Efficacy and Safety of BV100 Plus Low Dose Polymyxin B Versus Colistin Plus High-dose Ampicillin/Sulbactam in Patients With Hospital-acquired or Ventilator-associated Bacterial Pneumonia Due to Carbapenem-resistant Acinetobacter Baumannii-calcoaceticus Complex

Exclusion criteria

• . For Part A only, patients with an infection known to be resistant to colistin, with a known intolerance to polymyxins, or taking any drug that prevents them from receiving polymyxins.
• . Evidence of active concurrent pneumonia requiring additional antimicrobial treatment caused by, e.g., Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, Pneumocystitis jiroveci, Aspergillus spp, respiratory syncytial virus, influenza and parainfluenza viruses, Middle East respiratory syndrome coronavirus, mycobacteria, mucormycosis.
• . Any of the following health conditions:
• . Pulmonary disease that precludes evaluation of a therapeutic response.
• . Pleural empyema (exception: acceptable if drainage occurs within 24 hours of Screening and patient is expected to be treated in ≤ 14 days).
• . Solid organ transplant within 6 months prior to randomization.
• . Evidence of deep seated infection, e.g., Gram-negative osteomyelitis, or meningitis requiring prolonged therapy.
• . Acute infective endocarditis due to Gram-positive bacteria that requires urgent treatment/emergent indication of surgery, or patients in whom surgery is contraindicated due to prohibitive risk for surgery due to comorbidities.