Principal Toxicity Research Articles

Clinical and pharmacologic phase I study of Cemadotin–HCl (LU103793), a novel antimitotic peptide, given as 24-hour infusion in patients with advanced cancer: A study of the Arbeitsgemeinschaft Internistische Onkologie (AIO) Phase I Group and Arbeitsgruppe Pharmakologie in der Onkologie und Haematologie (APOH) Group of the German Cancer Society

To determine the maximum tolerable dose (MTD), principal toxicity, and pharmacologic behaviour of Cemadotin-HCl, a novel antimitotic peptide. Cemadotin-HCl (10.0 to 27.5 mg/m2/day every three weeks) was administered as a 24-hour intravenous (i.v.) continuous infusion to patients with advanced cancer. Pharmacokinetic analyses were performed during the first treatment cycle. Blood samples were taken over 48 hours and analyzed by radioimmunoassay. Hypertension was the dose-limiting toxicity (DLT). This type of toxicity was observed at all dose levels, but grade 3 (CTC) was observed only at dose levels 20.0, 25.0 and 27.5 mg/m2. This effect was reversible but in three patients associated with signs of cardiac ischemia. Other significant toxic effects were neutropenia, asthenia, tumor pain and transient liver enzyme elevation. A linear pharmacokinetics was observed. The best curve fit was obtained with a two-compartment model with a terminal half-life of approximately 10 hours at each dose level, a volume of distribution at steady state of approximately 9 l/m2 and a total clearance of approximately 0.6 l/hour/m2. Neither partial nor complete responses were observed although minor tumor regressions were seen in a patient with carcinoma of unknown primary (CUP) and in another patient with liver metastases from a colon cancer. Hypertension was the dose-limiting toxicity of Cemadotin-HCl administered as a continuous 24-hour infusion. The recommended dose for further evaluation of its anticancer efficacy in disease-oriented phase II studies with this schedule is 15.0 mg/m2. The nature of the principal cardiovascular toxicity remains unclear. The observed toxicities appeared to be significant but manageable.

Topotecan: An Oncologist's View

Topotecan (Hycamtin(R)) is a topoisomerase I inhibitor which demonstrated a wide spectrum of antitumor activity in preclinical models. During phase I assessment, evidence of activity was most promising when topotecan was administered on an i.v. daily x 5 schedule and a dose of 1.5 mg/m(2)/day was selected for phase II/III evaluation. This regimen has been shown to have activity in a wide range of tumor types, including recurrent ovarian cancer, relapsed small cell lung cancer (SCLC), non-small cell lung cancer, colon cancer, and breast cancer, as well as hematological malignancies. In patients with ovarian cancer who had failed standard therapy, topotecan demonstrated response rates of 13% to 25%, with median times to progression of 12 to 19 weeks. Compared with paclitaxel, the response rates were similar, 20.5% and 14.0%, respectively, as were median times to progression (19 weeks for topotecan versus 15 weeks for paclitaxel). Results in recurrent SCLC have also been encouraging. Patients sensitive to previous chemotherapy have shown response rates of 19% and 39%, and even patients resistant or refractory to previous chemotherapy have had responses of 3% and 7%. Survival ranged from 20 weeks in refractory disease to 12 months in both sensitive and resistant/refractory disease combined. The safety profile of topotecan is well established. The principal toxicity is noncumulative myelosuppression, and serious sequelae are uncommon. Nonhematological toxicities are generally mild. The use of topotecan in combination regimens is promising, although clinical results are currently at an early stage. To date, topotecan has demonstrated its activity in recurrent ovarian cancer and offers a valuable addition to treatment options in relapsed SCLC.

Dose intensification in small cell lung cancer chemotherapy

Lung cancer presents a major worldwide health problem, accounting for 10% of all cancers. The treatment for those patients with small cell lung cancer has been unsatisfactory, but combination chemotherapy administered with radiotherapy can effect a cure in a minority of patients. Intensification of chemotherapy can improve the cure rate, and there are now a variety of haemopoietic growth factors available to support this approach, as the principal toxicity of the drugs used today is bone marrow suppression. Strategies to protect the bone marrow are also in development and are likely to allow further dose intensification. Recently randomised trials have reported survival benefits for intensified treatments.

