CLL & Constipation

CURE, Summer 2008, Volume 7, Issue 2

Discussion of new drugs for CLL and to relieve constipation.

The Food and Drug Administration approved Treanda (bendamustine) on March 20 for chronic lymphocytic leukemia after results of a phase III trial showed an increase in response and progression-free survival when compared with chlorambucil, a standard chemotherapy for CLL.

Chronic lymphocytic leukemia is a slow-growing cancer where the bone marrow produces too many abnormal lymphocytes, a type of white blood cell. About 15,000 people each year are diagnosed with the disease, according to the National Cancer Institute.

The international trial, which involved more than 300 CLL patients, found that overall response more than doubled, with 59 percent of patients on Treanda responding to the drug compared with only 26 percent of patients on chlorambucil. In addition, the median progression-free survival with Treanda was 18 months compared with six months with chlorambucil. Complete responses were also seen in more patients on Treanda than the standard treatment (8 percent compared with less than 1 percent). The most common side effects reported in the trial with Treanda included neutropenic fever, nausea, vomiting, and low blood counts.

Researchers believe Treanda targets cancer by damaging the DNA of malignant cells and disrupting cancer cell division. The chemotherapy drug is currently being tested in various other cancers, including slow-growing B-cell non- Hodgkin’s lymphoma. The FDA plans to review the drug for approval in NHL later this year.

For more information, go to www.treanda.com.

The approval of Relistor (methylnaltrexone) will give patients with advanced cancer another option for relieving symptoms of constipation often caused by opioids, including morphine. The Food and Drug Administration approved the drug on April 24 for terminal patients with late-stage diseases, including advanced cancer, AIDS, and lung disease—making it the first drug approved specifically for opioid-induced constipation.

Opioids, which are typically prescribed for pain associated with advanced cancer, often cause constipation because of the mechanism of action. The class of narcotics inhibits a specific receptor, called the mu opioid receptor, found on cells in the central nervous system to relieve pain, and in the gastrointestinal tract to slow down the progression of waste products through the intestines. While Relistor is able to block the receptor in the gastrointestinal tract, it’s believed to be too large to cross the protective blood-brain barrier, preventing the drug from interfering with the opioid’s pain-relieving properties concentrated in the brain.

Constipation affects about half of all cancer patients taking opioids. Drugs to prevent or treat constipation are normally given to patients taking any type of opioid medication.

Relistor is administered by subcutaneous injection (under the skin) every one or two days as needed. Common side effects include abdominal pain, nausea, gas, and diarrhea.

For more information, visit www.relistor.com.