Precision radiation, delivered cell by cell.
Targeted alpha therapy pairs a tumor-seeking ligand with a high-energy alpha emitter — concentrating cytotoxic dose within a few cell diameters of the target, and building on the radioligand foundation clinical teams already know. [POTENTIAL TO ELEVATE ACTINIUM FURTHER HERE]
Why alpha makes biological sense
PrimerRadiopharmaceutical therapy
Radiopharmaceutical therapy (RPT) pairs a targeting molecule — an antibody, peptide, or small molecule — with a radioactive payload. It's given by IV infusion, travels systemically, and binds to a target expressed on tumor cells.
Unlike external beam radiation (aimed from outside) or chemotherapy (cytotoxic everywhere it circulates), RPT is systemically delivered but locally active — the radiation dose is deposited where the target is expressed, over millimeter-to-micrometer distances.
RPT is the category. The payload isotope determines the biology: beta-emitters (like Lu-177) have a longer path length and lower energy density; alpha-emitters (like Ac-225) travel only a few cell diameters and deposit far more energy per unit distance.
Alpha particles deliver high-LET radiation that creates clustered, double-strand DNA breaks — a damage pattern that is far less amenable to cellular repair than the predominantly single-strand breaks produced by low-LET radiation.
Combined with a path length of only a few cell diameters, this concentrates cytotoxic energy at the bound target while sparing surrounding tissue — a radiobiological profile that is compelling on its own terms, independent of any specific tumor type or prior therapy.
Investigational status
RYZ-101 is an investigational agent and has not been approved by the FDA or any other regulatory authority. The safety and efficacy of RYZ-101 have not been established. This page is for healthcare professional education and does not constitute promotion of an unapproved product or use.