortality included older age, higher comorbidity index, presence of septic shock, endocarditis, and persistent SAB at 48 hours, highlighting the need for early intervention in high-risk patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

All-Cause and Infection-Related Mortality in Staphylococcus aureus Bacteremia, a Multicenter Prospective Cohort Study. van der Vaart, TW., Prins, JM., Soetekouw, R., et al.[2023]

Older patients (≥65 years) with Staphylococcus aureus bacteremia (SAB) have a significantly higher mortality rate (47.5%) compared to younger patients (<65 years) at 23.2%, indicating that age is a critical factor in outcomes.

Management of older patients included fewer diagnostic procedures, such as transesophageal echocardiograms and imaging studies, which may negatively impact their treatment outcomes and should not be overlooked due to age.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical presentation, management and outcomes of Staph aureus bacteremia (SAB) in older adults. Yahav, D., Schlesinger, A., Shaked, H., et al.[2022]

Citations

1. armatapharma.com armatapharma.com/pipeline/ap-sa02/

Staphylococcus aureus Phage Product Candidate All subjects infected with MRSA and treated with AP-SA02 and BAT cleared their infection by TOC for BAT with no evidence of relapse through EOS, as compared to ...

2. lundquist.org lundquist.org/news/dr-loren-miller-presents-oral-late-breaker-at-idweek-2025-of-a-first-of-its-kind-clinical-trial-that-shows-efficacy-of-bacteriophage-therapy-for-staphylococcus-aureus-bacteremia/

Dr. Loren Miller presents oral late breaker at IDWeek 2025 ... Results showed that AP-SA02 was safe and demonstrated encouraging efficacy in patients with complicated S. aureus bacteremia, one of the most ...

3. prnewswire.com prnewswire.com/news-releases/armata-pharmaceuticals-highlights-positive-results-from-phase-2a-disarm-study-of-its-staphylococcus-aureus-bacteriophage-cocktail-ap-sa02-in-late-breaking-oral-presentation-at-idweek-2025-302590906.html

Armata Pharmaceuticals Highlights Positive Results from ... Patients treated with AP-SA02 showed trends toward rapid normalization of C-reactive protein, shorter time to negative blood culture, quicker ...

4. clinicaltrialsarena.com clinicaltrialsarena.com/analyst-comment/idweek-2025-ap-sa02-s-aureus-bacteremia/

IDWeek 2025: novel phage AP-SA02 leads to earlier ... On average, the AP-SA02 plus BAT–treated patients observed an initial resolution of their SAB infection in 2.7 days, compared to 9.3 days in the ...

5. medicalxpress.com medicalxpress.com/news/2025-10-clinical-trial-efficacy-bacteriophage-therapy.html

Clinical trial shows efficacy of bacteriophage therapy for ... Results showed that AP-SA02 was safe and demonstrated encouraging efficacy in patients with complicated S. aureus bacteremia, one of the most ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT05184764

NCT05184764 | Study Evaluating Safety, Tolerability, and ... Phase 2a will evaluate the efficacy, safety, and tolerability of multiple doses of AP-SA02 or placebo as an adjunct to BAT compared to BAT alone in subjects ...