Phase I clinical and pharmacologic study of weekly cisplatin combined with weekly irinotecan in patients with advanced solid tumors

Phase I study of weekly cisplatin, bolus fluorouracil and escalating doses of irinotecan in advanced solid tumors

PURPOSE

We performed a phase I study of 5-fluorouracil (5-FU), cisplatin and irinotecan.

METHODS

Twenty-nine patients received cisplatin 25 mg/m(2) and bolus 5-FU 425 mg/m(2), along with irinotecan at 40, 50, and 65 mg/m(2) weekly for 4 out of 6 weeks.

RESULTS

The maximum tolerated dose (MTD) for untreated patients was irinotecan 65 mg/m(2) while the MTD for previously treated patients was irinotecan 40 mg/m(2). Neutropenia and diarrhea were the major dose-limiting toxicities. Antitumor activity was noted in gastric, esophageal and pancreatic cancers.

CONCLUSION

Because of the toxicity profile, combinations with continuous infusion 5-FU or capecitabine should be explored.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Phase II trial of irinotecan plus cisplatin in patients with recurrent or metastatic squamous carcinoma of the head and neck

BACKGROUND

Patients with recurrent or metastatic HNC have a poor response and survival with currently available chemotherapy agents. Thus, new agents are needed. The authors report the results of a phase II trial of irinotecan and cisplatin in patients with metastatic or recurrent HNC.

METHODS

Patients were treated with irinotecan 65 mg/m2 IV over 90 minutes and cisplatin 30 mg/m2 were administered intravenously weekly for four weeks, followed by a two week rest. However, after 17 patients were treated with weekly irinotecan at a dose of 65 mg/m2, toxicity analysis demonstrated the poor tolerance of that dose in this patient population. Thus, the protocol was amended, and irinotecan was dose reduced to a starting dose of 50 mg/m2. Twenty-three additional patients were treated with this dose.

RESULTS

Forty patients were enrolled on study between February 2002 and April 2006, 17 patients at the first dose level and 23 patients at the amended dose level. Overall, 12 of 17 patients (71%) treated with irinotecan 65 mg/m2 experienced clinically significant grade 3 or 4 toxicity. Twelve patients required dose reductions. Toxicity was reduced but 17% of patients still experienced grade 3 or 4 toxicity on the lower irinotecan dose. The response rate was 35% for patients treated at irinotecan 65 mg/m2 and 22% for patients treated at 50 mg/m2. No complete responses were noted.

CONCLUSIONS

The combination of irinotecan and cisplatin is efficacious in a poor prognosis group of patients but toxicity is substantial.

Gastric cancer: an update

Gastric cancer is an aggressive malignancy, which, if metastatic or unresectable, is incurable. However, with metastatic or unresectable disease, patients receive a palliative benefit from chemotherapy. Although the understanding of the biology of this disease is increasing, the development of biologically targeted therapies for gastric cancer has been limited. Cytotoxic therapy remains the standard approach, and although there is agreement on the active agents and active combination chemotherapy regimens, consensus on the standard or reference regimen is lacking. This article reviews the pathophysiology of this disease, placing it in the context of its epidemiology, and the current advances in the treatment of this disease.

Chemotherapeutic agents for colorectal cancer with a defective mismatch repair system: The state of the art

Mismatch repair (MMR) proteins are capable of recognizing and processing not only single base-pair mismatches and insertion-deletion loops that occur during DNA replication, but also adducts in DNA resulting from treatment with cancer chemotherapy agents. MMR deficiency leads to microsatellite instability (MSI) and results in resistance to antimetabolites, alkylating and platinating agents, DNA minor groove binders, and inhibitors of topoisomerases. Therefore, anticancer agents that can be recommended for use in MMR deficient colorectal cancers are those that exert their cytotoxicity regardless of the MMR status. These include some alkylating drugs, brostacillin, gemcytabine, photodynamic therapy, taxanes. An approach that is currently receiving much attention is the use of agents such as 5-azacytidine, an inhibitor of the DNA methyltransferases, in combination with inhibitors of histone de-acetylation, to restore the MMR function. A strong anti-proliferative efficacy with a relatively low direct cytotoxicity, obtainable with oloumicine and roscovitine (selective cyclin-dependent kinases inhibitors) can represent a new expedient for the therapeutic treatment of MMR deficient colorectal cancers. The question of how MMR defects modulate the response to chemotherapeutics deserves further investigation, to enable a more aware choice of cancer treatment.

