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Biomedical subjects

Tomohide Tamura

Publications and source records attributed to Tomohide Tamura.

At least 37 records · Page 2Linked to original sources

Functional characterization of five novel CYP2C8 variants, G171S, R186X, R186G, K247R, and K383N, found in a Japanese population.

Cytochrome P450 2C8 is one of the primary enzymes responsible for the metabolism of a wide range of drugs such as paclitaxel, cerivastatin, and amiodarone. We have sequenced the CYP2C8 gene from 201 Japanese subjects and found five novel nonsynonymous single nucleotide polymorphisms (SNPs): 511G>A (G171S), 556C>T (R186X; X represents the translational stop codon), 556C>G (R186G), 740A>G (K247R), and 1149G>T (K383N), with the allele frequency of 0.0025. The CYP2C8 variants were heterologously expressed in COS-1 cells and functionally characterized in terms of expression level, paclitaxel 6alpha-hydroxylase activity, and intracellular localization. The prematurely terminated R186X variant was undetectable by Western blotting and inactive toward paclitaxel 6alpha-hydroxylation. The G171S, K247R, and K383N variants exhibited properties similar to those of the wild-type CYP2C8. Paclitaxel 6alpha-hydroxylase activity of the R186G transfectant was only 10 to 20% that of wild-type CYP2C8. Furthermore, the R186G variant displayed a lower level of protein expression in comparison to the wild type, which was restored by the addition of a proteasome inhibitor (MG-132; Z-Leu-Leu-Leu-aldehyde). The reduced CO-difference spectral analysis using recombinant proteins from an insect cell/baculovirus system revealed that the R186G variant has a minor peak at 420 nm in addition to the characteristic Soret peak at 450 nm, suggesting the existence of improperly folded protein. These results indicate that the novel CYP2C8 SNPs, 556C>T (R186X) and 556C>G (R186G), could influence the metabolism of CYP2C8 substrates such as paclitaxel and cerivastatin.

Animals↗

Randomized pharmacokinetic and pharmacodynamic study of docetaxel: dosing based on body-surface area compared with individualized dosing based on cytochrome P450 activity estimated using a urinary metabolite of exogenous cortisol.

PURPOSE: Docetaxel is metabolized by cytochrome P450 (CYP3A4) enzyme, and the area under the concentration-time curve (AUC) is correlated with neutropenia. We developed a novel method for estimating the interpatient variability of CYP3A4 activity by the urinary metabolite of exogenous cortisol (6-beta-hydroxycortisol [6-beta-OHF]). This study was designed to assess whether the application of our method to individualized dosing could decrease pharmacokinetic (PK) and pharmacodynamic (PD) variability compared with body-surface area (BSA) -based dosing. PATIENTS AND METHODS: Fifty-nine patients with advanced non-small-cell lung cancer were randomly assigned to either the BSA-based arm or individualized arm. In the BSA-based arm, 60 mg/m(2) of docetaxel was administered. In the individualized arm, individualized doses of docetaxel were calculated from the estimated clearance (estimated clearance = 31.177 + [7.655 x 10(-4) x total 6-beta-OHF] - [4.02 x alpha-1 acid glycoprotein] - [0.172 x AST] - [0.125 x age]) and the target AUC of 2.66 mg/L . h. RESULTS: In the individualized arm, individualized doses of docetaxel ranged from 37.4 to 76.4 mg/m(2) (mean, 58.1 mg/m(2)). The mean AUC and standard deviation (SD) were 2.71 (range, 2.02 to 3.40 mg/L . h) and 0.40 mg/L . h in the BSA-based arm, and 2.64 (range, 2.15 to 3.07 mg/L . h) and 0.22 mg/L . h in the individualized arm, respectively. The SD of the AUC was significantly smaller in the individualized arm than in the BSA-based arm (P < .01). The percentage decrease in absolute neutrophil count (ANC) averaged 87.1% (range, 59.0 to 97.7%; SD, 8.7) in the BSA-based arm, and 87.4% (range, 78.0 to 97.2%; SD, 6.1) in the individualized arm, suggesting that the interpatient variability in percent decrease in ANC was slightly smaller in the individualized arm. CONCLUSION: The individualized dosing method based on the total amount of urinary 6-beta-OHF after cortisol administration can decrease PK variability of docetaxel.

