Phase II study of irinotecan and etoposide in patients with metastatic non-small-cell lung cancer

History of Japan Clinical Oncology Group (JCOG) Lung Cancer Study Group

The Japan Clinical Oncology Group Lung Cancer Study Group has been carrying out clinical studies, exploring new strategies of treatment, supportive therapies (antiemetics, etc.), etc., for a variety of cancers, including not only small cell lung cancer and non-small cell lung cancer but also rare chest tumours (represented by thymoma) and cancer-associated conditions (cancerous pericarditis, cancerous pleuritis, etc.). In this review, an overview of all studies conducted from 1985 to 2019 is provided.

Review : Topoisomerase I inhibitors: 2. Irinotecan

Purpose. The primary objective of this article is to discuss the pharmacology, pharmacokinetics, clinical use, and adverse effects of the approved topoisomer ase I inhibitors. This is the second in a series of two articles and will focus on irinotecan.

Data Sources. We reviewed the literature through a MEDLINE search of English language arti cles from 1985 through 1998. Relevant articles cited in the titles obtained from the MEDLINE search were also used. The following terms were used for purpose of conducting the MEDLINE search: topoisomerase inhibitors, irinotecan, topoisomerase I, camptosar, and CPT-11.

Data Extraction. We have reviewed the current literature to discuss the pharmacology, pharmacokinet ics, clinical use, toxicity, drug interactions, indications, formulation, dosage and administration, and pharmaceu tical issues surrounding the use of irinotecan.

Data Synthesis. The topoisomerase I inhibitors are new antineoplastic agents with a unique mechanism of action. Promising areas of application include colo rectal cancer, non-small-cell lung cancer, small-cell lung cancer, cervical cancer, and lymphomas. Clinical trials detailing the activity of topoisomerase I inhibitors in these areas are presented.

Are there new therapeutic options for treating lung cancer based on herbal medicines and their metabolites?

ETHONOPHARMACOLOGICAL RELEVANCE: Lung cancer is one of the most lethal cancers in terms of mortality and incidence worldwide. Despite intensive research and investigation, treatment of lung cancer is still unsatisfactory due to adverse effects and multidrug resistance. Recently, herbal drugs have been recognized as one of attractive approaches for lung cancer therapy with little side effects. Furthermore, there are evidences that various herbal medicines have proven to be useful and effective in sensitizing conventional agents, prolonging survival time, preventing side effects of chemotherapy, and improving quality of life (QoL) in lung cancer patients.

AIM AND METHODS OF THE STUDY

Nevertheless, the underlying molecular targets and efficacy of herbal medicines in lung cancer treatment still remain unclear. Thus, we reviewed traditionally used herbal medicines and their phytochemicals with antitumor activity against lung cancer from peer-reviewed papers through Scientific Database Medline, Scopus and Google scholar.

CONCLUSIONS

We suggest that herbal medicines and phytochemicals can be useful anti-cancer agents for lung cancer treatment by targeting molecular signaling involved in the regulation of angiogenesis, metastasis and severe side effects, only provided quality control and reproducibility issues were solved.

Clarification of clinical features of interstitial lung disease induced by irinotecan based on postmarketing surveillance data and spontaneous reports

Irinotecan-induced interstitial lung disease (ILD) requires accurate diagnosis, followed by prompt and appropriate treatment. This study was conducted to compile information and imaging data to define the characteristics of irinotecan-induced ILD. Searches were performed on information collected for a drug reexamination application and on data from spontaneous safety reports submitted to Daiichi Sankyo Company, Limited. These database searches revealed 153 cases of serious ILD that occurred in association with irinotecan therapy, and which were reported as adverse drug reactions. Computed tomographic findings obtained after the onset of ILD were categorized based on four typical patterns. A total of 66 patients (including 15 for whom a relationship between death and serious ILD could not be excluded; incidence of serious ILD: 0.74%; death rate of ILD: 0.17%) were detected during the postmarketing surveillance along with 87 patients (22 deaths) that were identified from spontaneous reports. Within 16 weeks of starting treatment, 80.7% of the patients developed ILD. A total of 61.3% of the cases treated using steroids responded to the steroid therapy. These results indicate that there is no specific clinical or imaging feature associated with ILD related to irinotecan and that the prognosis of ILD related to irinotecan was poor in patients with preexisting ILD. The relative risk calculated for the association between preexisting ILD and death was 2.25 (P=0.29). During irinotecan treatments, patients need to be carefully observed for symptoms, especially at 16 weeks after starting treatment. In addition, when patients are receiving this type of therapy, they also need to undergo chest imaging studies.

Functional interaction of DNA topoisomerase IIalpha with the beta-catenin and T-cell factor-4 complex

BACKGROUND & AIMS

The Wnt signaling pathway is activated constitutively in the majority of colorectal cancers as a result of mutation in either the adenomatous polyposis coli or the CTNNB1 gene, and blockage of the pathway has been considered feasible as molecular therapy against colorectal cancer. DNA topoisomerase IIalpha (Topo IIalpha) is a component of the beta-catenin/T-cell factor-4 (TCF-4) nuclear complex. We examined the functional significance of Topo IIalpha in Wnt signaling.

