Phase I and pharmacologic study of the combination of paclitaxel, cisplatin, and topotecan administered intravenously every 21 days as first-line therapy in patients with advanced ovarian cancer

Chemotherapy Resistance in Advanced Ovarian Cancer Patients

Ovarian cancer is the seventh most common gynaecologic malignancy seen in women. Majority of the patients with ovarian cancer are diagnosed at the advanced stage making prognosis poor. The standard management of advanced ovarian cancer includes tumour debulking surgery followed by chemotherapy. Various types of chemotherapeutic regimens have been used to treat advanced ovarian cancer, but the most promising and the currently used standard first-line treatment is carboplatin and paclitaxel. Despite improved clinical response and survival to this combination of chemotherapy, numerous patients either undergo relapse or succumb to the disease as a result of chemotherapy resistance. To understand this phenomenon at a cellular level, various macromolecules such as DNA, messenger RNA and proteins have been developed as biomarkers for chemotherapy response. This review comprehensively summarizes the problem that pertains to chemotherapy resistance in advanced ovarian cancer and provides a good overview of the various biomarkers that have been developed in this field.

Phase I trial of weekly cisplatin, irinotecan and paclitaxel in patients with advanced gastrointestinal cancer

OBJECTIVES

To determine the maximum tolerated dose (MTD), toxicities, and suitable dose for weekly 1-h paclitaxel combined with weekly cisplatin and irinotecan to treat advanced gastrointestinal malignancies.

METHODS

Thirty patients with metastatic or locally advanced (unresectable or recurrent) gastrointestinal solid tumors were enrolled on this single-center, phase I study. Patients were treated with paclitaxel given over 1h at 1 of 4 dose levels (40, 50, 65, or 80 mg/m(2)). Paclitaxel was followed by fixed doses of cisplatin (30 mg/m(2)) and irinotecan (50 mg/m(2)). All treatment was administered sequentially, once a week, in 6-week cycles (4 weeks on, 2 weeks off). Dose-limiting toxicity (DLT) was defined as a 2-week delay in treatment for grade 3 or 4 non-hematologic toxicity, neutropenic fever, a 1-week delay for grade 4 hematologic toxicity, or a 2-week delay for grade 3 hematologic toxicity.

RESULTS

Thirty patients were recruited; 28 patients were assessable for safety. Most of the patients (70%) had no prior chemotherapy. The primary first-cycle DLTs were neutropenia, diarrhea, and nausea. Paclitaxel at 65 mg/m(2) was defined as the MTD. The most common grade 3-4 toxicities observed during all cycles were neutropenia (57%), febrile neutropenia (11%), diarrhea (29%), fatigue (29%), and nausea (18%). No patients had G-CSF (Neupogen, Amgen Inc., Thousand Oaks, CA) support. Responses were observed in gastric, esophageal, and pancreatic cancers.

CONCLUSION

Paclitaxel at 65 mg/m(2), cisplatin (30 mg/m(2)), and irinotecan (50 mg/m(2)) given weekly can be safely administered to patients with solid tumor malignancies. To improve cumulative toxicities, a schedule modification was required (3-week cycle; 2-on, 1-off) Neutropenia was the most common DLT. This combination showed substantial activity, particularly in patients with gastric and esophageal adenocarcinoma, and phase II evaluation could be considered.

Paclitaxel, topotecan, and carboplatin in metastatic endometrial cancinoma: a Hellenic Co-operative Oncology Group (HeCOG) study

OBJECTIVE

Taxanes, and platinum compounds represent the chemotherapeutic agents with the greatest activity in metastatic endometrial carcinoma. We administered the combination of paclitaxel, topotecan and carboplatin to patients with metastatic or recurrent carcinoma of the endometrium to evaluate its activity and to define its toxicity.

METHODS

Thirty-nine consecutive patients were treated on an outpatient basis with paclitaxel 150 mg/m(2), administered intravenously over a 3-h period and followed by carboplatin at AUC of 5 on day 3, with both agents proceding topotecan that was given at 0.75 mg/m(2)/day on days 1 through 3. The chemotherapy was repeated every 3 weeks with granulocyte colony-stimulating factor (G-CSF) support for a maximum of six courses.

RESULTS

Twenty-one (60%) patients achieved objective clinical response (95% CI, 42.2-75.7%) including 4 (11.4%) complete and 17 (48.6%) partial responses. The median times to progression and survival for all patients were 8.9 and 17.7 months, respectively. Grade 3 or 4 thombocytopenia and neutropenia occurred in 5 (13%) and 4 (10%) patients, respectively, but only 2 episodes of neutropenic fever were encountered. Grade 2 or 3 neurotoxicity was observed in 23% of patients.

CONCLUSIONS

The combination of paclitaxel, topotecan and carboplatin with G-CSF support appears active with acceptable toxicity in patients with metastatic or recurrent carcinoma of the endometrium.

