Microdosing in early lead discovery.

Microdosing provides a tool to enhance drug development by initiating human studies prior to Phase I studies. The purpose is to assist in the go versus no-go decision-making process and to eliminate early ineffective compounds from the drug pipeline. Selection of multiple potential leads can be performed at the clinical stage instead of in preclinical studies. The microdosing approach can be easily used for a molecularly targeted potential drug compound with a known mechanism of action. It provides useful data regarding accessibility and biodistribution that can be used in many estimations benefiting the development of the molecule. In addition, steady state and genetic investigations are becoming possible. Microdosing has a sparing effect on timelines and costs, however, the real importance is not yet known because, although it is known to be widely performed, only a few original reports have been published.

Docetaxel-ifosfamide combination chemotherapy in patients with metastatic hormone-refractory prostate cancer: a phase I pharmacokinetic study.

This phase I study was designed to evaluate the activity toxicity and pharmacokinetics of docetaxel combined with ifosfamide in the treatment of hormone-refractory prostate cancer. Ten patients received a median of 4.6 treatment cycles. Docetaxel was administered at a dose of 40 mg/m2 in a 1-hour infusion followed by ifosfamide 3,000 mg/m2 in a 24-hour infusion every 3 weeks. The optimal sequence of chemotherapeutic agents was investigated by reversing the order of administration in the second cycle and by collecting a total of six pharmacokinetic blood samples per cycle from all patients during the first and second cycles. The sequence of administration did not influence the pharmacokinetics of docetaxel. Prostate-specific antigen (PSA) responses were observed in four out of nine patients, with a PSA response rate of 44.4% (complete response + partial response). The treatment was well tolerated. No grade IV toxicities were recorded and grade III leucopenia resulted in dose-reductions in 6 cycles (13.3%). The pharmacokinetic parameters of docetaxel were similar in both sequences. Our recommendation for further phase II studies is ifosfamide followed by low-dose docetaxel. Further phase II efficacy studies are warranted.

Pharmacokinetics of a 24-hour intravenous ketoprofen infusion in children.

BACKGROUND: No pharmacokinetic data are available with respect to the plasma concentration of ketoprofen during intravenous infusion in children. METHODS: We present here the pharmacokinetics of ketoprofen after a 10-min intravenous infusion of 1 mg/kg followed by a 24-h infusion of 4 mg/kg in 18 children aged 7 months to 16 years. Venous blood samples were collected at 5 min, 1, 2, 4, 24 h following the loading dose, and then 1, 2 and 4 h after the end of the infusion. A validated HPLC method was used to measure plasma levels of ketoprofen. RESULTS: The steady state plasma concentration of ketoprofen was 2.0 microg/mL (range 1.3-2.7 microg/mL). The clearance of ketoprofen was 0.09 L x h(-1) x kg(-1) (range 0.06-0.13 L x h(-1) x kg(-1)). The distribution volume was 0.16 L/kg (range 0.12-0.21 L/kg). The terminal half-life was 1.3 h (range 0.8-1.7 h). CONCLUSION: The pharmacokinetics of ketopofen in children is similar to that reported in adults. Our results indicate that ketoprofen is a feasible drug for continuous intravenous infusion in acute pain treatment in children.

Docetaxel and irinotecan (CPT-11) in the treatment of malignant pleural mesothelioma--a feasibility study.

We chose to treat malignant pleural mesothelioma with a combination of docetaxel and irinotecan (CPT-11), because there have been preliminary reports that CPT-11 is active against mesothelioma, and docetaxel and CPT-11 were the most active agents in our in vitro experiments in human mesothelioma cell lines. Fifteen previously untreated patients with pleural mesothelioma (IMIG Stage III-IV) were given docetaxel 60 mg/m2 followed by CPT-11 190 mg/m2 on day 1, repeated every 3 weeks. All the patients were evaluable for toxicity and 13 patients were evaluated for response. No objective responses (complete or partial) were achieved, but there were two minor responses (overall response rate 15%) each of a duration of 4 months. Three patients had stable disease (23%); median time to progression was 7 months. Median survival in all the patients was 8.5 months from the first chemotherapy cycle and 11 months from diagnosis. Toxicity was severe with seven of 15 patients suffering neutropenic fever and six of 15 patients grade 3-4 diarrhea. The trial was discontinued because of toxicity and lack of activity. We do not recommend the combination of docetaxel and CPT-11 using the schedule presented here for further investigation in malignant mesothelioma. However, CPT-11 and docetaxel, individually, still warrant further study in this disease, especially in combination with cisplatin.

