BETHLEHEM, Pa., May 2 /PRNewswire/ -- Can a blood test improve treatment outcomes for colorectal cancer patients? Recently published studies indicate that personalized chemotherapy dose management -- measuring drug levels in patients' blood and adjusting them for optimal dosing -- can substantially reduce severe toxicity and improve efficacy in colorectal cancer.
A Phase III randomized study of 208 colorectal cancer patients, by Erick Gamelin, M.D., Ph.D. et. al., was published in the May 1 issue of the Journal of Clinical Oncology (JCO). It found that metastatic colorectal cancer patients whose dose of 5-fluorouracil (5-FU) was personalized based on results of regular blood tests experienced reduced severe toxicities and nearly doubled response rates compared to patients who received standard 5-FU dosing based on body surface area. Additionally, patients who received personalized dosing experienced a 48 percent relative improvement in survival at two years. 5-FU is the cornerstone chemotherapy in most treatment regimens for this type of cancer.
The current standard-of-care in dosing 5-FU is based on body surface area (BSA) and is calculated using patients' height and weight. In the JCO study, personalized dosing was based on blood tests to measure the actual level of the drug. The study demonstrated that only 25 percent of colorectal cancer patients achieved optimal chemotherapy blood levels when dosed by BSA. Seventeen percent of the BSA-dosed patients received toxic levels of the drug, while 58 percent were under-dosed.
The JCO study, "Individual 5-fluorouracil dose adjustment based on pharmacokinetic follow-up compared with conventional dosage: Results of a multicenter randomized trial of patients with metastatic colorectal cancer," evaluated patients being treated with 5-FU in combination with leucovorin. Half of the patients were dosed with 5-FU based on BSA. The other half were initially dosed based on BSA, with subsequent cycle doses adjusted based on blood tests that measured the actual concentration of chemotherapy in the patients' blood plasma. The primary endpoint was tumor response; the secondary endpoint was treatment tolerance.
Dr. Gamelin, director of the Paul Papin Cancer Center in Angers, France, stated, "Pharmacokinetically-guided or personalized 5-FU dose management is the standard-of-care at our cancer center. We routinely test the level of 5-FU in the blood of our colorectal cancer patients and adjust their doses to achieve optimal drug concentration. Clinical studies conducted over the past 20 years have demonstrated that there is significant variability in 5-FU blood levels when patients are dosed by BSA, the prevailing practice."
"Our Phase III study demonstrates that the majority of patients are either over-dosed or in most cases, under-dosed. Personalized 5-FU dosing allows us to substantially reduce severe toxicity while improving patient quality of life and treatment outcomes," said Dr. Gamelin.
The value of personalized 5-FU dose management was also reinforced in two studies reported earlier this year at the American Society of Clinical Oncology (ASCO) Gastrointestinal Symposium. Results from these Phase II studies of metastatic colorectal cancer patients treated with 5-FU (in combination regimens commonly used in the U.S., FOLFOX and FOLFIRI) demonstrated improved response rates and reduced toxicities with blood level dose management.(1)
New, Multicenter Study Seeks to Use Faster, Less Expensive Blood Test
To date, analysis of 5-FU patient blood concentrations could only be performed by complex, labor-intensive methods, such as liquid chromatography-mass spectroscopy (LC-MS). Saladax Biomedical, Inc., a Bethlehem, Pa.-based biotech company, is sponsoring a soon-to-enroll study to support the case for blood-based 5-FU dose management with the FOLFOX regimen. The study will employ a new immunoassay based on a patented technology from Saladax. The assay, called Personalized Chemotherapy Management (PCM), provides LC-MS-like performance but is easier to use and less expensive.
The multicenter, randomized Phase III study will enroll more than 200 patients with metastatic colorectal cancer to determine the efficacy of 5-FU dose management utilizing the PCM test. Edward Chu, M.D., chief of Medical Oncology and deputy director of the Yale Cancer Center in New Haven, Conn., will be the lead investigator of the study, which will involve several other cancer centers in the U.S., as well as the Paul Papin Cancer Center in France.
"Therapeutic dose management is common for many important drugs in other areas of medicine. Based upon recent evidence that we can lower toxicity and improve efficacy with personalized 5-FU dose management, it makes sense to use this same approach in cancer treatment," said Dr. Chu. "We hope that this study will provide oncologists with important evidence and guidance on the role of drug monitoring in their routine practice," he added.
About Colorectal Cancer
Colorectal cancer is a worldwide public health problem, with more than 940,000 new cases diagnosed each year, resulting in approximately 500,000 deaths.(2) In the U.S., it is the third leading cause of cancer mortality, and in 2008, nearly 50,000 deaths will be attributed to this disease.(3) Its incidence rate is strongly correlated with age. Data from industrialized countries demonstrate that the incidence of colorectal cancer rises three-fold between the ages of 60 and 80 years.(4)
Saladax Biomedical is pioneering the development of novel, fast, and inexpensive immunoassays that will enable routine blood-level monitoring of anti-cancer drugs to become the standard-of-care in treating cancer patients. With Personalized Chemotherapy Management (PCM), oncologists will be able to adjust the administered dose based on each patient's individual drug level, leading to reduced toxicity, improved outcome and lower cancer care costs. Saladax is headquartered at the business incubator of the Ben Franklin Technology Partners (BFTP) of Northeastern Pennsylvania on the campus of Lehigh University in Bethlehem. The 5-FU PCM test will be available to U.S. clinicians later this year through a major reference laboratory.
Cancer?," March 5, 2008, http://www.cancer.org/docroot/cri/content/cri_2_4_1x_what_are_the_key_statisti cs_for_colon_and_rectum_cancer.asp (April 22, 2008).
SOURCE Saladax Biomedical