This study tests a medicine called **Trimodulin** for adults with severe **community-acquired pneumonia (sCAP)** who are on a breathing machine (**invasive mechanical ventilation (IMV)**). Trimodulin is given along with usual hospital care to see if it helps more than a fake treatment (**placebo**). The study is **randomized** (participants are chosen by chance to get either Trimodulin or placebo) and **double-blind** (neither the participants nor the doctors know who gets the real treatment). Participants will get the treatment once a day for 5 days, followed by up to 28 days of follow-up checks.

To join, you must be an adult, already in the hospital, and have sCAP. Certain health conditions, like severe heart or lung disease, or being pregnant, might mean you can't participate. The study will check how Trimodulin moves through the body (**pharmacokinetics**) and its effects (**pharmacodynamics**).

• The study lasts up to 90 days, including follow-ups.
• Participants receive daily treatments for 5 days.
• There are specific health criteria for joining the study.