SCOTROC 2B: feasibility of carboplatin followed by docetaxel or docetaxel-irinotecan as first-line therapy for ovarian cancer

The feasibility of combination irinotecan, carboplatin and docetaxel chemotherapy as first-line treatment for advanced epithelial ovarian carcinoma was assessed. One hundred patients were randomised to receive four 3-weekly cycles of carboplatin (area under the curve (AUC) 7) followed by four 3-weekly cycles of docetaxel 100 mg m(-2) (arm A, n=51) or docetaxel 60 mg m(-2) with irinotecan 200 mg m(-2) (arm B, n=49). Neither arm met the formal feasibility criterion of an eight-cycle treatment completion rate that was statistically greater than 60% (arm A 71% (90% confidence interval (CI) 58-81%; P=0.079; arm B 67% (90% CI 55-78%; P=0.184)). Median-dose intensities were >85% of planned dose for all agents. In arms A and B, 15.6 and 12.2% of patients, respectively, withdrew owing to treatment-related toxicity. Grade 3-4 sensory neurotoxicity was more common in arm A (1.9 vs 0%) and grade 3-4 diarrhoea was more common in arm B (0.6 vs 3.5%). Of patients with radiologically evaluable disease at baseline, 50 and 48% responded to therapy in arms A and B, respectively; at median 17.1 months' follow-up, median progression-free survival was 17.1 and 15.9 months, respectively. Although both arms just failed to meet the formal statistical feasibility criteria, the observed completion rates of around 70% were reasonable. The addition of irinotecan to first-line carboplatin and docetaxel chemotherapy was generally well tolerated although associated with increased gastrointestinal toxicity. Further exploratory studies of topoisomerase-I inhibitors in this setting may be warranted.

A phase I study of intraperitoneal topotecan in combination with intravenous carboplatin and paclitaxel in advanced ovarian cancer

The aim of this study was to determine the maximum tolerated dose (MTD) of intraperitoneal (i.p.) topotecan combined with standard doses of intravenous (i.v.) carboplatin and paclitaxel and to investigate its pharmacokinetics. Women with primary ovarian cancer stage IIb - IV received six cycles of i.v. carboplatin and paclitaxel with escalating topotecan doses i.p. of 10, 15, 20 and 25 mg/m(2). Twenty-one patients entered this trial. Febrile neutropenia, thrombocytopenia requiring platelet transfusion and fatigue grade 3 were dose-limiting toxicities (DLT) at 25 mg/m(2) i.p. and 20 mg/m(2) i.p. of topotecan was considered to be the MTD. The mean plasma t(1/2) was 3.8 +/- 2.3 h for total topotecan and 4.4 +/- 3.9 h for active lactone. The area under the curve (AUC) was proportional with dose, R = 0.54, p < 0.05 for total topotecan and the peritoneal / plasma AUC ratio was 46 +/- 30. Fifteen patients who completed treatment had a median progression-free survival (PFS) of 27 months. In this setting the MTD of topotecan is 20 mg/m(2) i.p. The efficacy of this regimen should be explored further in a formal phase III study.

Intratumoral immunotherapy: using the tumour against itself

Summary Diverse immunotherapy approaches have achieved success in controlling individual aspects of immune responses in animal models. Transfer of such immunotherapies to clinical trials has obtained some success in patients, with clinical responses observed or effective antigen specific immune responses achieved, but has had limited impact on patient survival. Key elements required to generate de novo cell-mediated antitumour immune responses in vivo include recruitment of antigen-presenting cells to the tumour site, loading these cells with antigen, and their migration and maturation to full antigen-presenting function. In addition, it is essential for antigen-specific T cells to locate the tumour to mediate cytotoxicity, emphasizing the need for local inflammation to target effector cell recruitment. We review those therapies that involve the tumour site as a target and source of antigen for the initiation of immune responses, and discuss strategies to generate and co-ordinate an optimal cell-mediated immune response to control tumours locally.

Phase II study of sequential doublets: topotecan and carboplatin, followed by paclitaxel and carboplatin, in patients with newly diagnosed advanced ovarian cancer

OBJECTIVE

Incorporating topotecan into standard platinum/taxane chemotherapy for advanced ovarian cancer has been complicated by myelosuppression. This study evaluated sequential doublets of topotecan and carboplatin, followed by paclitaxel and carboplatin, in newly diagnosed advanced ovarian cancer patients.

METHODS

Forty-five patients (median age, 56 years; range, 38-77 years) with stage III/IV disease and GOG performance status <2 were enrolled and received four cycles of topotecan (1.0 mg/m(2)/day on days 1 to 3) and carboplatin (AUC 4 on day 1), followed by four cycles of paclitaxel (175 mg/m(2) via 3-h IV infusion on day 1) and carboplatin (AUC 5 on day 1). All cycles were 21 days. Antitumor response was assessed after four and eight cycles; patients with clinical complete response (CR) underwent second-look laparotomy for determination of pathologic CR (PCR). Dose reductions were instituted for grade 4 neutropenia and thrombocytopenia, and for grade 3/4 nonhematologic toxicity.

RESULTS

Among 41 CA-125 evaluable patients, complete and partial responses were observed in 29 (70.7%) and 11 (26.8%) patients, respectively. Of the 12 clinical CRs (43%) in 28 evaluable patients, 10 patients underwent second-look laparotomy, with 3 PCRs (30%). Median time to progression was 14 months and actuarial survival was 23 months. Neutropenia was the primary toxicity and cause of dose adjustments and delays, including two deaths.

CONCLUSION

The antitumor activity observed is comparable with other series, although neutropenic complications were increased. Progression-free and actuarial survivals were slightly inferior. A Phase III trial (GOG 182) of sequential doublets in the reverse sequence is ongoing.