Treatment of mosquito bites with ebastine: a field trial.

Wealing and pruritic, long-lasting papules are a common nuisance from mosquito bites. Antihistamines can be expected to decrease wealing, but their effect on the delayed bite symptoms needs to be elucidated. We studied the effect of ebastine in 28 mosquito-bite sensitive adult subjects exposed to Aedes communis bites in the field. Ebastine 20 mg and placebo were given for 4 days in a cross-over fashion, and the size of the bite lesion and the intensity of pruritus (visual analogue scale) were measured at 15 min and 2, 6 and 24 h after the bites. Ebastine decreased significantly (p <0.001) the size of the bite lesion and pruritus at 15 min. Ebastine also had a significant effect (p<0.01) on pruritus at 2 and 24 h, and this effect was highly significant when the measurements at all 4 time points were pooled. Five patients (18%) on ebastine, but none on placebo, experienced sedation (ns). The present field study shows that ebastine 20 mg given prophylactically is effective against immediate mosquito bite symptoms, and that it also significantly decreases pruritus associated with the delayed bite papules.

Treatment of acute low back pain with the COX-2-selective anti-inflammatory drug nimesulide: results of a randomized, double-blind comparative trial versus ibuprofen.

STUDY DESIGN: A prospective, randomized double-blind comparative trial. OBJECTIVES: To evaluate the efficacy and tolerability of nimesulide, a cyclooxygenase (COX)-2-selective anti-inflammatory agent versus ibuprofen in patients with acute lumbosacral back pain. SUMMARY OF BACKGROUND DATA: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been more effective than placebo in patients with uncomplicated acute low back pain in previous randomized controlled trials. The efficacy and tolerability of a new COX-2-selective anti-inflammatory drug have not yet been established. METHODS: One hundred four patients aged 18-65 years with acute low back pain were enrolled. The patients were randomly allocated either to oral nimesulide (100 mg twice daily for 10 days) or oral ibuprofen (600 mg three times daily for 10 days). Outcome measures on a visual analog scale were an average of the pain intensity and the pain relief, stiffness in the back, functional status, and the results of physical examinations. All side effects were recorded at each visit. RESULTS: With both study therapies, there was a clear improvement in all measured parameters of the pain and back function parameters measured from the third day of treatment onward. The patients' capacity for daily tasks, showed improvement in both groups (P < 0. 001), but a statistically significant difference was found between the two groups in favor of the nimesulide group (P < 0.05) after 10 days. Nimesulide was more effective than ibuprofen in improved lateral bending measurements (P = 0.026). Nimesulide and ibuprofen provided similar degrees of improvement in the modified Schober tests and in the pain intensity and back stiffness scores. More gastrointestinal side effects were reported with ibuprofen than nimesulide, and the comparison showed a trend (P = 0.067). Ten side effects occurred in the nimesulide group in 7 (13%) patients and 13 in the ibuprofen group in 11 (21%) patients. CONCLUSIONS: The results confirmed that the COX-2-selective inhibitor nimesulide is an effective and well-tolerated agent for use in general practices to treat acute low back pain. The incidence of gastrointestinal side effects seems to be lower with nimesulide than with ibuprofen.

In vitro sensitivity of normal human mesothelial and malignant mesothelioma cell lines to four new chemotherapeutic agents.

