Inter- and intrapatient variability in oral topotecan pharmacokinetics: implications for body-surface area dosage regimens.

Anticancer drugs still are dosed based on the body-surface area (BSA) of the individual patient, although the BSA is not the main predictor of the clearance for the majority of drugs. The relevance of BSA-based dosing has not been evaluated for topotecan yet. A retrospective pharmacological analysis was performed of kinetic data from four clinical Phase I studies in which topotecan was administered p.o. as a single agent combined with data from a combination study of topotecan and cisplatin. A strong correlation (r = 0.91) was found between the area under the plasma concentration time curve of the lactone and carboxylate forms of topotecan by plotting 326 data sets obtained from 112 patients receiving oral topotecan at dose levels ranging from 0.15-2.70 mg/m2. The intrapatient variability, studied in 47 patients sampled for 3 or more days, for the apparent lactone clearance, ranged from 7.4-69% (mean, 24 +/- 13%; median, 20%). The interpatient variabilities in the lactone clearance, calculated with the data of all studied patients, expressed in liter/h/m2 and in liter/h were 38% and 42%, respectively. In view of the relatively high inter- and intrapatient variabilities in topotecan clearance, in contrast to a variability of only 12% in the BSA of the studied patients, no advantage of BSA-based dosing was found over fixed dose regimens.     

Penetration of etoposide into human malignant brain tumors after intravenous and oral administration

Summary Penetration of etoposide into the cerebrospinal fluid, brain tumor, and brain tissue after intravenous administration was investigated in patients presenting with malignant brain tumors. A relatively low dose (55–65 mg/m²) was used to compare intravenous with oral administration. High-performance liquid chromatography with fluorescence detection was used to evaluate drug levels. Plasma and cerebrospinal fluid levels of etoposide after oral administration (50–150 mg/day) were also studied so as to determine the adequate oral dose for the treatment of malignant brain tumors. The peak plasma concentration after intravenous administration ranged from 7.01 to 10.47 g/ml, varying in proportion to the injected dose, whereas that after oral administration was lower, namely, 1.44–4.99 g/ml, and was unstable when the oral dose was 150 mg daily. The peak cerebrospinal fluid level following either intravenous or oral administration was much lower than the plasma concentration and was influenced by the peak plasma level and the sampling site. The etoposide concentration in cerebrospinal fluid taken from the subarachnoid space and ventricle of patients displaying no tumor invasion and of those presenting with meningeal carcinomatosis and in cerebrospinal fluid taken from the dead space after tumor resection was 0.7%±0.5%, 3.4%±1.0%, and 7.2% ± 8.5%, respectively, of the plasma concentration. Serial oral administration did not result in the accumulation of etoposide in cerebrospinal fluid. The tumor concentration (1.04–4.80 g/g) was 14.0%±2.9% of the plasma level after intravenous administration, was related to the injected dose, and was approximately twice the concentration detected in the brain tissue. Therefore, a relatively low dose of etoposide injected intravenously penetrates the brain tumor at an efficacious concentration. Our results indicate than an oral dose of 100 mg etoposide be given for malignant brain tumors, as limited penetration of the drug into the intracranial region was observed.     

Prolonged daily administration of oral etoposide in lymphoma following prior therapy with Adriamicin,an ifosfamide-containing salvage combination,and intravenous etoposide

Prolonged daily administration of oral etoposide has been reported to be active in refractory lymphoma. The purpose of this phase II trial was to confirm the activity of this schedule of etoposide in a selected group of heavily pretreated patients with non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD). A total of 26 patients (20 with NHL and 6 with HD) were entered in the trial; all had previously been treated with an Adriamycin-based chemotherapy, an ifosfamide-containing salvage combination, and i. v. etoposide. Etoposide was given in a fixed oral daily dose of 100 mg over 3 weeks; the weekly dose (500–700 mg) was selected such that the average daily dose was approximately 50 mg/m². Cycles were repeated on day 29. An objective response was seen in 16 patients (62%; 95% confidence interval, 42%–80%), with a complete response (CR) being observed in 3 cases (12%) and a partial response (PR), in 13 (50%). The median duration of PRs was 3 months. CRs lasted for 15 months in one patient and continue at 12+ and 20+ months in the remaining two patients. The overall actuarial survivial for the entire group was 40% at 2 years; the median survival time was 12 months. The main toxicity was myelosuppression; WHO grade 3 or 4 leukopenia and thrombocytopenia developed in 31% and 12% of the patients, respectively. There was no drug-related death. We conclude that oral etoposide is an effective and tolerable palliative treatment for heavily pretreated lymphoma patients.     