Clinical experience with topotecan in relapsed ovarian cancer

Topotecan is an established therapy for the treatment of recurrent ovarian cancer and has demonstrated significant antitumor activity in both platinum-sensitive and platinum-resistant patient populations. The main toxicity associated with topotecan when used in the standard 5-day dosing schedule is myelosuppression, which is generally predictable, reversible, noncumulative, and manageable. Comparative trials have shown that topotecan is as effective as paclitaxel and pegylated liposomal doxorubicin in achieving tumor response, disease stabilization, and improved overall survival. Follow-up data extending to 4 years indicate that the survival benefit persists in long-term therapy without cumulative toxic effects. There appears to be little cross-resistance between topotecan and paclitaxel, indicating that the use of concurrent or sequential combination therapy could be a valuable option. Encouraging preliminary data suggest that alternative dosing schedules may improve the therapeutic index of topotecan and that topotecan may also be active as first-line therapy in combination with taxanes and/or platinum agents. Optimization of the use of topotecan may offer potential opportunities for further improving the management of ovarian cancer.

First-line treatment regimens and the role of consolidation therapy in advanced ovarian cancer

Current first-line management for advanced ovarian cancer consists of cytoreductive surgery followed by chemotherapy, usually with a platinum/taxane combination. Although this approach has been shown to achieve overall response rates of 70-80% in clinical trials, the majority of patients relapse. A number of different approaches have been investigated to improve the efficacy of therapy, including the introduction of newer agents, such as topotecan, into chemotherapy regimens and the use of consolidation therapy. Encouraging results have been obtained in clinical trials of topotecan administered using a variety of different approaches, including replacement regimens, triplet regimens, and sequential doublet regimens. Other treatment modalities have included the use of drug resistance modifiers and intraperitoneal delivery of treatment. A variety of approaches to consolidation therapy have also been investigated, including radiotherapy, cytotoxic therapy, and intraperitoneal therapy. The use of topotecan has also shown promise in this setting, although further data from large, controlled trials are required. In summary, while good response rates are obtained using current first-line treatments, the high relapse rate indicates the need to develop more effective and durable treatment regimens including new agents with, perhaps, an increased emphasis on maintaining remission through the use of consolidation therapy.

Phase I trial of docetaxel, carboplatin, and gemcitabine as first-line therapy for patients with high-risk epithelial tumors of müllerian origin

OBJECTIVES

The aim of this study was to assess the feasibility of combining docetaxel, carboplatin, and gemcitabine (DoCaGem) as first-line treatment of ovarian and other müllerian origin tumors.

METHODS

Four dose levels were planned for this phase I trial. Treatment consisted of carboplatin on day 1 only, docetaxel on days 1 and 8, and gemcitabine on days 1 and 8, every 21 days.

RESULTS

Nineteen patients were enrolled, of whom 18 were evaluable for toxicity. The first 5 patients enrolled at dose level I (carboplatin AUC 5, 30 mg/m(2) docetaxel, 800 mg/m(2) gemcitabine) experienced no dose-limiting toxicity. At dose level II, 4/4 evaluable patients experienced significant bone marrow suppression that required dose reduction and/or dose delay. Further dose escalation was not attempted, and 9 additional patients were enrolled in dose level I. Of the 67 cycles administered on dose level I, day 8 treatment could not be administered due to bone marrow suppression in 16 cycles (24%), and prolongation of the cycle length from day 22 to day 29 was required in 13 cycles (19%). There were no episodes of febrile neutropenia in evaluable patients and no treatment-related deaths. Grade 3 nonhematologic toxicity (fatigue) occurred in 1 cycle. Response was determined in the 14 evaluable patients who tolerated 4 or more cycles of therapy, with 11 obtaining a complete clinical response and 3 obtaining a partial clinical response.

CONCLUSIONS

The DoCaGem regimen is highly active, but myelosuppression at dose level I prevents full dose delivery. Other strategies to combine these three active agents are reasonable to explore.

Topotecan is an active agent in the first-line treatment of metastatic or recurrent endometrial carcinoma: Eastern Cooperative Oncology Group Study E3E93

PURPOSE

To determine the clinical activity and the toxicity profile of the topoisomerase-I inhibitor, topotecan, in women with recurrent or advanced endometrial carcinoma.

PATIENTS AND METHODS

A prospective, phase II clinical trial was initiated by the Eastern Cooperative Oncology Group (ECOG). Patients had histologically confirmed advanced or recurrent endometrial carcinoma, measurable disease, no prior cytotoxic therapy, an ECOG performance status of 0 to 2, and evidence of disease progression while on progestins or after radiation therapy. Topotecan was administered at 1.5 mg/m(2) (or 1.2 mg/m(2) for patients with prior pelvic radiation) intravenously daily for 5 days every 3 weeks.

RESULTS

A total of 44 patients were enrolled; 42 were eligible. The study was suspended because of unexpected toxicities, primarily sepsis and bleeding. After toxicity review, the study was reopened using lower doses of topotecan (1.0 mg/m(2) or 0.8 mg/m(2) for patients with prior radiation therapy). In addition, prophylactic use of growth factors was allowed after the first cycle, and patients with performance status of 2 were excluded. The major toxicities were hematologic and gastrointestinal. Among the 40 assessable patients, there were three (7.5%) complete responders and five partial responders (12.5%), for an overall response rate of 20%. The median duration of response was 8.0 months and of overall survival was 6.5 months.

CONCLUSION

Topotecan is an active agent for the treatment of advanced endometrial carcinoma. At the doses and schedules initially used, toxicities were unacceptable; however, at the modified doses, toxicities were acceptable and clinical activity was preserved.