Combined chemotherapy of irinotecan and low-dose cisplatin (I/low-P) against metastatic biliary tract cancer

There is no established or effective standard therapy for metastatic biliary tract cancer, resulting in poor prognosis. Recently, we performed combination chemotherapy of irinotecan and low-dose cisplatin (I/low-P) for three consecutive patients with metastatic biliary tract cancer. The regimen of I/low-P therapy consisted of irinotecan (60 mg/m(2)) and low-dose cisplatin (6 mg/m(2)), administered by intravenous infusion weekly or biweekly. Of the three patients, two showed a partial response, with durations of more than 20 months, and 2 months, respectively, while the third patient had stable disease for 3 months. One patient, who had jaundice, had grade 3 thrombocytopenia, but the other patients did not have any severe toxicities. Survival times were more than 20 months, 10 months, and 13 months, respectively. These outcomes suggest that I/low-P therapy is safe and may be worth trying as a first-line chemotherapy for patients with metastatic biliary tract cancer.

A phase II trial of weekly fractionated irinotecan and cisplatin for advanced gastric cancer

PURPOSE

This study was to evaluate the activity and the safety of a combination chemotherapy regimen of weekly fractionated irinotecan and cisplatin in advanced gastric cancer patients.

METHODS

Patients with advanced gastric adenocarcinoma with either chemotherapy-naive or only one prior chemotherapy regimen received irinotecan 50 mg/m2 followed by cisplatin 30 mg/m2. Both drugs were administered weekly for 3 consecutive weeks, followed by 1-week rest. Treatment was repeated until disease progression occurred. Response evaluation was performed according to the RECIST criteria.

RESULTS

Forty-seven patients (13 chemo-naive, 34 prior chemotherapy) were enrolled. Of 46 evaluable patients, overall response rate was 25.5% (95% CI, 12.9-39.3%) and disease control rate was 63.8% (95% CI, 50.9-79.5%) by intent-to-treat analysis. The time to progression and overall survival duration were 21 and 44 weeks, respectively. One-year survival rate was 41.6%. The most frequent grade 4 toxicity was neutropenia, which was the major cause of treatment delay. Non-hematological toxicities of grade 3-4 were rare with occurrence rate of 14.9% for anorexia and emesis.

CONCLUSIONS

Fractionated irinotecan combined with cisplatin with 3-week-on and 1-week-off schedule produced favorable clinical results for advanced gastric cancer. Because of the feasible efficacy and low non-hematologic toxicity, this treatment could be a promising salvage regimen in patients who have failed to taxanes.

A phase II trial of irinotecan and cisplatin in patients with metastatic neuroendocrine tumors

The role of systemic chemotherapy in the treatment of patients with metastatic neuroendocrine tumors is controversial. While combination regimens containing cisplatin and etoposide have activity against more aggressive neuroendocrine tumor variants, such regimens appear to have little efficacy in patients with well-differentiated neuroendocrine tumor subtypes. The combination of irinotecan and cisplatin is active both against small cell lung cancer and in upper gastrointestinal malignancies but has not been prospectively evaluated in patients with metastatic neuroendocrine tumors. We therefore assessed the efficacy of an irinotecan/cisplatin combination in patients with this disease. Eighteen patients with metastatic neuroendocrine tumors (excluding small cell carcinoma) were treated with irinotecan, 65 mg/m2, and cisplatin, 30 mg/m2, administered weekly for 2 of every 3 weeks. Patients were followed for evidence of toxicity, response, and survival. The toxicities associated with this regimen were mild and included myelosuppression, nausea, and diarrhea. Only one radiologic response was observed among four patients with poorly differentiated neuroendocrine tumors. No radiologic responses were observed in 14 patients with well-differentiated tumors. The median overall survival duration of patients treated with this regimen was 11.4 months. We conclude that while the combination of irinotecan and cisplatin may have activity in aggressive neuroendocrine tumor subtypes, this combination is inactive in patients with well-differentiated neuroendocrine tumors.