Aged↗

Translational studies for target-based drugs.

The biological background for the clinical and prognostic heterogeneity among tumors within the same histological subgroup is due to individual variations in the biology of tumors. The number of investigations looking at the application of novel technologies within the setting of clinical trials is increasing. The most promising way to improve cancer treatment is to build clinical research strategies on intricate biological evidence. New genomic technologies have been developed over recent years. These techniques are able to analyze thousands of genes and their expression profiles simultaneously. The purpose of this approach is to discover new cancer biomarkers, to improve diagnosis, predict clinical outcomes of disease and response to treatment, and to select new targets for novel agents with innovative mechanisms of action. Gene expression profiles are also used to assist in selecting biomarkers of pharmacodynamic effects of drugs in the clinical setting. Biomarker monitoring in surrogate tissues may allow researchers to assess "proof of principle" of new treatments. Clinical studies of biomarkers monitoring toxicity profiles have also been done. Such pharmacodynamic markers usually respond to treatment earlier than clinical response, and as such may be useful predictors of efficacy. Epidermal growth factor receptor (EGFR) mutation in lung cancer tissues is a strong predictive biomarker for EGFR-targeted protein tyrosine kinase inhibitors. Monitoring of EGFR mutation has been broadly performed in retrospective and prospective clinical studies. However, global standardization for the assay system is essential for such molecular correlative studies. A more sensitive assay for EGFR mutation is now under evaluation for small biopsy samples. Microdissection for tumor samples is also useful for the sensitive detection of EGFR mutation. Novel approaches for the detection of EGFR mutation in other clinical samples such as cytology, pleural effusion and circulating tumor cells are ongoing.

Biomarkers, Tumor↗

Standard thoracic radiotherapy with or without concurrent daily low-dose carboplatin in elderly patients with locally advanced non-small cell lung cancer: a phase III trial of the Japan Clinical Oncology Group (JCOG9812).

BACKGROUND: The purpose of this study was to evaluate whether radiotherapy with carboplatin would result in longer survival than radiotherapy alone in elderly patients with unresectable stage III non-small cell lung cancer (NSCLC). METHODS: Eligible patients were 71 years of age or older with unresectable stage III NSCLC. Patients were randomly assigned to the radiotherapy alone (RT) arm, irradiation with 60 Gy; or the chemoradiotherapy (CRT) arm, the same radiotherapy and additional concurrent use of carboplatin 30 mg/m(2) per fraction up to the first 20 fractions. RESULTS: This study was terminated early when 46 patients were registered from November 1999 to February 2001. Four patients (one in the RT arm, three in the CRT arm) were considered to have died due to treatment-related causes. The JCOG Radiotherapy Committee assessed these treatment-related deaths (TRDs) and the compliance with radiotherapy in this trial. They found that 60% of the cases corresponded to protocol deviation and 7% were protocol violation in dose constraint to the normal lung, two of whom died due to radiation pneumonitis. As to the effectiveness for the 46 patients enrolled, the median survival time was 428 days [95% confidence interval (CI) = 212-680 days] in the RT arm versus 554 days (95% CI = 331 to not estimable) in the CRT arm. CONCLUSIONS: Due to the early termination of this study, the effectiveness of concurrent use of carboplatin remains unclear. We re-planned and started a study with an active quality control program which was developed by the JCOG Radiotherapy Committee.

Aged↗

Phase I pharmacokinetic and pharmacogenomic study of E7070 administered once every 21 days.