In this study, we used four human mesothelioma cell lines (M14K, M24K, M25K and M38K), one transformed human mesothelial cell line (MeT-5A) and one primary mesothelial culture (UPL) to test for in vitro sensitivity to docetaxel, paclitaxel, SN-38 [an active metabolite of irinotecan (CPT-11)] and gemcitabine, as single agents. Subconfluent cell cultures were treated with 2x10(-9), 5x10(-9), 10(-8), 2x10(-8) and 5x10(-8) M concentrations of each drug for 48 h. The sensitivity was measured in terms of cell viability using the Trypan blue exclusion method. All four drugs were potent inhibitors of mesothelioma cell growth, but cell lines from different patients diverged in their sensitivity to the individual agents. In most cases docetaxel, paclitaxel and SN-38 were more potent killers of mesothelioma cells than gemcitabine. The induction of DNA damage was investigated using the Comet assay; cells from two cell lines (M14K and M25K) were treated with subtoxic 10(-8) M concentrations of each drug for 4, 24 and 48 h. Each of the agents caused a slight increase in DNA single-strand breaks at a concentration of 10(-8) M.

Endoglin is a suitable target for efficient imaging of solid tumors: in vivo evidence in a canine mammary carcinoma model.

Increasing evidence suggests that endoglin (CD105) is a new powerful marker of neovascularization in solid malignancies; thus, using breast cancer as a model, we investigated whether targeting of CD105 by monoclonal antibody (mAb) MAEND3 can be used for in vivo imaging of solid tumors. Immunohistochemistry and flow cytometry identified differential expression of CD105 on breast cancer and endothelial cells; in fact, neoplastic cells were weakly and rarely stained by mAb MAEND3, which in contrast, strongly and invariably stained blood vessel endothelia within the breast adenocarcinomas investigated and cultured endothelial cells. Moreover, in contrast to CD31, which currently represents the reference marker to assess angiogenetic activity, CD105 expression was highest in semiconfluent and actively proliferating endothelial cells, and it progressively decreased as cells reached tight confluency and low [3H]thymidine uptake. i.v. administration of 18 MBq of 125I-labeled mAb MAEND3 efficiently imaged spontaneous mammary adenocarcinomas in two dogs; the uptake of radiolabeled mAb was rapid and intense because tumor: background ratios of 8.2:1 and 9.3:1 were reached 8 h after mAb administration, in the absence of immediate and/or long-term clinical side effects. Altogether, our present data suggest that targeting of CD105 on tumor-associated blood vessels may represent a new strategy for in vivo imaging of solid malignancies, regardless of their histological origin.

Pharmacokinetics of ketoprofen syrup in small children.

Ketoprofen is a nonsteroidal anti-inflammatory drug with analgesic, anti-inflammatory, and antipyretic properties. Its pharmacokinetics has not been determined in small children. The objective here was to determine the pharmacokinetics of ketoprofen syrup, 0.5 mg/kg, in two groups of 10 children. Group 1 was from ages 6 months up to 2 years (7/10 younger than 1 year), and Group 2 was from ages 2 to 7 years. Venous blood samples were collected before drug administration and 0.5, 1, 2, 4, 6, 8, and 12 hours after. A validated HPLC method was used to determine plasma levels of ketoprofen. The lower limit of quantification was 0.02 microgram/ml of plasma. Ketoprofen syrup was absorbed rapidly, the plasma level reaching its maximum at 0.5 hours, with C0.5 hours = 3 micrograms/ml. The pharmacokinetics was similar between the two groups of children. The elimination half-life, 2.0 hours in Group 1 or 1.9 hours in Group 2, was similar to that reported in adults.

Phase II study of docetaxel alternating with cisplatin in chemotherapy-naïve patients with advanced non-small cell lung cancer.