Safe administration of etoposide phosphate after hypersensitivity reaction to intravenous etoposide

Etoposide is commonly used in a variety of malignancies. A well known but rare toxicity are hypersensitivity reactions, usually manifested by chest discomfort, dyspnoea, bronchospasm and hypotension. We report the details of a patient who developed hypersensitivity reactions to intravenous etoposide, but subsequently tolerated the administration of intravenous etoposide phosphate with no sequelae.     

Randomized comparison of etoposide pharmacokinetics after oral etoposide phosphate and oral etoposide.

Etoposide phosphate is a water-soluble prodrug of etoposide. The plasma pharmacokinetics of etoposide following oral administration of etoposide phosphate or oral etoposide were compared. Seventeen patients with solid tumours were enrolled to receive oral etoposide phosphate 125 mg m(-2) on days 1-5 every 3 weeks, with escalation to 175 mg m(-2) from course 3 when possible. Patients were randomized to receive oral etoposide phosphate or oral etoposide on day 1 of course 1 and the alternative compound on day 1 of course 2. Fifteen patients received two or more courses and were evaluable for pharmacokinetic comparisons. The median AUC(inf) (area under the concentration vs time curve from zero to infinity) of etoposide was 77.7 mg l(-1) h after etoposide phosphate (95% CI 61.3-100.5) and 62.0 mg l(-1) h after oral etoposide (95% CI 52.2-76.9). The difference in favour of etoposide phosphate was borderline significant: median 9.9 mg l(-1) h (95% CI 0.1-32.8 mg l(-1) h; P = 0.05). However, the inter-patient variability of etoposide AUC(inf) was not improved (coefficients of variation 42.3% and 48.4%). Etoposide phosphate was undetectable in plasma after oral administration. Toxicities of oral etoposide phosphate were not different from those known for etoposide. In conclusion, oral etoposide phosphate does not offer a clinically relevant benefit over oral etoposide.     

Phase I and pharmacological study of sequential intravenous topotecan and oral etoposide.

We performed a phase I and pharmacological study to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of a cytotoxic regimen of the novel topoisomerase I inhibitor topotecan in combination with the topoisomerase II inhibitor etoposide, and to investigate the clinical pharmacology of both compounds. Patients with advanced solid tumours were treated at 4-week intervals, receiving topotecan intravenously over 30 min on days 1-5 followed by etoposide given orally twice daily on days 6-12. Topotecan-etoposide dose levels were escalated from 0.5/20 to 1.0/20, 1.0/40, and 1.25/40 (mg m-2 day-1)/(mg bid). After encountering DLT, additional patients were treated at 3-week intervals with the topotecan dose decreased by one level to 1.0 mg m-2 and etoposide administration prolonged from 7 to 10 days to allow further dose intensification. Of 30 patients entered, 29 were assessable for toxicity in the first course and 24 for response. The DLT was neutropenia. At doses of topotecan-etoposide 1.25/40 (mg m-2)/(mg bid) two out of six patients developed neutropenia grade IV that lasted more than 7 days. Reduction of the treatment interval to 3 weeks and prolonging etoposide dosing to 10 days did not permit further dose intensification, as a time delay to retreatment owing to unrecovered bone marrow rapidly emerged as the DLT. Post-infusion total plasma levels of topotecan declined in a biphasic manner with a terminal half-life of 2.1 +/- 0.3 h. Total body clearance was 13.8 +/- 2.7 l h-1 m-2 with a steady-state volume of distribution of 36.7 +/- 6.2 l m-2. N-desmethyltopotecan, a metabolite of topotecan, was detectable in plasma and urine. Mean maximal concentrations ranged from 0.23 to 0.53 nmol l-1, and were reached at 3.4 +/- 1.0 h after infusion. Maximal etoposide plasma concentrations of 0.75 +/- 0.54 and 1.23 +/- 0.57 micromol l-1 were reached at 2.4 +/- 1.2 and 2.3 +/- 1.0 h after ingestion of 20 and 40 mg respectively. The topotecan area under the plasma concentration vs time curve (AUC) correlated with the percentage decrease in white blood cells (WBC) (r2 = 0.70) and absolute neutrophil count (ANC) (r2 = 0.65). A partial response was observed in a patient with metastatic ovarian carcinoma. A total of 64% of the patients had stable disease for at least 4 months. The recommended dose for use in phase II clinical trials is topotecan 1.0 mg m-2 on days 1-5 and etoposide 40 mg bid on days 6-12 every 4 weeks.     

