Brand Name Drug: Camptosar
Active Ingredient Drug: irinotecan
Indication: Currently indicated as second-line treatment of metastatic colorectal cancer; soon to be approved for first-line treatment when administered with 5-fluorouracil and leucovorin
Company Name: Pharmacia & Upjohn
Availability: Approved by FDA for second-line therapy in 1998; FDA recommended approval as first-line therapy in March 2000
Introduction
Colorectal cancer can be cured if caught early. Nevertheless, it remains the second leading cause of cancer death in the US. According to the American Cancer Society, some 130,000 people will be diagnosed with the disease this year, and 53,000 will die from it. Indeed, in 40% of colorectal cancer patients, the cancer spreads – or metastasizes – to other parts of the body. A patient’s outcome is considered significantly poorer once a cancer has spread beyond its initial site.
In 1998, Pharmacia & Upjohn’s Camptosar (irinotecan hydrochloride) was approved by the FDA for the treatment of metastatic colorectal cancer in patients whose disease has recurred or progressed following treatment with the chemotherapy drug 5-fluorouracil (5FU). The drug was hailed by cancer specialists because it was the first new chemotherapy agent approved for colorectal cancer in more than 40 years.
Camptosar may soon be approved for initial treatment of metastatic colorectal cancer when administered in conjunction with 5FU and another drug, leucovorin. The FDA’s Oncologic Drugs Advisory Committee unanimously recommended approval of Camptosar for this indication on March 16, 2000.
Camptosar is given intravenously. It works by inhibiting an enzyme that cancer cells need to grow and divide.
Camptosar: Clinical Study Results
Clinical studies have shown that patients with metastatic colorectal cancer who received Camptosar in combination with 5FU and leucovorin before receiving any other chemotherapy responded better to this chemotherapy regimen than patients who received 5FU and leucovorin alone.
One study evaluated 387 patients with metastatic colorectal cancer who received 5FU/leucovorin plus Camptosar or 5FU/leucovorin alone. Patients who received the Camptosar combination treatment survived longer (17.4 vs. 14.1 months). More of them responded to the chemotherapy (49% vs. 31%), and it also took longer for their tumors to progress (6.7 vs. 4.4 months).
In another study, Camptosar was evaluated in 178 patients with metastatic colorectal cancer, 77.5% of whom had had prior chemotherapy with 5FU. The response rate was 17.7% in the patients who had received prior 5FU and 18.8% in the patients who had not received prior chemotherapy. A third study assessed the response to Camptosar in 41 patients with metastatic colorectal cancer who had not been treated with prior chemotherapy. Thirty-two percent of the patients achieved a partial response to treatment.
Camptosar is also being evaluated in clinical trials in patients with lung, ovarian, and pancreatic cancers.
What You Should Know
Severe diarrhea is commonly reported with Camptosar treatment. Patients who experience diarrhea should inform their healthcare providers so they can begin taking medication to halt the diarrhea. Other gastrointestinal complaints associated with Camptosar include nausea and vomiting. Patients may be given an antinausea drug before Camptosar treatment.
A significant decrease in white blood cell counts may develop in patients taking Camptosar. Sometimes Camptosar treatment needs to be temporarily stopped, or the dose reduced, depending on how severe the decrease is. Physicians may choose to give patients Neupogen, a drug that helps boost white blood cell counts so patients can continue their chemotherapy.
Because Camptosar may harm a fetus, women should not become pregnant while receiving treatment with Camptosar. Women who do become pregnant should be advised of the potential hazard to the fetus.
“We are pleased that an additional treatment option is available for the treatment of colorectal cancer,” said Nancy Roach, Board of Director of the Colon Cancer Alliance. “Each new drug approval gives survivors renewed hope for longer and better quality of life.”
Jennifer is a clinical pharmacologist. She helps doctors of all medical specialties choose medications. Jennifer consults about drug dosage, interactions, and side effects.