Emerging role of topotecan in front-line treatment of carcinoma of the ovary

The conventional front-line chemotherapy strategy for advanced epithelial ovarian carcinoma has become adjuvant administration of platinum (carboplatin and cisplatin), either alone or, most often, in combination with a taxane. However, a number of active agents have been identified in phase II/III trials of second-line and salvage ovarian cancer patients that may augment this front-line strategy. One agent, topotecan, has antitumor activity comparable with paclitaxel in patients with recurrent ovarian cancer and is an established treatment in second-line or salvage settings. Additionally, its mechanism of action is different from paclitaxel and is nonoverlapping. These properties, coupled with the in vitro synergy observed in tumor models among topotecan, paclitaxel, and platinum, have provided the rationale for investigators to examine topotecan in front-line ovarian cancer therapy. A number of strategies for incorporating topotecan into front-line therapy are under active investigation, including the replacement of paclitaxel with topotecan, a triplet regimen with cisplatin or carboplatin and paclitaxel, a consolidation regimen consisting of several courses of a platinum agent and paclitaxel followed by several courses of topotecan, and a sequential doublet regimen in which patients receive platinum in every course as part of a doublet with alternating or sequential topotecan and paclitaxel. Preliminary data from ongoing clinical trials of these new regimens show favorable response rates and generally manageable toxicity profiles. This review summarizes the preliminary clinical findings associated with the four strategies and outlines ongoing and future randomized studies of topotecan in front-line ovarian cancer.

Topotecan preceded by oxaliplatin using a 3 week schedule: a phase I study in advanced cancer patients

Combinations of topoisomerase I (topo I) poisons and platinum derivatives have synergistic antitumoral effects. However, their clinical development is limited by supra-additive haematological toxicity. The aim of this study was to determine whether sustained doses of topotecan and oxaliplatin could be achieved using a synergistic sequence. 34 advanced cancer patients and 186 cycles were evaluable for toxicity over five dosing levels. Oxaliplatin at 85-110 mg/m(2) was given on day 1, followed by topotecan 0.5-1.25 mg/m(2)/day x 5 from day 1 to 5, every 3 weeks. Plasma pharmacokinetics (PK) of total and ultrafiltrable platinum, total and lactone forms of topotecan were determined in the first cycle. The dose-limiting toxicity (DT) was identified as grade 4 thrombocytopenia. The occurrence of grade 4 thrombocytopenia did not correlate with topotecan PK, but it did with the patient's characteristics. Severe thrombocytopenia was seen in 1/8 of patients without clinical or biological evidence of malnutrition, with a creatinine clearance higher than 1 ml/s, and no more than two previous chemotherapy regimens, while it was seen in 8/10 patients with one of these characteristics (P<0.004). In conclusion, the recommended doses of oxaliplatin 110 mg/m(2) and topotecan 1 mg/m(2)/day, every 3 weeks can be administered to patients with a favourable general status and pretreatment characteristics and a phase II study is worthwhile in ovarian cancer patients.

Increased oral bioavailability of topotecan in combination with the breast cancer resistance protein and P-glycoprotein inhibitor GF120918

PURPOSE

We discovered that breast cancer resistance protein (BCRP), a recently identified adenosine triphosphate-binding cassette drug transporter, substantially limits the oral bioavailability of topotecan in mdr1a/1b(-/-) P-glycoprotein (P-gp) knockout and wild-type mice. GF120918 is a potent inhibitor of BCRP and P-gp. The aim was to increase the bioavailability of topotecan by GF120918.

PATIENTS AND METHODS

In cohort A, eight patients received 1.0 mg/m(2) oral topotecan with or without coadministration of one single oral dose of 1,000 mg GF120918 (day 1 or day 8). In cohort B, eight other patients received 1.0 mg/m(2) intravenous topotecan with or without 1,000 mg oral GF120918 to study the effect of GF120918 on the systemic clearance of topotecan.

RESULTS

After oral topotecan, the mean area under the plasma concentration-time curve (AUC) of total topotecan increased significantly from 32.4 +/- 9.6 microg.h/L without GF120918 to 78.7 +/- 20.6 microg.h/L when GF120918 was coadministered (P =.008). The mean maximum plasma concentration of total topotecan increased from 4.1 +/- 1.5 microg/L without GF120918 to 11.5 +/- 2.4 microg/L with GF120918 (P =.008). The apparent bioavailability in this cohort increased significantly from 40.0% (range, 32% to 47%) to 97.1% (range, 91% to 120%) (P =.008). Interpatient variability of the apparent bioavailability was 17% without and 11% with GF120918. After intravenous administration of topotecan, coadministration of oral GF120918 had a small but statistically significant effect on the AUC and systemic clearance of total topotecan but no statistically significant effect on maximum plasma concentration and terminal half-life of total topotecan.

CONCLUSION

Coadministration of the BCRP and P-gp inhibitor GF120918 resulted in a significant increase of the systemic exposure of oral topotecan. The apparent oral bioavailability increased from 40.0% without to 97.1% with GF120918.

Phase I study of alternating doublets of topotecan/carboplatin and paclitaxel/carboplatin in patients with newly diagnosed, advanced ovarian cancer

OBJECTIVE

The aim of this study was to evaluate topotecan with carboplatin in an alternating doublet with carboplatin and paclitaxel in first-line ovarian cancer.

METHODS

Patients with newly diagnosed stage III/IV ovarian cancer were studied. The maximum tolerated dose (MTD) of topotecan (cycles 1, 3, 5, 7) in an alternating doublet regimen was determined through standard dose escalation in cohorts of three; doses of carboplatin (area under the curve [AUC] 4 to 5) and paclitaxel (175 mg/m(2), cycles 2, 4, 6, 8) were fixed. Dose-limiting toxicity (DLT) was defined only for cycle 1 as febrile neutropenia, prolonged grade 4 granulocytopenia, grade 4 thrombocytopenia, > or =grade 3 nonhematologic toxicity, or failure to recover in < or =7 days. The use of granulocyte colony-stimulating factor (G-CSF) to permit further dose escalation was also studied.