Phase I studies of imatinib mesylate combined with cisplatin and irinotecan in patients with small cell lung carcinoma

BACKGROUND

Small cell lung carcinoma (SCLC) cell lines commonly express KIT and its ligand, stem cell factor, suggesting an autocrine loop promoting cell growth. Imatinib inhibits KIT kinase activity. SCLC cells treated with imatinib in vitro undergo cell cycle arrest. Imatinib reduces resistance to irinotecan in vitro. Common metabolic pathways suggest there may be drug interactions between imatinib and irinotecan or cisplatin. In the current study, the authors investigated the feasibility of combining these drugs in the treatment of patients with SCLC.

METHODS

Two Phase I studies were conducted independently at two institutions. Patients with extensive-disease SCLC underwent therapy with cisplatin, irinotecan, and imatinib using two similar regimens. In one study, immunohistochemical analysis of the expression of potential imatinib targets was performed on pretreatment biopsy specimens, and blood specimens were collected and analyzed for imatinib, irinotecan, and cisplatin pharmacokinetic parameters.

RESULTS

Nine patients were enrolled and were evaluable for toxicity. A high incidence of neutropenia, diarrhea, and thrombosis was observed that precluded dose escalation. Six patients were evaluable for response after four cycles; five patients experienced a partial response and the other patient had developed progressive disease. Four of six tumor specimens tested expressed platelet-derived growth factor receptor-alpha and two expressed KIT. Irinotecan clearance was found to be significantly decreased by imatinib (P < 0.04). No significant alteration in the disposition of cisplatin was observed.

CONCLUSIONS

The maximum tolerated dose for this combination with granulocyte-colony-stimulating factor support was identified as imatinib at a dose of 300 mg/day with irinotecan (at a dose of 65 mg/m(2)) and cisplatin (at a dose of 30 mg/m(2)) given on Days 1 and 8, every 21 days. The decreased irinotecan clearance may explain the high incidence of diarrhea and neutropenia noted in the current study.

A phase II study of irinotecan plus cisplatin for patients with advanced stage IIIB or IV NSCLC previously treated with nonplatinum-based chemotherapy

BACKGROUND

Irinotecan (1) and cisplatin (P) are active chemotherapy agents with clinical synergy in non-small-cell lung cancer (NSCLC). We evaluated the efficacy of IP regimen as a salvage treatment of patients with NSCLC that progressed after nonplatinum-containing regimen(s).

METHODS

Eligibility required histologically confirmed NSCLC, bidimensionally measurable disease, ECOG PS 0-2, and progressive disease after nonplatinum-based chemotherapy. Treatment consisted of I (65 mg/m2) and P (30 mg/m2) i.v. on Days 1 and 8 of a 21-day cycle, for a maximum of 6 cycles. An informed consent was obtained from all patients.

RESULTS

Between August 2002 and May 2004, 32 patients with median age of 56 years (range, 42-74) were enrolled. Twenty-four (75%) patients were men, and 28 (88%) had ECOG PS 0 or 1. Twenty-five patients had adenocarcinoma and 6 had squamous-cell carcinoma. All patients were evaluated for response and toxicity, and the response rate was 40.6%. After a median follow-up of 18.5 months, the median survival time was found to be 9.3 months, with a 1-year survival rate of 43.8%. Toxicities were moderate and manageable, with 47% G3 and 9% G4 neutropenia, 19% G3 diarrhea, and 22% G3 asthenia. There was no G4 nonhematologic toxicity.

CONCLUSIONS

The irinotecan and cisplatin combination is an active and well-tolerated regimen for the patients with advanced NSCLC that progressed after nonplatinum-containing regimen(s).

Randomized Phase II study of two opposite administration sequences of irinotecan and cisplatin in patients with advanced nonsmall cell lung carcinoma

BACKGROUND

Combined chemotherapy with irinotecan and cisplatin (IP) is active in patients with nonsmall cell lung carcinoma (NSCLC). However, the optimal administration schedule needs to be defined to maximize its synergic effect. The authors evaluated the efficacy, toxicity, and pharmacokinetics (PK) of IP chemotherapy given on two administration sequences in chemotherapy-naive patients with NSCLC.

