New Data Show First-Line Combination Treatment With Camptosar® May Significantly Improve Progression-Free Survival In Patients With Metastatic Colorectal Cancer
Camptosar-Based Combination Studied as a Therapeutic Option in Initial Treatment of Metastatic Colorectal Cancer
Atlanta, GA, May 15, 1999 - Preliminary results of a new study show that the addition of the anti-cancer agent Camptosar® (irinotecan hydrochloride injection) to standard first-line therapy may significantly increase progression-free survival - the time during which tumor growth was prevented - and anti-tumor response in patients with metastatic (advanced) colorectal cancer. These new data, which were presented today at the 35th annual meeting of the American Society of Clinical Oncology (ASCO), found that at six months, combination therapy with Camptosar prevented tumor growth in more than half of the patients (52 percent) treated, compared to standard therapy alone (35 percent). No new first-line treatment options for metastatic colorectal cancer have been introduced in 40 years.
In addition, the study found that adding Camptosar to standard therapy [fluorouracil (5-FU) and leucovorin] significantly increases the number of patients whose tumors shrink; nearly half of the patients studied (51 percent) who received the triple therapy had a significantly better overall tumor response rate compared to the current standard therapy (29 percent) alone. "These data are promising because they suggest the new combination has superior anti-tumor activity without increasing rates of side effects," said Leonard Saltz, M.D., Gastrointestinal Oncology Service, Memorial Sloan-Kettering Cancer Center in New York and lead investigator for the study.
Colorectal cancer is the number two cancer killer of all Americans, second only to lung cancer. Approximately 129,400 new cases will be diagnosed this year and 56,600 Americans will die from the disease. Almost 60,000 people each year develop metastatic colorectal cancer which has spread to other parts of the body. Currently, the standard first-line treatment for patients diagnosed with metastatic colorectal cancer is 5-FU-based chemotherapy‹a therapy introduced 40 years ago.
"The potential for new treatment options for this dreadful disease will help bring optimism to the thousands of patients diagnosed after the cancer has spread and for whom only one treatment option currently exists," said Ernestine Hambrick, M.D., founder of Stop Colon/Rectal Cancer Foundation. "We applaud studies like these, so that patients and their physicians may soon have more tools to fight this disease."
Significant Clinical Trial Results
The randomized, open-label Phase III study was conducted in patients with metastatic colorectal cancer. In the primary comparison of the study, patients were divided into two treatment arms: 225 patients in one arm received weekly Camptosar (125 mg/m2) with 5-FU (500 mg/m2) and leucovorin (20 mg/m2). In the second arm, 219 patients received the standard therapy, 5-FU (425 mg/m2/day) and leucovorin (20 mg/m2/day) both given for five days every four weeks.
The study showed that when Camptosar is combined with 5-FU and leucovorin, progression-free survival is significantly longer compared to standard therapy (p=0.008). Tumor growth was prevented in more than half (52 percent) of the patients who were given the Camptosar-based regimen versus standard therapy (35 percent) alone. On average, tumor growth was prevented for seven months in patients receiving the triple combination, with some patients benefiting for more than two years.
The overall tumor response rate was significantly better with the triple combination including Camptosar than with the standard 5-FU-based therapy alone. The overall tumor response rate was 51 percent in the triple therapy arm compared to 29 percent in the 5-FU/leucovorin arm (p<0.001).
Camptosar was established as the gold standard for second-line treatment of metastatic colorectal cancer, based on studies that demonstrated it increases survival in patients who experience failure with standard therapy. In fact, many of the patients in the trial who did not receive Camptosar as first-line therapy crossed over to receive the drug second-line after the trial ended. Pharmacia & Upjohn hopes to submit a supplemental New Drug Application (sNDA) for Camptosar for first-line therapy of metastatic colorectal cancer later this year.
"The results of this study add new information about the first-line treatment of this highly prevalent disease," said Dr. Saltz.
Treatment was generally safe with the overall incidence of serious side effects similar in the two treatment arms. Adverse events related to Camptosar were predictable and usually manageable. Clinically significant adverse events in the triple combination regimen arm were diarrhea and vomiting, with grades 3/4 of these side effects occurring in 23 percent and 10 percent of patients, respectively. Other side effects, such as neutropenia (a reduction in white blood cells), neutropenic fever, and mucositis (mouth sores) were less common with the Camptosar-based treatment than with 5-FU-containing therapy. Patients were asked to complete questionnaires (EORTC QLQ-C30) evaluating quality of life during treatment. The results suggest that the addition of Camptosar to 5-FU and leucovorin did not have a detrimental impact on quality of life.
European Study Results
A second, international study presented at ASCO corroborates the results of the U.S. trial. Preliminary results of a Phase III European study of 387 patients with metastatic colorectal cancer show that the addition of irinotecan to standard therapy (5-FU and leucovorin) as a first-line treatment demonstrated improved progression-free survival and tumor response rates compared to standard therapy alone. Patients receiving the triple combination had a progression-free survival of 8.2 months versus 4.3 months with standard therapy alone. The tumor response rate was 39 percent for patients in the irinotecan/standard therapy arm versus 22 percent with standard therapy alone. Grade 3/4 adverse events in the triple combination and standard therapy arms included neutropenia (40 percent v. 13 percent, respectively) and diarrhea (20 percent v. 10 percent respectively). Other toxicities were less than five percent and comparable in both groups.
More About Camptosar
In October 1998, Camptosar was the first treatment for metastatic colorectal cancer to receive full approval in more than 40 years, and the first to be approved based on its ability to increase survival in patients who failed current therapy for metastatic colorectal cancer. Results of preliminary clinical trials suggest Camptosar has broad activity in multiple tumor types, including lung, brain and esophageal cancer.
Camptosar is one of a new class of broad-spectrum anticancer agents called topoisomerase I inhibitors, and the only drug in its class known for its activity in colorectal cancer. It has a unique mechanism of action. Topoisomerase I is an enzyme that is essential for cancer cell division and inhibition of this enzyme's activity kills cancer cells.
Camptosar® is a trademark of Pharmacia & Upjohn. Pharmacia & Upjohn is a global, research-driven pharmaceutical and health care company whose products, services and employees demonstrate its commitment to improving quality of life for people worldwide.