E7070 is a novel sulfonamide anticancer agent that disrupts the G1/S phase of the cell cycle. The objectives of this phase I study of E7070 were to estimate the maximal tolerated dose (MTD), to determine the recommended dose for phase II, and to clarify the pharmacokinetic profile of E7070 and its relation to polymorphisms of CYP2C9 (*2, *3) and CYP2C19 (*2, *3) in Japanese patients. Patients received 1-2-h i.v. infusions of E7070 (400, 600, 700, 800 or 900 mg/m2) on day 1 of a 21-day cycle. Twenty-one patients received between one and eight cycles of E7070. The dose-limiting toxicities (DLT) comprised leukopenia, neutropenia, thrombocytopenia, elevation of aspartate aminotransferase, colitis, and ileus. The mean area under the plasma concentration-time curve (AUC) for successive dose levels increased in a non-dose-proportional manner. Two patients were heterozygous for the CYP2C9 mutation. For CYP2C19, eight patients were wild type and the remainder had heterozygous (n = 8) or homozygous mutations (n = 5). Regarding the CYP2C19 genotype, the AUC of patients with mutant alleles were higher than those of patients with wild type at a dose of 600 mg/m2 or more. The severity of toxic effects, such as myelosuppression, seemed to depend on the AUC. No partial responses were observed. One patient treated at a dose of 700 mg/m2 experienced a maximum tumor volume reduction of 22.5%. The MTD was estimated to be 900 mg/m2. A dose of 800 mg/m2 is recommended for further phase II studies. The pharmacokinetic/pharmacodynamic properties of E7070 seemed to be influenced by CYP2C19 genotype. The observed safety profile and preliminary evidence of antitumor activity warrant further investigation of this drug in monotherapy or in combination chemotherapy.

Adult↗

Small in-frame deletion in the epidermal growth factor receptor as a target for ZD6474.

ZD6474 is an inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2/KDR) tyrosine kinase, with additional activity against epidermal growth factor receptor (EGFR) tyrosine kinase. ZD6474 inhibits angiogenesis and growth of a wide range of tumor models in vivo. Gefitinib ("Iressa") is a selective EGFR tyrosine kinase inhibitor that blocks signal transduction pathways implicated in cancer cell proliferation. Here, the ability of gefitinib and ZD6474 to inhibit tumor cell proliferation was examined directly in eight cancer cell lines in vitro, and a strong correlation was noted between the IC(50) values of gefitinib and ZD6474 (r = 0.79). No correlation was observed between the sensitivity to ZD6474 and the level of EGFR or VEGFR expression. The NSCLC cell line PC-9 was seen to be hypersensitive to gefitinib and ZD6474, and a small (15-bp) in-frame deletion of an ATP-binding site (exon 19) in the EGFR was detected (delE746-A750-type deletion). To clarify the involvement of the deletional mutation of EGFR in the cellular sensitivity to ZD6474, we examined the effect of this agent on HEK293 stable transfectants expressing deletional EGFR that designed as the same deletion site observed in PC-9 cells (293-pDelta15). These cells exhibited a 60-fold higher sensitivity to ZD6474 compared with transfectants expressing wild-type EGFR. ZD6474 inhibited the phosphorylation of the mutant EGFR by 10-fold compared with cells with wild-type EGFR. In conclusion, the findings suggested that a small in-frame deletion in the EGFR increased the cellular sensitivity to ZD6474.

Base Sequence↗

Synergistic interaction between the EGFR tyrosine kinase inhibitor gefitinib ("Iressa") and the DNA topoisomerase I inhibitor CPT-11 (irinotecan) in human colorectal cancer cells.

