Carboplatin: current status and future prospects

Nanostructured mesoporous silica carriers for platinum-based conjugates with anti-inflammatory agents

This review discusses the relationship between inflammation and cancer initiation and progression, which has prompted research into anti-inflammatory approaches for cancer prevention and treatment. Specifically, it focuses on the use of inflammation-reducing agents to enhance the effectiveness of tumor treatment methods. These agents are combined with platinum(II)-based antitumor drugs to create multifunctional platinum(IV) prodrugs, allowing for simultaneous delivery to tumor cells in a specific ratio. Once inside the cells and subjected to intracellular reduction, both components can act in parallel through distinct pathways. Motivated by the objective of reducing the systemic toxicity associated with contemporary chemotherapy, and with the aim of leveraging the passive enhanced permeability and retention effect exhibited by nanostructured materials to improve their accumulation within tumor tissues, the platinum(IV) complexes have been efficiently loaded into mesoporous silica SBA-15 material. The resulting nanostructured materials are capable of providing controlled release of the conjugates when subjected to simulated plasma conditions. This feature suggests the potential for extended circulation within the body in vivo, with minimal premature release of the drug before reaching the intended target site. The primary emphasis of this review is on research that integrates these two approaches to develop chemotherapeutic treatments that are both more efficient and less harmful.

DNA Adducts in Cancer Chemotherapy

DNA adducting drugs, including alkylating agents and platinum-containing drugs, are prominent in cancer chemotherapy. Their mechanisms of action involve direct interaction with DNA, resulting in the formation of DNA addition products known as DNA adducts. While these adducts are well-accepted to induce cancer cell death, understanding of their specific chemotypes and their role in drug therapy response remain limited. This perspective aims to address this gap by investigating the metabolic activation and chemical characterization of DNA adducts formed by the U.S. FDA-approved drugs. Moreover, clinical studies on DNA adducts as potential biomarkers for predicting patient responses to drug efficacy are examined. The overarching goal is to engage the interest of medicinal chemists and stimulate further research into the use of DNA adducts as biomarkers for guiding personalized cancer treatment.

Liver Pathology Related to Onco-Therapeutic Agents

Oncotherapeutic agents can cause a wide range of liver injuries from elevated liver functions tests to fulminant liver failure. In this review, we emphasize a newer generation of drugs including immune checkpoint inhibitors, protein kinase inhibitors, monoclonal antibodies, and hormonal therapy. A few conventional chemotherapy agents are also discussed.

Mononuclear Co(II) polypyridyl complexes: synthesis, molecular structure, DNA binding/cleavage, radical scavenging, docking studies and anticancer activities

Mononuclear Co(II) complexes [CoII(L)Cl2]; 1, [CoII(L)(bpy)Cl]PF6; 2, [CoII(L)(phen)Cl]PF6; 3 and [CoII(L)(pic)Cl]; 4, (where L = N,N-bis(pyridin-2-ylmethyl)aniline, bpy = 2,2/-bipyridine, phen = 1,10-phenanthroline, pic = picolinic acid) were systematically synthesized and...

Synthesis, characterization, antimicrobial and cytotoxic activity of novel half-sandwich Ru(II) arene complexes with benzoylthiourea derivatives

Three new ruthenium(II)-arene complexes, [Ru(η⁶-p-cymene)(L¹)Cl₂] (C1) where L¹ is N-((4 methoxyphenyl)carbamothioyl)benzamide; [Ru(η⁶-p-cymene)(L²)Cl₂] (C2) where L² is 4-(3-benzoylthioureido)benzoic acid and [Ru(η⁶-p-cymene)(L³)Cl₂] (C3) where L³ is methyl 4-(3- benzoylthioureido)benzoate have been synthetized, characterized and evaluated for their antimicrobial and anticancer activity. Characterization was performed using ¹H and ¹³C NMR, IR spectroscopy, mass spectrometry, electrical conductivity measurements and X-Ray diffraction analysis. X-Ray diffraction analysis of C1 showed typical expected "piano-stool" geometry with ruthenium coordinated to ligand via nitrogen and sulfur atoms of benzoylthiourea derivatives. Interesting, in herein described complex, upon coordination the four-membered ring was formed, instead of six-membered chelate common for this type of ligands. Cytotoxic activity was determined in human cervix adenocarcinoma (HeLa) cell line and IC₅₀ values ranged from 29.68 to 52.36 μM and the complexes were more active than related ligands (except in case of C2 where it is found that IC₅₀ value is close to IC₅₀ value of related ligand). Complex [Ru(η⁶-p-cymene)(L¹)Cl₂] (C1) expressed the highest cytotoxic activity with IC₅₀ value of 29.7 μM. Complexes and ligands were tested against nine Gram-positive and Gram-negative bacteria and one yeast- Candida albicans. Clinical Candida spp. strains from microbiological laboratories were included in testing processes as well. Minimum inhibitory concentrations values ranged from 62.5 μg/ml for complexes against Candida albicans to over 1000 μg/ml for several bacterial species.

A Phase II Study of Liposomal Doxorubicin in Recurrent Epithelial Ovarian Carcinoma

Background

We conducted a phase II trial to evaluate the efficacy and safety of liposomal formulation of doxorubicin in recurrent ovarian carcinoma patients.

Methods

Thirty patients were included in the study after having obtained an informed consent. Their main characteristics were: median age, 64 years (range, 45-80), ECOG performance status 0 in 17 patients (56%), 1 in 11 patients (36%) and 2 in 2 patients (6.6%). Eighteen patients had metastatic disease and 12 locally advanced disease. All patients were pretreated with a platinum-based chemotherapy: 3 were considered refractory to platinum (progression or stable disease), 2 were platinum resistant (relapse <12 months), and 7 were platinum sensitive (relapse ≥12 months). Treatment consisted of liposomal doxorubicin, 50 mg/m2 every 4 weeks.

Results

The overall response rate was 26.6%, with 2 complete responses and 6 partial responses lasting 3.5 months. The incidence of grade 3-4 toxicity was 23.3% for neutropenia, 10% for mucositis and 10% for plantar-palmar erythrodysesthesia. Median survival was 12+ months (range, 2-26+).

Conclusions

Liposomal doxorubicin appears to be a moderately active drug in pretreated patients, and its activity seems to be similar to that reported for other active regimens in terms of response rate. The toxicological profile of liposomal doxorubicin suggests that it may be combined with other drugs in the treatment of patients with ovarian cancer.

Role of chemotherapy in the future treatment of ovarian cancer

Platinum-based chemotherapy has led to an improvement in complete response rates and duration of median remission, but has only given a modest improvement in overall survival in patients with advanced ovarian cancer. Chemotherapy will in the future focus upon: (1) improving the complete remission rate with new induction regimens; (2) identifying strategies capable of converting partial remission into complete remission; (3) preventing or delaying recurrences in patients who do achieve a complete remission; (4) identifying mechanisms of antineoplastic drug resistance and pharmacologic techniques capable of reversing drug resistance. Among the treatment approaches being utilized are high-dose chemotherapy with autologous bone marrow transplantation, development of new chemotherapeutic regimens which include Taxol and hexamethylmelamine, and intraperitoneal chemotherapy. In addition, our understanding of the mechanisms of antineoplastic drug resistance has led to the development of novel therapeutic approaches. It has been demonstrated that resistance to platinum and alkylating agents is associated with both increased concentrations of cellular glutathione (GSH) as well as an increased capacity of tumor cells to repair damage to DNA. Inhibition of GSH biosynthesis with buthionine sulfoximine (BSO), a synthetic inhibitor of the enzyme gamma glutamyl cysteine synthetase, has led to the potentiation of alkylating agent activity in vitro and in vivo. A phase I trial of BSO plus melphalan is currently in progress and a trial of BSO plus carboplatin is planned. Inhibition of the DNA repair process with aphidicolin potentiates the cytotoxicity of cisplatin in drug-resistant tumor cells. Clinical trials of aphidicolin plus cisplatin await the completion of ongoing phase I trials of aphidicolin.