METHODS

The physical and functional interaction between Topo IIalpha and the beta-catenin/TCF-4 nuclear complex was evaluated by immunoprecipitation, immunofluorescence microscopy, 2-hybrid assay, and luciferase reporter assay.

RESULTS

Amino acids 951-1301 of Topo IIalpha were necessary for binding to beta-catenin. Over expression of Topo IIalpha enhanced the TCF/lymphoid enhancer factor transcriptional activity in a dose-dependent manner, and knockdown of Topo IIalpha by RNA interference conversely attenuated the transcriptional activity. The Topo II inhibitors, merbarone and etoposide, suppressed the beta-catenin-mediated TCF/lymphoid enhancer factor transcriptional activity. The catalytic activity of Topo II was augmented by overexpression of beta-catenin as measured by the decatenation of kinetoplast DNA. Topo IIalpha was highly expressed and colocalized with beta-catenin in tumor cells of patients with familial adenomatous polyposis syndrome and patients with sporadic colorectal cancer.

CONCLUSIONS

Topo IIalpha interacts with beta-catenin as a novel transcriptional co-activator. A new drug targeting the interaction of Topo IIalpha with beta-catenin as well as its catalytic activity might be more effective for suppressing aberrant Wnt signaling and proliferation of colorectal cancer cells than the current Topo II inhibitors.

Pemetrexed combined with paclitaxel in patients with advanced or metastatic non-small-cell lung cancer: A phase I-II trial

Pemetrexed, a novel multi-targeted agent established for the treatment of mesothelioma, has been under investigation for other malignancies, and in recent years particularly for non-small-cell lung cancer (NSCLC). In the present trial we investigated pemetrexed in combination with paclitaxel as front-line treatment in advanced or metastatic NSCLC. Our objectives were to determine the response rate, median and overall survival and toxicity. From April 2005 until May 2006, 51 patients with advanced or metastatic NSCLC were enrolled and 48 were considered evaluable. There were 39 males and nine females, median age 62 years (range 37-81 years), one patient stage IIIA N(2), 23 patients, IIIB and 24, stage IV. All patients had a cytologically- or histologically-confirmed diagnosis. Pemetrexed was administered at a standard dose of 500mg/m(2) and paclitaxel at an escalating dose starting at 135mg/m(2), then 150mg/m(2) and ending at a dose of 175mg/m(2); the level was increased every three patients. Both agents were administered on day 1, repeated every 3 weeks for six courses. A 39.6% partial response rate was observed with a median survival of 14 months. Toxicity was mild with 8.3% grade 3 and 4 neutropenia and other very mild hematologic and non-hematologic adverse reactions. The combination of pemetrexed and paclitaxel at doses of 500mg/m(2) and 175mg/m(2), respectively, has been shown to be an effective combination with very limited toxicity.

Phase I and pharmacologic study of irinotecan and amrubicin in advanced non-small cell lung cancer

PURPOSE

We conducted a Phase I trial of irinotecan (CPT-11), a topoisomerase I inhibitor, combined with amrubicin, a topoisomerase II inhibitor. The aim was to determine the maximum tolerated dose (MTD) of amrubicin combined with a fixed dose of CPT-11 as well as the dose-limiting toxicities (DLT) of this combination in patients with advanced non-small cell lung cancer.

PATIENTS AND METHODS

Eleven patients with stage IIIB or IV disease were treated at 3-week intervals with amrubicin (5-min intravenous injection on days 1-3) plus 60 mg/m2 of CPT-11 (90-min intravenous infusion on days 1 and 8). The starting dose of amrubicin was 25 mg/m2, and it was escalated in 5 mg/m2 increments until the maximum tolerated dose was reached.

RESULTS

The 30 mg/m2 of amrubicin dose was one dose level above the MTD, since three of the five patients experienced DLT during the first cycle of treatment at this dose level. Diarrhea and leukopenia were the DLT, while thrombocytopenia was only a moderate problem. Amrubicin did not affect the pharmacokinetics of CPT-11, SN-38 or SN-38 glucuronide. Except for one patient, the biliary index on day-1 correlated well with the percentage decrease of neutrophils in a sigmoid Emax model. There were five partial responses among 11 patients for an overall response rate of 45%.

CONCLUSION

The combination of amrubicin and CPT-11 seems to be active against non-small cell lung cancer with acceptable toxicity. The recommended dose for Phase II studies is 60 mg/m2 of CPT-11 (days 1 and 8) and 25 mg/m2 of amrubicin (days 1-3) administered every 21 days.

