GT Biopharma filed an IND for GTB‑5550, a B7‑H3‑targeted TriKE intended for B7‑H3‑expressing solid tumors; the company plans a Phase 1 basket trial with subcutaneous dosing pending FDA clearance. The filing signals movement of a natural‑killer cell engager into the clinic, targeting solid tumors with an NK‑activating scaffold. Separately, Medicenna said it is advancing MDNA‑113, a conditionally activated PD‑1×IL‑2 bifunctional superkine directed to IL‑13, through preclinical development toward an IND filing planned in the second half of the year. MDNA‑113 is designed as a tumor‑targeted immune modulator that aims to limit systemic IL‑2 exposure while stimulating antitumor immunity. Together these filings reflect two converging trends: engineered immune‑cell engager formats and next‑generation conditional cytokine therapeutics advancing toward first‑in‑human testing. Clinical translation will hinge on dose‑limiting toxicities, on‑target pharmacology and biomarker‑driven patient selection.