Final answer:
Ontak (Denileukin diftitox) is a successful immunotoxin used to treat certain kinds of cancer, particularly T-cell lymphoma, by selectively killing cancer cells.
Step-by-step explanation:
The immunotoxin Denileukin diftitox, also known as Ontak, is a fusion protein used to treat certain kinds of cancer. It operates by joining portions of two different proteins to create a new entity that is specifically toxic to certain cells. Its success is attributable to its ability to selectively kill targeted cells, in this case, cancer cells. An example of its use is in the treatment of persistent or recurrent cutaneous T-cell lymphoma. The Ontak binds to the cells and then gets internalized, impeding protein synthesis which results in cell death. It is administered intravenously, often in multiple doses, over the course of several days.
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