Granulocyte growth factors in the treatment of non-small cell lung cancer (NSCLC)

Neutropenia and subsequent infections are common events that limit treatment of non-small cell lung cancer (NSCLC). Granulocyte growth factors (G- and GM-CSF) have been introduced in clinical practice and their use has yielded a reduction of the infection risk related to chemotherapy and a dose increase of drug delivery. Randomized clinical trials have shown that granulocyte colony-stimulating factors and, more recently, the longer-acting pegylated granulocyte colony-stimulating factor (pegfilgrastim) effectively reduce the incidence and severity of neutropenia and of its complications. Recommendations for the use of haematopoietic colony-stimulating factors from the American Society of Clinical Oncology (ASCO) have been published in 1994 and updated in 1996, 1997 and 2000. Recently, moreover, National Comprehensive Cancer Network (NCCN) guidelines for the myeloid growth factors in cancer treatment make available. Chemotherapy-associated myelosuppression is a major limitation of anticancer therapy also in early stage, local advanced and metastatic NSCLC. Recently, dose-dense chemotherapy has been shown to improve the outcome in early stage breast cancer and non-Hodgkin's lymphoma. However, few randomized trials have been reported on chemotherapy with or without granulocyte growth factors as primary prophylaxis in NSCLC. Presently, there is no evidence for a benefit in response rate and survival from the use of granulocyte growth factors as support of chemotherapy, in particular, for locally advanced and metastatic NSCLC. In clinical practice, the role of granulocyte growth factors for NSCLC treatment should be limited following the guidelines. An appropriate use of granulocyte growth factors may reduce the overall cost of treatment and improve the quality of life, important aims in the treatment of patients with local advanced or metastatic NSCLC. In the future, we need to identify patients who can benefit from granulocyte growth factors for optimize the schedule and doses, in advanced disease and also, after the recent positive results of adjuvant chemotherapy, in early stages. This review summarizes the present knowledge on the use of granulocyte growth factors in NSCLC.

Front-line paclitaxel and topotecan chemotherapy in advanced or metastatic non-small-cell lung cancer: a phase II trial

PURPOSE

Based on previous experience, we combined topotecan with paclitaxel (weekly administration) in patients with non-small-cell lung cancer (NSCLC). Our primary objective was to determine the response rate and survival and our secondary objective, the safety of the regimen.

METHODS

From October 2003, until March 2005, 45 patients all with histologically or cytologically confirmed NSCLC were enrolled. All patients were chemotherapy and radiotherapy naive. Both agents were infused on day 1 of every week once for three consecutive weeks, every 28 days. Three infusions were considered as one course. The treatment plan was to give three courses (nine infusions) and then to evaluate the response. Topotecan (1.75 mg/m2) was infused for 30 min and paclitaxel (70 mg/m2) for 90 min; these doses had been established as the maximum tolerated dose in a previous phase I-II trial.

RESULTS

Eighteen/45 (40%) patients responded, 2 (4.4%) complete responses and 16 (35.6%) partial responses. Twenty-one (46.7%) patients had stable disease, and 6 (13.3%) disease progression. The median duration of response was 8 months and median time to tumor progression 9 months. Grade 3 and 4 neutropenia was observed in two patients (in these two patients, the dose of both drugs was reduced by 25% and G-CSF was given), grade 4 thrombocytopenia in one patient and grade 4 anemia in one patient.

CONCLUSION

This novel combination of topotecan-paclitaxel in a weekly administration rendered a 40% response rate, with very low toxicity in stages IIIA, IIIB and IV NSCLC patients.

A phase I clinical trial of continual alternating etoposide and topotecan in refractory solid tumours

The goal of this phase I study was to develop a novel schedule using oral etoposide and infusional topotecan as a continually alternating schedule with potentially optimal reciprocal induction of the nontarget topoisomerase. The initial etoposide dose was 15 mg m(-2) b.i.d. days (D)1-5 weeks 1,3,5,7,9 and 11, escalated 5 mg per dose per dose level (DL). Topotecan in weeks 2,4,6,8,10 and 12 was administered by 96 h infusion at an initial dose of 0.2 mg m(-2) day(-1) with a dose escalation of 0.1, then at 0.05 mg m(-2) day(-1). Eligibility criteria required no organ dysfunction. Two dose reductions or delays were allowed. A total of 36 patients with a median age of 57 (22-78) years, received a median 8 (2-19) weeks of chemotherapy. At DL 6, dose-limiting toxicities consisted of grade 3 nausea, vomiting and intolerable fatigue. Three patients developed a line-related thrombosis or infection and one subsequently developed AML. There was no febrile neutropenia. There were six radiologically confirmed responses (18%) and 56% of patients demonstrated a response or stable disease, typically with only modest toxicity. Oral etoposide 35 mg m(-2) b.i.d. D1-5 and 1.8 mg m(-2) 96 h (total dose) infusional topotecan D8-11 can be administered on an alternating continual weekly schedule for at least 12 weeks, with promising clinical activity.

Phase I study of cisplatin, irinotecan, and epirubicin administered every 3 weeks in patients with advanced solid tumours

This phase I study was conducted to determine the recommended phase II doses, safety profile, and antitumour activity of a combination regimen of cisplatin, irinotecan, and epirubicin administered every 3 weeks in patients with advanced solid tumours. Cisplatin and epirubicin were given at fixed doses of 50 and 60 mg m(-2), respectively. The irinotecan dose was escalated at 10 mg m(-2) increments from a starting dose level of 70 mg m(-2). Epirubicin, irinotecan, and their metabolites were measured with HPLC methods. In all, 35 patients received 141 courses of treatment. Irinotecan dose was escalated in seven cohorts up to 130 mg m(-2), and then finally de-escalated to 110 mg m(-2). The dose-limiting toxicity was neutropenic fever. Nonhaematologic toxicities included mild to moderate nausea/vomiting, diarrhoea and fatigue. Of 34 patients with evaluable disease, one patient had a complete response and nine patients had partial response, yielding an overall response rate of 29.4%. Pharmacokinetic parameters of epirubicin were not affected by the sequence of drug administration. However, the AUCs of irinotecan and its metabolites were increased significantly when irinotecan and epirubicin were administered concurrently. This combination regimen has promising broad antitumour activity, and will be further evaluated in phase II studies in multiple tumour types.