Epidermal growth factor receptor [EGFR (HER1, erbB1)] is a receptor with associated tyrosine kinase activity, and is expressed in colorectal cancers and many other solid tumors. We examined the effect of the selective EGFR tyrosine kinase inhibitor (EGFR-TKI) gefitinib ("Iressa") in combination with the DNA topoisomerase I inhibitor CPT-11 (irinotecan) on human colorectal cancer cells. EGFR mRNA and protein expression were detected by RT-PCR and immunoblotting in all 7 colorectal cancer cell lines studied. Gefitinib inhibited the cell growth of the cancer cell lines in vitro with an IC(50) range of 1.2-160 microM by 3,(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Lovo cells exhibited the highest level of protein and autophosphorylation of EGFR and were the most sensitive to gefitinib. The combination of gefitinib and CPT-11 induced supra-additive inhibitory effects in COLO320DM, WiDR and Lovo cells, assessed by an in vitro MTT assay. Administration of gefitinib and CPT-11 had a supra-additive inhibitory effect on WiDR cells and tumor shrinkage was observed in Lovo cell xenografts established in nude mice, whereas no additive effect of combination therapy was observed in COLO320DM cells. To elucidate the mechanisms of synergistic effects, the effect of CPT-11-exposure on phosphorylation of EGFR was examined by immunoprecipitation. CPT-11 increased phosphorylation of EGFR in Lovo and WiDR cells in time- and dose-dependent manners. This EGFR activation was completely inhibited by 5 microM gefitinib and gefitinib-induced apoptosis was enhanced by combination with CPT-11, measured by PARP activation although no PARP activation was induced by 5 microM CPT-11 alone. These results suggested that these modification of EGFR by CPT-11, in Lovo cells, is a possible mechanism for the synergistic effect of CPT-11 and gefitinib. These findings imply that the EGFR-TKI gefitinib and CPT-11 will be effective against colorectal tumor cells that express high levels of EGFR, and support clinical evaluation of gefitinib in combination with CPT-11, in the treatment of colorectal cancers.

Animals↗

Haplotypes of CYP3A4 and their close linkage with CYP3A5 haplotypes in a Japanese population.

In order to identify single nucleotide polymorphisms (SNPs) and haplotype frequencies of CYP3A4 in a Japanese population, the distal enhancer and proximal promoter regions, all exons, and the surrounding introns were sequenced from genomic DNA of 416 Japanese subjects. We found 24 SNPs, including 17 novel ones: two in the distal enhancer, four in the proximal promoter, one in the 5'-untranslated region (UTR), seven in the introns, and three in the 3'-UTR. The most common SNP was c.1026+12G>A (IVS10+12G>A), with a 0.249 frequency. Four non-synonymous SNPs, c.554C>G (p.T185S, CYP3A4(*)16), c.830_831insA (p.E277fsX8, (*)6), c.878T>C (p.L293P, (*)18), and c.1088 C>T (p.T363M, (*)11) were found with frequencies of 0.014, 0.001, 0.028, and 0.002, respectively. No SNP was found in the known nuclear transcriptional factor-binding sites in the enhancer and promoter regions. Using these 24 SNPs, 16 haplotypes were unambiguously identified, and nine haplotypes were inferred by aid of an expectation-maximization-based program. In addition, using data from 186 subjects enabled a close linkage to be found between CYP3A4 and CYP3A5 SNPs, especially among the SNPs at c.1026+12 in CYP3A4 and c.219-237 (IVS3-237, a key SNP site for CYP3A5(*)3), c.865+77 (IVS9+77) and c.1523 in CYP3A5. This result suggested that CYP3A4 and CYP3A5 are within the same gene block. Haplotype analysis between CYP3A4 and CYP3A5 revealed several major haplotype combinations in the CYP3A4-CYP3A5 block. Our findings provide fundamental and useful information for genotyping CYP3A4 (and CYP3A5) in the Japanese, and probably Asian populations.

Cytochrome P-450 CYP3A↗

Treatment of small cell lung cancer in the elderly based on a critical literature review of clinical trials.

