A Beta-only IL-2 ImmunoTherapY Study

The study drug, MDNA11, long-acting "beta-only" recombinant interleukin-2 (rIL-2). MDNA11 specifically engineered to overcome the shortcomings of rhIL-2 (aldesleukin) by preferentially activating immune effector cells (CD8+ T- and NK cells) responsible for killing cancer cells, with minimal or no stimulation of immunosuppressive Tregs. It is designed to potentially enhance host immune response and fusion to albumin increases the half-life further avoiding frequent dosing required with rhIL-2. The study will be conducted at up to 30 clinical sites following regulatory authority and institutional review board / independent ethics committee (IRB/ IEC) approval and completion of informed consent. The study will be conducted in multiple parts: * Monotherapy (MDNA11 alone) dose escalation * Monotherapy (MDNA11 alone) dose expansion in select tumor types * Combination (MDNA11 + pembrolizumab) dose escalation * Combination (MDNA11 + pembrolizumab) dose expansion in select tumor types Approximately 115 patients will be enrolled. After commencing treatment (first exposure of MDNA11 alone or MDNA11 + pembrolizumab), tumor assessment by CT/MRI will be performed every 8 weeks ± 1 week until immune confirmed progressive disease ("iCPD") by iRECIST, discontinuation of study drug(s), withdrawal of consent or loss to follow-up. Treatment beyond progression may be permitted if criteria are met. Patients can withdraw from participation at any time.