Preventive effect of Kampo medicine (Hangeshashin-to) against irinotecan-induced diarrhea in advanced non-small-cell lung cancer

PURPOSE

Kampo medicine Hangeshashin-to (TJ-14) which contains baicalin, a beta-glucuronidase inhibitor, alleviates diarrhea induced by irinotecan (CPT-11). We conducted a randomized comparative trial to investigate whether support with TJ-14 would prevent and control CPT-11-induced diarrhea.

METHODS

Of 44 previously untreated patients with advanced non-small-cell lung cancer randomized, 41 (18 TJ-14 group, 23 control group) were available for evaluation. The chemotherapy regimen consisted of a combination of cisplatin and CPT-11. TJ-14 (7.5 g/day) was administered orally.

RESULTS

Of the 41 patients, 39 experienced diarrhea. Compared with the control group, the TJ-14 group showed a significant improvement in diarrhea grades ( P=0.044) as well as a reduced frequency of diarrhea grades 3 and 4 (one patient versus ten patients; P=0.018). However, the two groups showed no differences in the frequency of diarrhea or the number of days the symptoms continued. This study was stopped at an interim evaluation.

CONCLUSION

TJ-14 was effective in preventing and controlling CPT-11-induced diarrhea.

Phase I/II trial of weekly cisplatin, etoposide, and irinotecan chemotherapy for metastatic lung cancer: JCOG 9507

Combinations of cisplatin-irinotecan and cisplatin-etoposide are active and well tolerated in patients with both small-cell lung cancer (SCLC) and nonsmall-cell lung cancer (NSCLC). To define the recommended dose for phase II trials of irinotecan combined with cisplatin and etoposide in chemonaive patients with stage IV disease, 56 patients (11 having SCLC and 45 NSCLC) received cisplatin 25 mg m(-2) weekly for 9 weeks, etoposide 60 mg m(-2) for 3 days on weeks 1, 3, 5, 7 and 9, and irinotecan 20-100 mg m(-2) (levels 1-8) on weeks 2, 4, 6 and 8, together with a prophylactical granulocyte colony-stimulating factor support (50 microg m(-2) on days 4-7 on weeks 1, 3, 5, 7 and 9, and on days 2-7 on weeks 2, 4, 6 and 8). Grade 3-4 leukocytopenia, neutropenia and thrombocytopenia were noted in 20 (36%), 28 (50%) and nine (16%) patients, respectively. Grade 3 diarrhoea, grade 3 cardiac toxicity, and grade 4 transaminase elevation developed in one (1.8%) patient each. Totally, four of 56 patients were removed from the study because of toxicity and recovered, and two other patients died in situations where drug toxicity might contribute to their death. Dose-limiting toxicity was noted in less than one-third of patients at dose levels 1-7, but in all patients at dose level 8. Thus, the recommended dose was determined to be level 7 (irinotecan 90 mg m(-2)). The response rates for SCLC and NSCLC were 91% (10/11) and 38% (17/45), respectively. The median survival time and 1-year survival rate were 11.9 months and 46% for SCLC and 10.1 months and 40% for NSCLC, respectively. This regimen was considered to be feasible and promising for the treatment of stage IV SCLC and NSCLC.

A phase II trial of 9-aminocaptothecin (9-AC) as a 120-h infusion in patients with non-small cell lung cancer

In a previous phase II trial of the synthetic topoisomerase I inhibitor, 9-aminocamptothecin (9-AC), given as a 72-h infusion, we identified modest single agent activity of 9% in patients with previously untreated advanced non-small cell lung cancer (NSCLC). Preclinical studies suggested that a more prolonged continuous infusion of the drug might lead to greater antitumor activity. A phase I study recommended a phase II dose of 25 microg/m2/hr for 120 h (3000 microg/m2 over 5 days), administered for 2 consecutive weeks of a 3-week cycle. We utilized this schedule and enrolled 13 chemotherapy-naïve patients with Stage IIIB and IV NSCLC in this trial: median age 67 (range 57-74); 46% male; 92% stage IV; and median performance status 1. Twelve patients are available for response and toxicity evaluation after 2 cycles of therapy. One patient achieved a partial response. Four patients had stable disease while seven patients had progressive disease. Patients with stable or progressive disease after two cycles received no additional 9-AC, and were offered conventional chemotherapy. The median survival time was 10.2 months and the one-year survival rate 28% (95% confidence interval, 5-58%). Significant toxicities included myelosuppression, fatigue, and anorexia. One patient had grade 4 neutropenia following the first week of cycle 2, and did not receive additional therapy. There were no neutropenia-related infections. These data suggest that this prolonged schedule is unlikely to increase 9-AC's very modest activity in NSCLC above that seen with the simpler 72-h administration schedule. Further evaluation of 9-AC in NSCLC is not recommended.

