By Jim Shrine

Special to BioWorld Today

Endorex Corp. opened a second trial site Wednesday for its drug designed to treat bone cancer in children, while ProScript Inc. began human studies of its lead cancer drug.

Endorex, of Chicago, is testing ImmTher as a treatment for Ewing's sarcoma, a childhood bone cancer with a high relapse rate. The drug is a muramyl dipeptide immunomodulator designed to stimulate the patient's immune system to kill cancer cells.

The Phase II trial will evaluate ImmTher as an adjuvant therapy following surgery and chemotherapy to prevent disease recurrence. The drug has been granted orphan status by the FDA. ImmTher also received orphan status for osteosarcoma, a related bone cancer in children. The two indications are the most prevalent forms of pediatric bone cancer.

"These are not pivotal trials so we think, as we get into this trial, if we're seeing good results we'll probably redesign it so that hopefully it will be definitive toward an NDA (new drug application)," Dave Franckowiak, Endorex's vice president, finance and administration, told BioWorld Today. He said the company is not yet disclosing the trial's design or timeline.

"It's not a blockbuster area of cancer but it certainly is a high-profile area," Franckowiak said. "Any progress we can add to this huge unmet need would add quality of life to a child."

The company expects to add additional sites to the study and to test ImmTher in related cancers.

ImmTher is Endorex's second product. The first, perillyl alcohol, a monoterpene, is in Phase II trials for breast, ovarian and prostate cancers.

The other side of Endorex's business, under the name Orasomal Technologies Inc., is developing an oral delivery method for vaccines, proteins and peptides. The technology was licensed from the Massachusetts Institute of Technology, of Cambridge, Mass.

Endorex has a joint venture with Elan Corp., of Athlone, Ireland, to develop oral delivery systems for human and animal vaccines. The venture, called Innovax Corp., intends to partner with pharmaceutical and vaccine companies to convert injectable vaccines into an oral format to improve compliance and convenience.

ProScript's Lead Drug Hits The Clinic

Meanwhile, ProScript, of Cambridge, Mass., took the proteasome inhibitor PS-341 into Phase I trials. It is the company's lead product.

The safety and activity of PS-341 will be studied in up to 40 patients and in a variety of tumor types. The small molecule is designed to inhibit the ubiquitin-proteasome pathway, which regulates many cellular proteins. The drug has been shown to inhibit cell growth signaling pathways, induce apoptosis and inhibit expression of cellular adhesion molecules, the company said.

"Initiation of the PS-341 clinical trial is a key milestone in ProScript's proprietary drug discovery program for the treatment of cancer and inflammatory disease," President and CEO Dan Burns said in a statement. "We expect to complete the first trial within 12 months."

The company said it anticipates additional Phase I trials under National Cancer Institute sponsorship. *