Name of the Trial
Phase I Study of SS1(dsFv)-PE38 Immunotoxin in Patients with Advanced Mesothelin-Expressing Malignancies (NCI-03-C-0243). See the protocol summary at http://cancer.gov/clinicaltrials/NCI-03-C-0243.

Principal Investigator
Dr. Raffit Hassan, NCI Center for Cancer Research.

Why Is This Trial Important?
Mesothelin is a protein that is found on the outside of normal mesothelial cells. These cells are present in tissues that surround the lungs (pleura), the heart (pericardium), and the abdomen (peritoneum). Mesothelin is also found in large amounts in several different types of cancer, including mesothelioma and ovarian and pancreatic adenocarcinoma.

Researchers at NCI are investigating mesothelin as a possible target for immunotherapy (treatment to stimulate the immune system's ability to fight cancer). A new drug called SS1(dsFv)-PE38 (or SS1P) targets cells that make mesothelin and delivers a toxin to them that will kill the cells. This trial will test the safety of SS1P in patients who have advanced mesothelin-expressing cancers.

"Mesothelin is highly expressed on a number of tumors, and it appears to play a role in cancer spread," said Dr. Hassan. "These characteristics make it a very important molecule for targeted therapies.

"SS1P is the first targeted therapy for mesothelioma, an aggressive cancer and one for which there is no effective treatment currently available," added Dr. Hassan.

Who Can Join This Trial?
Researchers seek to enroll 10 to 15 patients with advanced, mesothelin-expressing solid tumors. See the full list of eligibility criteria at http://cancer.gov/clinicaltrials/NCI-03-C-0243.

Where Is This Trial Taking Place?
This study is taking place at the NIH Warren G. Magnuson Clinical Center in Bethesda, Md.

Who to Contact
For more information, call the NCI Clinical Studies Support Center (CSSC) at 1-888-NCI-1937. The CSSC provides information about cancer trials taking place on the NIH campus in Bethesda, Md. The call is toll free and confidential.

An archive of "Featured Clinical Trial" columns is available at http://cancer.gov/clinicaltrials/ft-all-featured-trials.