Irinotecan hydrochloride for the treatment of recurrent and refractory non-Hodgkin lymphoma: a single institution experience

BACKGROUND

Irinotecan hydrochloride (CPT-11) has a broad range of antitumor activity and has demonstrated little cross-resistance with doxorubicin or vincristine. In the current study, the authors investigated the efficacy and adverse effects of irinotecan in the treatment of recurrent and refractory non-Hodgkin lymphoma, for which current therapies appear to be unsatisfactory.

METHODS

Irinotecan was administered by intravenous infusion at a dose of 40 mg/m(2)/day for 3 days, and this regimen was repeated 2-3 times at weekly intervals, followed by 2 weeks off therapy. The subjects were 48 patients with recurrent or refractory non-Hodgkin lymphoma. The histologic classification (Working Formulation) was low grade in 8 patients, intermediate grade in 36 patients, high grade in 1 patient, and other (angiocentric lymphoma, Ki-1 lymphoma, and unidentified) in 3 patients.

RESULTS

Forty-five patients were determined to be evaluable. Therapy resulted in a complete disease remission in 2 patients and a partial remission in 15 patients. The response rate was 37.8%. The median duration of response was 64 days and the median time to disease progression was 77 days. The median survival time was 422 days. Major adverse reactions included myelosuppression and gastrointestinal toxicity. Leukopenia, anemia, and thrombocytopenia of Grade 3 or 4 (according to the National Cancer Institute Common Toxicity Criteria) was observed in 63.0%, 30.4%, and 6.5% of the patients, respectively, and Grade 3 or 4 diarrhea occurred in 30.4% of patients. Treatment was withdrawn because of diarrhea in three patients. Because of myelosuppression and diarrhea, approximately 67% of the patients required changes to the regimen, including dose reduction, prolongation of the interval between treatments, and reducing the number of days of consecutive treatment.

CONCLUSIONS

The results of the current study suggest the activity of irinotecan as salvage therapy for patients with recurrent and refractory non-Hodgkin lymphoma. However, the optimum dosing schedule remains to be determined.

Irinotecan (CPT-11): recent developments and future directions--colorectal cancer and beyond

Since its approval in the United States in 1996, irinotecan (CPT-11, Camptosar, Pharmacia Corp.; Peapack, NJ) has undergone extensive clinical evaluation. In the past five years, the focus of development has evolved from evaluation of single-agent activity in refractory disease settings to evaluation of front-line irinotecan-based combination chemotherapy regimens and integration of irinotecan into combined modality regimens. Important studies have been performed clarifying the role of irinotecan in treating colorectal and other gastrointestinal cancers, small cell and non-small cell lung cancer, and a variety of other malignancies. Preclinical studies performed in conjunction with these clinical trials have also provided significant insights into the pharmacology, metabolism, mechanisms of resistance, and molecular determinants of response. This review summarizes that progress, focusing on the achievements of the past five years.

Risk factors of treatment-related death in chemotherapy and thoracic radiotherapy for lung cancer

We retrospectively analysed the incidence and risk factors of treatment-related death in the treatment of chemotherapy- and thoracic radiotherapy-naïve patients with lung cancer. Between July 1992 and December 1997, 1799 patients were diagnosed as having lung cancer in our hospital and 926 patients received chemotherapy and/or thoracic radiotherapy. 25 patients (2.7%) died from toxicity of the treatment, 10 from pneumonia, 7 from radiation pneumonitis, 6 from sepsis, 1 from perforation of the small intestine and 1 for an unknown reason. 18 patients (2.3%) died from chemotherapy-related toxicity. The incidence of treatment-related death (TRD) from chemotherapy was highly correlated with the performance status (PS), PS 0: 0.7%, PS 1: 2.2%, PS 2: 4.0%, PS 3: 7.7% and PS 4: 25% (P=0.004). 7 patients (1.6%) died from pneumonitis after thoracic radiotherapy. Multivariate analyses demonstrated that poor PS (relative risk (RR): 1.95, 95% confidence interval (CI): 1.05-3.65, P=0.034) and chemotherapy using the cisplatin+vindesine+mitomycin C regimen (RR: 9.36, 95% CI: 1.29-68.0, P=0.027) are associated with treatment-related death from chemotherapy. Pulmonary fibrosis identified on a plain chest X-ray film (RR: 165.7, 95% CI: 8.79-3122, P<0.001), the combination of cisplatin+irinotecan (RR: 120.5, 95% CI: 2.90-4993, P=0.012), advanced age (RR: 1.17, 95% CI: 1.002-1.37, P=0.047), and elevated lactate dehydrogenase (LDH) (RR: 10.4, 95% CI: 1.20-90.2, P=0.033) were also associated with treatment-related death from thoracic radiotherapy. The administration of mitomycin C in addition to cisplatin-based regimens for patients with lung cancer should be carefully considered.