The objective of this study was to evaluate a regimen of full doses of docetaxel and cisplatin, using an alternating schedule, as first-line therapy for patients with inoperable non-small cell lung cancer (NSCLC). The standard concomitant schedule does not allow full doses of both drugs to be administered. We wanted to see if there was an advantage to be gained by administering full doses of both docetaxel and cisplatin, using a different schedule. Docetaxel 100 mg/m2 was given once every 6 weeks from week 1 and cisplatin (120 mg/m2 for two doses and 100 mg/m2 thereafter) once every 6 weeks from week 4, for six cycles (three docetaxel and three cisplatin). Thirty-six of the 44 patients enrolled were evaluable for efficacy. Forty-eight percent of the patients had good (KPS 90-100%) performance status. A median of five cycles was administered, for which no dose reductions were necessary. There were 13 of 36 partial responses (36%; 95% CI 21-54%) and 15 of 36 patients achieved stable disease (42%). The median duration of response was 10.5 months, the median time to progression was 4.5 months and the median survival was 9 months. The 1 and 2 year survival rates were 39 and 16%, respectively. The most frequent grade 3-4 toxicities were nausea (23% of patients), vomiting (18%) and neutropenia (77%). Infections were also common, but not severe. The alternating schedule produced response, toxicity and survival figures that compared favorable with those using the concomitant schedule. This study could serve as a model for future studies of non-cisplatin-containing regimens, in which full doses of docetaxel could alternate with full doses of other new agents active against NSCLC.

High response rate with a lower dose of paclitaxel in combination with cisplatin in heavily pretreated patients with advanced breast carcinoma.

BACKGROUND: Paclitaxel has been found to be efficacious in the treatment of breast carcinoma either when administered alone or in combination with other anticancer agents. Synergistic interaction between paclitaxel and cisplatin has been demonstrated in vitro. METHODS: Thirty-two patients with breast carcinoma that was resistant to anthracyclines and to several other antineoplastic agents were selected to receive 80 mg/m(2) of paclitaxel on Day 1 and 80 mg/m(2) of cisplatin on Day 2 with a 3-week interval between the courses. RESULTS: High response rates were observed, with 3 complete responses (9.4%) and 13 partial responses (40.6%) reported. Furthermore, the disease remained stable in 7 patients (21.9%) and progressed in only 9 patients (28.1%). CONCLUSIONS: The results show that high response rates can be achieved with the combination of paclitaxel and cisplatin, even in heavily pretreated breast carcinoma patients. The combination of paclitaxel plus cisplatin was found to be highly efficacious and well tolerated.

Granulocyte macrophage-colony stimulating factor (GM-CSF) and sucralfate in prevention of radiation-induced mucositis: a prospective randomized study.

PURPOSE: To compare subcutaneously given molgramostim (GM-CSF) and sucralfate mouth washings to sucralfate mouth washings in prevention of radiation-induced mucositis. METHODS AND MATERIALS: Forty head and neck cancer patients were randomly assigned to use either GM-CSF and sucralfate (n = 20) or sucralfate alone (n = 20) during radiotherapy. Sucralfate was used as 1.0 g mouth washing 6 times daily after the first 10 Gy of radiotherapy, and 150-300 microg GM-CSF was given subcutaneously. The grade of radiation mucositis and blood cell counts were monitored weekly. Salivary lactoferrin was measured as a surrogate marker for oral mucositis. RESULTS: We found no significant difference between the molgramostim and the control groups in the oral mucositis grade, oral pain, use of analgesic drugs, weight loss, or survival. The median maximum neutrophil counts (median, 9.2 x 10(9)/L vs. 5.9 x 10(9)/L, p = 0.0005), eosinophil counts (median, 1.3 x 10(9)/L vs. 0.2 x 10(9)/L, p = 0.0004), and salivary lactoferrin concentrations were higher in patients who received GM-CSF. The most common toxicities in the GM-CSF plus sucralfate group were skin reactions at the GM-CSF injection site (65%), fever (30%), bone pain (25%), and nausea (15%), whereas the toxicity of sucralfate given alone was minimal. CONCLUSION: We found no evidence indicating that subcutaneously given GM-CSF reduces the severity of radiation-induced mucositis.

Docetaxel, a promising novel chemotherapeutic agent in advanced breast cancer.