METHODS

Eighty eligible patients were assigned randomly to receive 1 of 2 irinotecan and cisplatin administration sequences on Day 1: irinotecan followed by cisplatin (I-P) (n = 39 patients) or cisplatin followed by irinotecan (P-I) (n = 41 patients). Treatment was comprised of irinotecan at a dose of 80 mg/m(2) intravenously on Days 1 and 8 and cisplatin at a dose of 60 mg/m(2) intravenously on Day 1 of a 21-day cycle for a maximum of 6 cycles. For PK analysis, serial plasma samples were obtained on Day 1 of the first cycle.

RESULTS

In total, 77 patients were assessable for efficacy. The overall response rate was 47%, and there was a trend in favor of P-I (54%) compared with I-P (39%). In multivariate logistic regression analysis, the P-I sequence and female gender were found to be significant predictors of a better response (P = 0.047 and P = 0.011, respectively). Overall toxicity profiles and PK parameters were similar in both arms.

CONCLUSIONS

IP chemotherapy showed promising activity with a favorable 1-year survival rate. For future clinical use, the authors recommend administering cisplatin first and then irinotecan, because that sequence was associated with a higher response rate.

Cisplatin and irinotecan in squamous cell carcinoma of the cervix: a phase II study of the Gynecologic Oncology Group

OBJECTIVE

To evaluate the combination of cisplatin and irinotecan as first-line treatment of patients with advanced, persistent, or recurrent squamous cell carcinoma of the cervix.

METHODS

Patients with no prior treatment for metastatic disease, presence of measurable tumors, performance status of 0 or 1, and adequate bone marrow, renal, and hepatic functions were potentially eligible for this trial. Cisplatin and irinotecan were given weekly at starting doses of 25 and 65 mg/m(2), respectively, for three consecutive weeks. Cycles were to be repeated every 28 days with dose adjustments as required. Patient accrual was based on a two-stage design with at least seven responses out of 28 patients in the first stage required to proceed to a second stage of accrual seeking a response rate of 40% or better.

RESULTS

Of 34 patients entered onto the study, 31 were eligible and 27 were evaluable for response. Ten had received prior chemoradiation containing cisplatin. Among the five (two complete and three partial) observed responses, two were in the subset of patients who had received prior chemoradiation. This level of activity was deemed insufficient to warrant a second stage of accrual. Predominant toxicities were myelosuppression and gastrointestinal symptoms, although six patients experienced none of these adverse effects.

CONCLUSION

At these doses, weekly cisplatin and irinotecan failed to demonstrate sufficient activity to undertake a phase III study. Although not apparent in this study, prior chemoradiation may affect response to platinum-based combinations and its impact should be considered in the design of future trials.

Combined modality therapy in esophageal cancer: the Memorial experience

Over the past 20 years in the United States, esophageal cancer has shown the most rapid rate of increase of any solid tumor malignancy. Esophageal cancer is an aggressive disease, and poor survival is achieved with surgery or chemoradiation therapy alone. Ongoing trials are investigating the use of preoperative chemoradiation followed by surgical resection. Chemoradiation employing a combination of cisplatin and a continuous infusion of 5-fluorouracil (5-FU) is the most commonly used therapy. The significant gastrointestinal toxicity of traditional cisplatin/5-FU-based regimens has prompted the evaluation of new agents in combined-modality therapy. The Memorial Sloan-Kettering Cancer Center has conducted chemoradiation trials with weekly paclitaxel/cisplatin and irinotecan/cisplatin, and the results suggest that this regimen has the potential to improve the therapeutic index without compromising efficacy. Randomized trials are now being conducted to evaluate the tolerance and efficacy of paclitaxel/cisplatin in comparison with paclitaxel/5-FU combined with radiotherapy in locally advanced esophageal cancer. The incorporation of these non-5-FU-based therapies with novel biologic agents is planned.

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.