The relevance of drug sequence in combination chemotherapy

The concept of combining chemotherapeutic agents to increase the cytotoxic efficacy has evolved greatly over the past several years. In the past, the rationale for combination chemotherapy centered on attacking different biochemical targets, overcoming drug resistance in heterogenous tumors, and increasing the dose-density of combination chemotherapy to take advantage of tumor growth kinetics. The overall goal was to improve clinical efficacy with acceptable clinical toxicity. It is now apparent that the sequence of drug administration can significantly enhance the therapeutic effect of chemotherapy. These sequence-dependent effects can be explained by chemotherapy-induced cell cycle perturbations, or by pharmacodynamic interactions between the agents in combination. In this review, we focus on drug combinations with taxanes and camptothecins, which we believe best illustrate the importance of the cell cycle and pharmacologic interactions in the sequential administration of chemotherapy. As our understanding of the cell cycle grows, our ability to appropriately sequence chemotherapy can have a great impact on the treatment of human cancers. Copyright 2000 Harcourt Publishers Ltd.

Clinical use of topoisomerase I inhibitors in anticancer treatment

The camptothecin analogs topotecan and irinotecan have shown to be among the most effective anticancer agents and, as S-phase specific agents, their antitumor effect is maximized when they are administered in protracted schedules. The documented activity as single agents in many adult and pediatric malignancies has been followed by their use in combination with other anticancer agents. These studies have shown promising results, and have placed topotecan and irinotecan in the first line treatment for some malignancies. However, studies to better determine the optimal schedules and sequence of combinations are needed.

Activity of crude extract of Rubus crataegifolius roots as a potent apoptosis inducer and DNA topoisomerase I inhibitor

The effects of methanol extract of Rubus crategifolius roots and its solvent fractions were investigated on the proliferation of MCF-7 human breast carcinoma cells. The methanol extract inhibited the proliferation of MCF-7 cells in a concentration dependent manner. Moreover, their methanol soluble (W-M) fraction had the greatest inhibitory effect on the growth of MCF-7 cells. To evaluate whether the W-M fraction affects on the cell cycle of MCF-7 cells, cells treated with this fraction were analyzed with flow cytometry. The W-M fraction increased G0/G1 phase after 24 h-treatment and induced apoptosis after 48 h-treatment. The hallmark of apoptosis, DNA fragmentation, also appeared by W-M fraction after 48 h-treatment. Furthermore, the methanol extract and its W-M fraction inhibited the activity of the topoisomerase I enzyme in the relaxation assay. From these results, their W-M fraction as well as methanol extract of R. crategifolius roots are necessary for further studies as a potent inhibitor of the growth of cancer cells.

Phase II study of irinotecan plus cisplatin in patients with advanced non-small-cell lung cancer

PURPOSE

To evaluate the antitumor efficacy and safety of a combination of irinotecan (CPT-11) and cisplatin in patients with inoperable non-small-cell lung cancer (NSCLC). A secondary objective was to characterize the pharmacokinetics and pharmacodynamics of CPT-11 and its active metabolite, SN-38.

PATIENTS AND METHODS

Patients with stage IIIB or IV NSCLC were treated with repeated 4-week courses comprising CPT-11 (60 mg/m(2)) administered on days 1, 8, and 15, and a single dose of cisplatin (80 mg/m(2)) after CPT-11 administration on day 1.

RESULTS

Fifty-two patients were enrolled, including 33 men and 19 women. The median age was 61 years (range, 29 to 79 years). Southwest Oncology Group performance status was 0 in 12 patients, 1 in 32 patients, and 2 in eight patients. Eleven and 41 patients had stage IIIB and IV disease, respectively. Objective responses occurred in 28.8% of patients (15 of 52; 95% confidence interval, 16.5% to 41.2%). The median survival duration was 9.9 months (range, 1.6 to 30.8 months). The 1-year survival rate was 37%. Grade 3/4 adverse events consisted primarily of nausea (32. 7% ) or vomiting (13.5%), late-onset diarrhea (17.3%), and neutropenia (46.1%). The study design led to preferential modification of CPT-11 doses, resulting in CPT-11 dose attenuations to < or = 40 mg/m(2) in the majority of patients (31 of 52; 60%), whereas dose reductions of cisplatin were uncommon. CPT-11 pharmacokinetic parameters were comparable to those reported previously in single-agent studies.

CONCLUSION

CPT-11/cisplatin is an active combination regimen with manageable toxicity in the therapy of stage IIIB/IV NSCLC. Future studies should be designed with schedules and dose modification provisions that avoid unnecessary CPT-11 dose reductions to exploit more directly the therapeutic synergy of these agents.

Open-label comparison of the antiemetic efficacy of single intravenous doses of dolasetron mesylate in pediatric cancer patients receiving moderately to highly emetogenic chemotherapy

BACKGROUND

Nausea and vomiting are among the most unpleasant adverse side effects of cancer therapy.

PROCEDURE

An open-label dose-escalation study was conducted to assess the appropriate intravenous dose of dolasetron for pediatric patients undergoing chemotherapy. Patients received dolasetron in single intravenous doses of 0.6 (n = 10), 1.2 (n = 12), 1.8 (n = 12), or 2.4 (n = 12) mg/kg 30 min before receiving emetogenic chemotherapy. Pharmacokinetic parameters were evaluated at each dose level and efficacy was evaluated over the first 24 hr following the administration of dolasetron.