UNLABELLED: Clinical practice in chemotherapy of breast cancer is undergoing changes. This study investigated the efficacy and toxicity of docetaxel, a novel chemotherapeutic agent in metastatic breast cancer. Focus was on the effect of the cumulative dose of previous anthracycline treatment on response rate, toxicity and survival in our own patients; published data were reviewed. PATIENTS AND METHODS: Thirty-one women, (median age 52 years, range 40-65) treated for metastatic breast cancer with docetaxel were included. RESULTS: The overall response rate was 48%, with 3 complete and 11 partial responses (95% CI 29-66). The duration of response was 7 months (range 2 to 16 months), the median overall survival after docetaxel 13.7 months for responding patients, 14.3 months in no-change patients and 6.5 months in patients with progressive disease. The mean cumulative anthracycline dose prior to docetaxel was 860 mg (range 200-1760 mg); in the case of responders, the previous cumulative total epirubicin doses were 200-1575 mg (median 766 mg.). Total dose or schedule of previous epirubicin treatment had no impact on docetaxel response rate, toxicity or survival. The response seen in this study is within the published range (24 to 60%) observed for docetaxel in anthracycline-treated patients. CONCLUSION: We conclude that docetaxel is active in metastatic breast cancer even as third- line treatment. Previous treatment with, or response to, epirubicin does not influence the response to docetaxel and this promising new drug is currently being tested for adjuvant use in breast cancer.

131I radioconjugated antibodies for the locoregional radioimmunotherapy of high-grade malignant glioma--phase I and II study.

Locoregional radioimmunotherapy (LR-RIT) was administered to 111 patients (20 were recruited in a phase I and 91 in a phase II study) with malignant gliomas: 1 patient with oligodendroglioma, 7 patients with anaplastic oligodendroglioma, 2 with grade II astrocytoma, 10 with anaplastic astrocytoma and 91 with glioblastoma, amounting to 58 newly diagnosed and 53 recurrent tumours. The 131I-labelled monoclonal antibodies BC-2 and BC-4 were used in order to recognize stromal and intracellular glycoprotein tenascin, an antigen present particularly in glioblastoma. The patients were enrolled between February 1990 and December 1997 after conventional therapy. The radiopharmaceutical was injected directly into the tumour site. Sequential scintigraphies demonstrated a high and enduring uptake in the tumour. The mean irradiation dose in the tumour was 300 Gy per cycle. In the group of 74 phase II glioblastoma patients the clinical responses were as follows: 10 patients with stable disease (SD), 9 with partial responses (PR), 23 with no evidence of disease (NED) and 1 patient with complete response (CR). The median survival was 19 months. The response rate (CR + PR + NED) was 17.8% for those patients with bulky lesions, with a median survival of 17 months, but 66.6% for patients with small lesions, with a median survival of 25 months. Better outcomes were recorded in cases with less aggressive diseases: oligodendroglioma, anaplastic oligodendroglioma and anaplastic astrocytoma. We conclude that fractionated LR-RIT can be safely performed, with promising results especially in patients with minimal disease.

The use of TL detectors in dosimetry of systemic radiation therapy.

A method for determining absorbed doses to organs in systemic radiation therapy (SRT) is evaluated. The method, based on thermoluminescent (TL) dosimeters placed on the patient's skin, was validated and justified through a phantom study showing that the difference between measured (TL dosimeters in the phantom) and derived (TL method) values is within 10%. Six radioimmunotherapy (RIT) patients with widespread intraperitoneal pseudomyxoma were also studied. In dose evaluations, special emphasis was on kidneys. In addition to the TL method, the absorbed doses to kidneys were calculated using MIRD formalism and a point dose kernel technique. We conclude that in SRT the described TL method can be used to estimate the absorbed doses to those critical organs near the body surface within 50% (1 SD).

Prognostic value of tumour vascularity in metastatic melanoma and association of blood vessel density with vascular endothelial growth factor expression.

