The kidneys are vital organs acting as the body's filters that eliminate drugs and other waste products from the body. For effective cancer therapy, a delicate balance is required in the drug treatment and its elimination, which is critical for drug accumulation, toxicity, and kidney malfunction. However, how renal cell carcinoma (RCC) affects the kidneys in safely eliminating the byproducts of drug treatments in patients with severely dysregulated kidney functions had remained elusive. Recent advancements in dose adjustment have added to our understanding regarding how drug treatments could be effectively regulated in aberrant kidney cells, driving safe elimination and reducing drug accumulation and toxicity at the right time and space. Dose adjustment is the only standard systemic way applicable; however, it presents certain limitations. There is significant room for developing new strategies and alternatives to improve it.

Our analysis of the available treatments in literature discusses the treatment and their safe eliminations. In this study, we give an overview of the measures that could be taken to maintain the elimination gradient of anti-cancer drugs and restore normal kidney function in RCC. Differential therapeutics of RCC/mRCC in various clinical phase trials and the interaction of targeted therapeutics in response to vascular endothelial growth factor (VEGF) were also discussed.

Such information might suggest a new direction in controlling treatment with safe elimination through dose adjustment and its associated alternatives in a judicious manner. A strategy to systematically focus on the safe elimination of anti-cancer drugs in RCC strongly needs advocating.

Anticancer drug nephrotoxicity is an important and increasing adverse drug event that limits the efficacy of cancer treatment. The kidney is an important elimination pathway for many antineoplastic drugs and their metabolites, which occurs by glomerular filtration and tubular secretion. Chemotherapeutic agents, both conventional cytotoxic agents and molecularly targeted agents, can affect any segment of the nephron including its microvasculature, leading to many clinical manifestations such as proteinuria, hypertension, electrolyte disturbances, glomerulopathy, acute and chronic interstitial nephritis, acute kidney injury and at times chronic kidney disease. The clinician should be alert to recognize several factors that may maximize renal dysfunction and contribute to the increased incidence of nephrotoxicity associated with these drugs, such as intravascular volume depletion, the associated use of nonchemotherapeutic nephrotoxic drugs (analgesics, antibiotics, proton pump inhibitors, and bone-targeted therapies), radiographic ionic contrast media or radiation therapy, urinary tract obstruction, and intrinsic renal disease. Identification of patients at higher risk for nephrotoxicity may allow the prevention or at least reduction in the development and severity of this adverse effect. Therefore, the aim of this brief review is to provide currently available evidences on oncologic drug-related nephrotoxicity.

Tyrosine kinase inhibitors (TKI) that target MET signaling have shown promise in various types of cancer, including lung cancer. Combination strategies have been proposed and developed to increase their therapeutic index. Based on preclinical synergy between inhibition of MET and topoisomerase I, a phase I study was designed to explore the combination of topotecan with the MET TKI tivantinib.

Eligible patients with advanced solid malignancies for which there was no known effective treatment received topotecan at doses of 1.0-1.5 mg/m²/day for five consecutive days in 21-day cycles with continuous, oral tivantinib given at escalating doses of 120-360 mg orally twice daily. Pharmacokinetic analyses of tivantinib were included. Circulating tumor cells (CTC) were collected serially to identify peripheral changes in MET phosphorylation.

The trial included 18 patients, 17 of whom received treatment. At the planned doses, the combination of topotecan and tivantinib was not tolerable due to thrombocytopenia and neutropenia. The addition of G-CSF to attenuate neutropenia did not improve tolerability. Greater tivantinib exposure, assessed through pharmacokinetic analysis, was associated with greater toxicity. No responses were seen. MET phosphorylation was feasible in CTC, but no changes were seen with therapy.

The combination of topotecan and oral tivantinib was not tolerable in this patient population.

The aim of the study was to determine the effect of renal impairment and prior platinum-based chemotherapy on the toxicity and pharmacokinetics of oral topotecan and to identify recommended doses for patients with renal impairment or prior platinum-based (PB) chemotherapy.

A multicentre phase I toxicity and pharmacokinetic study of oral topotecan was conducted in patients with advanced solid tumours. Patients were grouped by normal renal function with limited or prior PB chemotherapy or impaired renal function (mild [creatinine clearance (CLcr)  = 50-79 ml min(-1) ], moderate [CLcr  = 30-49 ml min(-1) ], severe [CLcr <30 ml min(-1) ]).

Fifty-nine patients were evaluable. Topotecan lactone and total topotecan area under the concentration-time curve (AUC) was significantly increased in patients with moderate and severe renal impairment (109% and 174%, respectively, topotecan lactone and 148% and 298%, respectively, total topotecan). Asian patients (23 in total) had higher AUCs than non-Asian patients with the same degree of renal impairment. Thirteen dose-limiting toxicities (DLTs) were observed, which were mostly haematological. The maximum tolerated dose (MTD) was 2.3 mg m(-2) day(-1) , given on days 1 to 5 in a 21 day cycle, for patients with prior PB chemotherapy or mild renal impairment, and 1.2 mg m(-2) day(-1) for patients with moderate renal impairment (suggested dose 1.9 mg m(-2) day(-1) for non-Asians). Due to incomplete enrolment of patients with severe renal impairment, the MTD was determined as ≥ 0.6 mg m(-2) day(-1) in this cohort.

Oral topotecan dose adjustments are not required in patients with prior PB chemotherapy or mildly impaired renal function, but reduced doses are required for patients with moderate or severe renal impairment.

The interindividual variability in pharmacokinetics represents one of the factors involved in difference of both efficacy and toxicity of anticancer drugs prescribed to patients with the same cancer disease. The causes of pharmacokinetic interindividual variability are themselves divers. The impaired organic function corresponding either to liver or kidneys represents the major cause since any impaired function is systematically responsible of pharmacokinetic modifications, and due to the amplitude of these modifications. In this article, the clinically relevant pharmacokinetic parameters are shown. The methodologies used to study the pharmacokinetic variability due to impaired organic functions and to control them are detailed.

To assess the feasibility of adding dose-intensive topotecan and cyclophosphamide to induction therapy for newly diagnosed high-risk neuroblastoma (HRNB).

Enrolled patients received two cycles of topotecan (approximately 1.2 mg/m(2)/d) and cyclophosphamide (400 mg/m(2)/d) for 5 days followed by four cycles of multiagent chemotherapy (Memorial Sloan-Kettering Cancer Center [MSKCC] regimen). Pharmacokinetically guided topotecan dosing (target systemic exposure with area under the curve of 50 to 70 ng/mL/hr) was performed. Peripheral-blood stem cell (PBSC) harvest and surgical resection of residual primary tumor occurred after cycles 2 and 5, respectively. Patients achieving at least a partial response received myeloablative chemotherapy with PBSC rescue and radiation to the presurgical primary tumor volume. Oral 13-cis-retinoic acid maintenance therapy was administered twice daily for 14 days in six 28-day cycles.