CPT-11 and cisplatin in the treatment of advanced gastric cancer in Asians

There is no standard chemotherapy for advanced gastric cancer. A combination of CPT-11 and cisplatin was evaluated for response and toxicity in Asians. 38 patients with histologically proven stage IV gastric/gastroesophageal junction adenocarcinoma were treated with CPT-11 50 mg/m2 and cisplatin 30 mg/m2 weekly for 3 weeks. Each cycle was repeated every 28 days. The median number of cycles was 1.66 (range 0.33-4.33). Dose delay was needed in 11 (29%) patients and dose reductions in 19 (50%) patients. The overall response rate was 42%. There was no complete response. Grade 3 and 4 hematological toxicity was 26%. Grade 3 or 4 diarrhea was not common. Median time to progression for all patients was 15 weeks. Median duration of survival of all patients was 42 weeks. Patients with better performance status and no prior chemotherapy did better. CPT-11 and cisplatin is a useful regimen with significant but manageable toxicity that can be administered without a central venous catheter.

The camptothecins

Supported by detailed understanding of their mechanism of action, and facilitated by chemical manipulations that have amplified their solubility, the camptothecins have advanced to the forefront of several areas of therapeutic and developmental chemotherapy. Additive and synergistic laboratory interactions with other cytotoxic drugs have been exploited to allow development of camptothecin-based multidrug regimens, which are showing important activity in several malignancies. Topotecan and irinotecan are already in widespread use in clinical practice, and newer agents with promising preclinical activity are in various stages of clinical assessment. As knowledge of molecular and biochemical mechanisms of action and resistance continues to expand, newer and better camptothecin-based strategies for treatment of malignant disease are likely to evolve.

Topoisomerase I interactive agents

Increased insight into the mechanism of interaction of topoisomerase I interactive agents will maximize the therapeutic index and enhance the development of additional agents. Preclinical studies designed to elucidate mechanisms by which the topoisomerase I interactive agents induce cell death will be essential. The role of ABC transporters in resistance to topoisomerase I interactive agents has been recently appreciated and future studies should be directed at circumventing this resistance. The results of preclinical studies must be translated into the design of clinical trials so that these agents can be used rationally. In this regard results of preclinical studies have clearly pointed to the enhanced antitumor activity from protracted dosing of topoisomerase I interactive agents and results of clinical trials are now supporting these preclinical findings. Finally, investigators are trying to understand better the mechanism(s) of the dose-limiting toxicities observed with the currently available topoisomerase I interactive agents in an effort to enable the optimal dosing of these agents. Even though the first priority must be to determine the therapeutic potential of the currently available agents, it is reassuring to know that other topoisomerase I interactive agents are currently under development.

Irinotecan plus cisplatin has substantial antitumor effect as salvage chemotherapy against germ cell tumors

BACKGROUND

Only 20-30% of patients with refractory or recurrent germ cell tumors (GCT) are cured by salvage chemotherapy. Irinotecan, a new derivative of camptothecin, is a potent anticancer agent against a variety of solid cancers. The current pilot study investigated the efficacy of salvage chemotherapy with irinotecan in combination with cisplatin (CDDP) or nedaplatin (NDP), a derivative of cisplatin, for GCT.

METHODS

The combination chemotherapy consisted of 100-150 mg/m(2) irinotecan on Days 1 and 15 or 200-300 mg/m(2) on Day 1 in combination with 20 mg/m(2) CDDP on Days 1-5 or 100 mg/m(2) NDP on Day 1 every 4 weeks. Patients with refractory GCT, ranging in age from 17 to 43 years, received 2-11 cycles of the combination chemotherapy. The median duration of follow-up is 28 months (8-140 months).

RESULTS

Twenty patients entered this study, 18 of whom were assessed for response and toxicity. The response rate was 50 % (two complete responses and seven partial responses). Nine patients remain alive without disease. However, six patients died of the disease and one patient died of a brain glioma. The 5-year survival rate was approximately 53%. Myelosuppression was the major toxicity, but was manageable.