Role of gemcitabine in the treatment of ovarian cancer

The US FDA has recently approved the combination of carboplatin and gemcitabine as a second-line therapy for recurrent platinum-sensitive ovarian cancer. This article briefly reviews the pharmacokinetics and mechanism of action of gemcitabine and its synergistic effect with platinum. An overview of the literature on the role of gemcitabine in the treatment of epithelial ovarian cancer is also presented.

Enhancing the efficacy of cisplatin in ovarian cancer treatment - could arsenic have a role

Ovarian cancer affects more than 200,000 women each year around the world. Most women are not diagnosed until the disease has already metastasized from the ovaries with a resultant poor prognosis. Ovarian cancer is associated with an overall 5 year survival of little more than 50%. The mainstay of front-line therapy is cytoreductive surgery followed by chemotherapy. Traditionally, this has been by the intravenous route only but there is more interest in the delivery of intraperitoneal chemotherapy utilizing the pharmaco-therapeutic advantage of the peritoneal barrier. Despite three large, randomized clinical trials comparing intravenous with intraperitoneal chemotherapy showing improved outcomes for those receiving at least part of their chemotherapy by the intraperitoneal route.

Cisplatin has been the most active drug for the treatment of ovarian cancer for the last 4 decades and the prognosis for women with ovarian cancer can be defined by the tumor response to cisplatin. Those whose tumors are innately platinum-resistant at the time of initial treatment have a very poor prognosis. Although the majority of patients with ovarian cancer respond to front-line platinum combination chemotherapy the majority will develop disease that becomes resistant to cisplatin and will ultimately succumb to the disease.

Improving the efficacy of cisplatin could have a major impact in the fight against this disease. Arsenite is an exciting agent that not only has inherent single-agent tumoricidal activity against ovarian cancer cell lines but also multiple biochemical interactions that may enhance the cytotoxicity of cisplatin including inhibition of deoxyribose nucleic acid (DNA) repair. In vitro studies suggest that arsenite may enhance the activity of cisplatin in other cell types. Arsenic trioxide is already used clinically to treat acute promyelocytic leukemia demonstrating its safety profile. Further research in ovarian cancer is warranted to define its possible role in this disease.

Inhibition of transcription by platinum antitumor compounds

Cisplatin, carboplatin, and oxaliplatin are three FDA-approved members of the platinum anticancer drug family. These compounds induce apoptosis in tumor cells by binding to nuclear DNA, forming a variety of structural adducts and triggering cellular responses, one of which is the inhibition of transcription. In this report we present (i) a detailed review of the structural investigations of various Pt-DNA adducts and the effects of these lesions on global DNA geometry; (ii) research detailing inhibition of cellular transcription by Pt-DNA adducts; and (iii) a mechanistic analysis of how DNA structural distortions induced by platinum damage may inhibit RNA synthesis in vivo. A thorough understanding of the molecular mechanism of action of platinum antitumor agents will aid in the development of new compounds in the family.

New and Emerging Intraperitoneal (IP) Drugs for Ovarian Cancer Treatment

Chemotherapy after surgical debulking represents an essential component of treatment for patients with advanced ovarian cancer. Three quarters of patients respond very well to initial treatment with platinum-containing drugs used either alone or in combination with a taxane, usually paclitaxel. With relapse rates exceeding 50% and median survival time of 2 years for patients after relapse, efforts are focused on treatment approaches to achieve and extend clinical complete remissions. These approaches include consolidation and maintenance therapy, intraperitoneal (IP) administration of cytotoxic agents, new combination chemotherapy regimens, development of new cytotoxic agents, and molecular-targeted therapies (beyond tumor DNA, the classical target of cytotoxic drugs). IP chemotherapy, which involves direct instillation of chemotherapy into the tumor site in the peritoneal cavity, is the focus of this review article. This article discusses studies involving new and emerging IP drugs for both first-line chemotherapy treatment of advanced ovarian cancer and recurrent platinum-sensitive ovarian cancer.

A pilot study of three-cycle consolidation chemotherapy with paclitaxel and platinum in epithelial ovarian cancer patients with clinical complete response after paclitaxel and platinum chemotherapy

The aim of this study is to evaluate the efficacy of three additional cycles of paclitaxel and platinum chemotherapy in epithelial ovarian cancer patients with clinical complete response (CR). Patients with histologically confirmed epithelial ovarian cancer stages II-IV with clinical CR after primary surgery and six cycles of chemotherapy with paclitaxel/platinum entered into the study. Three cycles of paclitaxel/platinum (cisplatin, carboplatin) were administered as a consolidation chemotherapy only in patients who agreed to the informed consent. Patients without further treatment served as controls. A total of 81 patients entered into the study. According to the informed consent, 42 patients were treated by the consolidation chemotherapy, and 39 patients were followed up without further treatment. The median actuarial disease-free survival for the patients with and without consolidation chemotherapy was 25.0 months and 26.0 months, respectively (P= 0.80). The median overall survival is not reached. World Health Organization grade 3-4 toxicities in the consolidation arm were increased but showed no significant differences statistically. Although the sample size is small and not randomized, these results suggest that three cycles of consolidation chemotherapy with paclitaxel/platinum might not provide a favorable outcome in patients with a clinical CR.

Phase I/II study of S-1 combined with carboplatin in recurrent and/or metastatic head and neck cancer as outpatient chemotherapy

BACKGROUND

The aims of this study were to determine the recommended dose (RD) in combination chemotherapy of S-1 and carboplatin in recurrent and/or metastatic head and neck cancer (phase I) and to examine response rate and toxicities at RD (phase II).

METHODS

S-1 was given orally at a fixed dose of 40, 50, or 60 mg twice daily based on the patient's body surface area for 21 days followed by a 14-day rest. In phase I, carboplatin was given intravenously to a cohort of three patients on day 8 at a dose of 2.5, 3.0, 3.5, or 4.0 area under the curve (AUC) values, depending on the dose-limiting toxicities (DLTs).

RESULTS

In phase I, the RD was estimated as 2.5 AUC. In phase II, thrombocytopenia and leukopenia were most commonly found as hematologic DLTs, which were manageable without hospitalization. The response rate was 40.9%.

CONCLUSIONS

This regimen is considered to be active against recurrent and/or metastatic head and neck cancer in an outpatient setting.

Multicenter Phase II Trial of Carboplatin/Vinorelbine in Elderly Patients with Advanced Non–Small-Cell Lung Cancer–Efficacy and Impact on Quality of Life: Groupe Français de Pneumo-Cancérologie Study 9902

BACKGROUND

Approximately 30% of lung cancer cases are diagnosed in patients > 70 years of age. Standard chemotherapy regimens are generally considered too toxic for elderly patients. We conducted a multicenter phase II trial to determine the efficacy and safety of carboplatin combined with vinorelbine every 4 weeks as first-line treatment for advanced non-small-cell lung cancer (NSCLC) in elderly patients.

PATIENTS AND METHODS

Patients were eligible if they were aged >OR= 70 years, had stage IIIB (with pleural effusion) or stage IV NSCLC, had a performance status of 0/1, had not previously received chemotherapy, and had normal organ function. Forty patients (31 men and 9 women) were enrolled and received 3-5 courses of treatment. Median age was 72 years (range, 70-82 years). Eighty percent of patients had stage IV NSCLC, with squamous cell (n=21), adenocarcinoma (n=12), and undifferentiated (n=7) histologies.

RESULTS

Forty patients were assessable for toxicity and 32 for treatment response. Among these 32 patients, 8 had a partial response (intent-to-treat response rate, 20%), and 10 (25%) had stable disease. The median survival was 7.8 months (range, 4-11.6 months). The 1- and 2-year survival rates were 25% and 7%, respectively; median time to progression was 4.3 months (range, 0.2-13.8 months). Grade 3/4 neutropenia was seen in 27 patients (68%), and grade 3/4 anemia was seen in 5 patients (13%). One patient died of febrile neutropenia during treatment. The main nonhematologic adverse effect was fatigue (grade 3/4 in 18% of patients).