Thirty-one patients were enrolled onto the study. No deaths related to toxicity or dose-limiting toxicities occurred during induction. Mucositis rarely occurred after topotecan cycles (9.7%) in contrast to 30% after MSKCC cycles. Thirty patients underwent PBSC collection with median 31.1 × 10(6) CD34+ cells/kg (range, 1.8 to 541.8 × 10(6) CD34+ cells/kg), all negative for tumor contamination by immunocytochemical analysis. Targeted topotecan systemic exposure was achieved in 26 (84%) of 31 patients. At the end of induction, 26 patients (84%) had tumor response and one patient had progressive disease. In the overall cohort, 3-year event-free and overall survival were 37.8% ± 9.4% and 57.1% ± 9.4%, respectively.

This pilot induction regimen was well tolerated with expected and reversible toxicities. These data support investigation of efficacy in a phase III clinical trial for newly diagnosed HRNB.

A series of exploratory investigations with multiple agents was carried out in normal rats and in rats with uranyl nitrate-induced acute renal failure to understand the disposition characteristics of intravenous topotecan (TPT) used as a model substrate. The disposition of TPT was unaltered in normal rats when treated with methotrexate, whereas treatment with probenecid increased the systemic exposure of TPT. In case of uranyl nitrate-induced acute renal failure (UN-ARF) rats, the systemic exposure of TPT was increased when compared with normal rats, whereas in UN-ARF rats treated with probenecid a further reduction in renal clearance of TPT was noted as compared with that of UN-ARF induced rats. Thus, TPT may be involved in the tubular secretory pathway when a passive glomerular filtration pathway for elimination was not possible. The disposition of TPT did not normalize in UN-ARF rats when treated with caffeine, a non-selective adenosine A1 receptor antagonist, whereas the selective adenosine A1 receptor antagonist (1,3-dipropyl-8-phenylxanthine, DPPX) normalized TPT pharmacokinetic disposition by improving renal function. Renal excretion studies demonstrated that CLR improved by almost fivefold following DPPX treatment in ARF rats. In addition, the qualitative stability/metabolism pattern of TPT in liver microsomes prepared from various groups of rats (normal rats, UN-ARF rats, rats treated with DPPX, and UN-ARF rats treated with DPPX) was found to be similar. In summary, using a pharmacokinetic tool as a surrogate, it has been shown that the pharmacokinetic disposition of TPT improved considerably upon treatment with DPPX, a selective adenosine A1 antagonist.

Most drugs do not have the pharmacokinetic features required for optimal pulmonary delivery. In this study, we developed PEGylated nanostructured lipid carriers (PEG-NLCs) to improve the delivery of anti-tumour agents to lung tumours. PEG-40 NLCs modified with PEG-40 stearate (molecular weight 2000 Da), PEG-100 NLCs modified with PEG-100 stearate (molecular weight 5000 Da) and NLCs without PEG modification were prepared by melt-emulsification and homogenization, and were loaded with 10-hydroxycamptothecin (HCPT). They were investigated in terms of physiological characteristics, biodistribution, cellular uptake, and anti-tumour effect in-vivo. PEG-NLCs exhibited regular morphology, with a spherical shape. The particle size (measured by laser diffraction) was approximately 100 nm. Encapsulation in PEG-NLCs protected the active lactone form of HCPT compared with HCPT solution after incubation with plasma. In biodistribution studies, PEG-NLCs, especially PEG-40 NLCs, had longer circulation time and decreased uptake by the reticuloendothelial system (RES) compared with unmodified NLCs. PEG-NLCs accumulated in the lungs after i.v. injection in mice. PEG-NLCs showed enhanced cellular uptake by human lung adenocarcinoma epithelial A549 cells. In-vivo experiments indicated that PEG-NLCs loaded with HCPT have superior efficacy against A549 lung cancer compared with HCPT solution and NLCs. These results suggest that PEG-NLCs is a promising delivery system for HCPT in the treatment of lung cancer.

Topotecan [(S)-9-dimethylaminomethyl-10-hydroxy-camptothecin hydrochloride] is primarily excreted into urine in humans, with approximately 49% of the dose recovered as total topotecan (topotecan lactone plus topotecan hydroxyl acid form). The renal elimination of topotecan involves tubular secretion in addition to glomerular filtration, but little is known about the molecular mechanism of the renal tubular secretion. In the present study, we investigated the transport characteristics of topotecan hydroxyl acid across the renal basolateral membrane using rat kidney slices and rat or human transporter-expressing Xenopus laevis oocytes. Pravastatin and probenecid significantly inhibited the uptake of topotecan hydroxyl acid by rat kidney slices with K(i) values of 10.6 and 8.1 microM, respectively, and p-aminohippurate was weakly inhibitory at high concentrations, whereas excess tetraethylammonium had no effect. The uptake of topotecan hydroxyl acid by oocytes injected with complementary RNA of either rat or human organic anion transporter 3 (rOAT3 or hOAT3) was greater than that of water-injected oocytes. Kinetic analysis showed that the K(m) values for rOAT3 and hOAT3 were 21.9 and 56.5 microM, respectively. Neither rOAT1 nor hOAT1 stimulated topotecan hydroxyl acid transport. These results suggest that the urinary excretion of topotecan hydroxyl acid is accounted for by transport via OAT3, as well as glomerular filtration, in both rats and humans; therefore, drug-drug interactions involving OAT3 may cause a change in clearance of topotecan.

Chronic kidney disease is a common occurrence in patients with gynecological cancer. Systemic anticancer treatment in such patients is a challenge for clinicians because of altered drug pharmacokinetics. For those drugs that are excreted mainly by the kidneys, decreased renal function may lead to increased systemic exposure and increased toxicity. Dose adjustment based on pharmacokinetic changes is required in this situation to avoid life-threatening toxicity. In this review, we summarize the nephrotoxicity and pharmacokinetic data of agents commonly used in systemic anticancer treatment of gynecological cancers and dose adjustment guidelines in the presence of impaired renal function. We review 17 medications that need dose adjustment (cisplatin, carboplatin, doxorubicin, epirubicin, cyclophosphamide, ifosfamide, topotecan, irinotecan, etoposide, capecitabine, bleomycin, methotrexate, actinomycin D, granulocyte-macrophage colony-stimulating factor, metoclopramide, cimetidine, and diphenhydramine) as well as 27 drugs that do not (paclitaxel, docetaxel, pegylated liposomal doxorubicin, gemcitabine, oxaliplatin, fluorouracil, vincristine, letrozole, anastrozole, tamoxifen, leuprorelin, megestrol, gefitinib, erlotinib, trastuzumab, leucovorin, granulocyte colony-stimulating factor, erythropoietin, ondansetron, granisetron, palonosetron, tropisetron, dolasetron, aprepitant, dexamethasone, lorazepam, and diazepam). We also review the formulae commonly used to estimate creatinine clearance, including Cockcroft-Gault, Chatelut, Jelliffe, Wright, and the Modification of Diet in Renal Disease study formulae.