At diagnosis, 25-40% of patients with small cell lung cancer (SCLC) are 70 years of age or older, and many of them have been undertreated because of fear of excessive toxicity associated with chemotherapy. Papers retrieved by a Medline search using the key words "elderly or older" and "small cell lung cancer" and by a manual search were classified into the three types: (1) case-series studies, (2) subgroup analyses of phase II and phase III trials by age, and (3) prospective clinical trials in the elderly. Treatment regimens, delivery, toxicity, antitumor activity, and patient survival were reviewed in elderly patients with good and poor general condition. The standard chemotherapy regimens for the general population could be applied to elderly patients in good general condition (performance status of 0-1, normal organ function, and no comorbidity), but etoposide and carboplatin regimen with dose modification was frequently used for unselected elderly patients. A combination of full-dose thoracic radiotherapy and chemotherapy was the treatment of choice for limited SCLC in the elderly. Full cycles of chemotherapy were tolerable by 80% of the elderly patients with good general condition, but two cycles may be optimal for unselected elderly patients. Although the evidence levels based on clinical trials available today are low, these results are helpful for clinical practice and future clinical trials for elderly patients with SCLC.

Age Factors↗

Risk factors for interstitial lung disease and predictive factors for tumor response in patients with advanced non-small cell lung cancer treated with gefitinib.

A high incidence of interstitial lung disease (ILD) has been reported in patients with non-small cell lung cancer (NSCLC) treated with gefitinib in Japan. We retrospectively analyzed 112 patients with advanced NSCLC who received gefitinib monotherapy. Univariate and multivariate analyses were used to identify risk factors for gefitinib-related ILD and predictive factors for tumor response to gefitinib. The incidence of ILD was 5.4%, and it was higher in the patients with pre-existing pulmonary fibrosis (33% versus 2%; P < 0.001). The results of a multivariate analysis showed that pulmonary fibrosis was a significant risk factor for ILD (odds ratio: 177, 95% confidence interval: 4.53-6927, P = 0.006). The response rate was 33% in the 98 evaluable patients and higher in women (53% versus 23%; P = 0.003), patients with adenocarcinoma (38% versus 6%; P = 0.010), never-smokers (63% versus 18%; P < 0.001), and the patients with no history of thoracic radiotherapy (39% versus 13%; P = 0.015). The results of a multivariate analysis showed that the predictors of tumor response were "no history of smoking" and "no history of thoracic radiotherapy". Never-smokers had a significantly longer survival time than smokers (P = 0.007). Although gefitinib therapy confers a clinical benefit on patients with advanced NSCLC, especially on women, patients with adenocarcinoma, never-smokers, and patients with no history of thoracic radiotherapy, it also poses a high risk of ILD, especially to patients with pulmonary fibrosis. The risk-benefit ratio must be carefully considered.

Adenocarcinoma↗

Anticancer effects of ZD6474, a VEGF receptor tyrosine kinase inhibitor, in gefitinib ("Iressa")-sensitive and resistant xenograft models.

ZD6474 is a novel, orally available inhibitor of vascular endothelial growth factor (VEGF) receptor-2 (KDR) tyrosine kinase, with additional activity against epidermal growth factor receptor (EGFR) tyrosine kinase. ZD6474 has been shown to inhibit angiogenesis and tumor growth in a range of tumor models. Gefitinib ("Iressa") is an selective EGFR tyrosine kinase inhibitor (TKI) that blocks signal transduction pathways. We examined the antitumor activity of ZD6474 in the gefitinib-sensitive lung adenocarcinoma cell line, PC-9, and a gefitinib-resistant variant (PC-9/ZD). PC-9/ZD cells showed cross-resistance to ZD6474 in an in vitro dye formation assay. In addition, ZD6474 showed dose-dependent inhibition of EGFR phosphorylation in PC-9 cells, but inhibition was only partial in PC-9/ZD cells. ZD6474-mediated inhibition of tyrosine residue phosphorylation (Tyr992 and Tyr1045) on EGFR was greater in PC-9 cells than in PC-9/ZD cells. These findings suggest that the inhibition of EGFR phosphorylation by ZD6474 can contribute a significant, direct growth-inhibitory effect in tumor cell lines dependent on EGFR signaling for growth and/or survival. The effect of ZD6474 (12.5-50 mg/kg/day p.o. for 21 days) on the growth of PC-9 and PC-9/ZD tumor xenografts in athymic mice was also investigated. The greatest effect was seen in gefitinib-sensitive PC-9 tumors, where ZD6474 treatment (>12.5 mg/kg/day) resulted in tumor regression. Dose-dependent growth inhibition, but not tumor regression, was seen in ZD6474-treated PC-9/ZD tumors. These studies demonstrate that the additional EGFR TKI activity may contribute significantly to the antitumor efficacy of ZD6474, in particular in those tumors that are dependent on continued EGFR-signaling for proliferation or survival. In addition, these results provide a preclinical rationale for further investigation of ZD6474 as a potential treatment option for both EGFR-TKI-sensitive and EGFR-TKI-resistant tumors.