CONCLUSION

Carboplatin/vinorelbine is well tolerated by elderly patients with extensive-stage NSCLC. Efficacy is low but similar to that of other treatments used in this setting.

Randomized phase III trial of paclitaxel, etoposide, and carboplatin versus carboplatin, etoposide, and vincristine in patients with small-cell lung cancer

BACKGROUND

Paclitaxel administered in combination with a topoisomerase-II inhibitor (such as etoposide) and carboplatin is an effective and safe first-line treatment for patients with small-cell lung cancer (SCLC). We conducted a randomized phase III multicenter trial to determine whether paclitaxel plus etoposide plus carboplatin improves the outcome of patients with primary SCLC relative to standard chemotherapy (carboplatin, etoposide, and vincristine).

METHODS

Between January 1998 and December 1999, 614 patients with SCLC stages I-IV were randomly assigned to the standard arm (309 patients) or the experimental arm (305 patients). Treatment courses were repeated every 21 days for a maximum of six courses. All patients were evaluated for response rate, survival, and toxicities every two courses. The primary endpoint was survival. Survival curves were estimated with the Kaplan-Meier method and compared using the log-rank test. All statistical tests were two-sided.

RESULTS

A total of 608 patients were evaluable for all endpoints (standard arm 307 patients, experimental arm 301 patients). The hazard ratio [HR] of death for patients receiving the standard treatment was statistically significantly higher than that for patients receiving the experimental treatment (HR = 1.22, 95% confidence interval [CI] = 1.03 to 1.45; P =.024). Progression-free survival was also statistically significantly shorter for patients in the standard arm relative to that of patients in the experimental arm (HR = 1.21, 95% CI = 1.03 to 1.42). There were no differences in the response rates (complete and partial combined) to the treatments (standard arm: 69.4%, 95% CI = 63.9% to 74.5%; experimental arm: 72.1%, 95% CI = 66.7% to 77.1%; difference = 2.7%, 95% CI = 4.5% to 9.9%). Rates of severe grade of anemia, leukocytopenia, neutropenia, and thrombocytopenia were lower in the experimental arm than in the standard arm.

CONCLUSION

Patients with previously untreated SCLC who received paclitaxel, etoposide, and carboplatin showed improved overall and progression-free survival and less frequent hematologic toxicities than those who received the standard therapy.

A phase II trial of ZD0473 in platinum-pretreated ovarian cancer

The primary aim of this phase II trial was to assess the antitumour activity of ZD0473 in ovarian cancer patients who had failed initial platinum-based therapy. Patients (n=94) were classified as either platinum-sensitive (n=35) or platinum-resistant (n=59) depending on whether they had relapsed or progressed within 26 weeks of completing first-line platinum-based chemotherapy. Patients initially received 120 mg/m(2) ZD0473 as a 1-h intravenous (i.v.) infusion on day 1 of a 3-week cycle. If well tolerated, the dose could be escalated to 150 mg/m(2). Few patients (9%) withdrew because of treatment-related adverse events and no clinically significant oto-, nephro- or neurotoxicity was observed. Objective response rates for platinum-resistant and sensitive patients were 8.3 and 32.4%, respectively, and clinical benefit was observed in 76.5% of the sensitive patients. Median time to progression was 57 and 180 days, and median time to death was 242 and 402 days, for resistant and sensitive patients, respectively. In conclusion, ZD0473 has a manageable toxicity profile and encouraging activity in platinum-sensitive ovarian cancer patients.

Results of ZD0473 in platinum-pretreated ovarian cancer: analysis according to platinum free interval

Resistance to platinum-containing regimens can develop in many women with ovarian cancer and may lead to relapse in > 80% of patients. ZD0473 is a new-generation platinum agent that, in preclinical studies, shows evidence of antitumour activity and overcomes platinum-resistance mechanisms. This Phase II trial has evaluated the efficacy and tolerability of ZD0473 in second-line ovarian cancer patients. Patients received ZD0473 120 mg/m2 (1-h iv infusion, day 1 q 3-weeks); the starting dose was increased to 150 mg/m2 after a safety review. We report here on results when patients are divided into four cohorts depending upon whether they were considered platinum-resistant or -sensitive. Patients were placed into one of 3 cohorts if they were platinum resistant (relapsed/progressed < or = 26 weeks after completion of prior platinum-based chemotherapy) or cohort 4 if this period was > 26 weeks (sensitive). Ninety-four patients were recruited to the trial (59 resistant, 35 sensitive; median age 58 [range 27-75] years; 86 with performance status [PS] < or = 1). Forty-nine patients received a starting dose of 120 mg/m2, of which 15 escalated to 150 mg/m2, and 45 received a starting dose of 150 mg/m2. Overall, the median number of treatment cycles received was 3 (range 1-8). Grade 3/4 thrombocytopenia was the most common haematological adverse event occurring in 62% of patients overall. Grade 3/4 lethargy, vomiting and nausea were the most common non-haematological toxicities. No clinically significant oto-, nephro- or neurotoxicity was observed. Overall response rates for all platinum-resistant and -sensitive patients were 8.3% and 32.4%, respectively. Stable disease occurred in 17 resistant and 15 sensitive patients.

Efficacy of carboplatin with an MEP (mitoxantrone, etoposide and prednisone) regimen for relapsed and CHOP-resistant diffuse large B-cell lymphomas

Mitoxantrone, etoposide and prednisone (MEP)-based regimens using granulocyte colony-stimulating factor (G-CSF) were designed for relapsed and CHOP-resistant diffuse large B-cell lymphomas in a single institution, and the therapeutic effects and adverse reactions were studied. In a total of 49 patients, the MEP regimen had a 41% (9/22) overall response rate compared with 48% (13/27) for the MEP plus carboplatin (C-MEP) regimen (Chi-squared test, P=0.602). Among 38 CHOP-resistant patients, however, the overall response rate to C-MEP [42% (10/24)] was significantly superior compared with MEP [7% (1/14)] (P=0.023), and the overall survival to C-MEP was superior compared with MEP (P=0.088). Taken together, our results, although non-randomized, suggest that a combination of MEP with carboplatin is better than MEP alone in CHOP-resistant diffuse large B-cell lymphomas.

A phase II study of etoposide, doxorubicin, and carboplatin in the treatment of advanced gastric cancer

Many phase II studies have reported improved response rates with severe toxicity of etoposide, doxorubicin (Adriamycin), and cisplatin in advanced gastric cancer. In an attempt to obtain a better regimen with high efficacy and less toxicity, a combination regimen of etoposide, doxorubicin, and carboplatin (EAC) had been developed and evaluated in this phase II study. Forty-six patients with advanced gastric cancer were enrolled in the study. The treatment consisted of doxorubicin 20 mg/m2 given intravenously on days 1 and 7, etoposide 70 mg/m2 intravenously on days 4, 5, and 6, and carboplatin 200 mg/m2 intravenously on days 2 and 8. Therapy was repeated every 4 weeks. Patients who had stable disease or who responded, received an additional two to six cycles of therapy. Among 45 patients evaluable for response and toxicity, there was a 49% objective response rate, including 7% complete remission and 42% partial response. There was 11% stable disease and 27% progressive disease. Among 11 patients with lymph node metastasis only after a curative gastrectomy, there was an 82% objective response rates with 27% having complete remission and 55% having partial response. The median follow-up was 16 months. The median survival duration of all 45 patients was 11 months. The median time to progression was 5 months. The main toxicity was myelosuppression, with a high incidence of 82% leukopenia but only 9% of grades III to IV. Gastrointestinal toxicity was mild, with a low incidence of 42% nausea and vomiting and only 2% of grades III to IV. There were no chemotherapy-related deaths. With mild and tolerable toxicity, the EAC regimen in our study has active antitumor activity in advanced gastric cancer, which may have a positive influence on long-term survival time. It has a high efficacy, especially in patients with lymph node metastasis only after a curative gastrectomy. This regimen deserves further clinical studies for testing activity and toxicity in advanced gastric cancer.

