The CHRISTUS Stehlin Foundation is currently one of the international leaders in the development and clinical (human) studies of a new family of anticancer drugs, the camptothecins, which have been in clinical trials since 1992.

More than 30 years ago it was found that extracts from a Chinese tree, Camptotheca Acuminata, had potent anticancer activity against a mouse leukemia. The active substance, designated Camptothecin, was tried clinically on incurable patients in the early 1970's by physicians at the National Cancer Institute in Washington D.C. It was found to have some anticancer activity, but was too toxic as administered in those days to be of practical use.

In 1988, in collaboration with scientists from Johns Hopkins and New York Universities, several derivatives of Camptothecin were tested in our laboratory against various types of human cancers transplanted in nude mice. To our amazement, these compounds proved to be more active and effective than any other chemotherapeutic agents (conventional or experimental) we had ever worked with.

Extensive research was then conducted on the toxicity, mechanisms of action, and biochemical properties of these compounds. The results of these studies were submitted to the Food and Drug Administration and, after careful scrutiny of our work, the agency authorized us to begin clinical (human) trials. The two compounds, Camptothecin proper and 9-Nitro Camptothecin, a derivative, were administered to patients with very advanced cancers.

Even though the patients enrolled in the studies had failed conventional treatments, such as surgery, radiation and chemotherapy, we were extremely encouraged that favorable responses were seen in individuals with breast, prostate, pancreas, ovarian, leukemia, and lymphoma cancers, as well as malignant melanoma. Toxicities associated with the compounds were manageable.

We have now begun Phase III clinical trials with 9-Nitro Camptothecin (9NC) which has demonstrated less toxicity than the mother compound, Camptothecin (CPT). We intend to concentrate these studies on pancreatic tumors which demonstrated a heightened sensitivity to 9NC. Investigations are also underway to determine if we can enhance the effectiveness of 9NC by using it in combination with other drugs and/or treatment modalities.

Pancreatic cancer is one of the most insidious cancers. Until now, there has been no effective treatment. There are approximately 30,000 new cases of pancreatic cancer in the United States each year, with about 29,000 deaths from the disease. After diagnosis, the average survival rate is around five months. Rarely in the media spotlight, pancreatic cancer recently gained wider public exposure when Cardinal Bernardin, entertainer Juliet Prowse, actress Donna Reed, and actor Michael Landon all succumbed to this disease.

We have published our results of a study conducted at the Stehlin, deIpolyi Clinic in the International Journal of Oncology, in May of 1999 (Volume 5, 14:821-831). No deaths were attributed to 9NC. The results of 60 evaluable patients were that 31.7% were responders (median survival 18.6 months, range 6.5 - 44.7 months), 31.7% were stable (median survival 9.7 months), and 36.6% were non-responders (median survival 6.8 months).

An additional advantage of the Camptothecin family of drugs is that they can be given orally on an outpatient basis, which should translate ultimately to be a less expensive form of administering anticancer therapy, as contrasted with those drugs that have to be given intravenously either in a hospital or physician's office.

Because of the initial results seen in patients with pancreatic cancer who are taking 9NC, the CHRISTUS Stehlin Foundation applied to the Food and Drug Administration for "orphan drug" designation. On September 19, 1996, the Food and Drug Administration approved the request for orphan drug status. The Stehlin Foundation is the only cancer center in the country with exclusive rights to market 9NC in the United States for a period of seven years from the time the FDA approves it for commercial use. This is another example of how the research conducted at our lab can be of enormous benefit to patients.

An additional advantage of the Camptothecin family of drugs is that they can be given orally on an outpatient basis, which should translate ultimately to be a less expensive form of administering anticancer therapy, as contrasted with those drugs that have to be given intravenously either in a hospital or physician's office.

An international conference on the Camptothecins sponsored by the New York Academy of Sciences and co-chaired by clinic physicians and scientists was held in Bethesda, Maryland from February 7-10, 1996. The New York Academy of Sciences, in its letter to the Camptothecin Conference participants, wrote, "The plant product, camptothecin and its derivatives, are rapidly establishing themselves as the most promising group of new anticancer drugs. Compared to other anticancer drugs at similar stages of development, camptothecins have demonstrated a much higher anticancer activity. Camptothecins can be envisioned as the ultimate anticancer drugs when fully developed."

More about the clinical trials

Stehlin Foundation Paves Way for New Studies On Camptothecins