CONCLUSIONS

This pilot study demonstrates that the chemotherapy with irinotecan in combination with CDDP or NDP showed significant anticancer activity for patients with refractory GCT, without serious side effects. Although this study comprised only a few patients, these findings suggest that the combination chemotherapy may be one of the options of salvage chemotherapy for patients with refractory GCT.

CPT-11 plus cisplatin in patients with advanced, untreated gastric or gastroesophageal junction carcinoma: results of a phase II study

BACKGROUND

This Phase II study assessed the response rate and toxicity profile of the combination CPT-11 and cisplatin administered weekly to patients with untreated, advanced adenocarcinoma of the stomach or the gastroesophageal junction.

METHODS

Patients with histologic proof of adenocarcinoma of the stomach or the gastroesophageal junction with adequate liver, kidney, and bone marrow functions were treated with 65 mg/m(2) CPT-11 plus 30 mg/m(2) cisplatin, both administered intravenously 1 day per week for 4 consecutive weeks, followed by a recovery period of 2 consecutive weeks. The response rate, time to disease progression, survival, and toxic effects were analyzed.

RESULTS

Thirty-six of 38 registered patients (95%) were assessable. The median number of 6-week cycles per patient was 2.5 (range, 1-7 6-week cycles). Four patients (11%) achieved a complete response, and 17 patients (47%) had a partial response for an overall response rate of 58%. The median time to progression of carcinoma was 24 weeks, and the median survival was 9 months (range, 1-23+ months). There was one treatment-related death. Major toxic effects included diarrhea, neutropenia, and fatigue. Ninety percent of all planned doses were delivered on time; however, 53 of 79 canceled or delayed weekly doses (66%) occurred in the third or fourth week of the therapy cycle.

CONCLUSIONS

The combination of CPT-11 and cisplatin is active against gastric or gastroesophageal adenocarcinoma and needs to be studied further. A modification in doses and schedules may be warranted to make the regimen more tolerable to patients. The addition of other active drugs or radiation therapy to this regimen would be of interest.

Phase I trial of gemcitabine and CPT-11 given weekly for four weeks every six weeks

BACKGROUND

Our previous studies have shown that the in vitro cytotoxicity of gemcitabine and SN-38, the active metabolite of irinotecan (CPT-11), is synergistic in human tumor cell lines.

PATIENTS AND METHODS

Twenty-four patients with solid tumors, refractory to standard chemotherapy or for whom no effective therapy existed (age range 31-74; 7 female, 17 male; ECOG PS 0 = 12, 1 = 11, 2 = 1), received gemcitabine and CPT-11 weekly for four weeks out of every six weeks. Fifty courses of treatment (median 2, range 1-8) were given through five dose levels of gemcitabine/CPT-11 (600/75, 800/75, 800/100, 1000/100, 1000/125 mg/m2).

RESULTS

Grade 3 and 4 neutropenia occurred in eight and two patients, respectively. Grade 3 and 4 thrombocytopenia occurred in one and three patients, respectively. Hematologic toxicity resulted in > or = 2 missed doses of treatment in two out of six patients and was therefore dose limiting at gemcitabine 1000 mg/m2 and CPT-11 125 mg/m2. Grade 3 and 4 diarrhea occurred in two and one patients, respectively. Other moderate non-hematologic toxicities included alopecia, anorexia, fatigue, nausea, vomiting, and weight loss.

CONCLUSIONS

The maximum tolerated dose for this study recommended for phase II testing is gemcitabine 1000 mg/m2 and CPT-11 100 mg/m2. A partial response was seen in transitional cell carcinoma.

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.