A Bioavailability and Pharmacokinetic Study of Oral and Intravenous Hydroxyurea

Despite the widespread usage of hydroxyurea in the treatment of both malignant and nonmalignant diseases and a recent expansion in the recognition of its potential therapeutic applications, there have been few detailed studies of hydroxyurea's pharmacokinetic (PK) behavior and oral bioavailability. Parenteral administration schedules have been evaluated because of concerns about the possibility for significant interindividual variability in the PK behavior and bioavailability of hydroxyurea after oral administration. In this PK and bioavailability study, 29 patients with advanced solid malignancies were randomized to treatment with 2,000 mg hydroxyurea administered either orally or as a 30-minute intravenous (IV) infusion accompanied by extensive plasma and urine sampling for PK studies. After 3 weeks of treatment with hydroxyurea (80 mg/kg orally every 3 days followed by a 1-week washout period), patients were crossed over to the alternate route of administration, at which time extensive PK studies were repeated. Three days later, patients continued treatment with 80 mg/kg hydroxyurea orally every 3 days for 3 weeks, followed by a 1-week rest period. Thereafter, 80 mg/kg hydroxyurea was administered orally every 3 days. Twenty-two of 29 patients had extensive plasma and urine sampling performed after treatment with both oral and IV hydroxyurea. Oral bioavailability (F) averaged 108%. Moreover, interindividual variability in F was low, as indicated by 19 of 22 individual F values within a narrow range of 85% to 127% and a modest coefficient of variation of 17%. The time in which maximum plasma concentrations (Cmax) were achieved averaged 1.22 hours with an average lag time of 0.22 hours after oral administration. Except for Cmax, which was 19.5% higher after IV drug administration, the PK profiles of oral and IV hydroxyurea were very similar. The plasma disposition of hydroxyurea was well described by a linear two-compartment model. The initial harmonic mean half-lives for oral and IV hydroxyurea were 1.78 and 0.63 hours, respectively, and the harmonic mean terminal half-lives were 3.32 and 3.39 hours, respectively. For IV hydroxyurea, systemic clearance averaged 76.16 mL/min/m2 and the mean volume of distribution at steady-state was 19.71 L/m2, whereas Cloral/F and Voral/F averaged 73.16 mL/min/m2 and 19.65 L/m2, respectively, after oral administration. The percentage of the administered dose of hydroxyurea that was excreted unchanged into the urine was nearly identical after oral and IV administration—36.84% and 35.82%, respectively. Additionally, the acute toxic effects of hydroxyurea after treatment on both routes were similar. Relationships between pertinent PK parameters and the principal toxicity, neutropenia, were sought, but no pharmacodynamic relationships were evident. From PK, bioavailability, and toxicologic standpoints, these results indicate that there are no clear advantages for administering hydroxyurea by the IV route except in situations when oral administration is not possible and/or in the case of severe gastrointestinal impairment.

