Sunitinib in combination with gemcitabine for advanced solid tumours: a phase I dose-finding study

BACKGROUND

This phase I, dose-finding study determined the maximum tolerated dose (MTD), safety, and pharmacokinetics of sunitinib plus gemcitabine in patients with advanced solid tumours.

METHODS

Two schedules with sunitinib (25-50 mg per day) and IV gemcitabine (750-1250 mg m(-2)) in escalating doses were studied. First, patients received sunitinib on a 4-weeks-on-2-weeks-off schedule (Schedule 4/2) plus gemcitabine on days 1, 8, 22, and 29. Second, patients received sunitinib on a 2-weeks-on-1-week-off schedule (Schedule 2/1) plus gemcitabine on days 1 and 8. The primary endpoint was determination of MTD and tolerability.

RESULTS

Forty-four patients received the combination (Schedule 4/2, n=8; Schedule 2/1, n=36). With no dose-limiting toxicities (DLTs) at maximum dose levels on Schedule 2/1, MTD was not reached. Grade 4 treatment-related AEs and laboratory abnormalities included cerebrovascular accident, hypertension, and pulmonary embolism (n=1 each), and neutropenia (n=3), thrombocytopenia and increased uric acid (both n=2), and lymphopenia (n=1). There were no clinically significant drug-drug interactions. Antitumor activity occurred across dose levels and tumour types. In poor-risk and/or high-grade renal cell carcinoma patients (n=12), 5 had partial responses and 7 stable disease ≥ 6 weeks.

CONCLUSION

Sunitinib plus gemcitabine on Schedule 2/1 with growth factor support was well tolerated and safely administered at maximum doses of each drug, without significant drug-drug interactions.

Clinical evaluation of continuous daily dosing of sunitinib malate in patients with advanced gastrointestinal stromal tumour after imatinib failure

AIMS

To assess the antitumour activity, safety, pharmacokinetics and pharmacodynamics of continuous daily sunitinib dosing in patients with imatinib-resistant/intolerant gastrointestinal stromal tumour (GIST) and to assess morning dosing versus evening dosing.

PATIENTS AND METHODS

In this open-label phase II study, patients were randomised to receive morning or evening dosing of sunitinib 37.5mg/day. The primary end-point was clinical benefit rate (CBR; percent complete responses+partial responses [PRs]+stable disease [SD] 24 weeks). Secondary end-points included progression-free survival (PFS), overall survival (OS), safety, pharmacokinetic parameters and plasma biomarker levels.

RESULTS

Sixty of 61 planned patients received treatment (30 per dosing group); 26 completed the study. Overall, the CBR was 53% (95% exact CI, 40-66): eight patients (13%) achieved objective PRs; 24 (40%) achieved SD 24 weeks. Median PFS was 34 weeks (95% CI, 24-49); median OS was 107 weeks (95% CI, 72 - not yet calculable). Most adverse events (AEs) were of grade 1 or 2 in severity, and were manageable through dose modification or standard interventions. No new AEs were apparent compared with the approved intermittent dosing schedule. Antitumour activity and safety were generally similar with morning and evening dosing. Continuous daily sunitinib dosing achieved and sustained effective drug concentrations without additional accumulation across cycles. Decreases from baseline in plasma levels of soluble KIT after 20 and 24 weeks of dosing correlated with longer OS.

CONCLUSION

For patients with imatinib-resistant/intolerant GIST, continuous daily sunitinib dosing appears to be an active alternative dosing strategy with acceptable safety.

Development and genetic mapping of sequence-tagged microsatellites (STMs) in bread wheat (Triticum aestivum L.)

The density of SSRs on the published genetic map of bread wheat (Triticum aestivum L.) has steadily increased over the last few years. This has improved the efficiency of marker-assisted breeding and certain types of genetic research by providing more choice in the quality of SSRs and a greater chance of finding polymorphic markers in any cross for a chromosomal region of interest. Increased SSR density on the published wheat genetic map will further enhance breeding and research efforts. Here, sequence-tagged microsatellite profiling (STMP) is demonstrated as a rapid technique for the economical development of anonymous genomic SSRs to increase marker density on the wheat genetic map. A total of 684 polymorphic sequence-tagged microsatellites (STMs) were developed, and 380 were genetically mapped in three mapping populations, with 296 being mapped in the International Triticeae Mapping Initiative W7984 x Opata85 recombinant inbred cross. Across the three populations, a total of 479 STM loci were mapped. Several technological advantages of STMs over conventional SSRs were also observed. These include reduced marker deployment costs for fluorescent-based SSR analysis, and increased genotyping throughput by more efficient electrophoretic separation of STMs and a high amenability to multiplex PCR.