For the subgroup of patients with inoperable gastrointestinal stromal tumors, progress has been made by the rapid development and approval of the targeted therapy imatinib mesylate. Small round cell sarcoma, such as Ewing/PNET, desmoplastic small round cell sarcoma and rhabdomyosarcoma, are chemotherapy-sensitive and potentially curable malignancies, which are treated with multimodality, dose-intensitive and neoadjuvant protocols regardless of size or overt metastatic disease. A limited number of effective agents available for the treatment of patients with metastatic adult soft-tissue sarcoma exists, which have failed anthracyline and ifosfamide-based chemotherapy. Most other high-grade (grading >I) so-called adult-type soft-tissue sarcomas such as fibro, lipo, pleomorphic and synovial sarcoma are treated with a anthracycline-based regimen with or without ifosfamide as front-line therapy. In this review, the therapeutic activities of drugs currently available as second-line treatment in patients with metastatic soft tissue sarcoma are summarized, providing an overview of contentious or emerging treatment issues. In relapsed 'adult-type' soft-tissue sarcomas trofosfamide, gemcitabine and ecteinascidin (ET-743) appear to be drugs associated with moderate activity and an acceptable toxicity profile. An interesting finding to be noted is that the different drugs have particular effects in distinct subtypes of soft-tissue sarcoma; however, it has to be taken into account that the number of patients included in those phase II trials are limited. The role of the newer agents (e.g. patupilone derivates, brostallicin) is currently not definable. The so-called selective therapy targeting vascular endothelial growth factor (receptor), epidermal growth factor receptor, c-kit, Raf kinase or platelet-derived growth factor receptor and bcl-2 antisensing, proteasome, protein kinase C/B, and mammalian target of rabamycin inhibition will continue to be tested in gastrointestinal stromal tumors patients refractory to imatinib mesylate as well as in selected sarcoma subtypes.

A SIOG taskforce was formed to discuss best clinical practice for elderly cancer patients with renal insufficiency. This manuscript outlines recommended dosing adjustments for cancer drugs in this population according to renal function. Dosing adjustments have been made for drugs in current use which have recommendations in renal insufficiency and the elderly, focusing on drugs which are renally eliminated or are known to be nephrotoxic. Recommendations are based on pharmacokinetic and/or pharmacodynamic data where available. The taskforce recommend that before initiating therapy, some form of geriatric assessment should be conducted that includes evaluation of comorbidities and polypharmacy, hydration status and renal function (using available formulae). Within each drug class, it is sensible to use agents which are less likely to be influenced by renal clearance. Pharmacokinetic and pharmacodynamic data of anticancer agents in the elderly are needed in order to maximise efficacy whilst avoiding unacceptable toxicity.

Topotecan, a semisynthetic camptothecin, exerts its cytotoxic effect through inhibition of DNA topoisomerase I. Single-agent topotecan has demonstrated activity against persistent, metastatic and recurrent cancer of the uterine cervix. When combined with cisplatin in Phase II trials, further improved response rates have been reported. The cisplatin/topotecan doublet subsequently proved to be the first regimen in a series of multiple Phase III studies to demonstrate improved disease-free and overall survival in this setting compared with cisplatin alone, thus leading to its third indication by both the US FDA and the European Medicines Agency in 2006. This survival advantage was achieved at the expense of an increase in grade 3-4 hematologic toxicity; however, there was no difference in patient-reported quality of life between the cisplatin/topotecan doublet and single-agent cisplatin. This article reviews the pharmacology of topotecan and its evolution as an active agent in advanced and metastatic cervical cancer that is not amenable to cure with surgery or radiotherapy.

Oxaliplatin and topotecan have demonstrated activity as single agents against recurrent platinum-sensitive and -resistant ovarian cancer, as well as synergy in vitro. This was a dose-finding study of combination therapy with weekly topotecan and alternating-week oxaliplatin in patients with recurrent epithelial ovarian cancer.

Eligible patients had a diagnosis of recurrent ovarian or primary peritoneal carcinoma, a performance status of 0-2, and normal bone marrow, renal, and hepatic function. On days 1 and 15 of a 28-day cycle, patients received a fixed dose of oxaliplatin (85 mg/m2) via intravenous infusion. On days 1, 8, and 15, patients received an escalating dose of intravenous topotecan (2.0-4.0 mg/m2). Five dose levels were planned with a minimum cohort of 3 patients at each level.

Thirteen patients were enrolled and received a total of 50 cycles of chemotherapy. The maximum tolerated dose was 85 mg/m2 of oxaliplatin and 3.0 mg/m2 of topotecan, and grade 3 neutropenia was the dose-limiting toxicity. Four of nine (44%) evaluable patients had stable disease or a partial response to the drug combination as assessed by cancer antigen-125 levels.

A 28-day schedule of oxaliplatin and topotecan is safe and well tolerated. Because of the in vitro synergy observed between topoisomerase I inhibitors and platinum derivatives and the tolerability reported in the current study, this regimen warrants further investigation.

Camptothecins represent an established class of effective agents that selectively target topoisomerase I by trapping the catalytic intermediate of the topoisomerase I-DNA reaction, the cleavage complex. The water-soluble salt camptothecin-sodium - introduced in early trials in the 1960s - was highly toxic in animals, whereas the semisynthetic derivatives irinotecan and topotecan did not cause haemorrhagic cystitis because of their higher physicochemical stability and solubility at lower pH values. Myelosuppression, neutropenia and, to a lesser extent, thrombocytopenia are dose-limiting toxic effects of topotecan. In contrast to the structurally-related topotecan, irinotecan is a prodrug which has to be converted to SN-38, its active form. SN-38 is inactivated by conjugation, thus patients with Gilbert's syndrome and other forms of genetic glucuronidation deficiency are at an increased risk of irinotecan-induced adverse effects, such as neutropenia and diarrhoea. The cytotoxic mechanism of podophyllotoxin is the inhibition of topoisomerase II. Common adverse effects of etoposide include dose-limiting myelosuppression. Hypersensitivity reactions are more common with etoposide and teniposide than with etoposide phosphate because the formulations of the former contain sensitising solubilisers. Leukopenia and thrombocytopenia occur in 65% and 80%, respectively, of patients after administration of conventional doses of teniposide. Anorexia, vomiting and diarrhoea are generally of mild severity after administration of conventional doses of topoisomerase II inhibitors. Clinical pharmacokinetic studies have revealed substantial interindividual variabilities regarding the area under the concentration-time curve values and steady-state concentrations for all drugs reviewed in this article. Irinotecan, etoposide and teniposide are degraded via complex metabolic pathways. In contrast, topotecan primarily undergoes renal excretion. Regarding etoposide and teniposide, the extent of catechol formation over time during drug metabolism may be associated with a higher risk for secondary malignancies.

