Practicing Clinical Oncologists to the Rescue

Cancer patients and their physicians can find themselves at the wrong end of many scientific discoveries. For example, the drug capecitabine, sold commercially as Xeloda, was originally marketed at a daily dose of 2500 mg/m2 given for two weeks.

This schedule developed by the pharmaceutical investigators, is known as the maximum tolerated dose (MTD) and it performed well against other regimens for breast and colon cancer. With an FDA approval in hand, oncologists began administering the drug on the recommended schedule.

MTD2It did not take long before physicians and their patients realized that 2500 mg/m2/day was more than many patients could tolerate. Hand-foot Syndrome (an inflammation of the skin of palms and soles), mucositis (oral ulcers) myelosuppression (lowered blood counts) and diarrhea were all observed. Immediately clinical physicians began to dose de-escalate. Soon these astute practitioners established more appropriate dose schedules and the drug found its rightful place as a useful therapeutic in many diseases.

What was interesting was that activity continued to be observed. It appeared that the high dose schedule was simply toxic and that lower doses worked fine, with fewer side effects.

Modern targeted agents have been introduced over recent years with dose schedules reminiscent of capecitabine. The drug sunitinib, approved for the treatment of renal cell carcinoma, is given at 50 mg daily for four weeks in a row, followed by a two week rest. Despite good activity, toxicities like mucositis and skin rash often set in by the third week. What remained unclear was whether these schedules were warranted. A recent report in the Annals of Oncology examined this very question. In a retrospective analysis of patients with kidney cancer the physicians found that lowering the dose of sunitinib preserved activity but reduced toxicity.

As a practitioner, I have long reduced my patient’s schedule of sunitinib to two weeks on, one week off or even 11 days on, 10 days off. In one patient that I treated for a gastrointestinal stromal tumor (GIST), I achieved a durable complete remission with just 25 mg/day, given seven days each month, a remission that persists to this day, seven years on.

We are in a new world of targeted therapy, one in which very few people understand the kinetics, pharmacodynamics and response profiles of patients for novel drugs. In our laboratory, favorable dose response curves often suggest that many agents could be administered at lower doses. More interestingly, some patients who do not carry the “targets” for these drugs nonetheless respond. This has broad implications for multi-targeted inhibitors like sunitinib that can influence multiple targets simultaneously.

As so often happens, it is the nimble clinical physicians with their feet on the ground, confronting the very real needs of their patients who can outmaneuver and outthink their academic colleagues. The trend toward consolidation in medicine and the absorption of clinical practices into hospital groups all using standardized algorithms has the risk of stifling the very independence and creativity of practicing oncologists that has proven both effective and cost-effective for our patients and our medical system at large.

About Dr. Robert A. Nagourney
Dr. Nagourney received his undergraduate degree in chemistry from Boston University and his doctor of medicine at McGill University in Montreal, where he was a University Scholar. After a residency in internal medicine at the University of California, Irvine, he went on to complete fellowship training in medical oncology at Georgetown University, as well as in hematology at the Scripps Institute in La Jolla. During his fellowship at Georgetown University, Dr. Nagourney confronted aggressive malignancies for which the standard therapies remained mostly ineffective. No matter what he did, all of his patients died. While he found this “standard of care” to be unacceptable, it inspired him to return to the laboratory where he eventually developed “personalized cancer therapy.” In 1986, Dr. Nagourney, along with colleague Larry Weisenthal, MD, PhD, received a Phase I grant from a federally funded program and launched Oncotech, Inc. They began conducting experiments to prove that human tumors resistant to chemotherapeutics could be re-sensitized by pre-incubation with calcium channel blockers, glutathione depletors and protein kinase C inhibitors. The original research was a success. Oncotech grew with financial backing from investors who ultimately changed the direction of the company’s research. The changes proved untenable to Dr. Nagourney and in 1991, he left the company he co-founded. He then returned to the laboratory, and developed the Ex-vivo Analysis - Programmed Cell Death ® (EVA-PCD) test to identify the treatments that would induce programmed cell death, or “apoptosis.” He soon took a position as Director of Experimental Therapeutics at the Cancer Institute of Long Beach Memorial Medical Center. His primary research project during this time was chronic lymphocytic leukemia. He remained in this position until the basic research program funding was cut, at which time he founded Rational Therapeutics in 1995. It is here where the EVA-PCD test is used to identity the drug, combinations of drugs or targeted therapies that will kill a patient's tumor - thus providing patients with truly personalized cancer treatment plans. With the desire to change how cancer care is delivered, he became Medical Director of the Todd Cancer Institute at Long Beach Memorial in 2003. In 2008, he returned to Rational Therapeutics full time to rededicate his time and expertise to expand the research opportunities available through the laboratory. He is a frequently invited lecturer for numerous professional organizations and universities, and has served as a reviewer and on the editorial boards of several journals including Clinical Cancer Research, British Journal of Cancer, Gynecologic Oncology, Cancer Research and the Journal of Medicinal Food.

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