This study tests a new drug called **MDNA11** for patients with advanced solid tumors. MDNA11 is a special form of a protein called interleukin-2 (IL-2) that helps boost the body's immune system to fight cancer. The study has two parts: one where patients get only MDNA11, and another where they get MDNA11 plus a cancer drug called pembrolizumab. **Pembrolizumab** is a type of medicine known as a checkpoint inhibitor, which helps the immune system recognize and attack cancer cells. Participants will have their tumors checked every 8 weeks using CT or MRI scans.
- The study could have **up to 115 participants** and will occur at as many as **30 different locations**.
- Participants must be at least **18 years old** and have advanced solid tumors.
- The study requires regular visits for scans and checkups over several weeks.