Novel combination chemotherapy in the treatment of non-small cell lung cancer

Treatment of patients with advanced non-small cell lung cancer (NSCLC) remains a vexing problem and long-term survival beyond 5 years is extremely rare. Five new agents, paclitaxel, docetaxel, vinorelbine, gemcitabine and irinotecan, have been introduced for the treatment of NSCLC and investigated extensively both preclinically and clinically. Monotherapy with one of these agents has produced survival benefits over the best supportive care in Phase III studies. Combination chemotherapy with a new agent and platinum produced a higher response rate than conventional cisplatin-based chemotherapy and improved survival was observed in some randomised trials. There was little difference in efficacy and toxicity between the chemotherapeutic regimens with a new agent and a platinum in Phase III trials, suggesting the clinical utility of these regimens is similar. Many trials have focused on regimens containing two new agents, with or without platinum. Preliminary results of Phase III trials of three drug combinations versus two drug combinations suggested the former to be more promising, in terms of response rates and survival. Whether the era of platinum-based chemotherapy in the treatment of NSCLC should continue or not must be determined by Phase III trials, evaluating the use of a platinum agent with one of the new agent combinations. These aggressive chemotherapeutic combinations will hopefully improve survival and quality of life for patients with advanced NSCLC.

Oral topoisomerase 1 inhibitors in adult patients: present and future

The renewed interest in topoisomerase 1 inhibitors, based on new insights on the mechanism of action and the development of semi-synthetic derivates of camptothecin with a more favourable toxicity profile, has led to extensive preclinical and clinical research. Significant levels of anti-tumor activity in human tumor xenografts were seen especially with prolonged duration of exposure. Since oral drug delivery is a more convenient method for prolonged drug administration, and preferred by patients, further development of oral formulations seems attractive. Common concerns in the development of oral formulations are their sometimes low oral bioavailability and the frequently large intra- and interpatient variation in systemic exposure. Efforts to improve absorption and minimize intestinal metabolism/efflux of the oral chemotherapeutic agent using new formulas might lead to better bioavailability. Pharmacokinetic and pharmacodynamic evaluations have enabled guidance in recommendations of schedules. Given the interpatient variation in exposure it is interesting to note that flat dosing of topotecan resulted in the same systemic exposure compared with the more complex dosing per body surface area. In order to diminish the interpatient variation in exposure to 9-AC a limited sampling model for oral 9-AC was developed, enabling prediction of the systemic exposure for 9-AC and optimizing treatment for any given patient. Drug sequencing plays a key role in the combination topotecan/cisplatin and might be important for combination with other classes of drugs. Therefore, forthcoming phase 1 trials on combination therapy with oral topoisomerase 1 inhibitors should include studies on sequence dependence and pharmacokinetic analyses to evaluate any mutual interaction.

Phase I study of 3-week schedule of irinotecan combined with cisplatin in patients with advanced solid tumors

PURPOSE

To assess the feasibility, pharmacokinetic interaction, and possible sequence-dependent effects of the irinotecan/cisplatin combination given every 3 weeks, and to assess the influence of additional granulocyte colony-stimulating factor (G-CSF) on the hematologic toxicity.

PATIENTS AND METHODS

Patients who had received no more than one prior combination chemotherapy regimen or two single-agent regimens were entered. Treatment consisted of a 90-minute irinotecan infusion followed by a 3-hour cisplatin infusion on day 1, with cycles repeated once every 3 weeks. After the maximum-tolerated dose was determined, the sequence of administration was reversed. In a separate cohort of six patients, we assessed the effect of G-CSF on the experienced hematologic toxicity and dose-intensity. Irinotecan doses ranged from 175 to 300 mg/m(2) and cisplatin doses ranged from 60 to 80 mg/m(2).

RESULTS

Fifty-two patients entered the study; one was not eligible, and two were not assessable for response. Twenty-five patients were pretreated, and 26 were not. Fifty-one patients received a total of 223 courses. The dose-limiting toxicity was a combination of neutropenic fever, diarrhea, and fatigue at a dose level combining irinotecan 300 mg/m(2) with cisplatin 80 mg/m(2). Neutropenia was common (grades 3 to 4, 68%). Irinotecan pharmacokinetics were linear over the dose range studied. No sequence-dependent side effects were observed. Tumor responses included three complete responses and eight partial responses.

CONCLUSION

For phase II studies, we recommend irinotecan 260 mg/m(2) combined with cisplatin 80 mg/m(2) once every 3 weeks for chemotherapy-naive patients in good physical condition, and irinotecan 200 mg/m(2) combined with cisplatin 80 mg/m(2) for other patients.