A Bioavailability and Pharmacokinetic Study of Oral and Intravenous Hydroxyurea

AbstractDespite the widespread usage of hydroxyurea in the treatment of both malignant and nonmalignant diseases and a recent expansion in the recognition of its potential therapeutic applications, there have been few detailed studies of hydroxyurea's pharmacokinetic (PK) behavior and oral bioavailability. Parenteral administration schedules have been evaluated because of concerns about the possibility for significant interindividual variability in the PK behavior and bioavailability of hydroxyurea after oral administration. In this PK and bioavailability study, 29 patients with advanced solid malignancies were randomized to treatment with 2,000 mg hydroxyurea administered either orally or as a 30-minute intravenous (IV) infusion accompanied by extensive plasma and urine sampling for PK studies. After 3 weeks of treatment with hydroxyurea (80 mg/kg orally every 3 days followed by a 1-week washout period), patients were crossed over to the alternate route of administration, at which time extensive PK studies were repeated. Three days later, patients continued treatment with 80 mg/kg hydroxyurea orally every 3 days for 3 weeks, followed by a 1-week rest period. Thereafter, 80 mg/kg hydroxyurea was administered orally every 3 days. Twenty-two of 29 patients had extensive plasma and urine sampling performed after treatment with both oral and IV hydroxyurea. Oral bioavailability (F) averaged 108%. Moreover, interindividual variability in F was low, as indicated by 19 of 22 individual F values within a narrow range of 85% to 127% and a modest coefficient of variation of 17%. The time in which maximum plasma concentrations (Cmax) were achieved averaged 1.22 hours with an average lag time of 0.22 hours after oral administration. Except for Cmax, which was 19.5% higher after IV drug administration, the PK profiles of oral and IV hydroxyurea were very similar. The plasma disposition of hydroxyurea was well described by a linear two-compartment model. The initial harmonic mean half-lives for oral and IV hydroxyurea were 1.78 and 0.63 hours, respectively, and the harmonic mean terminal half-lives were 3.32 and 3.39 hours, respectively. For IV hydroxyurea, systemic clearance averaged 76.16 mL/min/m2 and the mean volume of distribution at steady-state was 19.71 L/m2, whereas Cloral/F and Voral/F averaged 73.16 mL/min/m2 and 19.65 L/m2, respectively, after oral administration. The percentage of the administered dose of hydroxyurea that was excreted unchanged into the urine was nearly identical after oral and IV administration—36.84% and 35.82%, respectively. Additionally, the acute toxic effects of hydroxyurea after treatment on both routes were similar. Relationships between pertinent PK parameters and the principal toxicity, neutropenia, were sought, but no pharmacodynamic relationships were evident. From PK, bioavailability, and toxicologic standpoints, these results indicate that there are no clear advantages for administering hydroxyurea by the IV route except in situations when oral administration is not possible and/or in the case of severe gastrointestinal impairment.

A Risk-Benefit Assessment of Irinotecan in Solid Tumours

Irinotecan is a water-soluble camptothecin analogue. Its cytotoxicity effects are exerted through interaction with the topoisomerase I-DNA complex, eventually leading to cell death. In preclinical studies, irinotecan has demonstrated a broad spectrum of activity in vitro and in vivo, and synergistic effects have been observed when it is administered in combination with other antineoplastic agents. Phase I studies of irinotecan conducted in Europe, Japan and the US have provided useful information on optimal dosage and scheduling, as well as thorough evaluation of the toxicity profile of the drug. Phase II and III trials utilising either irinotecan alone or in innovative combinations with other drugs are currently in progress. Available data indicate that irinotecan alone or in combination with other cytotoxic agents has therapeutic potential in several types of malignancy, including colorectal, lung, ovarian, cervical and gastric cancers and non-Hodgkin's lymphoma. It is the first drug since fluorouracil to possess consistent antitumour activity against metastatic colorectal cancer. The principal toxicities associated with irinotecan are diarrhoea and leucopenia. Effective strategies have been developed to circumvent both the early- and delayed-onset diarrhoea induced by irinotecan, thus allowing safer delivery of this promising agent in the clinical setting.

Clinical pharmacokinetics of stavudine.

Stavudine (d4T) is a pyrimidine nucleoside analogue used in the treatment of human immunodeficiency virus (HIV) infection. It inhibits viral reverse transcriptase as do zidovudine (AZT), didanosine (ddI), zalcitabine (ddC) and lamivudine (3TC), which comprise the family of nucleoside HIV-reverse transcriptase inhibitors. Stavudine is currently approved by the US Food and Drug Administration for the treatment of patients who have become intolerant to or have failed to response to zidovudine, didanosine or zalcitabine therapy. Oral administration of stavudine results in maximal concentrations within 2 hours and increases linearly as doses increase. The absolute oral bioavailability is high, approaching 100%. There is evidence to suggest that stavudine does not accumulate in the plasma. It distributes into total body water and appears to enter cells by non-facilitated diffusion. Penetration into the cerebrospinal fluid occurs, as does the transfer of the drug across human placental tissue. Stavudine is cleared quickly by both renal and nonrenal processes. The pharmacokinetic properties of stavudine in children are similar to those of adults. The pharmacokinetic parameters of stavudine were not affected by simultaneous administration of didanosine. It appears that stavudine at doses < 2 mg/kg/day is most efficient at increasing CD4 + cell numbers. While stavudine is reported to be less cytotoxic than zidovudine, the principal toxicity in humans is peripheral neuropathy and appears to be related to daily, but not cumulative, doses.