Simple and rapid determination of carboplatin in plasma by high-performance liquid chromatography. Error pattern and application to clinical pharmacokinetic studies

Carboplatin is an antitumor agent widely employed in cancer chemotherapy. A specific and selective method for the determination of carboplatin in human plasma and its applications to pharmacokinetic investigations is described. One ultrafiltration step, through a Centrifree micropartition system (Amicon) at 2000 g for 10 min, is the only requirement as sample treatment. The resulting solution is injected into an Inertsil ODS-2 (5 microm, 25 cm x 4.6 mm I.D.) analytical column. The mobile phase consisted of 0.1 M potassium dihydrogenphosphate with 1 mM dipotassium edetate adjusted to a pH between 3 and 3.5. The limit of quantitation was 1 mg/l. The method showed good recovery (100.68+/-5.49%) and precision: the within-day relative standard deviation (RSD) for carboplatin (3-350 mg/l) was 2.07% and the between-day RSD for carboplatin, in the previously described range, was 1.31%. We determined the assay error pattern for proper weighting of serum level data in pharmacokinetic models. The selectivity (discrimination between the parent drug and platinum-containing species such as carboplatin metabolites), simplicity and speed of this assay for free carboplatin quantitation should facilitate pharmacokinetic investigations and therapeutic drug monitoring.

Survival advantage for carboplatin substituting cisplatin in combination with vindesine and mitomycin C for stage IIIB and IV squamous-cell bronchogenic carcinoma: a randomized phase III study

This communication represents the definitive report of a randomized phase III study comparing cisplatin and carboplatin, in combination with vindesine and mitomycin C in stage IIIB and IV squamous-cell bronchogenic carcinoma. A total of 221 patients entered the study and were randomized into two arms. Of these, 114 patients (109 evaluable for activity) were randomized to arm A, receiving cisplatin 120 mg/m(2), mitomycin C 8 mg/m(2) and vindesine 3 mg/m(2) per cycle; 107 patients (101 evaluable for activity) were randomized to arm B receiving carboplatin 500 mg/m(2) with the same doses of mitomycin C and vindesine per cycle. Patients with progressive disease (PD) were excluded from the study after the 2nd cycle, and those with stable disease (SD), partial response (PR) and complete response (CR) received six cycles of chemotherapy (or less in case of early progression). Patients were stratified according to the clinical stage (IIIB vs. IV), performance status (0+1 vs. 2+3) and tumor histological grade (I+II vs. III). In the cisplatin arm two patients (1.9%) achieved a CR, 38 (34.9%) a PR, 45 (41.2%) a SD and 24 (22.0%) had PD; the overall response rate was 40/109 (36.8%). In the carboplatin arm five patients (5.0%) achieved a CR, 31 (30.7%) a PR, 40 (39.6%) a SD, and 25 (24.7%) had PD; the overall response rate was 36/101 (35.7%). No statistically significant difference in response rate was present between the two arms, and the response rate was not influenced by performance status, histological grade or clinical stage. The Kaplan-Meyers curves displayed a significant advantage both for time to progression (P=0.005) and overall survival (P=0.008) for patients in the carboplatin arm. The advantage for patients receiving carboplatin instead of cisplatin appeared evident in univariate setting for patients with a good performance status and clinical stage IV, and occurred irrespectively of tumor histological grade; response duration and survival of responders was identical in the two arms. Patients achieving a stable disease survived longer in the carboplatin than in the cisplatin arm (P=0.012). Thus, substitution of cisplatin by carboplatin in the combination chemotherapy regimen, although more hematologically toxic (but less emetogenic) resulted in a similar response rate, but a significantly longer time to progression and overall survival.

Capillary electrophoretic study of carboplatin and analogues with nucleoside monophosphates, di- and trinucleotides

Carboplatin (cis-diammine-1,1-cyclobutane-dicarboxylatoplatinum(II)) is the only cisplatin (cis-diammine-dichloroplatinum(II)) derivative currently available for the treatment of cancer worldwide. The higher stability of the carboxylate ligand compared to the coordinated chloride in cisplatin results in a reduced reactivity of the molecule. Capillary electrophoresis has been applied for investigating the adduct formation of carboplatin and analogues with nucleoside monophosphates, di- and trinucleotides. Adduct formation results in a significant shift of the absorption maximum to lower energy compared to free nucleotides. Therefore, characterization of the analytes was performed by UV additionally to NMR spectroscopy. A preference for GMP- and AMP-coordination was found. The ability of separating all four common nucleotides and their major platinum adducts in a single run demonstrates the suitability of CE for this kind of investigations.

Clinical pharmacokinetics and administration of established platinum drugs

We review the pharmacology and clinical administration of the commonly used platinum-based anticancer drugs cisplatin and carboplatin, and the more recently approved diamminocyclohexane-based oxaliplatin. The development of analogues of cisplatin has been focused upon identifying compounds with less toxicity and with a different spectrum of activity. Carboplatin exemplifies the former, while the initial data with oxaliplatin support its activity in cisplatin-resistant tumours. The clinical pharmacokinetics of the drugs are reviewed. Incorporation of these data into the design of clinical regimens has permitted individualised therapy with carboplatin, and has enhanced safety. Additional investigation of the pharmacodynamics of all of these agents is expected to result in their selective application. The clinical effects of these analogues are discussed.

Clinical development of platinum complexes in cancer therapy: an historical perspective and an update

The vast amount of basic research on platinum coordination complexes has produced, over the past 25 years, several thousand new molecules for preclinical screening and 28 compounds which have entered clinical development. The goals of these research activities have been to identify compounds with superior efficacy, reduced toxicity, lack of cross-resistance or improved pharmacological characteristics as compared with the parent compound, cisplatin. After the remarkable therapeutic effects of cisplatin had been established, only a few other platinum compounds succeeded in reaching general availability. Whereas carboplatin is an analogue with an improved therapeutic index (mostly driven by reduced organ toxicity) over that of cisplatin, new compounds clearly more active than or non-cross-resistant with cisplatin have not yet been identified. The platinum analogues that remain under investigation are focusing on expanding the utilisation of platinum therapy to tumour types not usually treated with, or responsive to, cisplatin or carboplatin. In addition, novel routes of administration constitute another avenue of research. The clinical development of platinum coordination complexes, with emphasis on those compounds still under active development, is reviewed.

Carboplatin and cisplatin pharmacokinetics after intrapleural combination treatment in patients with malignant pleural effusion

BACKGROUND

Cisplatin (DDP) and carboplatin (CBDCA) are two of the most effective drugs in a locoregional approach. Since simultaneous combined treatment with intrapleural DDP and CBDCA has not been reported in humans, we investigated its use in patients with malignant effusions, focusing on pharmacokinetics.

PATIENTS AND METHODS

The pharmacokinetics of DDP and CBDCA were studied in 10 patients with malignant pleural effusion treated intrapleurally with a combination of DDP (60 mg/m2) and CBDCA (270 mg/m2) and in additional patients who received the same doses of drugs administered intravenously as single agents or in combination. Platinum (Pt) species originating from DDP (metabolites plus unchanged DDP) and intact CBDCA in plasma and pleural fluid ultrafiltrates were measured by means of high performance liquid chromatography and atomic absorption spectrometry.

