Safety and Efficacy Study of BT086 to Evaluate Adjunctive Therapy in sCAP

Inclusion Criteria: * Written informed consent: * given by the patient or * a legal/authorised representative of the patient or * a waiver for written informed consent due to emergency situation, in compliance with all local legal requirements. * Male or female patients aged 18 years or older * Patient receiving adequate antibiotic treatment for pneumonia * Prior to endotracheal ventilation and therapy, the patient must have at least one of the following two signs of inflammation: * Fever/Hypothermia Fever defined as an oral, tympanic, oesophageal or vesical temperature of \>38°C, tympanic temperature of \>38°C or rectal temperature of \>38.5°C, or hypothermia (rectal temperature \<35.5°C) (measurement with temperature probe or device) or * White blood cell (WBC) count \>10,000/mm³ or WBC \<4,500/mm³ * Patient must have at least one of the following signs and symptoms of pneumonia: * New or increased cough * Production of purulent sputum or change in sputum characteristics * Dyspnoea or tachypnoea (respiratory rate \>20 breaths/minute) * Pleuritic chest pain * Auscultatory findings on pulmonary examination of rales and/or crackles and/or evidence of pulmonary consolidation (e.g. dullness on percussion, bronchial breath sounds, or egophony) * Radiological (or other imaging technique) evidence of (an) infiltrate(s) consistent with bacterial pneumonia * Pneumonia has been acquired outside the hospital. In hospital-admitted patients, pneumonia has been diagnosed a maximum of 72 hours after admission. Patients from nursing homes or similar institutions are eligible. * Major sCAP criterion: need for endotracheal ventilation * Treatment of patient with BT086 must start within 12 hours but not earlier than 1 hour after start of endotracheal ventilation Exclusion Criteria: * For incapacitated patients: any indication that the patient's presumed will would be against inclusion in the trial * Patients with suspected hospital-acquired pneumonia * Severe lung diseases interfering with sCAP therapy e.g. patients with cystic fibrosis, * Patients receiving Xigris® (drotrecogin alfa, activated Protein C) or medications not approved for sCAP (e.g. Dornase alpha) are excluded from inclusion in the study * Patients on dialysis * Presence of other severe diseases impairing life expectancy (e.g. patients are not expected to survive 28 days given their pre-existing uncorrectable medical condition). * Patients unable to be treated due to obesity * Selective, absolute IgA deficiency with known antibodies to IgA * Patients with neutrophil count \<1,000/mm³ or platelet count \<50,000/mm³ * Pregnant or lactating women. A pregnancy test will be performed in all women aged \<65 years and the result must be available at study inclusion. * Known relevant intolerance to immunoglobulins, vaccines or other substances of human origin * Participation in another interventional clinical trial within 30 days before entering the study or during the study, and/or previous participation in this study (participation in non-interventional trials is allowed).