Phase I study of daily times five topotecan and single injection of cisplatin in patients with previously untreated non-small-cell lung carcinoma

The objectives were to determine the dose-limiting toxicity of topotecan in combination with cisplatin, to describe the principal toxicities, and to define the maximally-tolerated doses of the drugs in previously untreated patients with advanced non-small-cell lung carcinoma. The study was designed to evaluate escalated doses of topotecan (starting at 0.75 mg/m2/day) as a 30-minute infusion daily for five consecutive days with a fixed clinically-relevant dose of 75 mg/m2 cisplatin given on day 1, every three weeks. Fifteen chemotherapy-naive patients entered the study and 14 were evaluable for toxicity. All 11 patients treated at the first topotecan/cisplatin dose level of 0.75/75 mg/m2, experienced at least one episode of grade 4 neutropenia. For six patients, absolute neutrophil counts were below 500/ml for more than five days, and two of them developed a grade 4 thrombocytopenia. At the next higher topotecan/cisplatin dose level (1.0/75 mg/m2), grade 4 neutropenia lasting longer than five days occurred in all three evaluable patients, including one patient who expired due to a severe neutropenia associated with sepsis. Non-hematologic toxicities, predominantly nausea and vomiting, were mild to moderate in severity and manageable. Four patients had partial responses (30.7%; 95% confidence interval (9%-61%) of relatively short duration. Both severe neutropenia and thrombocytopenia precluded dose escalation of topotecan and cisplatin administered on this schedule. In previously untreated patients, the first topotecan/cisplatin dose level (0.75/75 mg/m2), was associated with intolerable myelosuppression, and, therefore, the dose levels evaluated in this study cannot be recommended for subsequent phase II investigations. The high toxicity of this schedule and the recent understanding of the pharmacokinetic interaction between those drugs may encourage the investigation of the alternate sequence of cisplatin after TPT in phase II studies.

Carboplatin as radiosensitizer in non-small cell lung cancer after cisplatin containing chemotherapy.: A Phase I study of a groupe francais de pneumo-cancerologie (G.F.P.C.)

A Phase I trial of carboplatin therapy was performed on patients with locally advanced non-small cell lung cancer who had been previously treated with cisplatin, mitomycin and a vinca alkaloı̈d. This was administered as a daily bolus infusion or as a continuous infusion for 6 weeks with concurrent daily thoracic radiation. All patients had to be objective responders or to show no change after chemotherapy. The carboplatin was started at 10 mg/m2 per day, and increased to 15 mg/m2 per day and 20 mg/m2 per day, if treatment was feasible in successive cohorts of at least six patients. The radiation therapy consisted of 62–66 Gray on the tumor and the ipsilateral mediastinal nodes, 50 Gray on the mediastinum and 40–45 Gray on the supraclavicular lymph nodes. Twenty-nine patients took part in this study. Thrombocytopenia was the principal dose-limiting toxicity, with 15 mg/m2 per day of bolus or continuous infusion. Other toxicities included a fall in haemoglobin level, a fall in white-blood cell count, nausea and vomiting. The median survival time is 12 months, but the response rate cannot be determined among patients selected on the basis of response to chemotherapy. The recommended Phase II dose for patients previously treated with cisplatin containing chemotherapy, is 10 mg/m2 per day of either a bolus or continuous infusion.

254 Carboplatin as radiosensitizer in non-small cell lung cancer after a cisplatin containing chemotherapy. A phase I study of a groupe francais de pneumo-cancerologie (G.F.P.C.)

A Phase I trial of carboplatin therapy was performed on patients with locally advanced non-small cell lung cancer who had been previously treated with cisplatin, mitomycin and a vinca aklaloïd. This was administered as a daily bolus infusion or as a continuous infusion for 6 weeks with concurrent daily thoracic radiation. All patients had to be objective responders or to show no change after chemotherapy. The carboplatin was started at 10 mg/m2 per day, and increased to 15 mg/m2 per day and 20 mg/m2 per day, if treatment was feasible in successive cohorts of at least six patients. The radiation therapy consisted of 62-66 Gray on the tumor and the ipsilateral mediastinal nodes, 50 Gray on the mediastinum and 40-45 Gray on the supraclavicular lymph nodes. Twenty-nine patients took part in this study. Thrombocytopenia was the principal dose-limiting toxicity, with 15 mg/m2 per day of bolus or continuous infusion. Other toxicities included a fall in haemoglobin level, a fall in white-blood cell count, nausea and vomiting. The median survival time was 12 months, but the response rate cannot be determined among patients selected on the basis of response to chemotherapy. The recommended Phase II dose for patients previously treated with cisplatin containing chemotherapy, is 10 mg/m2 per day of either a bolus or continuous infusion.