Chronic daily administration of oral etoposide in refractory lymphoma

In a phase II study, 25 patients with previously treated lymphoma received oral etoposide for 21 consecutive days. All patients were considered incurable with standard therapy. Etoposide was administered at 50 mg/m² per day: courses were repeated every 28–35 days, depending on myelosuppression. 15 patients (60%) had partial responses (95% CI 41–77%), while 10 patients had no response. Median time to disease progression was 5 months (range 2–13 months). Oral etoposide was active against indolent and aggressive (intermediate and high grade) lymphomas; however, median time to progression was only 3 months in aggressive lymphoma compared with 8 months in indolent lymphoma. Myelosuppression was the major side-effect; 7 patients (28%) had a leucocyte nadir below 1000/μl during the first course, and 11 patients required dose reduction during subsequent courses due to unacceptable leukopenia. All patients had total alopecia, but other side-effects were uncommon. These results highlight the importance of schedule in the administration of etoposide.     

Phase II trial of oral estramustine, oral etoposide, and intravenous paclitaxel in hormone-refractory prostate cancer.

PURPOSE: To evaluate the combination of intravenous (IV) paclitaxel, oral estramustine, and oral etoposide in patients with advanced hormone-refractory prostate cancer. PATIENTS AND METHODS: Forty patients with carcinoma of the prostate that was progressing despite hormonal therapy and who had undergone antiandrogen withdrawal (if previously treated with an antiandrogen) were enrolled onto this phase II trial. Patients were treated with oral estramustine 280 mg tid and oral etoposide 100 mg/d for 7 days, with paclitaxel 135 mg/m(2) IV over 1 hour on day 2 of each 21-day treatment cycle. Patients received a maximum of six cycles of therapy. RESULTS: Thirty-seven patients were assessable for response. Twenty-two had measurable disease at baseline; response was not assessable in six of these patients. Overall response was 45% (10 of 22 patients; 95% confidence interval [CI], 24% to 68%), and response was 63% (10 of 16) in assessable patients. Twenty-six patients had a > or = 50% decrease from their baseline prostate-specific antigen levels during therapy, for a response rate of 65% (95% CI, 48% to 79%) by this criterion. Median duration of response was 3.2 months, with an estimated median survival of 12.8 months. Major toxicities of therapy were leukopenia (eight patients had > or = grade 4 leukopenia) and anemia. Hematologic toxicity seemed to be associated with liver metastases. Serial measurements in 24 patients using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) showed no significant change in quality of life (QOL) as a result of therapy. CONCLUSION: The combination of IV paclitaxel, oral estramustine, and oral etoposide is active in patients with advanced prostate cancer. The regimen is tolerable and does not have a significant impact on QOL as measured by the FACT-P in a limited sample of patients.     

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.     

A phase II study of etoposide (NK 171) in small cell lung cancer--comparison of results between intravenous administration and oral administration

A phase II study of Etoposide (NK 171) was carried out in 13 institutions of the National Chest Hospital Lung Cancer Cooperative Study Group. Twenty-two patients (pts.) were treated by intravenous (i.v.) administration of etoposide, 80 mg/m2/day, for 5 consecutive days, and 25 pts. by oral administration of the same drug, 130 mg/m2/day, for 5 consecutive days. Eight (36.4%) out of 22 evaluable pts. given i.v. etoposide showed partial response (PR) while 7 (28%) out of 25 evaluable pts. given oral etoposide showed PR. Thirteen (41%) out of 32 previously untreated pts. were responders, but only 2 (13%) out of 15 previously treated pts. responded. The average total dose of i.v. etoposide was 664 (368-1552) mg/m2 while that of oral etoposide was 1320 mg/m2, or about double the dose of i.v. etoposide. The major dose-limiting factor was leukopenia (less than 3000/mm3). being observed in 63.6% of the i.v. treated pts. and 31.8% of the orally-treated pts. The oral and i.v. etoposide provided equivalent results. Despite the advantage of the reduced myelotoxicity of oral etoposide, we may recommend that all pts. are treated parenterally at present until the problem of erratic absorption of the oral drug is resolved.     

