Etoposide/Carboplatin/Paclitaxel Effective in Extensive SCLC

NEW ORLEANS—The addition of paclitaxel (Taxol) to a regimen of etoposide and carboplatin (Paraplatin) led to a modest improvement in response rate and a trend toward improved survival in patients with small-cell lung cancer (SCLC), investigators from Response Oncology Inc., Memphis, Tennessee, reported at the 36^th Annual Meeting of the American Society of Clinical Oncology (ASCO).

The improvement was seen, however, only in patients with extensive disease and not in patients with limited disease, according to preliminary results.

The study, reported by Robert Birch, PhD, randomized 170 patients to four cycles of etoposide plus carboplatin (EP) or EP plus paclitaxel.

The EP regimen was carboplatin (AUC 6 IV over 30 to 60 minutes on day 1) and etoposide (120 mg/m² IV on days 1 to 3). The experimental arm added paclitaxel (200 mg/m² IV over 1 hour on day 1), to carboplatin (AUC 6 IV over 30 to 60 minutes), and oral etoposide (50/100 mg/m² on alternating days 1 to 10).

Patients with limited disease received radiation therapy, 45 Gy over 5 weeks concurrent with cycles 3 and 4. Patients in the paclitaxel arm received the taxane at a dose of 135 mg/m² for these two cycles.

Other characteristics, including age, sex, and sites of extensive disease, were well balanced between the two arms; about half the patients had extensive disease and half had limited disease.

Preliminary Results

A total of 121 patients completed therapy and were evaluable. The preliminary analysis found an overall response rate for the paclitaxel combination of 94% in extensive-disease patients and 75% in limited-disease patients. Patients with extensive small-cell lung cancer were significantly more likely to respond favorably to the addition of paclitaxel, Dr. Birch said.

In the 31 extensive-disease patients in the EP arm, complete responses were noted in 19% of patients and partial re-sponses in 52%. In the 34 extensive-disease patients receiving EP/paclitaxel, complete and partial response rates were 18% and 76%, respectively (P = .04).

There were no significant differences in complete or partial responses in the patients with limited disease, either before or after radiotherapy.

There was also a trend toward improved survival for patients with extensive disease who received paclitaxel (see Figure). Median survival was 7.8 months for the EP arm and 10.6 months for EP/paclitaxel (P = .055). Median survival in patients with limited disease was 15.2 months for EP and has not been reached for EP/paclitaxel (P = .48).

The addition of paclitaxel did not increase the incidence of hematologic toxicity. Leukopenia grades 3 and 4 occurred, respectively, in 42% and 25% of the EP arm and 46% and 17% of the EP/paclitaxel arm. Grade 3-4 neutropenia was noted in 14% and 49% of patients on the EP arm and 25% and 31%, respectively, of those on the EP/paclitaxel arm. Thrombocytopenia and anemia were not increased with the addition of paclitaxel.