Adenocarcinoma↗

Phase I study of cisplatin, vinorelbine, and concurrent thoracic radiotherapy for unresectable stage III non-small cell lung cancer.

To determine the recommended phase II dose of vinorelbine in combination with cisplatin and thoracic radiotherapy (TRT) in patients with unresectable stage III non-small cell lung cancer (NSCLC), 18 patients received cisplatin (80 mg/m2) on day 1 and vinorelbine (20 mg/m2 in level 1, and 25 mg/m2 in level 2) on days 1 and 8 every 4 weeks for 4 cycles. TRT consisted of a single dose of 2 Gy once daily for 3 weeks followed by a rest of 4 days, and then the same TRT for 3 weeks to a total dose of 60 Gy. Fifteen (83%) patients received 60 Gy of TRT and 14 (78%) patients received 4 cycles of chemotherapy. Ten (77%) of 13 patients at level 1 and all 5 patients at level 2 developed grade 3-4 neutropenia. Four (31%) patients at level 1 and 3 (60%) patients at level 2 developed grade 3-4 infection. None developed > or = grade 3 esophagitis or lung toxicity. Dose-limiting toxicity was noted in 33% of the patients in level 1 and in 60% of the patients in level 2. The overall response rate (95% confidence interval) was 83% (59-96%) with 15 partial responses. The median survival time was 30.4 months, and the 1-year, 2-year, and 3-year survival rates were 72%, 61%, and 50%, respectively. In conclusion, the recommended dose is the level 1 dose, and this regimen is feasible and promising in patients with stage III NSCLC.

Adult↗

[Subset analysis of data in the Japanese patients with NSCLC from IDEAL 1 study on gefitinib].

The multinational, multi-institutional clinical Phase II trial of gefitinib monotherapy, IDEAL (IRESSA Dose Evaluation in Advanced Lung Cancer) 1, included Japanese and non-Japanese patients with advanced non-small-cell lung cancer (NSCLC) pretreated with one or more chemotherapy regimens, at least one including platinum. To investigate whether survival is affected by gender or histological type of cancer, a retrospective, exploratory subset analysis was conducted including only Japanese patients from IDEAL 1 (n = 102 in total, 51 each in 250 and 500 mg/day groups). The median survival time of the 102 patients was 12.0 months and the one year survival rate was 50%. The median survival time was 13.8 months for the 250 mg/day group and 11.2 months for the 500 mg/day group and the one-year survival rate was 57% and 45% respectively. Survival was longer in patients with adenocarcinoma than those with other histological types of cancer, and was longer in those with symptom improvement than without. The median survival time in females was longer than that in males. The results suggest that gefitinib could be superior to classical anticancer agents with regard to not only the response rate but also survival time in patients with NSCLC, particularly adenocarcinoma, previously treated with chemotherapy. Further studies are needed to identify factors affecting survival.

Adult↗

Strategy for the development of novel anticancer drugs.

