Phase I study of paclitaxel and etoposide for metastatic or recurrent malignancies

A phase I study of sequential administration of escalating doses of intravenous paclitaxel, oral topotecan, and fixed-dose oral etoposide in patients with solid tumors

BACKGROUND

Based on preclinical findings and on the clinical antitumor efficacy of sequential paclitaxel/topotecan and topotecan/etoposide, the authors sought to define the maximum tolerated doses (MTDs) and dose-limiting toxicities (DLTs) associated with a sequential combination of paclitaxel, topotecan, and etoposide in patients with solid tumors.

METHODS

The MTDs were determined through standard dose escalation in cohorts of three patients. Patients with refractory solid tumors and performance status < or = 2 were treated with intravenous paclitaxel 50-110 mg/m(2) (Day 1), oral topotecan 0.5-2.0 mg/m(2) (Days 2-4), and oral etoposide 160 mg/m(2) (Days 5-7) during every 21-day cycle. For dose-limiting neutropenia, granulocyte-colony-stimulating factor (G-CSF) was administered on Day 8 in subsequent cohorts. Blood samples were obtained before treatment during Cycle 1 (Days 1, 2, and 5) for topoisomerase I assessment.

RESULTS

Twenty-eight patients received a combined total of 129 cycles. The MTDs were paclitaxel 80 mg/m(2), topotecan 1.5 mg/m(2), and etoposide 160 mg/m(2) without G-CSF. In minimally pretreated patients, G-CSF allowed paclitaxel dose escalation to 110 mg/m(2). Three patients (11%) had radiologic partial responses, and 4 patients (14%) had stable disease. Day 2 topoisomerase I levels increased by 2-15 times relative to baseline levels in 7 of 14 patients analyzed (50%).

CONCLUSIONS

The novel sequential combination that was evaluated generally was well tolerated and active in patients with refractory solid tumors. Based on hematologic DLTs, the authors recommend further evaluation of paclitaxel 110 mg/m(2), topotecan 1.5 mg/m(2), and etoposide 160 mg/m(2) with G-CSF support in minimally pretreated patients.

Combination of paclitaxel and etoposide in the treatment of advanced non-small cell lung cancer: a phase I-II study

Thirty-six patients (pts) with unpretreated advanced non-small cell lung cancer (NSCLC) stages IIIB and IV were enrolled in this two-stage phase I-II study aimed to establish the maximum tolerated dose (MTD) of paclitaxel and to evaluate the efficacy and safety of paclitaxel combined with etoposide every 3 weeks for a maximum of 6 courses, increasing the dose of paclitaxel according to a modified Fibonacci scheme. Nineteen pts were enrolled in the first stage and 17 pts in the second stage. The characteristics of the pts were as follows: median age 56 years (40-70), median Karnofsky's Performance Status 80% (70-80), 11 pts were stage IIIB and 25 pts stage IV. The doses of etoposide administered were 50 mg/m2 for 15 pts and 100 mg/m2 for 21 pts. MTD has not been reached and the study proceeded with the dose of paclitaxel 250 mg/m2. We obtained 9 (25%) partial remissions (PR) and 11 (31%) stable disease (SD) in 33 objectively evaluable pts. Median time to progression (TTP) was 4 months (0.3-21), median survival was 9.3 months (0.3-27). The main toxicity was neutropenia and neurotoxicity, while the gastrointestinal toxicity was mild. Two pts deceased after the first course. The causes of death were necrotizing enteritis in the first pt and congestive heart failure in the second pt. A total of 156 courses were administered at 7 dose levels, with a median of 4 courses per patient (1-6). The results seem to support the use of this combination in advanced non-small cell lung cancer.

Phase I trial of paclitaxel and etoposide for recurrent ovarian carcinoma: a Gynecologic Oncology Group Study

A phase I study was performed to determine the maximum tolerated doses of intravenous etoposide and paclitaxel for women with previously treated persistent or recurrent ovarian cancer. Starting doses were paclitaxel 135 mg/m2 during 24 hours and etoposide 50 mg/m2/day for 3 consecutive days. The study was designed to escalate first the dose of etoposide, and then the dose of paclitaxel, in successive cohorts of patients. In an attempt to determine whether toxicity was affected by sequence of the drugs, the order of administration of the two drugs was reversed on alternate cycles. The starting doses of paclitaxel (135 mg/m2/24 hours) and etoposide (50 mg/m2/day x 3) caused severe neutropenia even with the addition of granulocyte colony-stimulating factor, and the trial was amended to administer the paclitaxel during 3 hours. However, this also proved too myelosuppressive without growth factor support. Twenty-one women were treated. A complete response was observed in one of nine patients with measurable disease, and a major decrease in CA-125 was noted in two patients who did not have measurable disease. Because of the severe myelosuppression observed in most patients, dose reduction was often required after the first cycle. The power to detect sequence-dependent variation in toxicity was minimal; however, no large differences were observed. A combination of the usual doses of these drugs will be difficult to administer in patients who have received previous chemotherapy for ovarian cancer.

Phase I study of paclitaxel, carboplatin, and increasing days of prolonged oral etoposide in ovarian, peritoneal, and tubal carcinoma: a gynecologic oncology group study

PURPOSE

Given the activity of prolonged oral etoposide in platinum and paclitaxel-resistant ovarian carcinoma, a phase I trial was conducted that combined increasing days of oral etoposide therapy with paclitaxel and carboplatin in chemotherapy-naive patients with ovarian peritoneal and tubal carcinoma to establish a maximum-tolerated dose (MTD) of this combination.

PATIENTS AND METHODS

Paclitaxel at 175 mg/m(2) given over 3 hours and carboplatin at an area under the curve of 5 were administered on day 1 followed by oral etoposide 50 mg/m(2)/d beginning on day 2. The number of days of etoposide therapy was escalated on the basis of toxicity. Toxicity end points included neutropenic sepsis, grade 4 thrombocytopenia, or grade 3 neutropenia or thrombocytopenia during etoposide administration. Cycles were repeated every 21 days for a maximum of six courses. Due to hematologic toxicity, the duration of the paclitaxel infusion was decreased to 1 hour for a second stage of accrual.

RESULTS

Of 52 patients studied, 29 were in the first stage of accrual. Dose-limiting toxicity occurred with 8 days of oral etoposide, making the MTD six days of therapy. Twenty-three patients were entered into the second stage of accrual. Dose-limiting toxicity occurred at 12 days of oral etoposide, making the MTD 10 days of therapy. Three patients developed acute myeloid leukemia 16, 27, and 35 months after receiving a cumulative dose of 200 mg/m(2), 1,200 mg/m(2), and 2,400 mg/m(2), respectively.

CONCLUSION

One-hour paclitaxel, carboplatin, and oral etoposide at 50 mg/m(2)/d for 10 days is tolerable without supportive therapy. The leukemogenic potential is cause for concern and precludes its use in chemotherapy-naive ovarian carcinoma.