RESULTS

Both in the plasma and pleural fluid, the total levels of free Pt represented the additive result of the individual concentrations of CBDCA and Pt-species derived from DDP. After intrapleural combination, high pleural-plasma ratios of the peak concentrations and AUCs were observed both for CBDCA and DDP-derived Pt species, highlighting a distinct local pharmacological advantage. However, the Pt species originating from DDP were absorbed more rapidly from the pleural cavity than CBDCA (Ka = 86 x 10(-3) vs. 37 x 10(-3) min-1, P < 0.05). Intrapleural combination of CBDCA and DDP produced therapeutic plasma levels of reactive (free) DDP species and increased the extent of their residence time (MRT) compared with single intravenous DDP treatment [peak concentration: 1.1 +/- 0.1 (SD) vs. 1.6 +/- 0.2 microgram/ml; MRT: 5.2 +/- 1.9 vs. 0.5 +/- 0.06 h]. Furthermore, the plasma AUC of free CBDCA after intrapleural combined treatment (2.1 +/- 0.5 mg/ ml x min) was similar to that after intravenous administration of CBDCA alone (2.1 +/- 0.2 mg/ml x min). The intrapleural treatment was well tolerated by all patients. Toxicity consisted of mild nausea and vomiting (grade 1-2 according to the WHO scale) in four patients. Myelosuppression (grade 1-2) was remarkable only in two heavily pretreated patients. No evidence of recurrence of the pleural effusion was observed in six patients (complete response), while an asymptomatic minimal fluid reaccumulation not requiring drainage (partial response) was observed in four patients.

CONCLUSIONS

The pharmacologic results seem to exclude a pharmacokinetic interaction between CBDCA and DDP and suggest that a dose of CBDCA 2-fold higher than that used in this study associated intrapleurally with 60 mg/m2 DDP could induce an acceptable and predictable myelosuppression.

Carboplatin dosing based on measurement of renal function--experience at the Peter MacCallum Cancer Institute

BACKGROUND

Carboplatin is used in treating many types of cancer. Because renal excretion is the major variable determining the pharmacokinetics of this drug, a dosing formula based on glomerular filtration rate (GFR) has been proposed and is being increasingly used in carboplatin dosing. This method of dosing is critically dependent on accurate measurement of GFR.

AIMS

To report the experience at a single major oncology centre of carboplatin dosing based on GFR, and comparisons of different methods of measuring renal function for use in this dosing method.

METHODS

An initial group of patients (n = 24) was studied where GFR was measured by Cr51EDTA clearance and compared to Tc99mDTPA clearance, measured 24 hour urine creatinine clearance and the Cockcroft and Gault formula. The carboplatin area under the plasma concentration versus time curve (AUC) was calculated using total platinum measured in a single blood sample assayed by flameless atomic absorption spectrophotometry. A subsequent patient group (n = 16) was then studied using Tc99mDTPA clearance to measure GFR.

RESULTS

Carboplatin dosing using Cr51EDTA clearance to measure GFR was accurate (< 25% difference between planned and measured AUC) in 87% of samples. Estimation of renal function using the Cockcroft and Gault formula correlated with Cr51EDTA clearance only in patients with GFR < 100 mL/minute. The measured 24 hour urine creatinine clearance did not correlate with Cr51EDTA clearance. Using Tc99mDTPA clearance to measure GFR, carboplatin dosing was accurate in 81% of samples. Across a GFR range of 42-239 mL/minute, the Cr51EDTA and Tc99mDTPA clearance were closely correlated (r = 0.98, slope of regression line = 1.02).

CONCLUSIONS

Carboplatin dosing using a pharmacological formula based on GFR produces accurate targeting of the carboplatin AUC. Tc99mDTPA clearance can be used to measure GFR instead of Cr51EDTA clearance, which is both more convenient and has potential cost savings. Estimates of renal function using the Cockcroft and Gault formula or measured 24 hour creatinine clearance are insufficiently accurate to use for carboplatin dosing.

Phase I/II study of concomitant irradiation and carboplatin for locally advanced carcinoma of the uterine cervix: an interim report

The outcome of women treated with either definitive irradiation alone or in combination with cisplatin-based chemotherapy for locally advanced (>IIb) squamous cell carcinoma of the cervix has been disappointing. To improve upon our reported results with irradiation alone, a trial using irradiation plus carboplatin chemotherapy was designed for these patients. Twenty-seven women with unresectable squamous cell carcinoma of the uterine cervix were referred to our institution between July 1991 and September 1994. Seven of these patients were enrolled in a phase I/II protocol combining concurrent irradiation and carboplatin chemotherapy. Megavoltage irradiation was used to deliver 45-50.4 Gy to the pelvis (and paraaortic chain when nodes were involved) through a multiple-field technique followed by the application of Fletcher-Suit-Delclos tandem and ovoids to boost the point A dose to 85 Gy. Chemotherapy consisted of intravenous carboplatin (60 mg/m2) administered in conjunction with irradiation to a total dose of 300 mg/m2. The enrolled patients consisted of six women with stage IIIb disease and one with stage IIa with concomitant paraaortic adenopathy. All seven patients enrolled in the study completed the planned course of treatment and tolerated the treatment without severe acute morbidities. No dose modifications were required for the radiation therapy regimen. For one patient, a dose of carboplatin was withheld to allow recovery from thrombocytopenia. The overall response rate was 100% (four complete response, three partial response). The combination of concurrent irradiation (pelvic or pelvic + paraaortic fields) and carboplatin chemotherapy can be safely administered to patients with locally advanced squamous cell carcinoma of the cervix. The treatment is well tolerated and is associated with a high rate of response. Longer follow-up will be necessary to assess the durability of response. In the meantime, we have elected to escalate the dose of carboplatin (90 mg/m2) in the hope of increasing the rate of complete response without incurring unacceptable toxicity.

High-dose cyclophosphamide, carboplatin, and etoposide with autologous stem cell rescue in patients with breast cancer

This study was designed to establish the toxicity and response rates o observed with a combination of high-dose cyclophosphamide, carboplatin, and etoposide with stem cell rescue in patients with breast carcinoma. Eligibility criteria included metastatic or locally advanced breast carcinoma ; aged < or equal to 60 years; performance status Eastern Cooperative Oncology Group (ECOG) 0-1; and creatinine clearance > or equal to 65 ml/min. Chemotherapy consisted of cyclophosphamide 25 mg/kg i.v. X 4 days, etoposide 400 mg/m(2) i.v. X 4 days, and carboplatin 375 mg/m(2) X 4 days. Bone marrow or peripheral blood stem cells were reinfused 48 h after completion of chemotherapy. Seventeen patients were treated in this study. The major toxicity was gastrointestinal (grades I and II). Fevers associated with neutropenia were observed in all the patients, but no episodes of bacteremia were documented. Hematopoietic toxicities were acceptable. No toxic deaths were observed. Six patients had chemotherapy-sensitive disease at time of transplant, nine had refractory disease, and two were untested. A response rate of 62% with 18% complete response (CR) was achieved. Two patients are free of disease at +7 and +9 months after transplantation. The combination of high-dose cyclophosphamide, carboplatin, and etoposide is well tolerated with a response rate comparable to previously reported high-dose chemotherapy regimens. However, in a poor prognostic risk group, namely patients with chemoinsensitive disease, this therapeutic approach seems to be of no advantage over standard chemotherapy.

Amputation and carboplatin for treatment of dogs with osteosarcoma: 48 cases (1991 to 1993)

Forty-eight dogs with histologically confirmed appendicular osteosarcoma (OSA) entered a prospective clinical trial evaluating treatment with amputation and up to 4 doses of carboplatin given every 21 days. The median disease-free interval (DFI) was 257 days, with 31.2% of the dogs disease-free at 1 year. The median survival time was 321 days, with 35.4% of the dogs alive at 1 year. Dogs with proximal humeral OSA had shorter DFI (P = .016) and survival (P = .037) times than dogs with OSA at other locations. Dogs with lower body weights ( < 40 kg) had longer DFI (P = .0056) and survival (P = .007) times than larger dogs. Survival times for dogs that received carboplatin were statistically longer than those previously reported for amputation alone (P < .001). DFI and survival times are similar to those previously reported for 2 to 4 doses of cisplatin. Carboplatin appears to be a well-tolerated chemotherapeutic drug that can be given safely every 21 days at a dose of 300 mg/m2. Neutropenia was the dose-limiting toxicity in this study.