Progress in molecular pharmacology has demonstrated each anticancer drug to have a unique molecular target. Recent drug development has focused on compounds that specifically inhibit and/or modify tumor-specific molecular biological changes (target-based drug development). These compounds are generally classified as either small molecules or macromolecules. With the exception of antibodies, the majority of recently developed target-based drugs are small molecules. Assessing the effects of these compounds on their targets would probably help researchers to predict the antitumor effects of these anticancer drugs; however, actually assessing this hypothesis, even in preclinical models, is difficult. Most preclinical experiments attempt to show tumor growth inhibition or shrinkage, leading to a longer survival period or higher cure rate. Few experiments have examined the correlation between antitumor activity and the effect of a compound on its target. In phase I clinical trials of target-based drugs, the determination of maximum tolerated dose is not enough; the effect of the drug on its target should also be evaluated. Recently, dose-escalation strategies based on the effects of drugs on their targets have been proposed, even though an appropriate target effect is necessary but not sufficient to demonstrate clinical efficacy. Compounds that are not specifically directed against molecular targets on or within tumor cells, but against blood vessels, matrix, etc., usually do not cause tumor shrinkage. These compounds include angiogenesis inhibitors and matrix metalloproteinase inhibitors and are usually used in combination with other treatments at the start of clinical trials. Whether the methodology of clinical trials is sensitive enough to detect the subtle effects of these compounds remains uncertain. The effects of experimental drugs on their targets are rarely examined in clinical trials. Few data from translational studies are available and data obtained using surrogate tissues do not necessarily reflect the effects of the drugs on in situ tumors. Parameters such as time to progression, changes in tumor markers, and growth rates often vary significantly and are regarded as soft endpoints. Phase III trials evaluating survival benefit require extensive resources, including a large number of patients, a sophisticated data center, and well-trained study groups. The problems and future prospects of novel anticancer drug development are discussed.

Antineoplastic Agents↗

Multi-institutional randomized phase II trial of gefitinib for previously treated patients with advanced non-small-cell lung cancer (The IDEAL 1 Trial) [corrected].

PURPOSE: To evaluate the efficacy and tolerability of two doses of gefitinib (Iressa [ZD1839]; AstraZeneca, Wilmington, DE), a novel epidermal growth factor receptor tyrosine kinase inhibitor, in patients with pretreated advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This was a randomized, double-blind, parallel-group, multicenter phase II trial. Two hundred ten patients with advanced NSCLC who were previously treated with one or two chemotherapy regimens (at least one containing platinum) were randomly assigned to receive either 250-mg or 500-mg oral doses of gefitinib once daily. RESULTS: Efficacy was similar for the 250- and 500-mg/d groups. Objective tumor response rates were 18.4% (95% confidence interval [CI], 11.5 to 27.3) and 19.0% (95% CI, 12.1 to 27.9); among evaluable patients, symptom improvement rates were 40.3% (95% CI, 28.5 to 53.0) and 37.0% (95% CI, 26.0 to 49.1); median progression-free survival times were 2.7 and 2.8 months; and median overall survival times were 7.6 and 8.0 months, respectively. Symptom improvements were recorded for 69.2% (250 mg/d) and 85.7% (500 mg/d) of patients with a tumor response. Adverse events (AEs) at both dose levels were generally mild (grade 1 or 2) and consisted mainly of skin reactions and diarrhea. Drug-related toxicities were more frequent in the higher-dose group. Withdrawal due to drug-related AEs was 1.9% and 9.4% for patients receiving gefitinib 250 and 500 mg/d, respectively. CONCLUSION: Gefitinib showed clinically meaningful antitumor activity and provided symptom relief as second- and third-line treatment in these patients. At 250 mg/d, gefitinib had a favorable AE profile. Gefitinib 250 mg/d is an important, novel treatment option for patients with pretreated advanced NSCLC [corrected]

Administration, Oral↗

Translational and clinical studies of target-based cancer therapy.