Ovarian cancer is more fatal than all the other gynaecological malignancies combined. Although most patients respond to first-line combination chemotherapy, the vast majority (50-75%) of patients with advanced disease will relapse. The management of patients with recurrent ovarian cancer is based on their response profile to platinum: patients with platinum-sensitive disease can be rechallenged with platinum-based chemotherapy, whereas the management of patients with platinum-resistant or -refractory disease remains an area of active investigation. In this review, the data for second-line therapy in this latter group of patients will be summarised and recommendations for their optimal management will be made.

The objective of this study was to determine the efficacy and toxicity of topotecan in Chinese patients with ovarian cancer. A retrospective analysis on recurrent ovarian cancer patients receiving topotecan 1.25 mg/m(2) daily for 5 consecutive days on a 21-day cycle from 1997 to 2002 was conducted. The patients included were all treated with at least two cycles of topotecan. The patient characteristics were compared in relation to their toxicity profile and their response to treatment. Response was evaluated by physical findings, imaging techniques, and serum CA125 level. A total of 60 patients were included in the study. All patients were evaluable for response and toxicities. A total of 361 cycles were given (median, 5 per patient; range 2-15). The major toxicity was neutropenia, which was grade 4 in 45.0% of the patients and 10.2% of the cycles. Age was the only covariate predicting the occurrence of grade 4 neutropenia (logistic regression P= 0.046, CI 1.01-1.12). Neutropenic fever occurred in 8.3% of the patients. Eighteen (30%) patients were required to delay their chemotherapy and 11 (18.3%) required dose reduction. Nonhematologic toxicities were mild. The overall response rate was 21.6%, with eight (13.3%) complete responses and five (8.3%) partial responses. The median duration of response and median time to progression were 11 and 5 months, respectively. The median survival was 14 months. Topotecan 1.25 mg/m(2) in a five-times-daily schedule was well tolerated in a cohort of Chinese patients. Myelotoxicity was the most important side effect in our study, but the incidence is much lower than that reported in other studies. Age was an independent factor predicting the occurrence of grade 4 neutropenia.

We report on a three-drug myeloablative regimen designed to consolidate remission and to prevent central nervous system (CNS) relapse of high-risk neuroblastoma (NB). Sixty-six NB patients received topotecan 2 mg/m2/day, x 4 days; thiotepa 300 mg/m2/day, x 3 days; and carboplatin approximately 500 mg/m2/day, x 3 days. Post-SCT treatments included radiotherapy, immunotherapy, 13-cis-retinoic acid, +/-oral etoposide. Significant nonhematologic toxicities were mucositis and skin-related in all patients, convulsions in three patients, and cardiac failure and venocclusive disease of liver in one patient each. Grade 2 hepatotoxicity led to truncating cytoreduction in two patients; both later relapsed in brain. Among 46 patients transplanted in first complete/very good partial remission (CR/VGPR), event-free survival is 54% (s.e.+/-8%) at 36 months post-SCT; notable events were three non-NB-related deaths (adenovirus on day +9, bowel necrosis at 5 months, multiorgan failure at seven months) and four relapses in brain. Of 12 patients transplanted with evidence of NB, two became long-term event-free survivors and two relapsed in the brain. Of eight patients transplanted in second or greater CR/VGPR, one became a long-term event-free survivor and seven relapsed though not in the CNS. This regimen has manageable toxicity but does not prevent CNS relapse.

The most commonly prescribed schedule of topotecan administration is daily for five days, every 21 days. Both pre-clinical and clinical studies suggest that a more protracted schedule may increase its therapeutic index. The current study was undertaken to determine the maximum tolerated number of days with 30-minute i.v. infusion of topotecan daily at fixed area under the plasma concentration-time curve (AUC) (i.e., 35 microg/Lxh).

Topotecan was administered i.v. over 30 min. The planned levels of number of days of administration were: 7, 10, 13, 15 and 17. The dose was individualized according to the patient's individual topotecan clearance observed after the first infusion of each cycle.

Twenty-three patients were enrolled and received 71 cycles of therapy. The 13-day level was defined as the maximum number of days of administration. The main side effects were thrombocytopenia and anaemia, whereas neutropenia was infrequent. The mean (coefficient of variation) observed AUC was 34.6 (21%), and 33.4 (19%) microg/Lxh, for the last day of cycle 1, and of cycle 2, respectively. Confirmed partial responses were observed in one patient with metastatic desmoplastic tumour and in two patients with small round metastatic endocrine carcinoma.

The recommended number of topotecan administration is 10 days. Beyond the potential clinical interest of topotecan administered for a 10-day period, this is the first trial showing the feasibility of a phase-I study exploring a number of administrations of daily AUC rather than a total dose in mg/m(2).

The purpose was to conduct an integrated analysis of the cumulative hematologic toxicity of topotecan in patients with relapsed ovarian cancer and small cell lung cancer (SCLC). Data were pooled from eight phase II and phase III clinical studies performed in patients with relapsed stage III/IV ovarian cancer or extensive SCLC treated with topotecan at a dose of 1.5 mg/m(2) per day on days 1-5 of a 21-day course. Quantitative hematologic toxicities were assessed using the National Cancer Institute Common Toxicity Criteria. A total of 4,124 courses of therapy was administered to the 879 patients in the pooled population. Grade 4 neutropenia was experienced by 78% of patients. The lowest nadirs for neutrophils and platelets generally occurred after the first course of therapy, followed by improvement or stabilization in subsequent courses. Neutropenia was noncumulative. During the first course, significant risk factors were identified: renal impairment and advanced age (grade 3/4 thrombocytopenia and grade 4 neutropenia) and prior radiotherapy; performance status score > or =2; SCLC; and exposure to both cisplatin (Platinol; Bristol-Myers Squibb, Princeton, NJ, http://www.bms.com) and carboplatin (Paraplatin; Bristol-Myers Squibb) (grade 3/4 thrombocytopenia only). The most frequent interventions for hematologic toxicities were RBC transfusions, treatment delays, G-CSF support, and dose reductions. Analysis of neutrophil and platelet nadirs and dosing for each course of therapy showed no apparent evidence of cumulative neutropenia or thrombocytopenia. The risk of grade 3 or 4 anemia was higher during the first four courses of therapy and may need to be more aggressively managed with erythropoietin therapy.

To evaluate medication adherence, pharmacokinetics and exposure versus response relationships in patients with myelodysplastic syndromes (MDS).

Ninety adult patients with MDS received oral topotecan (1.2 mg/m2) either once a day for 10 days or twice a day for 5 days every 21 days for up to six cycles. Dosing histories were collected using electronic monitoring devices fitted to medication vials. Topotecan plasma concentrations were measured, and exposure was determined by a sparse sampling approach and Bayesian estimation methods. Relationships between exposure and clinical response and toxicity were evaluated using logistic regression.

Overall adherence was excellent with 90% of patients taking the prescribed number of doses in cycle 1. Adherence did not differ between the two regimens. Topotecan pharmacokinetics were described using a one compartment open model with first order absorption and elimination. Pharmacokinetic parameter estimates did not differ between the once a day and twice a day dosing groups. While topotecan exposure was greater in the twice a day arm compared to the once a day arm due to drug accumulation, exposure did not correlate with clinical response. However, the probability of needing a platelet transfusion in the twice a day arm was significantly increased (by 35%) as a result of greater steady-state plasma topotecan concentrations.