Carboplatin alone compared with its combination with epirubicin and cyclophosphamide in untreated advanced epithelial ovarian cancer: a Hellenic co-operative oncology group study

We compared, in a multicentric randomised prospective study, the efficacy and toxicity of carboplatin 400 mg/m2 as a single agent (CB) to a combination of carboplatin 300 mg/m2, epirubicin 50 mg/m2 and cyclophosphamide 500 mg/m2 (CB-EC) in advanced ovarian cancer patients. The treatment was scheduled to be administered every 3 weeks for six courses. Following initial laparotomy and cytoreductive surgery, 130 previously untreated patients entered the study. 73 patients were treated with carboplatin alone while 57 received the combination chemotherapy. In the majority of the patients, the regimens had to be given every 4 weeks due to myelosuppression. Nausea, vomiting and alopecia were more severe in the CB-EC arm. Overall, clinical complete response was observed in 73 (56%) and partial response in 20 (15%) patients. The median time to progression was 16.89 months and median survival was 29.54 months. No significant differences in response rate, time to progression, disease-free survival and overall survival were observed between the two treatment arms. The prognostic role of residual disease after initial surgery, complete remission at second-look laparotomy, tumour stage and performance status was confirmed.

Preoperative chemotherapy with carboplatin alone in high risk medulloblastoma

Few studies have been carried out regarding preoperative chemotherapy utilized in the treatment of primitive neuroectodermal tumors/medulloblastomas (PNET/MB). In this paper, the authors report 3 cases of children under three years of age, with a presumed diagnosis of PNET/MB, who were preoperatively treated with chemotherapy consisting of high doses of carboplatin alone. The treatment improved the childrens' clinical condition prior to surgery and facilitated tumor removal, resulting in partial regression of the tumor. The preoperative single-drug therapy did not affect the histological diagnosis or prevent the presence of an effective degree of tumor sensitivity to the drug. All three children are still disease-free, after a mean follow-up period of 42 months.

Carboplatin in childhood medulloblastoma/PNET: feasibility of an in vivo sensitivity test in an "up-front" study

Sixteen patients with high risk MB/PNET at diagnosis were included in a pilot study employing carboplatin (CBDCA) as a single drug prior to conventional therapy. The main goal of the study was to identify in a short-term trial a significant response that would predict further response to CBDCA in the single patient. Exploration of CBDCA activity was focused on response after the first course as compared to the response following the second course. A course consisted of CBDCA 600 mg/m2 on days 1 and 2 administered in a 1 h infusion to be repeated 3-4 weeks later. After two cycles we observed 1 CR and 9 PR, that is a 62% response rate. The first course resulted in 5 PR, 5 MR, 5 SD, and 1 PD; after the subsequent course in all responding patients, response persisted or improved whereas in no patient with SD any improvement was observed. The correlation of response to the first course with response to the second course was statistically significant (P = 0.0009). The main toxicity of the single course was hematologic and consisted of rapidly reversible grade 3-4 neutropenia and thrombocytopenia in 94% of patients. Pharmacokinetic studies showed a very limited interpatient variability of both Cmax 57.6 +/- 9.9 micrograms/ml) and AUC (15.3 +/- 1.5 mg/ml.min) of free CBDCA, which eliminates an important variable in the evaluation of response. In conclusion, this "in vivo test" appears effective, reasonably safe, and reproducible in identifying patients likely to benefit from CBCDA: after a period of time as short as 3-4 weeks following the first course, multidrug chemotherapy including CBDCA may be employed in the responding patients, whereas an alternative regimen would be indicated in the non-responding patients.

Potentiation of cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) by amphotericin B in BALB/c nude mice bearing human ovarian carcinoma cells

Human ovarian carcinoma cells (HRA) were sensitized to cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) 1.2-, 2.1- and 3.4-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4, and 10.8 microM, respectively. Moreover, the intracellular accumulation of platinum after 2-h exposure to CBDCA was increased significantly by AMB treatment. For estimating the enhancing effect of AMB on CBDCA cytotoxicity in vivo, we prepared HRA cell-inoculated nude mice. Ascites was evident 7 to 9 days after intraperitoneal (i.p.) inoculation of HRA cells, and the mice died of intraabdominal carcinomatosis 11 to 14 days (mean survival time (MST): 12.0 +/- 1.0 days) after inoculation. Treatment with AMB (2.0 mg/kg) alone increased the MST by only 1.2 days. Simultaneous treatment with CBDCA (12 or 15 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CBDCA alone. Maximal MST (38.5 days) was obtained by treatment with 15 mg/kg CBDCA plus 2.0 mg/kg AMB, whereas the MST with 15 mg/kg CBDCA alone was 15.8 days. A drug accumulation study demonstrated that platinum accumulation in tumor tissues after i.p. treatment with CBDCA and AMB in tumor-bearing nude mice was increased significantly compared to treatment with CBDCA alone. These findings indicate that intraperitoneal combination chemotherapy with CBDCA and AMB is useful in nude mice with advanced ovarian carcinoma.

Clinical pharmacokinetics of carboplatin in children

The present study was undertaken to evaluate in children the plasma pharmacokinetics of free carboplatin given at different doses and schedules and to evaluate the inter- and intrapatient variability and the possible influence of schedule on drug exposure. A total of 35 children (age range, 1-17 years) with malignant tumors were studied. All patients had normal renal function (creatinine clearance corrected for surface body area, above 70 ml min-1 m-2; range, 71-151 ml min-1 m-2) and none had renal involvement by malignancy. Carboplatin was given at the following doses and schedules: 175, 400, 500, and 600 mg/m2 given as as a 1-h infusion; 1,200 mg/m2 divided into equal doses and infused over 1 h on 2 consecutive days; and 875 and 1,200 mg/m2 given as a 5-day continuous infusion. A total of 57 courses were studied. Carboplatin levels in plasma ultrafiltrate (UF) samples were measured both by high-performance liquid chromatography and by atomic absorption spectrophotometry. Following a 1-h infusion, carboplatin free plasma levels decayed biphasically; the disappearance half-lives, total body clearance, and apparent volume of distribution were similar for different doses. In children with normal renal function as defined by creatinemia and blood urea nitrogen (BUN) and creatinine clearance, we found at each dose studied a limited interpatient variability of the peak plasma concentration (Cmax) and the area under the concentration-time curve (AUC) and a linear correlation between the dose and both Cmax (r = 0.95) and AUC (r = 0.97). The mean value +/- SD for the dose-normalized AUC was 13 +/- 2 min m2 l-1 (n = 57).2+ The administration schedule does not seem to influence drug exposure, since prolonged i.v. infusion or bolus administration of 1,200 mg/m2 achieved a similar AUC (13.78 +/- 2.90 and 15.05 +/- 1.44 mg ml-1 min, respectively). In the nine children studied during subsequent courses a limited interpatient variability was observed and no correlation (r = 0.035) was found between AUC and subsequent courses by a multivariate analysis of dose, AUC, and course number. The pharmacokinetic parameters were similar to those previously reported in adults; however, a weak correlation (r = 0.52, P = 0.03) between carboplatin total body clearance and creatinine clearance varying within the normal range was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Carboplatin, methotrexate, and vinblastine in the treatment of patients with advanced urothelial cancer. A phase II trial

BACKGROUND

A Phase II study with carboplatin, methotrexate, and vinblastine (CAMV) was conducted with patients who had advanced urothelial cancer to investigate the activity and toxicity of carboplatin when used in combination chemotherapy.

METHODS

Thirty-six patients with advanced urothelial cancer were treated with carboplatin 300 mg/m2 (day 1), methotrexate 40 mg/m2 (days 1 and 8) and vinblastine 4 mg/m2 (days 1 and 8) every 4 weeks. Characteristics of the patients were as follows: men:women, 32:4; median age, 65 years (range, 42-76 years); and median Eastern Cooperative Oncology Group performance status, 0 (range, 0-2). Thirty-six patients were evaluable for toxicity and 33 for response.