The increasing number of negative trials in cancer treatment has prompted a systematic re-evaluation of target-based drugs. It is our impression that the sensitivity of current clinical trial methodology is inadequate to demonstrate the effectiveness of target-based drugs, in terms of tumor shrinkage, delay in progression, or improved survival. Enrichment of sensitive populations, based on the data from translational studies, is essential for a better understanding of the role of novel therapies in cancer. Translational and clinical studies are key to the identification and maximization of benefit of target-based therapy

Antineoplastic Agents↗

Phase I and pharmacokinetic study of KRN5500, a spicamycin derivative, for patients with advanced solid tumors.

BACKGROUND: KRN5500, a novel spicamycin derivative, shows an inhibitory effect on protein synthesis. This phase I study was aimed at investigating the toxicity, maximum tolerated dose (MTD) and pharmacokinetics of this compound. PATIENTS AND METHODS: Patients with solid tumors not amenable to standard forms of treatment were eligible. KRN5500 was administered as a 2 h intravenous infusion every 4 weeks at doses of 3, 6, 10, 15 and 21 mg/m(2). Pharmacokinetic evaluation was performed at the first cycle. RESULTS: Eighteen patients with advanced solid tumors were enrolled. A total of 26 cycles of KRN5500 were administered. The major toxicities were nausea, vomiting, diarrhea, fatigue and a mild reversible prolongation of prothrombin time. Grade 4 pulmonary toxicity (interstitial pneumonitis) was observed in one patient at a dose level of 15 mg/m(2). Severe fatigue was observed in one patient at a dose level of 21 mg/m(2) and the duration of fatigue tended to increase with the dose of KRN5500. Nausea and vomiting were frequently observed and became prolonged with increasing dose of KRN5500. These toxicity profiles were identified as unacceptable and further dose escalation above 21 mg/m(2) was withheld. The MTD was therefore determined as 21 mg/m(2). The peak plasma concentration and the area under the concentration-time curve of KRN5500 increased proportionally to the dose, suggesting linear pharmacokinetics. No objective antitumor response was observed. CONCLUSION: KRN5500, a structurally novel protein synthesis inhibitor, warrants further investigation to overcome these toxicity profiles and improve its efficacy.

Adult↗

Study of paclitaxel and dose escalation of cisplatin in patients with advanced non-small cell lung cancer.

BACKGROUND: We conducted a dose-finding and feasibility study in which we administered a fixed dose 3-h infusion of paclitaxel and an escalating dose of cisplatin in Japanese patients with advanced non-small cell lung cancer. METHODS: Chemotherapy consisted of fixed dose (210 mg/m(2)) paclitaxel given over 3 h on day 1 and an escalating dose of cisplatin on day 2, every 3-4 weeks. The dose of cisplatin was 40 mg/m(2) at level 1, 60 mg/m(2) at level 2 and 80 mg/m(2) at level 3. RESULTS: Between October 1999 and February 2001, 24 patients were enrolled and 58 cycles were administered. The major hematological toxicities were leukopenia and neutropenia. Grade 4 neutropenia developed in 83.3%, 66.7% and 83.3% of patients at the dose levels of 1, 2 and 3, respectively. The major non-hematological toxicities consisted of alanine aminotransferase (ALT) elevation and peripheral neuropathy. Grade 3 ALT elevation was observed in two of the 12 patients at level 3, but both recovered within 3 days. The peripheral neuropathy was sensory-dominant and frequent, and it was almost tolerable. The maximum tolerated dose was not identified even at the highest dose of paclitaxel (210 mg/m(2)) and cisplatin (80 mg/m(2)) administered in the study. The recommended dose was determined to be paclitaxel 210 mg/m(2) on day 1 and cisplatin 80 mg/m(2) on day 2, every 3-4 weeks. Seven partial responses were observed in the 24 patients. CONCLUSIONS: The combination of paclitaxel 210 mg/m(2) and cisplatin 80 mg/m(2) was found to be a well-tolerated active regimen in Japanese patients with advanced non-small cell lung cancer.

Adult↗