Tumour angiogenesis is essential for tumour growth and metastasis. Several lines of evidence indicate that vascular endothelial growth factor (VEGF) is a major regulator both of physiological and pathological angiogenesis. In this study we assessed the blood vessel density and VEGF expression of 94 melanoma metastases of 70 patients by immunohistochemistry, utilizing antibodies against human platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) and VEGF. The number of blood vessels ranged from 4 to 131 vessels/high power field (HPF), with a mean value of 32 vessels/HPF (+/-21) and a median of 29 vessels/ HPF. Survival since diagnosis of the primary disease and from the start of chemoimmunotherapy, as well as the disease-free survival period, was significantly shorter in the high vascularity group of patients compared with the low vascularity group (P< 0.05 and P< 0.01, respectively). A high overall expression of VEGF in the metastatic melanoma samples was observed. The degree of VEGF expression appeared to have a strong association with the blood vessel density (P= 0.017). This study demonstrates the clinical role of tumour vascularity in the prognosis of patients with metastatic melanoma. In addition, the strong association between vascularity and VEGF expression suggests a crucial role for this growth factor in the neovascularization of metastatic melanoma.

Concomitant chemotherapy and IFN-alpha for small cell lung cancer: a randomized multicenter phase III study.

Patients with any stage of small cell lung cancer were given low-dose interferon-alpha (IFN-alpha) from the first day of treatment as long as possible irrespective of changes in treatment dictated by disease progression. All patients received 6 cycles of the chemotherapy (CT): cisplatin 70 mg/m2 i.v. day 1 and etoposide 100 mg/m2 i.v. days 1, 2, 3 every 28 days. Seventy-eight patients were assigned to arm 1: CT alone, 75 patients to arm 2: CT + natural IFN-alpha (3 MU three times a week i.m.), and 66 patients to arm 3: CT + recombinant IFN alpha-2a (3 MU three times a week i.m.). There was no difference in median survival between the arms (10.2 months, 10.0 months, 10.1 months, respectively), p = 0.32. The 2-year survival rates were 15%, 3%, and 11%, respectively. Grade 3 and 4 leukopenia occurred more frequently in the IFN arms than in the CT alone arm and resulted in dose reductions. Antibodies occasionally developed to recombinant IFN. We conclude that IFN-alpha can be administered concomitantly with chemotherapy but is probably better kept for maintenance therapy so that optimal full doses of induction CT can be given.

Paclitaxel (Taxol) and carboplatin followed by concomitant paclitaxel, cisplatin and radiotherapy for inoperable stage III NSCLC.

We assessed the efficacy and toxicity of low-dose paclitaxel (Taxol) given combined with carboplatin before radiotherapy, and with cisplatin concomitantly with radiotherapy, in 27 patients with previously untreated inoperable stage IIA/IIIB non-small cell lung cancer. The induction chemotherapy consisted of paclitaxel 135 mg/m2 given over 1 h on day 1 and carboplatin 200 mg/m2 on day 2 repeated every 3 weeks for three cycles. Patients free of progression after induction chemotherapy received megavoltage radiation (56 Gy, 2 Gy/fraction) along with paclitaxel (30 mg/m2/1 h) and cisplatin (30 mg/m2/1 h) given 2-4 h before irradiation on days, 1, 2, 3, 22, 23 and 24. A combination of antero-posterior and oblique treatment fields was used to limit the dose to the spinal cord and to the left side of the heart to 36 Gy. The overall response rate was 78% (complete response, 19%). With a median follow-up of 19 months the median survival is 12 months, the estimated 2-year survival rate is 36%, and all patients with a complete response survived for at least 12 months after starting treatment. A total of 17 deaths occurred with metastases predominantly in the brain. Major acute toxicities (> grade 3) during induction chemotherapy included leuko-/neutropenia (n = 5/27, 19%), and during chemoradiotherapy leuko-/neutropenia (n = 10/23, 43%), thrombocytopenia (n = 1, 4%), oesophagitis (n = 3, 13%) and pneumonitis (n = 7, 30%). No toxic deaths occurred. Marked renal toxicity was not observed. We conclude that this chemoradiotherapy regimen is effective and well-tolerated, and should be further evaluated in a randomised phase III trial.