Tiny particles that can carry drugs and target cancer cells may offer treatment hope for those suffering with pancreatic cancer. New research to be presented in November at the American Association of Pharmaceutical Scientists (AAPS) Annual Meeting in Los Angeles reveals that tumor-penetrating microparticles (TPM) have been specifically designed to break through hard-to-infiltrate barriers and deliver drugs more effectively and efficiently than the standard form of chemotherapy such as those injected through a vein.

According to Jessie L.S. Au, Pharm.D., Ph.D., an AAPS fellow and a distinguished university professor at Ohio State University who initiated the study, TPM are designed to treat cancer in the peritoneal cavity. The peritoneal cavity contains organs, including the pancreas, that are home to more than 250,000 new cases of cancer a year in the United States alone. “Pancreatic cancer cells are surrounded by specialized cells that protect them from chemotherapy,” explains Dr. Au. “Our goal is to use TPM to pass this barrier and successfully deliver drugs to the tumor cells, which is currently the biggest hurdle a physician faces in pancreatic cancer treatment.”

According to the American Cancer Society, pancreatic cancer is the fourth leading cause of cancer in the U.S., with more than 80 percent of the 38,000 patients stricken with the disease dying within one year of diagnosis.

Dr. Au, who is also co-founder of Optimum Therapeutics LLC, the company bringing TPM to clinical trials, goes on to explain that TPM releases what the researchers call a “smart bomb” of drugs to create holes in the tumor so TPM can reach tumor cells. Once inside a tumor, TPM slowly releases drug levels that are sustained over several weeks, targeting both the rapid- and slow-growing tumors. Because the TPM were designed to move about and reach tumors without being swept away by the lymphatic system, they are able to stay in the peritoneal cavity longer and deliver highly concentrated drug doses to the cancer-affected organ. It is this two-tiered drug attack that is unique in pancreatic cancer treatment.

With just one TPM dose of drugs proving to be equally as effective as multiple injections of chemotherapy, TPM delivers less toxicity to patients, making it a safer option than the standard form of other therapies. “Based on the encouraging results in mice carrying implants of human pancreatic cancer, we are cautiously optimistic that TPM may provide benefits to patients with this disease,” says Ze Lu, Ph.D., principal scientist and project leader. “TPM may prove to be especially helpful to patients with late stages of the disease.” According to Dr. Lu, the researchers have been working on TPM for more than 10 years and look forward to receiving FDA approval for testing TPM in patients in 2010.

The researchers are collaborating with physicians at the Medical University of South Carolina who believe a potential use of TPM, in addition to treating patients with peritoneal metastases, is to downstage or downsize the tumors so that they are operable.

Date: November 2, 2009
Source: American Association of Pharmaceutical Scientists