Combination paclitaxel (TaxolR)-carboplatin as first-line therapy for advanced ovarian cancer

Data from a recent study conducted by the Gynecologic Oncology Group showed that combination cisplatin–paclitaxel (Taxol®, Bristol-Myers Squibb Company) is superior to standard combination cisplatin–cyclophosphamide in previously untreated patients with ovarian cancer. This dose-finding trial was subsequently initiated to determine whether combination carboplatin–paclitaxel would be as effective as, but less toxic than, cisplatin–paclitaxel in 38 patients with previously untreated ovarian cancer. Paclitaxel was given over 3 h in escalating doses, beginning at a dose of 135 mg m−2 and increasing in 25-mg increments to the maximum tolerated dose. Carboplatin was administered to an area under the concentration–time curve (AUC) of 5; upon reaching the paclitaxel maximum tolerated dose of 185 mg m−2, the carboplatin dose was increased to AUC 6, and then 7.5. All 193 courses administered were evaluable for toxicity. Neutropenia was the principal dose-limiting toxicity encountered, with severe neutropenia observed at every dose level. Nonhematologic toxicity was generally mild and short lasting. It was concluded that paclitaxel and carboplatin can be combined at full therapeutic doses and administered on an outpatient basis with tolerable toxicity and efficacy comparable with that of other active regimens.

Phase II study of the combination carboplatin and paclitaxel in patients with ovarian cancer

Recently the feasibility of combining carboplatin with paclitaxel has been demonstrated in dose-finding studies. Maximum tolerated doses were 550 mg/m2 and 200 mg/m2 (three hours), respectively. We report now a phase II study in ovarian cancer patients. Twenty-one chemo-naïve patients with optimally (n = 6) or suboptimally (n = 15) debulked stage III or IV ovarian cancer were treated every three weeks for six courses with paclitaxel (200 mg/m2) as a three-hour infusion, immediately followed by carboplatin (550 mg/m2) as a 30-minute infusion. Uncomplicated neutropenia was the principal toxicity, with mild anemia occurring regularly. As observed in the preceding phase I study, a relative lack of thrombocytopenia, generally grade III was found. Other toxicities consisted of mild neurotoxicity, nausea and vomiting, alopecia, myalgia, and bone pain. All suboptimally debulked patients responded to therapy. Overall, 12 patients underwent second-look laparoscopy, which revealed a pathologically confirmed complete remission in six. The median follow-up interval at the time of analysis was 14 months. Twelve patients are currently free of progression, at 8+ to 19 +/- months after the start of therapy. The carboplatin/paclitaxel combination appears to be a well-tolerated regimen, yielding high response rates. This combination has now gone forward to be evaluated in prospective randomized trials versus the cisplatin/paclitaxel combination.

Durable Remission After Aggressive Chemotherapy for Post-Cardiac Transplant Lymphoproliferation

A frequently fatal complication of organ transplantation, post-transplant lymphoproliferative disorder (PTLD) develops in 2%-6% of cardiac recipients. Treatment remains poorly defined. Reduction in immunosuppression is effective in a proportion of cases, but mortality in the order of 80% is reported for patients requiring chemotherapy. The reason for such poor outcomes is unclear, but may be partly due to the concomitant use of immunosuppressives. An update report is provided on nineteen consecutive cardiac recipients with PTLD, studied retrospectively in terms of clinical features and outcome. Patients were managed according to a uniform treatment approach. Initial therapy was a trial of reduced immunosuppression with concomitant acyclovir followed, if unsuccessful, by aggressive combination chemotherapy. The regimen used was predominantly ProMACE-CytaBOM. Six patients with phenotypically polyclonal PTLD presented <6 months after transplantation (median 6 weeks). Only 1/4 (25%) treated patients responded to reduced immunosuppression; the remainder died of multiorgan failure. Thirteen patients presented with phenotypically monoclonal disease ≥6 months after transplantation. In 8/12 (75%) treated patients initial therapy was reduction in immunosuppression. None achieved CR; 2 experienced fatal rejection. Two patients achieved durable surgical CR. The remaining 8 patients received chemotherapy; 2/8 (25%) died during treatment, 6/8 (75%) achieved CR. None have relapsed, at a median duration of follow-up of 64 months. Neutropenic sepsis, and subclinical doxorubicin cardiotoxicity at a mean cumulative dose of 63 mg/m2 were the principal toxicities. Our data indicate that aggressive chemotherapy is feasible and can produce very durable remissions in phenotypically monoclonal PTLD refractory to reduced immunosuppression. ProMACE-CytaBOM is well suited to cardiac recipients, minimizing doxorubicin exposure and obviating the need for concurrent immunosuppressives.