Adherence is high in patients with MDS receiving oral topotecan, whether the drug is prescribed once or twice daily. The optimal schedule cannot be determined from this study, as there was no evident relationship between any pharmacokinetic parameter and clinical response.

To investigate weekly topotecan in heavily pretreated patients with recurrent ovarian cancer.

The records of patients with recurrent epithelial ovarian cancer who were treated with weekly topotecan after failure of > or =1 prior regimen were reviewed. Patients received topotecan (median starting dose approximately 2.5 mg/m(2)) on days 1, 8, and 15 of a 28-day cycle. Antitumor response was assessed after 2 cycles by serial CA-125 levels.

Thirty-five heavily pretreated patients received a mean of 5 cycles of topotecan (range, 1-13 cycles). Thirty-two patients had definable platinum sensitivity (16 sensitive, 8 resistant, 8 refractory). Median age was 56 years. A total of 177 cycles (534 weeks) of topotecan was administered. Hematologic toxicity was generally mild, and no grade 4 toxicities were observed. Grade 3 hematologic toxicity, including leukopenia, neutropenia, thrombocytopenia, and anemia, was observed in 2, 2, 1, and 0 patients, respectively. No patients experienced grade 3 or 4 nonhematologic toxicity. Based on serial CA-125 measurements, there were 1 (3%) complete and 5 (15%) partial responses, with 1 of the partial responses in a patient with platinum-refractory disease. Stable disease was reported in 13 (38%) patients, including 5 patients with platinum-resistant/refractory disease.

Weekly topotecan demonstrates activity and is well tolerated compared with historical data with the standard 5-day schedule. Higher doses may be warranted because of the high tolerability shown for weekly topotecan. Weekly topotecan may be an appropriate treatment option for patients with recurrent ovarian cancer, especially heavily pretreated patients who might require dosing schedules with improved tolerability.

The number of effective cytotoxic agents for the treatment of patients with metastatic adult soft tissue sarcoma is limited, especially when patients have failed anthracycline- and ifosfamide-based chemotherapy. For the subgroup of patients with inoperable gastrointestinal stromal tumour (GIST), progress has been made via the rapid development and approval of the targeted therapy imatinib. Small round cell tumours (SRCTs), such as Ewing's sarcoma/primitive neuroectodermal tumour, desmoplastic SRCT and rhabdomyosarcoma, are chemotherapy-sensitive and potentially curable malignancies, which are treated with multimodality, dose-intensive, neoadjuvant protocols regardless of size or overt metastatic disease. Most other high-grade (grading >I), so-called 'adult type', soft tissue sarcomas such as fibrosarcoma, liposarcoma, pleomorphic and synovial sarcomas are treated with an anthracycline-based regimen with or without ifosfamide as front-line therapy. In relapsed 'adult type' soft tissue sarcomas, trofosfamide, gemcitabine and trabectedin (ecteinascidin 743) appear to be drugs associated with some activity and an acceptable toxicity profile. A high activity has been reported for the taxanes, in particular for paclitaxel, in vascular sarcomas located in the scalp or face and in Kaposi's sarcoma. It is interesting to note that the different drugs have particular effects in distinct subtypes of soft tissue sarcoma; however, it should be taken into account that the number of patients included in the phase II trials is limited. The role of the newer agents (e.g. epothilones, brostallicin) is currently undefinable. Targeted therapy inhibiting vascular endothelial growth factor receptor, epidermal growth factor receptor, RAF kinase, c-KIT or platelet-derived growth factor receptors will continue to be tested in GIST patients refractory to imatinib and in other sarcoma histologies.

To retrospectively investigate the safety and efficacy of weekly topotecan in heavily pretreated patients with ovarian cancer.

Data were collected by retrospective review of patient records. Eligible patients had received > or =2 prior regimens for ovarian cancer before treatment with weekly topotecan. Efficacy was determined by measurable disease or CA 125 levels. Adverse event and growth factor support data were also collected.

Fifty patients (median age, 61 years) were evaluable for safety and received a total of 244 4-week cycles of therapy (median, 3; range, 1-21 cycles). Most patients (84%) had measurable disease, and 30% had performance status of > or =2. Patients had received two to six prior treatments for ovarian cancer. Median weekly dose per patient was topotecan 3.7 mg/m(2). Grade 4 hematologic toxicities (generally manageable) occurred in 4% of patients. One patient had febrile neutropenia. Grade 3/4 nonhematologic toxicities were fatigue in two (4%) patients. Forty-two patients were evaluable for response. Of 35 evaluable patients with measurable disease, 11 (31%) had a partial response (median duration, 3 months), and 15 (43%) patients had stable disease (median duration, 3.5 months). Of 41 evaluable patients with elevated CA 125 (median, 154 U/l; range, 47-7200 U/l), 11 (27%) had > or =50% decreases or normalization of CA 125 levels. Median time to progression in all patients with stable disease has not been reached (follow-up range, 1.5-17.3 months).

Weekly topotecan is active and well tolerated in heavily pretreated patients with relapsed ovarian cancer. Prospective studies of this regimen are warranted.

Although limited data are available about topotecan disposition in patients with renal insufficiency, nothing has been reported in anephric patients. The objective of this report is to characterize topotecan disposition in an anephric child with Wilms tumor, both on and off hemodialysis. The patient received topotecan and cyclophosphamide for four cycles; topotecan was administered daily for 5 days, with hemodialysis on the second and fourth day. Therapy was well tolerated, with grade 3 thrombocytopenia and grade 2 neutropenia noted after cycle four. The median topotecan lactone clearance was 15.5 L/h/m off hemodialysis and 18.7 L/h/m on hemodialysis. Topotecan clearance was minimally affected by hemodialysis and was similar to that observed in children without renal failure.

The number of effective cytotoxic agents for the treatment of patients with metastatic soft tissue sarcoma (STS) is limited, especially when patients have failed anthracyline-based chemotherapy.

Between 1999 and 2000 a total of 16 patients with histologically proven STS progressing during or after first-line anthracycline-based chemotherapy were entered into this open-label, noncomparative study. Topotecan was administered as a 30-min infusion at a dosage of 1.5 mg/m(2) on five consecutive days every 3 weeks. All patients had received an anthracycline- or ifosfamide-based first-line chemotherapy.

None of the 16 included patients achieved an objective response to topotecan. Six patients achieved stable disease (38%), lasting for at least 6 weeks in four patients (25%) and for less than 6 weeks in two patients (13%). Ten patients (62%) had progressive disease. The median time to progression was 79 days calculated from the start of topotecan therapy (range, 28-230). The treatment was well tolerated; however, both anemia and thrombopenia grade III/IV occurred in 25% of the patients as well as severe neutropenia in 69% of the patients. Nonhematologic toxicities grade III/IV such as diarrhea and severe bleeding occurred only in one patient each (6%).