RESULTS

Thirty-seven patients received 142 cycles of topotecan/carboplatin. Hematologic DLTs included grade 4 neutropenia (59 events, 42% of cycles) and thrombocytopenia (32 events, 23% of cycles). Granulocytopenia was generally short-lived, and only 2 cases of febrile neutropenia occurred. The MTD was 1.0 mg/m(2)/day topotecan and carboplatin AUC 4, alternating with 175 mg/m(2) paclitaxel and carboplatin AUC 4. Although G-CSF effectively managed myelosuppression, thrombocytopenia developed in later cycles, limiting further topotecan dose escalation. The median progression-free survival was 20.5 months, and elevated pretreatment CA-125 levels normalized in 29 of 34 (85%) patients.

CONCLUSION

The establishment of a reasonably well-tolerated alternating doublet regimen, coupled with evidence of antitumor activity, provides the basis for further investigation of topotecan in first-line therapy of ovarian cancer. Topotecan (1.0 mg/m(2) daily for 3 days) was chosen for further evaluation in a phase II study.

Developmental chemotherapy in advanced ovarian cancer: incorporation of newer cytotoxic agents in a phase III randomized trial of the Gynecologic Oncology Group (GOG-0182)

Despite improvements in median and overall survival using a combination of platinum and paclitaxel, long-term survival rates for patients with advanced epithelial ovarian carcinoma (EOC) remain disappointing, and the development of more effective primary therapy remains a priority. In particular, several interesting chemotherapy agents have demonstrated activity individually in patients with recurrent EOC. Among these are gemcitabine, topotecan, liposomal doxorubicin, and prolonged oral etoposide. Preclinical models have suggested an advantage for combinations of these agents with platinum, which has been attributed to inhibition of DNA synthetic pathways involved in the repair of platinum-DNA adducts. However, efforts to develop multidrug combinations with platinum and paclitaxel have encountered substantial bone marrow toxicity, prompting exploration of alternative schedules and sequences of drug administration. In this regard, the Gynecologic Oncology Group (GOG) and other organizations have conducted a series of phase I pilot studies in previously untreated patients to define combinations that are suitable for group-wide phase III trials. With international collaboration, GOG has launched a five-arm trial (GOG-0182) that will compare these combinations against carboplatin-paclitaxel. The selection of candidate regimens for this trial illustrates the challenges of drug development in EOC.

Topoisomerase I levels in white blood cells of patients with ovarian cancer treated with paclitaxel-cisplatin-topotecan in a phase I study

Topotecan stabilizes the topoisomerase I (Topo I) cleavable complex. We measured Topo I levels in white blood cells of patients with ovarian cancer treated with topotecan. Topotecan was given i.v. daily x 5 q 3 weeks in combination with paclitaxel (1 day before topotecan) and cisplatin (just prior topotecan). Our aim was to correlate Topo I levels to pharmacokinetics and toxicity. Topo I levels were determined using Western blotting and were expressed relative to the Topo I level present in 10 microg cell lysate of the human IGROV1 ovarian cancer cell line. We found no correlation between Topo I levels and (non-)hematological toxicity. Topo I levels after the fifth topotecan infusion were significantly negatively correlated with the AUC of topotecan (R = -0.64, p = 0.026), in contrast with Topo I levels prior to (R = -0.25, p = 0.4) and after (R = -0.30, p = 0.3) the first topotecan infusion. Topo I levels after the fifth topotecan infusion (48 +/- 27%, mean +/- SD) were higher than Topo I levels prior to and after the first topotecan infusion (3.0 +/- 4.7 and 2.7 +/- 3.6%, respectively) (p = 0.001). In conclusion, we detected a significant inverse correlation between Topo I level and topotecan AUC at day 5, and we found increasing Topo I levels during a daily x 5 schedule of treatment with topotecan.

A phase I and pharmacokinetic study of intraperitoneal topotecan

PURPOSE

To evaluate the feasibility and pharmacology of intraperitoneal (IP) topotecan.

PATIENTS AND METHODS

Fifteen patients with recurrent ovarian cancer in a phase I trial were treated with escalating IP topotecan doses (5-30 mg/m(2)) for pharmacokinetic analysis.

RESULTS

Dose limiting toxicity (DLT) was acute hypotension, chills and fever at the 30 mg/m(2) dose level. Haematological toxicity and abdominal pain were mild for all dose levels studied.

PHARMACOKINETICS

Peak plasma levels of total topotecan were reached at 2.7 +/- 1.1 h after IP instillation. The apparent V(ss) was 69.9 +/- 25.4 L/m(2), plasma clearance 13.4 +/- 2.5 L/h/m(2) and plasma T1/2 3.7 +/- 1.3 h. The plasma AUC was correlated with the dose (R = 0.95, P < 0.01). The plasma AUC ratio of lactone versus total topotecan (lactone + carboxy-forms) increased with the dose from 16% to 55%, (R = 0.84, P < 0.01). Peritoneal total topotecan was cleared from the peritoneal cavity at 0.4 +/- 0.3 L/h.m(2) with a T1/2 = 2.7 +/- 1.7 h. The mean peritoneal/plasma AUC ratio for total topotecan was 54 +/- 34.