RESULTS

A complete response was achieved in 10% of patients given 0.6 mg/kg, 25% of patients given 1. 2 mg/kg, 67% of patients given 1.8 mg/kg, and 33% of patients given 2.4 mg/kg. Peak plasma concentrations (Cmax) were observed between 0. 33 and 0.75 hr following dolasetron infusion. Cmax and area under plasma concentration-time (AUC) increased with larger doses of dolasetron, while terminal disposition half-life (t1/2) and apparent clearance (Clapp) were not significantly changed with respect to dose. For 1.8-mg/kg dolasetron, the t1/2 was 4.98 hr and the maximum plasma concentration (tmax) 0.47 hr. Adverse events were mild to moderate. No serious events occurred. Conclusions. This study suggests that a single intravenous dose of 1.8 mg/kg is the optimum single intravenous dose for controlling chemotherapy-induced emesis in pediatric patients.

Safety, tolerability, antiemetic efficacy, and pharmacokinetics of oral dolasetron mesylate in pediatric cancer patients receiving moderately to highly emetogenic chemotherapy

PURPOSE

The safety, antiemetic efficacy, and pharmacokinetics of single oral doses of dolasetron, a new highly selective 5-HT3 receptor antagonist, were evaluated in children with cancer undergoing treatment with moderately to highly emetogenic chemotherapy.

PATIENTS AND METHODS

A total of 32 children, ages 3 to 18 years, were enrolled in a nonrandomized, multicenter, open-label, dose-escalation study. Three oral dose levels (0.6, 1.2, or 1.8 mg/kg) were studied. Safety, efficacy, and pharmacokinetic parameters were assessed over 24 hours at each dosage level.

RESULTS

The most effective dose was 1.8 mg/kg; 60% of the patients achieved a complete or major response (< or =2 emetic episodes in 24 hours). A complete response was achieved in 3 of 9 patients (33%) who received 0.6 mg/kg, 4 of 13 (31%) patients who received 1.2 mg/kg, and 5 of 10 (50%) patients who received 1.8 mg/kg of dolasetron. Overall, dolasetron was well tolerated. Adverse events were mild and similar to those reported in adults. Peak plasma concentrations (Cmax) of dolasetron's active reduced metabolite, MDL 74,156, were dose proportional and occurred, on the average, within 1 hour of oral administration. The half-life (t1/2) in plasma was approximately 6 hours for all dose levels, and the mean clearance (CLapp) was unrelated to dose.

CONCLUSIONS

Oral dolasetron is safe and effective in reducing chemotherapy-induced nausea and vomiting, particularly at the 1.8-mg/kg dose level. These results support further evaluation of oral dolasetron in larger randomized clinical trials in the pediatric cancer population.

Control of inducible chemoresistance: enhanced anti-tumor therapy through increased apoptosis by inhibition of NF-kappaB

Programmed cell death (apoptosis) seems to be the principal mechanism whereby anti-oncogenic therapies such as chemotherapy and radiation effect their responses. Resistance to apoptosis, therefore, is probably a principal mechanism whereby tumors are able to overcome these cancer therapies. The transcription factor NF-kappaB is activated by chemotherapy and by irradiation in some cancer cell lines. Furthermore, inhibition of NF-kappaB in vitro leads to enhanced apoptosis in response to a variety of different stimuli. We show here that inhibition of NF-kappaB through the adenoviral delivery of a modified form of IkappaBalpha, the inhibitor of NF-kappaB, sensitizes chemoresistant tumors to the apoptotic potential of TNFalpha and of the chemotherapeutic compound CPT-11, resulting in tumor regression. These results demonstrate that the activation of NF-kappaB in response to chemotherapy is a principal mechanism of inducible tumor chemoresistance, and establish the inhibition of NF-kappaB as a new approach to adjuvant therapy in cancer treatment.

Control of inducible chemoresistance: enhanced anti-tumor therapy through increased apoptosis by inhibition of NF-kappaB

Programmed cell death (apoptosis) seems to be the principal mechanism whereby anti-oncogenic therapies such as chemotherapy and radiation effect their responses. Resistance to apoptosis, therefore, is probably a principal mechanism whereby tumors are able to overcome these cancer therapies. The transcription factor NF-kappaB is activated by chemotherapy and by irradiation in some cancer cell lines. Furthermore, inhibition of NF-kappaB in vitro leads to enhanced apoptosis in response to a variety of different stimuli. We show here that inhibition of NF-kappaB through the adenoviral delivery of a modified form of IkappaBalpha, the inhibitor of NF-kappaB, sensitizes chemoresistant tumors to the apoptotic potential of TNFalpha and of the chemotherapeutic compound CPT-11, resulting in tumor regression. These results demonstrate that the activation of NF-kappaB in response to chemotherapy is a principal mechanism of inducible tumor chemoresistance, and establish the inhibition of NF-kappaB as a new approach to adjuvant therapy in cancer treatment.

Irinotecan: a new antineoplastic agent for the management of colorectal cancer

OBJECTIVE

To review the pharmacologic, pharmacokinetic, therapeutic, and safety aspects of irinotecan, a new antineoplastic agent, and to assess its role in the treatment of colorectal and lung cancer.

DATA SOURCES

English-language articles from the MEDLINE database, January 1990-March 1998; Pharmacia & Upjohn Company; published articles and meeting abstracts.