Topotecan is well tolerated in anthracycline-resistant patients with metastatic STS, but no objective response has been observed in this trial.

Topotecan dosing considerations and alternative dosing schedules to reduce and manage myelosuppression during the treatment of relapsed ovarian cancer were reviewed. The myelosuppression patterns from phase I, II, and III clinical trials were analyzed to evaluate the degree of hematologic toxicity and to determine risk factors predictive of myelosuppression. Additionally, recent publications of alternative topotecan doses and schedules were examined. Extent of prior therapy, prior platinum therapy (particularly carboplatin), advanced age, impaired renal function, and prior radiation therapy were identified as potential risk factors for greater hematologic toxicity after topotecan therapy. Reducing the starting topotecan dose to 1.0 or 1.25 mg/m2/day is recommended to reduce the incidence of severe myelosuppression in high-risk individuals receiving topotecan for 5 consecutive days. Hematopoietic growth factors, transfusion therapy, and schedule adjustments may also help manage myelosuppression. Alternative schedules of 3-day or weekly dosing appear to have less myelotoxicity and are currently under evaluation. The clinical aspects of topotecan-related myelosuppression and results from clinical trials indicate that the dose, and possibly the dosing schedule, of topotecan can be modified to reduce hematologic toxicity and improve tolerance without compromising efficacy. Prospective individualization of topotecan dosing may prevent or minimize dose-limiting myelosuppression and allow patients to achieve the maximum topotecan benefit by improving their ability to complete therapy with fewer treatment delays. Ongoing clinical trials evaluating alternative dosing schedules with superior hematologic tolerability may facilitate the inclusion of topotecan in combination regimens for patients with ovarian cancer. Proposed topotecan dosing guidelines to reduce and manage myelosuppression are outlined.

Aging is associated with multidimensional changes, including alterations in physiological functions, co-morbidities and poly-medications. These changes may lead to modifications in the absorption, distribution, metabolism and excretion of drugs. The lack of a scientific basis for optimal drug dosing in the elderly is a major problem. The development and validation of guidelines are therefore essential to improve treatment administration and monitoring in elderly patients. Even though it has been widely demonstrated that standard therapies used in adults may be of great benefit in the elderly, there may be a higher incidence of toxicity. This could be avoided by using dosage individualization based on a sound knowledge of the physiological factors implicated in the pharmacokinetic (PK) characteristics of the drugs administered and in their observed pharmacodynamic (PD) effects in each patient. The so-called "population modeling" approach renders such studies feasible by allowing the analysis of PK-PD relationships from sparse observational data.

The study described here was designed to investigate the influence of the hydration schedule of cisplatin on the pharmacokinetics of topotecan. To test this hypothesis, 13 adult cancer patients were treated with intravenous (i.v.) cisplatin followed by i.v. topotecan for 5 days every 3 weeks using a short hydration schedule (SHS) for cisplatin in the first course and a hyper-hydration schedule (HHS) in the second course or vice versa. Topotecan pharmacokinetic analysis was performed in plasma, whole blood and red blood cells in both courses on days 1, 2 and 5. 11 patients received both courses and were pharmacokinetically evaluable. No significant differences between the two studied schedules were noted in the clearances of topotecan on day 1 in the different matrices. However, in both hydration schedules, on average, slightly lower topotecan clearances were observed on both days 2 and 5 compared with day 1 in all of the matrices, while no differences were noted between days 2 and 5. This alteration was independent of the schedule used and was less pronounced than that which has been initially reported for SHS and, overall, will not have clinical consequences.

The topoisomerase I inhibitor exatecan mesylate (DX-8951f ) is a water-soluble hexacyclic analogue of camptothecin that does not require enzymatic activation. This study determined the toxicity, maximum tolerated dose (MTD), pharmacokinetics and pharmacodynamics of a weekly intravenous (i.v.) schedule of DX-8951f.

Thirty-five patients with advanced solid malignancies, stratified as minimally (MP) or heavily (HP) pre-treated, received escalating doses of DX-8951f as 30-min i.v. infusions for three out of every 4 weeks. Pharmacokinetics were described after the first infusion of DX-8951f.

Infusions (244) of DX-8951f were administered with a median of two cycles (range 1-10). The main toxicity observed was haematological. There was no significant gastrointestinal toxicity. Two patients (6%) had confirmed partial responses. Twelve patients (39%) had stable disease. DX-8951f had a terminal elimination half-life of approximately 8 h and a clearance of 2 l/h/m(2). The area under the plasma concentration versus time curve (AUC( infinity )) and the maximum plasma concentration (C(max)) increased linearly with the dose. A linear relationship was present for the percentage decrease in neutrophil counts or platelet counts and AUC( infinity ) as well as C(max).

The dose-limiting toxicity of DX-8951f is neutropenia for MP patients and neutropenia and thrombocytopenia for HP patients. Evidence for clinical activity was seen, suggesting phase II study of the drug is indicated. Using this schedule the recommended dose is 2.75 mg/m(2)/week for MP patients and 2.10 mg/m(2)/week for HP patients.

Toxicity is a major concern for anticancer drugs. These compounds present a narrow therapeutic index, with a small difference between the dose required for an antitumor effect and that responsible for unacceptable toxicity. Their recommended doses are determined according to the toxicity endpoint. Moreover, toxicity is observed earlier than the therapeutic effect, so, toxic effects represent a major endpoint for pharmacodynamic studies of cytotoxic drugs. Knowledge of toxicity patterns and main factors of toxicity of anticancer drugs is required before modeling data of these studies. Hematological toxicities represent the main toxicity of the cytotoxic. However, non-hematological toxicities have become more important than hematological toxicities as pharmacodynamic endpoints in some circumstances such as high-dose chemotherapy associated with bone marrow transplantation. This paper will describe the main toxicity of the cytotoxic drugs, and its factors of both inter- and intra-patient variability. The toxicity pattern of topotecan will be examined as an example. Knowledge of the toxicity pattern of a drug constitutes a prerequirement before modeling its pharmacodynamics.

Previously, a gender dependency of topotecan was found in the pharmacokinetics in the plasma compartment. Here, we prospectively studied the red blood cell (RBC) partitioning of topotecan and evaluated its consequences for overall drug disposition. Blood samples were obtained from 12 patients receiving cisplatin followed by i.v. topotecan. Topotecan pharmacokinetic analysis was performed in whole blood, plasma and RBCs. Significantly slower clearance was noted in females (n=7) compared to males (n=5) for lactone and total topotecan in plasma (p<0.0001), and for total drug in RBCs (p=0.027), but not in whole blood. In addition, no gender-dependent differences were observed in the terminal half-lives of topotecan in any of the compartments. The area under the curve ratios for RBC total to plasma lactone were 2.53+/-0.0640 and 2.13+/-0.442 in males and females, respectively. Hence, topotecan displays preferential affinity for RBCs compared to plasma, although these cells do not act as a depot in which drug accumulates over time. RBCs thus play a principal role in the distribution kinetics of topotecan and have a major impact on its plasma pharmacokinetics. The data warrant a change from current practice in pharmacokinetic studies with this agent and provide further evidence that, in general, the choice of the appropriate assay matrix should be rationally based.