Mycophenolate mofetil in kidney transplantation

Mycophenolate mofetil is a new immunosuppressive agent recently released for clinical use, in conjunction with steroids and cyclosporine, for the prevention of acute rejection in renal transplant patients. It inhibits the enzyme inosine monophosphate dehydrogenase, which is essential for de-novo synthesis of guanine nucleotides. The result is lymphocyte-selective arrest of cell division, with little effect on other tissues. In clinical trials in renal transplant, its efficacy and safety have been established: mycophenolate mofetil reduces acute rejection episodes by approximately 50%, with the principal toxicity being gastrointestinal, and perhaps some increase in cytomegalovirus infection. Overall, mycophenolate mofetil (plus cyclosporine and steroids) has a toxicity profile similar to that of azathioprine but with considerably increased efficacy. Despite its cost, mycophenolate mofetil is likely to be used in many renal transplant centres to reduce acute rejection, especially in the first year. Future trials are necessary to establish its long-term role in renal transplantation and its usefulness in the transplantation of other organs.

Anti-diabetic properties and phytochemistry of Momordica charantia L. (Cucurbitaceae)

Unripe fruit, seeds and aerial parts of Momordica charantia Linn. (Cucurbitaceae) have been used in various parts of the world to treat diabetes. Oral administration of the fruit juice or seed powder causes a reduction in fasting blood glucose and improves glucose tolerance in normal and diabetic animals and in humans. Animal and in vitro data support both insulin secretagogue and insulinomimetic activity of the fruit. However, enhanced insulin levels in vivo in response to its administration have not been observed. Although a wide range of compounds have been isolated from Momordica charantia, notably steroidal compounds and proteins, the orally active antidiabetic principle has not been adequately identified. A polypeptide, p-insulin, produces hypoglycaemic effects in humans and animals on subcutaneous injection, but oral activity is questionable. Other reported hypoglycaemic principles from Momordica charantia include the sterol glucoside mixture charantin (fruit) and the pyrimidine nucleoside vicine (seeds). However these are only effective at doses too high to account for all the activity of the plant extract. Principal toxicity of Momordica charantia in animals is to the liver and reproductive system. These effects have not been reported in humans despite widespread use of the fruit medicinally and as a vegetable.

Phase I/II study of combined granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor administration for the mobilization of hematopoietic progenitor cells.

To study the toxicity and efficacy of combined granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) administration for mobilization of hematopoietic progenitor cells (HPCs). Cohorts of a minimum of five patients each were treated subcutaneously as follows: G-CSF 5 micrograms/kg on days 1 to 12 and GM-CSF at .5, 1, or 5 micrograms/kg on days 7 to 12 (cohorts 1, 2, and 3); GM-CSF 5 micrograms/kg on days 1 to 12 and G-CSF 5 micrograms/kg on days 7 to 12 (cohort 4); and G-CSF and GM-CSF 5 micrograms/kg each on days 1 to 12 (cohort 5). Ten-liter aphereses were performed on days 1 (baseline, pre-CSF), 5, 7, 11, and 13. Colony assays for granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) were performed on each harvest. The principal toxicities were myalgias, bone pain, fever, nausea, and mild thrombocytopenia, but none was dose-limiting. Four days of treatment with either G-CSF or GM-CSF resulted in dramatic and sustained increases in the numbers of CFU-GM per kilogram collected per harvest that represented 35.6 +/- 8.9- and 33.7 +/- 13.0-fold increases over baseline, respectively. This increment was attributable both to increased numbers of mononuclear cells collected per 10-L apheresis and to increased concentrations of progenitors within each collection. The administration of G-CSF to patients already receiving GM-CSF (cohort 4) caused the HPC content to surge to nearly 80-fold the baseline (P = .024); the reverse sequence, ie, the addition of GM-CSF to G-CSF, was less effective. The CFU-GM content of the baseline aphereses correlated with the maximal mobilization achieved (r = .74, P = .001). Combined G-CSF and GM-CSF administration effectively and predictably mobilizes HPCs and facilitates apheresis.