STUDY SELECTION

Studies in humans with cancer, clinical case reports, and open clinical studies were reviewed. Efficacy studies were limited to trials with at least 20 evaluable patients.

DATA EXTRACTION

Relevant data were extracted from published reports and abstracts.

DATA SYNTHESIS

Irinotecan is an effective agent for the treatment of advanced colorectal cancer. It demonstrates significant activity as a first-line agent and in patients with disease that is refractory to fluorouracil-containing regimens. Activity against lung cancer has also been demonstrated. Limited data indicate activity against cancers of the ovary, cervix, stomach, and in non-Hodgkin's lymphomas. Major toxicity consists of myelosuppression and diarrhea.

CONCLUSIONS

Irinotecan is a useful addition to the antineoplastic drug family and offers significant efficacy for treatment of patients with fluorouracil-refractory colorectal cancer.

Unexpected hepatotoxicities in patients with non-Hodgkin's lymphoma treated with irinotecan (CPT-11) and etoposide

BACKGROUND

Irinotecan (CPT-11) is a topoisomerase I inhibitor that has been confirmed to be active against a broad spectrum of neoplasms including non-Hodgkin's lymphoma (NHL). Because the combination of topoisomerase I and II inhibitors seemed to be an attractive therapeutic strategy owing to their complementary functions, we conducted a combination phase I study of CPT-11 and etoposide, a topoisomerase II inhibitor, in relapsed or refractory non-Hodgkin's lymphoma (NHL).

METHODS

The starting doses of CPT-11 and etoposide were 30 mg/m2/day (days 1-3 and 8-10) and 40 mg/m2 (days 1-3), respectively.

RESULTS

All three patients who received the starting dose developed dose-limiting toxicities including one case of grade 4 neutropenia lasting for > 7 days, one of grade 3 serum transaminase elevation and one of grade 3 hyperbilirubinemia. All three patients presented hepatotoxicity > or = grade 2. The starting dose level was judged to be the maximum tolerated dose (MTD) and further dose escalation of this combination was halted. The patient who developed grade 3 hyperbilirubinemia presented a second peak of plasma SN-38, an active metabolite of CPT-11, on the concentration-time curve for day 3, suggesting the possibility of the enterohepatic circulation of SN-38 and of a drug-to-drug interaction. No durable objective response was observed in the three patients treated at the starting dose.

CONCLUSIONS

We conclude that etoposide is not recommended for combination with CPT-11 in NHL patients because of unexpected frequent hepatotoxicities.

New chemotherapeutic agents for the treatment of non-small cell lung cancer: the Japanese experience

Non-small cell lung cancer (NSCLC) is refractory to systemic chemotherapy, compared with small cell lung cancer. Until recently, only five drugs--cisplatin, vindesine, mitomycin, ifosfamide, and vinblastine--could produce overall response rates of 15% against NSCLC. However, recent efforts have contributed to the development of new drugs with activity against NSCLC, including irinotecan hydrochloride (CPT-11), paclitaxel, docetaxel, vinorelbine, and gemcitabine. Combination chemotherapy against NSCLC using these agents has demonstrated high response rates. In Japan, various combination chemotherapy and combined-modality regimens employing CPT-11 have been evaluated for their efficacy. Randomized controlled trials to establish new state-of-the-art treatments for NSCLC are ongoing.

The role of plant-derived drugs and herbal medicines in healthcare

Many of our present medicines are derived directly or indirectly from higher plants. While several classic plant drugs have lost much ground to synthetic competitors, others have gained a new investigational or therapeutical status in recent years. In addition, a number of novel plant-derived substances have entered into Western drug markets. Clinical plant-based research has made particularly rewarding progress in the important fields of anticancer (e.g. taxoids and camptothecins) and antimalarial (e.g. artemisinin compounds) therapies. In addition to purified plant-derived drugs, there is an enormous market for crude herbal medicines. Natural product research can often be guided by ethnopharmacological knowledge, and it can make substantial contributions to drug innovation by providing novel chemical structures and/or mechanisms of action. In the end, however, both plant-derived drugs and crude herbal medicines have to take the same pharmacoeconomic hurdle that has become important for new synthetic pharmaceuticals.

Topoisomerase I inhibitors: review and update

This review presents a summary of preclinical and clinical data on the topoisomerase I (topo I) inhibitors that are under clinical development. To date, all of the topo I inhibitors that have been clinically evaluated are analogues of camptothecin, an extract of the Chinese tree Camptotheca acuminata. The therapeutic development of camptothecin was initially limited by its poor solubility and unpredictable toxicity. More recently, a number of water-soluble camptothecin analogues have undergone extensive evaluation and have demonstrated significant clinical activity. These include irinotecan (CPT-II), topotecan, and 9-aminocamptothecin (9-AC). Preliminary data are also reviewed on other camptothecin analogues (GG-211 and DX-8951f), on oral formulations, and on non-camptothecin topoisomerase I inhibitors. The topoisomerase I inhibitors have already demonstrated a broad spectrum of antitumour activity, most probably due to their unique mechanism of action and lack of clinical cross-resistance with existing antineoplastic compounds. The challenge for the next five years is to identify ways to integrate the topo I inhibitors into multidrug and multimodality therapies to achieve optimal antitumour effect, while keeping the side effects of these therapies manageable.