RESULTS

Objective responses (OR) were achieved in 13 patients: 2 were complete responses (CR) (6%) and 11 were partial responses (33.4%). Median duration of OR was 7 months (range, 3-27 months). Median duration of CR was 10 months (range, 4-27 months), and median survival time for patients achieving complete response was 30.5 months (range, 28-33 months). Patients with a pretreatment creatinine clearance greater than or equal to 50 ml/minute showed a higher response rate: 48% OR and 10% CR. Toxicity was evaluated (World Health Organization criteria) on 164 cycles and was generally mild.

CONCLUSION

CAMV is an active and safe regimen in patients with advanced urothelial cancer, even in those with impaired renal function. It is recommended that future studies with this regimen be performed with pharmacokinetic modulation of carboplatin to improve the drug's tolerability and therapeutic activity.

Carboplatin and alpha-2b interferon intraperitoneal combination as first-line treatment of minimal residual ovarian cancer. A pilot study

21 untreated ovarian cancer patients with stage III and minimal tumour size, were given weekly intraperitoneal (i.p.) carboplatin (150 mg/m2) and alpha-2b interferon (IFN) (30 million U/m2) for a total of 12 courses, from June 1989 to February 1993. To date, a total of 248 courses have been administered. Toxicity was seldom severe, although fever (179 courses), fatigue (141 courses) and other IFN-related side-effects were very frequent. No patient refused to continue treatment, but in 5 patients IFN dose had to be reduced, and in 1 it was discontinued. The IFN mean delivered dose intensity was 19.8 million U/m2 week. Grade 3-4 myelotoxicity occurred in 7 patients (39 courses), but no deaths related to treatment occurred. The actual mean dose intensity of carboplatin was 121.5 mg/m2 week. To date, 20 patients have completed treatment and are evaluable for response. Of 11 patients with tumour size < or = 5 mm, 10 (91%) achieved a pathological complete response (pCR) as did 4/9 (44%) of those with tumour > 5 mm at entry, for a 70% (95% confidence interval 50-90) overall pCR rate. At a median follow-up of 21 months (range 4-46), only one death occurred. The probability of being alive at almost 4 years was 91% in the entire group (100% in those with tumour size less than 5 mm). Only 1 of 14 patients who achieved a pCR relapsed. This i.p. combination seems a feasible approach to previously untreated ovarian cancer patients with minimal tumour burden. IFN dosage should be reduced to improve tolerance. In view of the very high pCR rate achieved in the group of patients with smaller tumours, a randomised trial is warranted to compare this approach to standard treatment in these patients.

Epidoxorubicin and lonidamine in refractory or recurrent epithelial ovarian cancer

Lonidamine (150 mg x 3 day orally, days 1-5) plus high dose epidoxorubicin (120 mg/m2 intravenously, day 3) was tested in 26 patients with refractory or recurrent epithelial ovarian cancer, to assess the anti-tumour activity and the toxicity of this combination of drugs. All patients were evaluable for toxicity and 24 for tumour response. Two complete responses (8.3%) and six partial responses (25.0%) were recorded for a total response rate of 33.3%. 6 of 8 responding patients were pretreated with anthracyclines. Stable disease was obtained in 7 patients (29.2%). Toxicity was acceptable; only 1 (3.8%) patient stopped chemotherapy because of a left ventricular ejection rate reduction > 20%. The most relevant side-effect was leucopenia (grade 3-4, 34.6%). In conclusion, the association of lonidamine and high-dose epidoxorubicin has promising activity as second-line treatment in patients with refractory or recurrent epithelial ovarian cancer.

Combination treatment of cis- and carboplatin in cancers restricted to the peritoneal cavity in the rat

In the present study, cisplatin (cDDP) and carboplatin (CBDCA) were combined in different in vitro and in vivo assays to determine whether combined cDDP and CBDCA treatment would eventually lead to a better antitumor response. Co-incubation of CC531 cells with cDDP and CBDCA led to higher intracellular Pt concentrations (30.5 +/- 3.4 ng Pt/10(6) cells) than did cDDP (16.9 +/- 9.4 ng Pt/10(6) cells) or CBDCA (1.28 +/- 0.72 ng Pt/10(6) cells) incubation alone. In survival assays an additive cell kill was seen after combined treatment with cDDP and CBDCA. DNA binding experiments using isolated salmon-sperm DNA exposed to the drugs separately or in combination were in agreement with the survival studies (for cDDP a binding of 12.42 micrograms Pt/mg DNA; for CBDCA, 0.49 microgram Pt/mg DNA; and for combined CBDCA and cDDP, 12.9 micrograms Pt/mg DNA at 76 h). Toxicity studies in rats treated with cDDP plus CBDCA required a dose reduction for cDDP amounting to 20% of the MTD, whereas the CBDCA dose could be maintained. Pharmacokinetics studies showed higher AUCs and t1/2 beta in plasma as well as the peritoneal cavity after combined treatment with cDDP and CBDCA (both given i.p.) or following cDDP given i.p. and CBDCA given i.v. Pt concentrations in peritoneal tumors corresponded with these observations, with higher Pt concentrations following combined treatment than after single-agent injection. In addition, combined administration of cDDP i.p. and CBDCA i.v. led to higher Pt concentrations in peritoneal tumors than did administration of both drugs i.p. (3.93 +/- 0.9 vs 2.76 +/- 0.2 mg Pt/g tissue). The higher Pt concentrations in the peritoneal tumors after combined treatment was associated with a significantly better antitumor response in comparison with that observed after single-agent treatment (a growth delay of 30.2 +/- 5.6 days for cDDP i.p. plus CBDCA i.v. vs 16.1 +/- 5.4 days for cDDP alone and 10.8 +/- 4.2 days for CBDCA alone).

Carboplatin in combination as first-line therapy in advanced breast cancer

Carboplatin, a platinum analog with single-agent activity in previously untreated breast cancer, is characterized by comparatively less renal toxicity and emesis than cisplatin. We combined carboplatin at different dose levels [from 200 to 350 mg/m2 by intravenous (IV) infusion on day 1] with 5-fluorouracil (500 mg/m2 IV on days 1 and 8) and cyclophosphamide (500 mg/m2 IV on day 1), with all three drugs recycled every 28 days, to evaluate anti-tumor activity and toxicity of this novel combination [5-fluorouracil/carboplatin/cyclophosphamide (FCC)] in untreated locally advanced (LABC) or metastatic breast cancer (M+). Of 37 patients treated between March 1990 and August 1991 [LABC 25, M+ 8; World Health Organization (WHO) performance status, 0-1; median number of treatment cycles, 5; median follow-up, 20 months], 33 are evaluable for response and toxicity. The overall complete plus partial remission rate was 57% (LABC 68%, M+ 25%). The median duration of response was 19+ months. The cumulative carboplatin dose ranged from 800 to 2350 mg/m2 (median, 1450 mg/m2). In this series, no correlation was observed between the carboplatin dose level and response rate or toxicity. Leukopenia and thrombocytopenia represented the most frequent toxicities. WHO grades 3 and 4 neutropenia were documented in 34% and 8% of patients, respectively. Thrombocytopenia below 50 x 10(9)/l was observed in 8%. No renal toxicity was observed, and moderate emesis occurred in 67% of patients. These results indicate that FCC is an active and relatively safe combination for the treatment of advanced breast cancer in patients not previously treated with chemotherapy.