The toxicity outcome of cancer patients receiving chemotherapy is difficult to predict. In this study the influence of malnutrition and inflammation on acute haematological toxicity was investigated.

Between January 1999 and January 2000, 48 consecutive cancer patients experienced severe haematological toxicity (SHT), either neutropenic fever or severe thrombocytopenia, following various chemotherapy regimens. Their baseline characteristics were compared with those of 59 control patients. Previous chemotherapy regimens, type of chemotherapy, performance status (PS), calculated creatinine clearance, bilirubin, C-reactive protein (1), alpha-1 acid glycoprotein (2), albumin (3), pre-albumin (4) and the nutritional and inflammatory status (NIS) ratio [NIS = (1 x 2)/(3 x 4)] were studied. Statistical analysis was carried out using either a t-test or a chi-square test. A receiver operating characteristic (ROC) curve determined the cut-off value for NIS.

Patients experiencing SHT had a higher PS (P <0.001), inflammatory serum protein levels (P <0.001) and NIS ratio (P <0.0001), but lower haemoglobin (P <0.05) and serum-albumin levels (P <0.0001). Using a cut-off of 0 or 1 for PS and 1 for NIS, sensitivity was 98%, 43% and 89%; specificity was 38%, 90% and 66%, respectively. In 37 patients treated with topotecan as single agent, the determinants for SHT were PS (P <0.0001) and NIS (P <0.0001).

Altered nutritional and inflammatory status correlates with increased risk of severe haematological toxicity following anticancer chemotherapy.

The prescribed dose of anticancer agents is most commonly calculated using body surface area as the only independent variable, and it has been shown that this approach still results in large interpatient variability in drug exposure. Here, we retrospectively assessed the pharmacokinetics of 33 investigational agents tested in phase I trials from 1991 through 2001, as a function of body surface area in 1650 adult cancer patients. Twelve of the drugs were administered orally, 19 were administered intravenously, and two were administered by both routes. Body surface area-based dosing was statistically significantly associated with a reduction in interpatient variability in drug clearance for only five of the 33 agents: docosahexaenoic acid (DHA)-paclitaxel, 5-fluorouracil/eniluracil, paclitaxel, temozolomide, and troxacitabine. These results do not support the use of body surface area in dose calculations and suggest that alternate dosing strategies should be evaluated. We conclude that body surface area should not be used to determine starting doses of investigational agents in future phase I studies.

Ovarian cancer is the fifth leading cause of cancer death in women. Most patients with ovarian cancer respond to first-line chemotherapy, but many relapse within 18 to 22 months. The development of efficacious salvage therapies that increase overall survival while maintaining quality of life is a great challenge in the treatment of this disease. Topotecan, a novel topoisomerase I inhibitor, is currently indicated for the treatment of recurrent metastatic carcinoma of the ovary. In patients with relapsed ovarian cancer, the overall response rates on treatment with topotecan range from 19%-33% in platinum-sensitive patients, 14%-18% in platinum-resistant patients, and 5%-11% in platinum-refractory patients. The proportion of patients achieving stable disease ranges between 17% in refractory and 48% in sensitive patients. In phase III studies, topotecan was shown to be equivalent in efficacy to both paclitaxel and liposomal doxorubicin as second-line therapy in patients with relapsed ovarian cancer. Further, non-cross-resistance between topotecan and paclitaxel was demonstrated in a third-line, phase III crossover study, suggesting that topotecan may be effective in the first-line setting with paclitaxel and/or platinum. Hematologic toxicities include neutropenia, thrombocytopenia, and anemia; however, these toxicities are usually short lived, noncumulative, and manageable with dose modifications, including low-dose topotecan regimens. Nonhematologic toxicities are usually mild to moderate in severity. These data support the use of topotecan for second-line therapy and suggest that topotecan may also be effective in first-line therapy. Further studies with topotecan alone and in combination with other agents are needed to fully characterize the role and sequencing of topotecan in the salvage and first-line settings.

Recognition of recurrent ovarian cancer as a disease with significant secondary responses and remissions has led to an increase in the need for oncologists to plan for the long-term therapy of patients. However, many of the currently available front-line and salvage agents used in advanced ovarian cancer are associated with cumulative and/or irreversible toxicities that pose challenges in long-term planning. The irreversible effects associated with some of these therapies may render patients less tolerant to subsequent treatments and lead to a cycle of diminishing treatment options with each remission and disease relapse. Additionally, the potential for patients to experience cumulative toxicity must be carefully weighed against the goals of prolonging the disease-free interval and improving patient quality of life. A number of agents are available in the treatment armamentarium (platinum, paclitaxel, gemcitabine, etoposide, liposomal doxorubicin, and topotecan), many, but not all of which are associated with cumulative toxicity. For instance, cumulative neurotoxicity associated with cisplatin as first-line therapy may diminish the option for retreatment with platinum at first relapse. In contrast, the main toxicity associated with topotecan is noncumulative, manageable myelosuppression. In this review, the major toxicities associated with the predominant chemotherapy agents used in advanced ovarian cancer are discussed along with selected management approaches in the context of long-term treatment planning and sequencing.

Relapsed ovarian cancer and small cell lung cancer are frequently treated with topotecan (Hycamtin), for which the standard dose and schedule are 1.5 mg/m(2) daily for five consecutive days every 3 weeks. Clinical experience has shown that this dose and schedule may be too toxic for some patients, especially those who have been heavily pretreated with platinum-based therapeutics, and it has been suggested that starting doses of topotecan be reduced to 1.0-1.25 mg/m(2)/d. Recently, multiple clinical trials have begun to evaluate the feasibility and preliminary antitumor activity of an alternative schedule based on weekly administration of topotecan. The potential benefits of weekly administration include not only reduced toxicity without significant compromise of antitumor activity, but also greater patient convenience and quality of life and greater potential for developing new topotecan-containing combination therapies. This report reviews the rationale for a weekly schedule, as well as a growing base of emerging clinical data. These preliminary data suggest that weekly topotecan is active; further evaluations are planned to confirm the activity and therapeutic index and to determine optimal dosing of a weekly schedule.

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.

Topotecan and cisplatin combinations have shown schedule-dependent toxicity, which may in part be due to cisplatin nephrotoxicity. As carboplatin is less nephrotoxic and increasingly replacing cisplatin in clinical practice, the aim of this study was to define the optimal sequence and dose for topotecan in combination with carboplatin.

Two parallel phase I trials, with pharmacokinetic studies, were conducted administering carboplatin on day 1 with topotecan on days 1-5 (schedule A) or days 8-12 (schedule B). repeated every 3 weeks.