CONCLUSION

A substantial dose of topotecan can be delivered by the IP route, achieving cytotoxic plasma levels of topotecan, with acceptable toxicity. The recommended dose for further phase II trials is 20 mg/m(2) IP, which enables combination with active doses of other cytotoxic drugs, in view of its limited myelotoxicity when given by this route.

Repetitive high-dose topotecan, carboplatin, and paclitaxel with peripheral blood progenitor cell support in previously untreated ovarian cancer: results of a Phase I study

OBJECTIVE

In view of the significant activity of topotecan in ovarian cancer with dose-limiting toxicity (DLT) of myelosuppression, we evaluated the addition of topotecan to carboplatin and paclitaxel with peripheral blood progenitor cell (PBPC) support.

METHODS

Patients with previously untreated stage IIIC or IV ovarian cancer with macroscopic residual disease following primary debulking surgery were eligible. Patients received two cycles of carboplatin AUC = 5 and 175 mg/m(2) of paclitaxel with collection of PBPCs after the second cycle. Patients subsequently received three cycles of high-dose therapy (HDT) with topotecan on a daily x5 schedule, paclitaxel (250 mg/m(2) over 24 h), and carboplatin (AUC = 12-16).

RESULTS

Nineteen patients with a median age of 49 years (range 21-63) were enrolled and topotecan was escalated in 6 patient cohorts up to a dose of 4.5 mg/m(2)/day. Fifty-two of the planned 57 treatment cycles were delivered with no treatment-related deaths. Neutrophil and platelet recovery was rapid and the interval between HDT was 28 days. Febrile neutropenia occurred following 57% of all HDT cycles. DLTs of mucositis and diarrhea were observed at topotecan (4.5 mg/m(2)/day), paclitaxel (250 mg/m(2)) and carboplatin (AUC = 12). The protocol was subsequently modified to administer topotecan (2.5 mg/m(2)/day) with carboplatin (AUC = 16); however, 2 patients developed grade 4 diarrhea (1 with grade 3 mucositis and 1 with grade 4 mucositis). The clinical CR rate was 73% (14/19) with an overall clinical response rate of 95% (18/19). Of the 14 patients with a CCR, 13 of these underwent a second-look laparotomy with 8 (61%) achieving a pathological CR. With a median follow-up of 28 months (range 11-40 months), the median PFS is 36 months and OS has not been reached.

CONCLUSION

When combined with carboplatin (AUC = 12) and paclitaxel (250 mg/m(2)), the recommended topotecan dose is 3.5 mg/m(2)/day for 5 days. This outpatient HDT regimen combines three of the most active drugs in ovarian cancer with acceptable toxicity and promising activity.

Phase I dose escalation study of topotecan combined with alternating schedules of paclitaxel and carboplatin in advanced solid tumors

BACKGROUND

Combining topotecan with other cytotoxics has been problematic due to marrow suppression. A phase I trial was initiated to identify the optimal sequence and maximum-tolerated dose of topotecan in combination with paclitaxel and carboplatin.

PATIENTS AND METHODS

Patients with advanced cancer and performance status ECOG < or = 2. The starting dose was paclitaxel 175 mg/m2 day 1, carboplatin AUC 6.0 day 1, and topotecan 0.5 mg/m2 daily day 1-5 (early sequence). The next course of paclitaxel and carboplatin administration was delayed to day 5 (late sequence). Treatment was repeated every three weeks. After determining maximum-tolerated dose without cytokines, granulocyte colony-stimulating factor (G-CSF) was added and further dose escalation was pursued.

RESULTS

Fifty-one patients were entered; men: women ratio 30:21. Dose-limiting toxicity (DLT) for the early sequence was neutropenia at doses paclitaxel mg/m2/carboplatin AUC 5/topotecan mg/m2 (PCT) 175/5/0.75 for four to five days. DLT for the late sequence was neutropenia at PCT doses of 175/5/ 1.0 for four days. G-CSF 5 microg/kg subcutaneously starting day 6 permitted further topotecan dose escalation. After adding G-CSF, late sequence DLT was neutropenia at doses 175/5/1.25 for four days. Forty-six patients were evaluable for response and of those, there were thirteen partial responses.

CONCLUSIONS

The late sequence resulted in less toxicity and was better tolerated. The early sequence maximum-tolerated dose (MTD) was 175/6/0.5 for five days. The late sequence MTD was PCT 175/5/0.75 for five days. The late sequence MTD with G-CSF was 175/5/1.0 for four days. The recommended phase II PCT dose is the late sequence 175/5/1.0 for four days with G-CSF.

Granulocyte colony-stimulating factor (G-CSF) receptor gene expression of ovarian carcinoma does not correlate with G-CSF caused cell proliferation

BACKGROUND

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a growth factor commonly used to avoid leukopenia after chemotherapy. Endogenous G-CSF is produced by macrophages and granulocytes that infiltrate tumors. It has been reported that rhG-CSF stimulates the proliferation of several cell lines as well as bladder carcinoma cells. Conversely, in some hematopoietic cell lines such as U-937, WEHI-3B, and K-562 no effect or in some cases a differentiation pattern was found. Moreover, the role of rhG-CSF on the proliferation of solid tumors is not well understood.

METHODS

In this study, 10 ovarian carcinoma biopsies were characterized for the presence of G-CSF and G-CSF receptor by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Proliferation was analyzed by ATP viability assays.