Pharmacokinetic and phase I evaluation of carboplatin in dogs

Thirty dogs with spontaneously occurring malignant neoplasms were treated monthly with carboplatin (CBDCA) given as a 30-minute intravenous infusion in a dose escalation study. Twenty-eight dogs were considered evaluable for toxicity. The maximally tolerated dose of CBDCA was conceptually defined as that dose, determined by logistic regression analyses of toxicity data, resulting in a 50% incidence of moderate toxicity (MOD50) or a 5% incidence of severe toxicity (SEV5). Each designated maximally tolerated dose was calculated for the first course of treatment only and for the first and second courses of treatment combined to estimate cumulative drug toxicity. The MOD50 and SEV5 for the first treatment course were 340 and 278 mg/M2, respectively. MOD50 and SEV5 values for the first plus second treatment courses were 327 and 231 mg/M2, respectively. The nadir of neutrophil and platelet counts occurred approximately 14 days after treatment. The mean neutrophil and platelet values for all dogs experiencing myelosuppression during the first two treatment courses were 1541/microL and 62,600/microL, respectively. Nonparametric pharmacokinetic analysis of plasma CBDCA values suggested that half-life (T1/2), area-under-the-curve and total body clearance (CLb) were not dose dependent. Volume of distribution (VDss) significantly increased with dose only between 100 and 150 mg/M2, not between 150 and 300 mg/M2. Dose-independent serum CBDCA pharmacokinetic disposition indicates that detailed investigation of tissue CBDCA distribution would be warranted and may identify novel dosing strategies that could improve the therapeutic index of CBDCA by minimizing toxicity.

Combined carboplatin and cisplatin. Limited prospects for dose intensification

BACKGROUND

The relative lack of overlapping toxicities and less-than-complete cross-resistance of tumors treated with both carboplatin and cisplatin may allow these two analogues to be given in combination to exploit platinum dose intensity therapeutics. Early experience with combined platinum regimens, however, found myelosuppression, particularly severe thrombocytopenia, to be dose-limiting. It was postulated that a 2-day interval between carboplatin and cisplatin would allow for near complete clearance of the former before cisplatin administration and a potential gain in dose intensity.

METHODS

Other carboplatin-cisplatin regimens produced Grade 3-4 toxicity in 20% of patients. By defining 95% confidence limits around this observed rate of Grade 3-4 toxicity, the accrual needs of this study were determined in a two-stage process. Sixteen patients with advanced malignancies were entered onto a trial of 300 mg/m2 of carboplatin on day 1, followed by 125 mg/m2 of cisplatin on day 3 every 28 days. Hematologic and nonhematologic toxicity was closely monitored, including the use of serial audiograms, to allow appropriate dose modification.

RESULTS

A total of 40 courses of combination platinum therapy was administered to 15 patients who were evaluable for toxicity. Higher-than-anticipated ototoxicity and neurosensory toxicity was observed. WHO Grade 3 ototoxicity (hearing loss) was documented in 12 of 15 patients (80.0%, 95% confidence interval [CI]: 52.0-97.0%) and emerged as the dose-limiting side effect of this regimen. High-frequency hearing loss, as demonstrated by conventional audiograms, was universal among all 12 patients who received at least 2 courses of combination platinum therapy (100%, 95% CI: 73.5-100%). Grade 2 or 3 neurosensory toxicity also was observed in 4 of 15 patients. Hematologic toxicity was manageable. WHO Grade 3-4 neutropenia or thrombocytopenia occurred in only 14% and 11%, respectively, of 40 courses. There was no evidence of cumulative marrow toxicity. Calculated dose intensities (mg/m2/week) were 94 +/- 26.0 for carboplatin, 39.3 +/- 12.4 for cisplatin, and 64.0 +/- 19.2 for the combination (expressed as cisplatin equivalents). Objective responses (complete response+partial response) occurred in 8 of 16 subjects (50.0%, 95% CI: 24.7-75.4%), with 1 patient achieving a complete response of 14+months.

CONCLUSIONS

The schedule of day 1 carboplatin plus day 3 cisplatin every 4 weeks appeared to allow a higher platinum dose intensity with less myelotoxicity than previously reported schedules combining these two analogues. Ototoxicity, however, was unexpectedly severe and limits future prospects for the use of combined platinum analogues to achieve dose intensification.

Carboplatin, methotrexate, vinblastine and epirubicin (Carbo-MVE) for transitional cell bladder carcinoma

BACKGROUND

MVAC is considered the most effective chemotherapy regimen for transitional cell bladder carcinoma. However, due to its significant toxic effects we substituted carboplatin for cisplatin and epirubicin for adriamycin in an attempt to produce the same response with less toxicity.

PATIENTS AND METHODS

Twenty-seven patients with invasive transitional cell bladder carcinoma received Carbo-MVE: carboplatin (300 mgr/m2 d2), methotrexate (30 mgr/m2 d1, 15, 22), vinblastine (3 mgr/m2 d2, 15, 22) and epirubicin (30 mgr/m2 d2) every 4 weeks.

RESULTS

There were 2 complete clinical responses (8.4%), 5 partial clinical responses (20.8%), 8 stabilizations (33.3%) and 9 progressions (37.5%). The overall clinical response rate was 29.2% (11%-47.4%, 95% CI), but 2 partial clinical remissions were not pathologically confirmed; were they to be considered as non-responses the response rate would fall even lower (20.8%). Toxicity was moderately severe, with 77.8% developing WHO grade III-IV granulocytopenia, 22.2% grade III-IV thrombocytopenia and 59.3% grade II-III vomiting. There were no toxic deaths nor any renal toxicity.

CONCLUSIONS

Our results suggest that Carbo-MVE is less active and at least as hematotoxic as multiagent CDDP-based regimens.

A phase I study of 1,2-diamminomethyl-cyclobutane-platinum (II)-lactate (D-19466; lobaplatin) administered daily for 5 days

A phase I trial was conducted with lobaplatin (D-19466; 1,2-diamminomethyl-cyclobutane-platinum (II)-lactate) i.v. bolus daily for 5 days every 4 weeks. After entering five patients toxicity appeared to be related to renal function, therefore the individual dose (total dose 20-100 mg m-2 over 5 days) of lobaplatin was modified according to creatinine clearance (CRCL) and escalated in patients. Twenty-seven patients with refractory solid tumours received 72 courses. Thrombocytopenia was dose-limiting, its degree was related to dose and CRCL at time of drug administration. With a CRCL of 60-80 ml min-1 the maximum tolerated dose was 40 mg m-2, with a CRCL of 81-100 ml min-1 70 mg m-2, and with a CRCL > 100 ml min-1 it was 85 mg m-2. Platelet and leukocyte nadirs were observed around day 21. The percentual platelet nadir (percentage of day 1 platelet count) correlated with CRCL at different dose levels and could be described by 0.76 x CRCL (ml min-1) - (1.45 x dose (mg m-2) + 43.38. This equation tested in 20 patients (28 courses) produced a correlation between observed and predicted percentual platelet nadir (r = 0.82, P < 0.001). No renal function impairment occurred. Urinary excretion of platinum (by A.A.S) was estimated in six patients and revealed that 91.5% (s.e. +/- 7.9) of the platinum dose was excreted within 4 h. Responses (one PR, one CR) occurred in two patients with ovarian cancer (both pretreated with carboplatin and cisplatin). The recommended dose of lobaplatin i.v. bolus daily for 5 days for phase II studies depends on renal function, namely 30 mg m-2 at CRCL 60-80 ml min-1; 55 mg m-2 at CRCL 81-100 ml min-1; 70 mg m-2 at CRCL > 100 ml min-1.

Carboplatin in advanced hormone refractory prostatic cancer patients

25 patients with measurable or evaluable metastatic prostate cancer, progressive after hormonal treatment, were treated weekly with carboplatin 150 mg/m2 intravenously. The weekly schedule allowed higher dose intensity carboplatin administration with respect to the common monthly cycles. Toxicity was manageable even in elderly patients with extensive bone metastases and consisted primarily of myelosuppression. 4 out of 24 evaluable patients (17%) had a partial response and 12 (50%) had disease stabilisation. The median response duration was 7 months. Prostate-specific antigen and prostatic acid phosphatase serial values showed a correlation with disease response in only 47 and 50% of patients, respectively. These results suggest that carboplatin possesses a moderate but definite activity in prostate cancer patients.