Paclitaxel and carboplatin in the treatment of advanced non-small cell lung cancer

Based on the superior response rates (21% to 24%) of patients treated with single-agent paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in Eastern Cooperative Oncology Group and M.D. Anderson Cancer Center trials in non-small cell lung cancer (NSCLC) and on the superior 1-year survival rates of NSCLC patients treated with carboplatin in a randomized study of cisplatin combination and analogues, we initiated a phase II trial of paclitaxel/carboplatin in patients with stage IV or effusion-positive stage III NSCLC. Eligibility stipulated chemotherapy-naive patients with measurable disease, good performance status, and adequate hematologic, hepatic, and renal function. Previous radiotherapy was restricted to < or = 30% of marrow-bearing bone. Paclitaxel was initially given at 135 mg/m2 over 24 hours followed by carboplatin dosed to a targeted area under the concentration versus time curve (AUC) of 7.5, with treatment repeated at 3-week intervals for six cycles. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, with the paclitaxel dose sequentially escalated in 40 mg/m2 increments to a maximum dose of 215 mg/m2 in patients with less than grade 4 granulocytopenia and less than grade 3 thrombocytopenia. Of 54 patients enrolled, 30 currently are evaluable for response, 23 for toxicity. Myelosuppression has been the principal toxicity, with grade 3 or 4 granulocytopenia occurring in 70% of patients after the first cycle. After the introduction of granulocyte colony-stimulating factor, granulocytopenia decreased to 37% during the second cycle and then consistently to 20% or lower during subsequent cycles. Only 22% of cycles have been delayed for 1 week or more. Neutropenic fever has occurred in five (5%) of 100 evaluable cycles. Other grade 3 or 4 toxicities include thrombocytopenia (13%), anemia (9%), fatigue (9%), and hemorrhagic cystitis (1%). The paclitaxel dose was boosted to 215 mg/m2 in 12 (70%) of 17 patients by cycle 3 or 4. At an AUC of 7.5, the median first-cycle carboplatin dose was 434 mg/m2 (range, 293 to 709 mg/m2). The objective response rate is 50%, with three complete, 12 partial, and five minor responses. We conclude that the paclitaxel/carboplatin combination is active in advanced NSCLC and, with AUC-based dosing of carboplatin, can be given at 3-week intervals. Although dose limiting at a paclitaxel dose of 135 mg/m2, granulocytopenia can be reduced substantially with granulocyte colony-stimulating factor, allowing sequential dose escalation of paclitaxel to 175 mg/m2 and 215 mg/m2 in 70% of patients receiving three or more cycles.

Aggressive Treatment for Postcardiac Transplant Lymphoproliferation

Posttransplant lymphoproliferative disorder (PTLD) is a frequently fatal complication of organ transplantation, occurring in 2% to 6% of cardiac recipients. Treatment remains poorly defined. Reduction in immunosuppression is effective in a proportion of cases, but mortality on the order of 80% is reported for patients requiring chemotherapy. The reason for such poor outcomes is unclear, but may be partly caused by the concomitant use of immunosuppressives. Nineteen consecutive cardiac recipients with PTLD were studied retrospectively in terms of clinical features and outcome. Patients were managed according to a uniform treatment approach. Initial therapy was a trial of reduced immunosuppression with concomitant acyclovir followed, if unsuccessful, by aggressive combination chemotherapy. The regimen used was predominantly ProMACE-CytaBOM. Six patients with phenotypically polyclonal PTLD presented less than 6 months after transplantation (median 6 weeks). Only 1 of 4 (25%) treated patients responded to reduced immunosuppression; the remainder died of multiorgan failure. Thirteen patients presented with phenotypically monoclonal disease > or = 6 months after transplantation. In 8 of 12 (75%) treated patients initial therapy was reduction in immunosuppression. None achieved complete remission (CR) and 2 experienced fatal rejection. Two patients achieved durable surgical CR. The remaining 8 patients received chemotherapy; 2 of 8 (25%) died during treatment, 6 of 8 (75%) achieved CR. None have relapsed, at a median duration of follow-up of 38 months. Neutropenic sepsis and subclinical doxorubicin cardiotoxicity at a mean cumulative dose of 63 mg/m2 were the principal toxicities. Our data indicate that aggressive chemotherapy is both feasible and effective in phenotypically monoclonal PTLD refractory to reduced immunosuppression. ProMACE-CytaBOM is well suited to cardiac recipients, minimizing doxorubicin exposure and obviating the need for concurrent immunosuppressives.