Combination chemotherapy with oral etoposide plus intravenous cyclophosphamide in liver metastases of breast cancer

Sixteen patients with hepatic metastases of histologically documented breast cancer were treated with etoposide (VP 16-213) and cyclophosphamide. Previously, 6 had shown relapse in the liver after adjuvant chemotherapy, 2 had failed to respond to another chemotherapy combination, and 8 had never undergone chemotherapy. Fifty percent responded to treatment, including 1 complete remission and 7 partial responses. Median survival was 16 months and median duration of response was 13 months. All patients showed alopecia and moderate leukopenia; 13 experienced moderate gastrointestinal toxicity; there was 1 mild case of anemia and 1 case of moderate hemorrhagic cystitis. This study suggests that the combination of VP 16-213 and cyclophosphamide is a well-tolerated and effective treatment in advanced breast cancer patients with liver metastases.     

Phase II evaluation of oral estramustine, oral etoposide, and intravenous paclitaxel in patients with hormone-sensitive prostate adenocarcinoma

Purpose

The primary objective of this study was to assess the feasibility and efficacy of administering etoposide/estramustine/paclitaxel in hormone-sensitive metastatic prostate cancer responding to hormonal therapy.

Patients and Methods

Eligible patients had metastatic prostate cancer and had received combined androgen blockade for 6-8 months with a ≤ 80% decrease in prostate-specific antigen from pretreatment. They received 4 cycles of chemotherapy consisting of estramustine 280 mg orally 3 times daily, etoposide 50 mg/m² orally on days 1-14, and paclitaxel 135 mg/m² intravenously for 1 hour on day 2 of each 21-day cycle and were then followed until time to treatment failure (TTF).

Results

Twenty-six patients were evaluable for response and toxicity. Median TTF was 21.7 months (range, 11.9-64.5 months; 95% confidence interval, 15.3-26.2 months). Median survival from time of initiation of hormone therapy was 5.1 years. Neutropenia was the most common grade 3/4 toxicity, occurring in 3 patients. Significant toxicities were limited to nausea, diarrhea, and febrile neutropenia in 3 patients, respectively.

Conclusion

The administration of paclitaxel/estramustine/etoposide in this setting is feasible and well tolerated. Although the TTF of 21.7 months by prostate-specific antigen criteria is similar to historical controls in the emergence of clinically evident androgen-independent disease after starting hormone therapy, direct comparisons cannot be made. More trials are needed to investigate the timing of chemotherapy in patients with prostate cancer.     

Pharmacokinetic comparison of oral and intravenous etoposide in patients treated with the CHOEP-regimen for malignant lymphomas

Background The addition of etoposide to the CHOP protocol (CHOEP) has been shown to improve outcome in patients with aggressive non-Hodgkin’s lymphoma. The intravenous administration of etoposide on three consecutive days represents a logistic problem and needs resources particular in the outpatient setting. This could be avoided by using etoposide capsules on days 2 and 3. However, the oral administration of cytotoxic agents is often affected by variable absorption and drug interactions. Patients and methods We investigated the pharmacokinetic equivalency of oral and intravenous etoposide in ten patients (male, n = 7; female, n = 3; median age 56 years) with aggressive lymphomas. Treatment consisted of standard CHOP plus etoposide 100 mg/m² given intravenously on day 1, and 200 mg/m² orally on days 3 and 4. Samples from blood and urine were taken on days 1 (i.v. study) and 3 (p.o. study) before and after etoposide administration. Etoposide levels were determined by high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were calculated with the TOPFIT computer program. Results Mean peak plasma level after intravenous etoposide was significantly higher compared to oral administration (16.3 ± 3.7 vs. 12.0 ± 4.2 μg/ml; P = 0.015). The mean bioavailability of oral etoposide was 58 ± 15% with an interpatient variability of 26%. Significant differences of bioavailability of oral etoposide between the used dose levels (350, 400 and 450 mg) were not observed. Mean AUC after a 100 mg/m² intravenous and a 200 mg/m² oral dose of etoposide were 74.0 ± 18.3 and 84.9 ± 29.6 μg h/ml (P = 0.481). Interpatient variability of AUC was 25% for the intravenous route and 35% after oral intake. Urinary etoposide excretion as percentage of administered dose was 39.4 ± 10.6% after intravenous infusion versus 35.4 ± 9.4% after oral intake (P = 0.422). Renal clearance was also very similar with intravenous and oral route (18.5 ± 7.4 vs. 16.7 ± 6.6 ml/min; P = 0.546). Conclusion The equivalency of AUC after 200 mg/m² of oral and 100 mg/m² of intravenous etoposide support the use of the oral preparation in patients treated with the CHOEP regimen, which makes the chemotherapy more convenient for the patients and help to reduce costs.     