Twenty-one patients were treated over two dose levels, carboplatin AUC 4 [glomerular filtration rate (GFR) calculated from 51Cr-EDTA clearance] with topotecan 0.5 or 0.75 mg/m2. At the first dose level, six patients were evaluable for each schedule. With schedule A, from 34 cycles, there were two dose reductions and 10 treatment delays due to myelosuppression. With schedule B from 25 cycles, there was one reduction and 10 delays. At dose level 2, both patients in schedule A had dose-limiting neutropenia. In contrast, there was no dose-limiting toxicity with schedule B in six patients, although the majority of cycles were delayed.

The combination of topotecan and carboplatin using these 3-weekly schedules lead to significant myelotoxicity with attendant dose reductions and delays; the optimal scheduling of these agents remains to be defined.

Camptothecin analogs, agents that target the intranuclear enzyme topoisomerase I, represent a promising new class of anticancer drugs for the treatment of childhood cancer. In preclinical studies, camptothecins, such as topotecan and irinotecan, are highly active against a variety of pediatric malignancies including neuroblastomas, rhabdomyosarcomas, gliomas, and medulloblastomas. In this paper, we review the status of completed and ongoing clinical trials and pharmacokinetic studies of camptothecin analogs in children. These and future planned studies of this novel class of cytotoxic agents are critical to defining the ultimate role of topoisomerase I poisons in the treatment of childhood cancer.

Topotecan (1.5 mg/m(2)) administered daily for 5 consecutive days of a 21-day cycle is an established chemotherapeutic regimen in recurrent ovarian cancer. However, noncumulative myelosuppression has limited its use by many clinicians. We sought to determine whether a lower dose of topotecan could provide comparable tumor activity and higher tolerability in pretreated ovarian cancer patients.

A retrospective chart review was conducted on recurrent ovarian, peritoneal, or fallopian tube cancer patients with measurable disease or elevated cancer antigen 125 levels (evaluable disease). Patients were treated with topotecan (1.0 mg/m(2)) given by 30-min intravenous infusion for 5 consecutive days every 21 days until disease progression or unacceptable toxicity.

Treatment records from 37 women who had been treated with a median of 3 courses (range, 1 to 17) of lower dose topotecan were evaluated; all were evaluable for tolerability and 36 were evaluable for response. Patients had received a median of 3 (range, 1 to 6) previous treatments. The overall response rate was 22% (8/36); the response rates for patients with evaluable disease and measurable disease were 35.7 (5/14) and 13.6% (3/22), respectively. An additional 8 patients (22%) achieved stable disease. Grade 4 neutropenia, thrombocytopenia, and anemia occurred in 48.6, 5.4, and 5.4% of patients, respectively. Granulocyte colony-stimulating factor support was used in 37% of patients, including 5 who experienced febrile neutropenia.

Topotecan at 1.0 mg/m(2) x 5 days every 21 days is active in platinum- and paclitaxel-resistant ovarian cancer, with significant improvements in hematologic toxicity. In heavily pretreated patients-topotecan can be safely given at reduced doses without apparent loss of efficacy.

Multiple factors interact during the evolution of renal diseases. In the present study, we examined the expression of DNA topoisomerases type I and IIalpha, which reflect gene transcription and DNA replication, respectively. Enzyme content was assessed by immunohistochemistry using two specific monoclonal antibodies, C21 and Ki-S4, on 81 archival punch-biopsy specimens from patients with renal diseases, including minimal change disease (MCD; n = 10), focal segmental glomerular sclerosis (FSGS; n = 6), mesangial proliferative glomerulonephritis (MPGN; n = 11), membranous glomerulonephritis (MGN; n = 10), mesangial capillary glomerulonephritis (MCGN; n = 7), rapidly progressive glomerulonephritis (RPGN; n = 12), lupus nephritis (LN; n = 15), and tubulointerstitial nephritis (TIN; n = 10). Both enzymes were strongly expressed in diseases tending to rapid progression, notably RPGN and LN, whereas MCD and MGN showed low protein levels in both the glomerular and tubular compartments. Moreover, topoisomerase expression was significantly associated with the density of monocytogenic infiltrates (monitored by means of the monoclonal antibody Ki-M1p), such pathogenesis-associated factors as antinuclear antibodies and paranuclear antineutrophilic antibodies, and serum immunoglobulin levels. There also was a positive correlation with serum creatinine levels and an inverse association with proteinuria and nephrotic syndrome. We conclude that the expression of DNA topoisomerases may be linked to pathogenetic mechanisms and may provide prognostic information. Because of their comparatively low nephrotoxicity, topoisomerase inhibitors might prove to be useful therapeutic agents in the treatment of renal diseases.

Topotecan appears to be relatively unaffected by the most common multidrug resistance mechanisms, may potentiate cytotoxicity of alkylators, has good penetration into the central nervous system, is active against a variety of neoplasms, and has myelosuppression as its paramount toxicity. We present our experience with a myeloablative regimen that includes topotecan. Twenty-one patients with poor-prognosis tumors and intact function of key organs received topotecan 2 mg/m2 by 30-min intravenous (i.v.) infusion on days -8, -7, -6, -5, -4; thiotepa 300 mg/m2 by 3 h i.v. infusion on days -8, -7, -6; and carboplatin by 4 h i.v. infusion on days -5, -4, -3 with a daily dose derived from the pediatric Calvert formula, using a targeted area under the curve of seven mg/ml* min ( approximately 500 mg/m2/day). Stem cell rescue was on day 0. The patients were 1 to 29 (median 4) years old; 18 were in complete remission (CR) and three in partial remission (PR). Early toxicities were severe mucositis and erythema with superficial peeling in all patients and a seizure, hypertension, and renal insufficiency followed by veno-occlusive disease in one patient each. Post-transplant treatment included radiotherapy alone (four patients) or plus biological agents (11 patients with neuroblastoma). With a follow-up of 6+ to 32+ (median 11+) months, event-free survivors include 10/11 neuroblastoma patients (first CR), 4/5 brain tumor patients (second PR or CR), 1/3 patients with metastatic Ewing's sarcoma (first or second CR), and a patient transplanted for multiply recurrent immature ovarian teratoma; a patient with desmoplastic small round-cell tumor (second PR) had progressive disease at 8 months. Favorable results for disease control, manageable toxicity, and the antitumor profiles of topotecan, thiotepa, and carboplatin, support use of this three-drug regimen in the treatment of neuroblastoma and brain tumors; applicability to other tumors is still uncertain.

The administration of systemic chemotherapy to patients with moderate-to-severe organ impairment remains a challenge. In renal failure, guidelines for dose adjustments exist for very few chemotherapy agents. Subsequently, oncologists typically withhold treatment with systemic chemotherapy for patients with severe renal dysfunction. We present the case of a patient with metastatic transitional cell carcinoma of the bladder and renal failure who underwent successful systemic chemotherapy with paclitaxel and carboplatin. The data on systemic chemotherapy in patients with severe renal dysfunction are reviewed.

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.