Autologous bone marrow transplantation for advanced neuroblastoma using teniposide, doxorubicin, melphalan, cisplatin, and total-body irradiation.

Disseminated neuroblastoma after infancy has a dismal prognosis; long-term survival with conventional therapy occurs in approximately 10% of cases. Between 1985 and 1992, we followed a strategy aimed to achieve remission with an induction combination of intensive chemotherapy, primary resection, and tumor-bed radiotherapy (TBRT). Patients who achieved remission proceeded to myeloablative chemoradiotherapy and unpurged autologous bone marrow transplant (ABMT). Twenty-eight patients older than 1 year presented with stage IV disease during the study period; six died of progressive disease and three died of complications of therapy. Nineteen patients achieved remission, two of whom did not receive ABMT. Seventeen patients proceeded to ABMT. Conditioning was with teniposide 130 mg/m2, doxorubicin 30 mg/m2, melphalan 120 mg/m2, cisplatin 80 mg/m2, and total-body irradiation 12 Gy in six fractions (modified VAMP-TBI). Principal nonhematologic toxicities were mucositis and diarrhea. There were no ABMT-related deaths. Two patients relapsed at 8 and 26 months post-ABMT, respectively. Fifteen patients remain in complete remission (CR) at 24 to 102 months (median, 71) from ABMT and 30 to 114 months (median, 78) from diagnosis. Survival rates of all 28 patients are 61% and 50% at 2 and 5 years, respectively, and the disease-free survival (DFS) of the ABMT group is 94% and 87% at 2 and 5 years, respectively. Modified VAMP-TBI appears to be an effective conditioning regimen, with 15 of 17 patients remaining disease-free, with no toxic deaths. This result compares favorably with that of other groups. Larger numbers of patients need to be treated to confirm the efficacy of this therapy.

Cyclosporin, leflunomide and nitrogen mustard

Cyclosporin A (CSA) Cyclosporin inhibits IL-2 release and T-cell activation and, secondarily, affects B-cell function. It also inhibits bone resorption, at least in vitro. This drug's bio-availability averages 25-35% but is highly variable. Food and grapefruit juice enhance bio-availability and newer formulations may make its absorption more reliable. It is highly concentrated in fatty tissues and red blood cells but does not cross the blood-brain barrier. CSA is metabolized to numerous metabolites by the liver and its elimination half-life is 6-12 hours in the absence of severe liver disease. Biliary excretion accounts for 94% of CSAs elimination. Because it is highly metabolized, its metabolism can be inhibited by other drugs (e.g. ketoconazole and erythromycin) or its metabolism can be induced (e.g. anticonvulsants). Cyclosporin is more effective than placebo for the treatment of rheumatoid arthritis and as effective as other antirheumatics. There is potential for the use of CSAs in DMARD combinations. The principal toxicities of cyclosporin are gastro-intestinal and renal, with the latter being of more concern. Leflunomide (LF). Leflunomide may be a pyrimidine synthesis inhibitor, although tyrosine kinase inhibitor may also be part of its mechanism of action. Its active metabolite is excreted renally to a large degree, with a prolonged elimination half-life of about 11 days. Since LF is activated by liver metabolism, renal failure may have less effect on kinetics than severe liver disease. Early data on efficacy indicate efficacy at 10-25 mg/day, although more well-controlled data is necessary. Toxicity relates to the skin, liver and GI tract, although some degree of weight loss was also found. Nitrogen mustard (NM). Nitrogen mustard is an alkylating agent whose pharmacokinetics are poorly understood. Small, open studies in RA indicate that NM has a potential for relatively rapid response (1-2 weeks) but, clearly, much work remains to be done. As an alkylating agent, GI and hematological toxicities are of greatest concern.