Docetaxel Plus Irinotecan Promising as Nonplatinum Regimen for Advanced Non–Small-Cell Lung Cancer

OSAKA, Japan—Docetaxel (Taxotere) plus irinotecan (Camptosar) seems to have activity comparable to docetaxel plus cisplatin (Platinol) in advanced non–small-cell lung cancer (NSCLC), according to the results of a randomized phase II study reported at ASCO.

Koji Takeda, MD, reporting for the West Japan Thoracic Oncology Group, concluded that further randomized phase III studies comparing docetaxel plus irinotecan to platinum-containing standard regimen are warranted. The combination of docetaxel plus irinotecan would be promising as a nonplatinum regimen, he said.

From October 1998 to August 1999, 112 patents were enrolled in the study and 108 patients were randomized between the docetaxel/cisplatin arm and the docetaxel/irinotecan arm. Patients in both arms were well matched, according to the investigators.

Patient eligibility included ECOG performance status 0-1, documented stage IIIB and IV disease, no previous chemotherapy, and adequate bone marrow, renal, and hepatic function.

The trial was designed to compare the efficacy and toxicity of the two regimens. The primary endpoint was response rate. Secondary endpoints included survival, time to progression, response duration, and toxicity.

Patients enrolled in the docetaxel/cisplatin arm received docetaxel 60 mg/m² on day 1 and cisplatin 80 mg/m² on day 1 every 3 weeks.

Patients enrolled in the docetaxel/irinotecan arm received docetaxel 60 mg/m² on day 8 and irinotecan 60 mg/m² on days 1 and 8 every 3 weeks.

In the docetaxel/cisplatin arm, there were 51 patients. Complete response and partial response was evident in 0 and 19 patients, respectively. No change was seen in 22 patients, and 6 patients had progressive disease. Four patients were not evaluable. The overall response rate was 37.3%. Median survival time was 50.3 weeks.

In the docetaxel/irinotecan arm, there were 57 patients. Complete response and partial response occurred in 0 and 18 patients, respectively. No change was seen in 25 patients, and 14 patients had progressive disease. The response rate was 31.6%, and median survival time was 45.6 weeks.

Toxicity in both regimens was comparable and generally well tolerated, Dr. Takeda said. Three treatment-related deaths were seen in the docetaxel/cisplatin arm (5.9%). There were no deaths in the docetaxel/irinotecan arm.

Toxicity by the National Cancer Institutes’ Common Toxicity Criteria was grade 3-4 anemia 13.7%/8.8%; grade 3-4 neutropenia 74.5%/82.5%; grade 3-4 thrombocytopenia 2.0%/1.8%; and grade 2-4 diarrhea 22.0%/43.9% in the docetaxel/cisplatin arm and docetaxel/irinotecan arm, respectively.

Vomiting was more pronounced in the docetaxel/cisplatin arm (P < .001). Diarrhea was more severe in the docetaxel/irinotecan arm (P = .024).

“The combination of docetaxel/cisplatin has not yet been proven better than any of the older regimens. There have been no phase III studies,” commented Alan Sandler, MD, of Vanderbilt University Medical Center, in an interview with ONI.

He added, “It’s an interesting selection. They basically looked at two novel agents to see if they could eliminate cisplatin. The two regimens appear to be similar.”

Dr. Sandler noted, however, that it is difficult to reach any firm conclusions due to the limited sample size.