Pharmacokinetics of ftorafur after intravenous and oral administration

The pharmacokinetics of ftorafur (FT), an antineoplastic agent, has been studied in seven cancer patients by determining concentrations of the unchanged compound in serum after single IV and PO doses of 2 g FT. Serum drug concentrations were determined by a new quantitative thin-layer chromatographic method. After IV administration, the mean half-lives of the distribution phase and elimination phase were 1.0 h and 7.6 h, respectively. Total serum clearance was 69 ml/h . kg and the apparent volume of distribution was 0.66 l/kg. Following PO administration there was a short lag-time, 11 min, before the appearance of FT in peripheral serum, and the maximum concentration in peripheral serum was achieved in 3.2 h. Oral absorption was complete and no significant first-pass metabolism could be observed. FT elimination, measured in serum taken from the portal vein and a peripheral vein, occurred substantially at the same rate after IV and PO administration. In contrast, after the PO dose FT appeared in the portal serum significantly earlier than in the peripheral serum, resulting in a difference of 1.7 h in the time of maximum serum concentration. This indicates fast gastrointestinal absorption of FT but hepatic retention (without metabolism) before the appearance of FT in the peripheral serum.     

Prolonged administration of oral etoposide in non-small-cell lung cancer: a phase II trial.

PURPOSE: The trial was undertaken to investigate the activity and toxicity of a prolonged schedule of oral etoposide in the treatment of advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Between March 1989 and August 1990, 25 patients with advanced NSCLC were treated with oral etoposide 50 mg/m2/d for 21 consecutive days, repeated every 28 to 35 days. The median patient age was 60 years (range, 38 to 84 years); male:female ratio was 12:13. Eight patients had stage IIIB disease; 17 had stage IV. Seventy-six percent of patients had Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. No patient had received previous chemotherapy with standard agents; nine patients had received previous or concurrent radiation therapy. Plasma etoposide concentrations were measured to estimate etoposide bioavailability and kinetics. RESULTS: Five of 22 patients (23%; 95% confidence interval [CI], 10% to 43%) had partial responses. Median response duration was 5 months (range, 2 to 6 months). Four of five responders were female. Besides alopecia, which occurred in all patients, myelosuppression was the most common toxicity, but was mild or moderate in most patients. Median leukocyte nadir during course 1 was 3,200/microL; only four of 69 courses produced a leukocyte nadir less than 1,000/microL. Severe thrombocythemia (less than 75,000/microL) did not occur. Gastrointestinal toxicity was uncommon. Median peak etoposide concentration was 3.4 micrograms/mL. A mean serum etoposide concentration greater than 1 microgram/L was maintained for more than 13 hours; the plasma concentration-time curve (AUC) was estimated to be 90% of that predicted after an identical dose of etoposide given intravenously. CONCLUSIONS: Etoposide given by this dose and schedule has moderate activity as first-line systemic therapy for advanced NSCLC. In previously untreated patients, chronic oral etoposide is well tolerated, and incorporation into combination regimens should be feasible. Etoposide bioavailability may be increased at lower oral doses.     

Comparison between continuous intravenous and oral administration of 5-FU with LV

In case of 5-fluorouracil (5-FU)/leucovorin (LV) treatment, which is one of the most effective forms of chemotherapy for colorectal carcinoma, 5-FU is usually continuously infused from the venous route. However, since this continuous infusion limits the patients' active daily life, oral administration is preferable. In the present study, we evaluated the efficacy and side effects of orally administered 5-FU/LV. MATERIAL AND METHODS: In the continuous intravenous infusion group (civ group), colon 26 bearing mice were cannulated into central vein from external jugular vein. From this route, either 5, 10, or 20 mg/kg of 5-FU was continuously infused for 7 days (n = 6). In another group, either 10, 20, 40 mg/kg of 5-FU was infused orally (po group, n = 6). The other 6 animals were used for the non-treatment group. In the next series, 100 mg/kg of LV was added for each group above. Tumor volume, thymidylate synthase inhibition rate (TSIR) and body weight were measured at the end of infusion. During the experimental period, mice had free access to chow and water. RESULTS: The tumor/control (T/C) volumes ratio showed that approximately twice the orally administered 5-FU dose had an anti-tumor effect equal to that of 5-FU administered intravenously. Synergic antitumor effects by LV were only revealed in the civ group. Significant body weight loss was recognized only in the po group at a 5-FU dose of more than 20 mg/kg. In summary, since the modulation effect of LV was recognized only with continuously intravenous infusion of 5-FU, further improvement of oral administration is required in the LV/5-FU combination therapy.     

