Alpha Tau is a clinical-stage medical device company developing Alpha DaRT (Diffusing Alpha-emitter Radiation Therapy), a localized radiation therapy for solid tumors. The treatment involves inserting small radioactive wires embedded with Radium-224 directly into a tumor, where the decay chain releases alpha-emitting atoms that diffuse through tumor tissue and kill cancer cells. Alpha Tau argues the approach destroys tumors with minimal damage to surrounding healthy tissue and may also stimulate an immune response that could attack cancer cells elsewhere in the body. The company has received marketing approval in Israel and Japan but has not yet commercialized in either market. Alpha Tau's primary focus is the U.S., where it is running a pivotal trial (ReSTART) targeting recurrent cutaneous squamous cell carcinoma, with data expected in the second half of 2026 for potential FDA submission. Beyond SCC, Alpha Tau is running trials across pancreatic cancer, glioblastoma (where it holds FDA Breakthrough Device Designation), prostate cancer, and several other solid tumor types. The business model centers on selling single-use, patient-specific kits to hospitals and physicians on a per-treatment basis. Because Radium-224 has a short half-life, each kit is manufactured to order and must be used within 24 hours of receipt. Alpha Tau manufactures its own radioactive sources and is building a commercial-scale facility in Hudson, NH. The company currently generates no product revenue and is funded through capital raises.