Pharmacokinetic, metabolic, and pharmacodynamic profiles in a dose-escalating study of irinotecan and cisplatin

PURPOSE

To investigate the pharmacokinetics and pharmacodynamics of irinotecan and cisplatin administered once every 3 weeks in a dose-escalating study in patients with solid tumors.

PATIENTS AND METHODS

Fifty-two cancer patients were treated with irinotecan administered as a 90-minute infusion at doses ranging from 175 to 300 mg/m(2) followed by cisplatin administered as a 3-hour intravenous infusion at doses ranging from 60 to 80 mg/m(2). After reaching the maximum-tolerated dose, the sequence of drug administration was revised. For pharmacokinetic analysis, serial plasma samples were obtained on days 1 through 3 of the first cycle. Forty-five patients were assessable for irinotecan pharmacokinetics, and 46 were assessable for cisplatin pharmacokinetics.

RESULTS

Irinotecan and cisplatin demonstrated linear pharmacokinetics comparable to that observed with single-agent administration, which suggests an absence of pharmacokinetic interaction. SN-38G constituted the major plasma metabolite of irinotecan, whereas 7-ethyl-10-[4-N-(1-piperidino)1-amino]-carbonyloxycamptothecine (NPC) was only a minor metabolite in plasma, possibly indicating a rapid conversion of NPC to SN-38. The terminal elimination phases of SN-38 and SN-38G were similar and relatively delayed when compared with the elimination of irinotecan. Maximal DNA adduct formation did not significantly differ from that observed with single-agent administration. The percentage decrease in WBC was significantly related to the areas under the plasma concentration-time curve (AUCs) of the lactone form of irinotecan (P =.0245) and SN-38 (P =. 0123). The severity of diarrhea was not significantly related to the AUCs of irinotecan and SN-38, nor to the systemic glucuronidation rate of SN-38.

CONCLUSION

There was no apparent pharmacokinetic interaction between irinotecan and cisplatin in this study. Reversion of the administration sequence of the drugs did not seem to have any influence on the pharmacokinetics. The incidence and severity of delayed-type diarrhea was not related to any of the studied parameters.

Phase II trial of weekly irinotecan plus cisplatin in advanced esophageal cancer

PURPOSE

To evaluate the response, toxicity, survival, and quality of life in patients with unresectable or metastatic esophageal cancer treated with weekly irinotecan and cisplatin.

PATIENTS AND METHODS

Thirty-five patients with metastatic or unresectable esophageal adenocarcinoma (23 patients) or squamous cell carcinoma (12 patients) were treated. No prior chemotherapy was allowed. The majority of patients had metastatic and bidimensionally measurable disease (34 patients each [97%]). Patients were treated with cisplatin 30 mg/m(2) and irinotecan 65 mg/m(2), repeated weekly for 4 weeks, followed by a 2-week rest period. Treatment was recycled every 6 weeks. Degree of dysphagia relief was monitored, and quality of life was measured prospectively using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C-30 and Functional Assessment of Cancer Therapy-General instruments.

RESULTS

Thirty-five patients were assessable for response and toxicity. Major objective responses were observed in 20 patients (57%; 95% confidence interval, 41% to 73%), including two complete responses (6%). Similar response rates were observed for adenocarcinoma (12 of 23 patients; 52%) and squamous carcinoma (eight of 12 patients; 66%). The median duration of response was 4.2 months (range, 1 to 8.8+ months). Median actuarial survival was 14.6 months (range, 1 to 15.2+ months). In 20 patients with dysphagia assessable at baseline, 18 (90%) noted either improvement or resolution of dysphagia on chemotherapy. Global quality of life improved in responding patients, primarily because of improvements in pain, emotional state, and relationships with family and friends. Toxicity was relatively mild and included only three patients (9%) with grade 4 neutropenia and four (11%) with grade 3 diarrhea. There were no treatment-related deaths.

CONCLUSION

The combination of weekly cisplatin plus irinotecan had significant activity in metastatic esophageal carcinoma and resulted in significant relief of dysphagia. The regimen was well tolerated, with acceptable myelosuppression and rare treatment-related diarrhea. Further evaluation of the combination of weekly irinotecan and cisplatin, including the addition of other agents to this regimen, is indicated.

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.