RESULTS

Performing RT-PCR, these biopsies and four ovarian carcinoma cell lines were analyzed for endogenous G-CSF production, which was found in some biopsies and in all cell lines. Despite the presence of the G-CSF receptor in all biopsies and cell lines, no proliferation was found after rhG-CSF incubation of the cell lines or the tumor samples for 3 and for 6 days, respectively.

CONCLUSIONS

Summarizing the authors' in vitro studies, rhG-CSF does not affect the proliferation of ovarian carcinoma cells in vitro.

Topoisomerase I inhibition with topotecan: pharmacologic and clinical issues

Topoisomerase I (topo-I) inhibitors are a new class of anticancer agents with a mechanism of action aimed at interrupting DNA replication in cancer cells, the result of which is cell death. Most, if not all, topo-I inhibitors are derivatives of the plant extract camptothecin. Topotecan is a derivative of camptothecin which has been structurally modified to increase water solubility. The pharmacokinetic profile of topotecan is usually characterised by a two-compartment model and is linear in the dose range of 0.5 - 3.5 mg/m(2). Current clinical trials suggest antitumour activity against a variety of human tumour types, including ovarian cancer, non-small cell lung cancer (NSCLC) and non-lymphocytic haematologic malignancies. The main dose-limiting toxicity (DLT) is non-cumulative myelosuppression. Non-haematologic toxicities are usually mild. Based on several Phase I studies, the recommended Phase II dose was 1.5 mg/m(2)/day iv. for 5 days. Current Phase I and Phase II trials are evaluating the combination of topotecan with other chemotherapeutic agents to increase the therapeutic benefits of topotecan. The DLT in these trials is mainly myelosuppression.

Phase I trial of multiple cycles of high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell support as front-line therapy

PURPOSE

To determine the safety and feasibility of delivering multiple cycles of front-line high-dose carboplatin, paclitaxel, and topotecan with peripheral-blood stem-cell (PBSC) support.

PATIENTS AND METHODS

Patients were required to have a malignant solid tumor for which they had received no prior chemotherapy. Mobilization of PBSC was achieved with either filgrastim alone or in combination with cyclophosphamide and paclitaxel. Patients then received three or four cycles of high-dose carboplatin (area under the concentration-time curve [AUC] 16), paclitaxel (250 mg/m(2)), and topotecan (10-15 mg/m(2)), with the latter two agents administered as 24-hour infusions and supported with PBSC and filgrastim. Cycles were repeated every 28 days.

RESULTS

Twenty patients were enrolled onto the trial and were assessable for toxicity and clinical outcome. Dose-limiting toxicities were stomatitis and prolonged hematopoietic recovery. The maximum-tolerated dose of topotecan was 12.5 mg/m(2) when given with high-dose carboplatin and paclitaxel for three cycles. Four cycles were able to be given with a dose of topotecan of 10 mg/m(2). The pharmacokinetics of each compound were not affected by the other agents. Eleven (85%) of 13 patients with assessable disease responded.

CONCLUSION

Multiple cycles of high-dose carboplatin, paclitaxel, and topotecan can be safely administered with filgrastim and PBSC support. The recommended doses for phase II study are carboplatin AUC 16, paclitaxel 250 mg/m(2), and topotecan 10 mg/m(2). Trials are currently being conducted with this regimen as front-line treatment in patients with advanced ovarian cancer and extensive small-cell carcinoma. This approach remains experimental and should be used only in the context of a clinical trial.

Phase II feasibility study of sequential couplets of Cisplatin/Topotecan followed by paclitaxel/cisplatin as primary treatment for advanced epithelial ovarian cancer: a National Cancer Institute of Canada Clinical Trials Group Study

PURPOSE

Despite the improved results in advanced ovarian cancer achieved with the addition of paclitaxel to frontline therapy, there remains room for improvement. One approach is to add new agents such as topotecan. Because myelosuppression limits the delivery of topotecan with paclitaxel/cisplatin in a three-drug combination, we explored giving sequential couplets of cisplatin/topotecan followed by paclitaxel/cisplatin.

PATIENTS AND METHODS

Forty-four patients with residual epithelial ovarian carcinoma after primary surgery were studied. Cisplatin 50 mg/m(2) on day 1 and topotecan 0.75 mg/m(2) on days 1 through 5 were administered at 21-day intervals for four cycles, followed by interval debulking surgery (if optimal debulking was not achieved with primary surgery), and then paclitaxel 135 mg/m(2) over 24 hours on day 1 and cisplatin 75 mg/m(2) on day 2 at 21-day intervals for four cycles.

RESULTS

Such sequential couplets are feasible. Myelotoxicity was the major toxic effect, but it was of short duration. The granulocyte nadir with topotecan/cisplatin occurred late (median, day 18), so retreatment on day 21 was not always possible. There was no unexpected nonhematologic toxicity. The regimen was active in this group of patients who had undergone largely suboptimal debulking surgery. In 34 patients with clinically measurable disease, the overall response rate was 78%, and 30 (77%) of the 39 patients with elevated CA 125 levels at baseline had normalization of CA 125 levels by the end of therapy.

CONCLUSION

Sequential couplets of cisplatin/topotecan followed by paclitaxel/cisplatin are feasible. The efficacy data in this suboptimal group of patients has encouraged us to proceed with a randomized study based on this approach.