C/EBPα expression by immunohistochemistry lacks prognostic or predictive significance in primary resected non-small cell lung cancer

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Background: The transcription factor CCAAT/enhancer binding protein alpha (C/EBPα) is down-regulated in a majority of lung cancers. We sought to determine if C/EBPα could be a prognostic or predictive factor in non-small-cell lung cancer (NSCLC). Methods: Our cohort originated from ECOG 3590/4592 (randomized trial of postoperative adjuvant therapy with thoracic radiation or cisplatin and etoposide plus thoracic radiation in patients with completely resected stages II and IIIA NSCLC; and its laboratorial study). 166 tumor samples contained material for immunohistochemical (IHC) analysis of C/EBPα expression. We used a scoring system comparing tumor staining to that of basal bronchial cells (3+). 0 or 1+ (weak) staining suggested lack of, while 2 or 3+ (strong) suggested C/EBPα expression. Our primary outcomes were differences in progression-free and overall survival between the groups with weak or strong staining. Results: Among the 166 patients analyzed for C/EBPα IHC, the median progression free and overall survival were 30.7 and 40.3 months, respectively; which do not differ from the complete E4592 cohort. 92 patient samples (55%) had 0 or 1+ staining, and the remaining 74 (45%) 2 or 3+. The median progression free survival for patients with weak and strong C/EBPα IHC expression was 31.5 and 30.2 months, respectively (p = 0.84). The median overall survival between the weak and strong groups was 47.5 and 38.3 months, respectively (p = 0.54). 10 years after enrollment, 27% (25/92) of patients were alive in the weak, and 24% (18/74) in the strong C/EBPα IHC group. No difference between our primary outcomes by C/EBPα expression was identified. There was no difference in outcome by treatment arm, tumor histology, stage, or patient’s characteristics. There was a trend towards loss of C/EBPα and less differentiated tumor samples (p = 0.07). Conclusions: C/EBPα is a novel tumor suppressor gene in lung cancer with loss of expression in over 50% of NSCLC. However, our data demonstrate that in a subset of patients with resected NSCLC, C/EBPα IHC status is neither a prognostic nor a predictive marker. Further studies are needed to establish the molecular mechanisms of C/EBPα inactivation in lung cancer and its possible role as a new therapeutic target.

No significant financial relationships to disclose.

High levels of genetic diversity throughout the range of the Portuguese wheat landrace 'Barbela'

BACKGROUND AND AIMS

Landrace populations represent an important intra-crop reservoir of biodiversity and source of novel gene alleles for use in breeding programmes. Here the aim was to measure the diversity of a wheat landrace, 'Barbela', from the north of Portugal.

METHODS

DNA was extracted from 59 accessions of Barbela collected across its geographical range. Diversity was measured by microsatellite length polymorphisms using 27 primer pairs amplifying 34 polymorphic microsatellite loci.

KEY RESULTS

High levels of polymorphism were found, with an average polymorphism information content of 0.52; an average of 4.77 alleles (range 2-11) were present at each locus, and half of these loci showed an additional allele in the reference variety 'Chinese Spring'.

CONCLUSIONS

'Barbela' is maintained from seeds collected by farmers, but it maintains high allelic variation, and no groupings of accessions were detected when analysed by geographical region, farm or climate, indicating that the wheat landrace is a homogeneous entity. The diversity within the farmer-maintained landrace demonstrates the importance of characterization and maintenance of landrace collections before valuable genetic combinations are lost as uniform commercial crops are introduced.

A new approach to extending the wheat marker pool by anchored PCR amplification of compound SSRs

A study was undertaken to determine the utility in bread wheat of anchored PCR for the development of single locus SSR markers targeted at compound repeat motifs. In anchored PCR, microsatellite amplification is achieved using a single primer complementary to the flanking sequence, and one which anchors to the repeat junction of the compound SSR. The recovery rate of useable markers was found to be similar (43%) to that reported for conventionally generated SSRs. Thus, anchored PCR can be used to reduce the costs of marker development, since it requires that only half the number of primers be synthesised. Where fluorescence-based platforms are used, marker deployment costs are lower, since only the anchoring primers need to be labelled. In addition, anchored PCR improves the recovery of useful markers, as it allows assays to be generated from microsatellite clones with repeat sequences located close to their ends, a situation where conventional PCR amplification fails as two flanking primers cannot be designed. Strategies to permit the large-scale development of compound SSR markers amplified by anchored PCR are discussed.

