Naptumomab estafenatox is a drug being developed for the treatment of various types of cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 like non-small cell lung carcinoma and renal cell carcinoma

Renal cell carcinoma

Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that filter the blood and remove waste products. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases...

.

Mechanism of action

Chemically, it is a fusion protein

Fusion protein

Fusion proteins or chimeric proteins are proteins created through the joining of two or more genes which originally coded for separate proteins. Translation of this fusion gene results in a single polypeptide with functional properties derived from each of the original proteins...

 consisting of the antigen-binding fragment (Fab) of a monoclonal antibody with the superantigen

Superantigen

Superantigens are a class of antigens which cause non-specific activation of T-cells resulting in oligoclonal T cell activation and massive cytokine release...

 staphylococcal enterotoxin E (SEA/E-120, "estafenatox"). The Fab binds to 5T4, an antigen

Antigen

An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

 expressed by various tumor cells, and the superantigen induces an immune response by activating T lymphocytes.