Pilot study of the paclitaxel, oxaliplatin, and cisplatin combination in patients with advanced/recurrent ovarian cancer

To determine the feasibility of the paclitaxel, oxaliplatin, cisplatin combination in advanced ovarian cancer (AOC), 15 patients with AOC (8 chemonaive, and 7 second-line, disease-free interval > or = 12 months) received paclitaxel 135 mg/m2 at day 1, with oxaliplatin 100 mg/m2 and cisplatin 75 mg/m2 at day 2, every 3 weeks for 6 cycles. Pretreated patients received prophylactic granulocyte colony-stimulating factor (5 microg/kg/d, days 6-13). Seventy cycles were administered; median 5 (range: 2-6 cycles) in chemonaive, and 4 (range: 2-6) in pretreated patients. There were grades III to IV neutropenia in 77%, febrile neutropenia in 24%, and grades III to IV thrombocytopenia in 4% of the cycles. Besides neutropenia, cumulative neurosensory toxicity was also limiting although reversible, with National Cancer Institute Common Toxicity Criteria grades II to III observed in 13 patients. Three of the pretreated patients had complete responses (43%), three had partial responses, and one had disease stabilization. Six of the 8 chemonaive patients had complete responses (75%), 1 had disease stabilization, and 1 had disease progression. The median follow-up is 17 months (range: 9-20 months) in chemonaive and 41 months (range: 13-58 months) in pretreated patients, and time to progression has been consistently more than 12 months, with 6 patients (5 chemonaive) still progression free (range: 15+ to 22+ months). This active combination shows acceptable hematologic toxicity, and reversible cumulative neurosensory toxicity. Further clinical exploration of the present combination appears warranted.

Phase II study of liposomal doxorubicin in advanced gynecologic cancers

OBJECTIVE

Pegylated liposomal doxorubicin (Doxil) may have enhanced therapeutic efficacy and reduced toxicity compared with the parent compound. This phase II study further evaluates the activity of Doxil in patients with ovarian cancer and explores activity in other gynecologic cancers.

METHODS

Sixty-three patients were treated with Doxil 50 mg/m(2) infused over 1 h; 44 were evaluable. Forty-eight had epithelial ovarian cancer and all received prior treatment with cisplatin and paclitaxel: 27 received two to six prior regimens, 44 were platinum resistant, 21 patients had measurable disease, and 27 had evaluable disease only.

RESULTS

The overall survival of these patients was 10 months (range, 0.25-33); progression-free survival was 3 months (range, 0.25-18). The response rate among those with measurable disease was 19%, with a median duration of 4.5 months (range, 3-12). The response rate of 22 patients with elevated CA-125 was 59%; median duration was 3.5 months (range, 1-12). Also, 27% achieved prolonged stabilization of disease for a median of 7 months (range, 5-18). Overall, treatment was well tolerated in this heavily pretreated population. Grade 3 and 4 toxic effects were: 5 grade 3 stomatitis, 3 grade 3 skin, 1 each grade 4 neutropenia and thrombocytopenia, 5 admits for infection, and no neutropenic fever; nausea and vomiting were uncommon in 204 cycles to ovarian cancer patients.

CONCLUSION

This study demonstrates the activity of Doxil in heavily pretreated patients with ovarian cancer and poor prognostic features and confirms the prolonged responses and favorable toxicity profile. Encouraging findings were also observed in the patients with nonovarian gynecologic cancers.

Licania michauxii Prance root extract induces hsp 70 mRNA and necrotic cell death in cultured human hepatoma and colon carcinoma cell lines

An extract of Licania michauxii Prance root was found to be cytotoxic to cultured human hepatoma (HepG2) and colon carcinoma (Caco-2) cells. Morphological and nuclear characteristics of treated cells were consistent with necrotic death. Increases in the chaperone protein hsp 70 and hsp 70 mRNA were dose dependent reaching peak mRNA levels (40-fold above control) at 6 h. Increases in nuclear localization of hsp 70 was also observed with treatment. Heat treatment of cells for 45 min to induce hsp 70 prior to treatment with the extract provided transient protection from the necrotic response.

New cytotoxics and non-cytotoxics in epithelial ovarian cancer

Several new cytotoxic agents with activity in relapsed ovarian cancer are being combined with paclitaxel plus platinum as the first step to assess their impact in randomized trials against the standard treatment. These include topotecan, gemcitabine, epirubicin, and liposomal doxorubicin. Because of overlapping toxicities, there have been challenges in combining some of these agents in full dose with combination paclitaxel plus platinum. These have been overcome by use of sequenced administration. In addition to these new agents, novel non-cytotoxic drugs targeting specific signaling molecules or the tumor microenvironment provide additional avenues for clinical investigation. Many of these agents are rational to assess in ovarian cancer where laboratory research has pinpointed a number of alterations in molecules involved in cell signaling and cell cycle control. Examples include the antibody to HER 2/neu, agents targeting protein kinase C alpha, the p53 gene, and matrix metalloproteinase inhibitors. The challenges facing their assessment include how to determine adequate dosing when toxic effects are minimal and how to assess evidence of antitumor activity, short of conducting randomized studies. Finally, how best to use such agents together with conventional chemotherapy, in combination or in sequence, is unknown. Large clinical studies with some of these agents will provide some answers to their impact and how best to use them in the first-line management of advanced epithelial ovarian cancer.

Dose-intensive approaches to ovarian cancer

Increasing the total dose or the dose intensity of platinum does not improve survival in women with ovarian cancer. High-dose chemotherapy with hematologic support has not been shown to be more effective than standard-dose chemotherapy. Regional dose intensity, through intraperitoneal chemotherapy, may have a role in the treatment of advanced ovarian cancer. Further studies are needed to identify the optimal combination of agents, in addition to a platinum and a taxane, to be used in primary therapy for ovarian cancer.