Oral etoposide for Merkel cell carcinoma in patients previously treated with intravenous etoposide

We describe three patients with advanced Merkel cell carcinoma who were treated with etoposide given orally for recurrent regional lymph node involvement 18 to 30 months after exposure to etoposide given intravenously. Etoposide given orally (100 mg/day) was given for 10 to 14 consecutive days and repeated every 21 to 28 days for a median of three courses (range: two to four). Toxicity was minimal and mainly hematologic. Two patients showed a complete response and one a partial response, all of very rapid onset. All three patients are alive 6, 9, and 42 months from the start of oral treatment. Two remain progression free, and one had a recurrence 1 month after completion of chemotherapy. We suggest that orally administered etoposide, a topoisomerase II inhibitor, has a strong antitumor effect in advanced Merkel cell carcinoma, even in patients previously treated parenterally with the same drug. This action may be explained by the greater dependence of the drug's efficacy on the duration of administration rather than the dose intensity.     

A case of recurrent endometrial cancer successfully treated with oral administration of etoposide]

A 61-year-old female with recurrent endometrial cancer (serous papillary adenocarcinoma) was treated with etoposide because the pelvic tumor progressively increased in size with external beam irradiation. The etoposide (25 mg/day) was given orally for 10 days; the tumor decreased in size. And after an additional two courses of etoposide for 8 and 4 days, respectively, the tumor disappeared and the serum CA 125 level came to within normal limits. Because of moderate nausea and vomiting the etoposide could not be given for 14 days in the first 3 courses. Myelosuppression was not evident. Ten courses of etoposide (for 14 consecutive days a month) were followed without gastro-intestinal side effects, and the patient is alive with no evidence of recurrence at this writing. This case suggests that oral administration of etoposide may be effective for a patient with recurrent endometrial cancer, and this treatment could be administered on an outpatient basis.     

Phase II study of oral etoposide and intravenous paclitaxel in extensive-stage small cell lung cancer

BACKGROUND: This study evaluated the activity and tolerance for the combination of oral etoposide and paclitaxel as first-line therapy for patients with extensive SCLC. METHODS: A total of 57 patients were enrolled in this study. A cycle of chemotherapy consisted of oral etoposide administered as 50 mg BID on days 1 through 10 and paclitaxel administered as 150 mg/m(2) IV (3 h infusion) along with the first dose of etoposide on day 10. Patients were assessed for response to therapy (regression, stable disease, progression), survival, time to disease progression, and toxicity. RESULTS/CONCLUSIONS: Fifty-five patients were evaluable for efficacy parameters. Among the 55 patients, there were six with complete regression of disease, 18 with partial regression, 11 with regression, five with stable disease, and 15 with progressive disease, yielding an overall response rate of 63.6% (95% confidence interval, 50.0-76.0%). The 6-month and 1-year progression-free survival rates were 48.2 and 18.9%, respectively. The median time to disease progression was 5.8 months. The overall survival rates were 67.3% at 6 months and 41.8% at 1 year. The combination of oral etoposide and paclitaxel demonstrated significant efficacy as first-line therapy for extensive SCLC, with an overall response rate of 63.6% for 55 evaluable patients. In addition, the treatment was well tolerated with no unexpected toxicities.     

Pharmacokinetic study and side effects of chronic daily administration of oral etoposide]

Eleven inoperable patients with non-small cell lung cancer were treated as a maintenance therapy with oral etoposide 25 mg daily. The toxicity appeared during the chemotherapy were assessed in all cases, but the blood concentration of the drug were measured in 5 cases on the first and the seventh day of treatment. While the peak plasma level (Cmax) was 0.92 +/- 0.43 microgram/ml on the first day and 1.02 +/- 0.30 micrograms/ml on the seventh day of chemotherapy, AUC was 12.3 +/- 5.41 micrograms.hr/ml and 11.9 +/- 4.52 micrograms.hr/ml on the first and the seventh day, respectively. Cumulative effect of the drug did not exist, since in any of these two measurements there was no significant statistical difference between values obtained on the first and on the seventh day. Regarding the toxicity of the drug, bone marrow suppression with abnormal reduction of peripheral white blood cells was observed. Though grade 2 adverse reaction was found in 6 cases, stopping drug administration for 2 weeks, enabled to re-administer the drug. Alopecia and liver or renal injury were not observed, and in spite of the presence of nausea and anorexia in one case, maintenance therapy could continue in all cases. Based on these results we concluded that etoposide can be safely administered as a maintenance therapy on out-patient basis.