October. 17 (HealthDay News) -- The Eisai Corp. drug Ontak (denileukin diftitox) has been approved to treat cutaneous T-cell lymphoma (CTCL) whose cells contain a certain receptor known as IL2.

A receptor is a molecule found on the surface of cells. Ontak works by killing cancer cells that have the IL2 receptor by targeting a component of the receptor called CD25, the company said in a news release.

T-cells are used by the body to fight infections. In CTCL, these cells become cancerous, causing skin lesions. About 2,900 people in the United States are diagnosed with the disease each year, Eisai said.

A clinical trial involving 144 patients with CTCL cells that bore the CD25 receptor showed the drug offered a significant benefit over a non-medicinal placebo, the company said. Common side effects included fatigue, mild nausea and elevated liver function.

People who take the drug also are at higher risk of capillary leak syndrome, which is characterized by at least two of the following symptoms: edema (swelling), low blood pressure, and low levels of albumen -- a protein found in human and animal tissues. In severe cases, this condition can lead to hospitalization and death.