A Phase II trial of cisplatin plus WR-2721 (amifostine) for metastatic breast carcinoma: an Eastern Cooperative Oncology Group Study (E8188)

BACKGROUND

Cisplatin has minimal antitumor activity when used as second- or third-line treatment of metastatic breast carcinoma. Older reports suggest an objective response rate of 8% when 60-120 mg/m2 of cisplatin is administered every 3-4 weeks. Although a dose-response effect has been observed with cisplatin, the dose-limiting toxicities associated with cisplatin (e.g., nephrotoxicity, ototoxicity, and neurotoxicity) have limited its use as a treatment for breast carcinoma. WR-2721 or amifostine initially was developed to protect military personnel in the event of nuclear war. Amifostine subsequently was shown to protect normal tissues from the toxic effects of alkylating agents and cisplatin without decreasing the antitumor effect of the chemotherapy. Early trials of cisplatin and amifostine also suggested that the incidence and severity of cisplatin-induced nephrotoxicity, ototoxicity, and neuropathy were reduced.

METHODS

A Phase II study of the combination of cisplatin plus amifostine was conducted in patients with progressive metastatic breast carcinoma who had received one, but not more than one, chemotherapy regimen for metastatic disease. Patients received amifostine, 910 mg/m2 intravenously over 15 minutes. After completion of the amifostine infusion, cisplatin 120 mg/m2 was administered over 30 minutes. Intravenous hydration and mannitol was administered before and after cisplatin. Treatment was administered every 3 weeks until disease progression.

RESULTS

Forty-four patients were enrolled in the study of which 7 (16%) were ineligible. A median of 2 cycles of therapy was administered to the 37 eligible patients. Six partial responses were observed for an overall response rate of 16%. Most patients (57%) stopped treatment because of disease progression. Neurologic toxicity was reported in 52% of patients. Seven different life-threatening toxicities were observed in patients while receiving treatment.

CONCLUSIONS

The combination of cisplatin and amifostine in this study resulted in an overall response rate of 16%. Neither a tumor-protective effect nor reduced toxicity to normal tissues was observed with the addition of amifostine to cisplatin in this trial.

Modelling femoral curvature in the sagittal plane: a cadaveric study

This study examined the possibility of representing the mid third of the human femur with two straight sections. This portion of the femur visually has a distinct curvature, which can potentially present problems when considering implant stem designs to be introduced in this region. Sixteen femora were sectioned at 10 mm intervals along the femoral shaft in the mid third region (35-65 per cent of femoral length). Photographic records were obtained of each section against a consistent axis system to which all coordinates were referenced. The position of the centre of the medullary canal cross-sectional area along the femur, in relation to fixed orthogonal planes, has been analysed; the outer anterior cortex was also modelled. The results showed that the medullary centre of area plots and the anterior cortex coordinates are suitably modelled as two straight lines. For each bone it was possible to define the intersection point between the two straight sections (point of angulation), and the subtended angle between these sections (angle of incidence). The average point of angulation for the medullary plots occurred at 57 per cent along the femur, while the mean angle of incidence was 6.5 degrees. The anterior surface had an average point of angulation at 58 per cent along the femur with the mean angle of incidence being 22.2 degrees. The centre-line of the medulla was also found to be almost parallel to the outer anterior surface for sections distal to the point of angulation. It is proposed therefore, that this difference in angulation is the result of medullary expansion/cortical thinning towards the proximal extremity of the femur, causing the straight-line model of the medulla to angulate less than the outer anterior cortex.

Cross-sectional geometry of the human femur in the mid-third region

The design of a medical implant requires that the geometry and anatomy of the host region is fully understood. For any prosthesis to be located in the mid-third of the human femur it is therefore vitally important that an in-depth understanding of this region is obtained. This study focuses on the geometry of the medulla and the cortex and the relationship between them in the diaphyseal region of the human femur. Sixteen femora obtained from the Human Biology Department of the University of Leeds were sectioned at 10 mm intervals along the shaft and scaled photographs of each section were taken. These photographs then provided the raw data to enable the variation in long bone cross-sectional geometry to be evaluated. The results show that the medulla is almost cylindrical in the mid-third region, being most cylindrical between 35 and 50 per cent of the total bone length. The medullary width is found to be greater in the antero-posterior direction (> 90 per cent maximum diameter) than in the medio-lateral direction (78-88 per cent maximum diameter) along the studied femoral length. The cortex is also analysed and it is found that the mean cortical thickness on the anterior side is significantly smaller than the medial cortex and the lateral cortex, with the posterior cortex being the thickest. All the above findings suggest that the medulla does not lie centrally within the femur but is positioned slightly anteriorly. Anatomical characteristics such as this can have profound effects on the design of prostheses to be implanted in this region.

Towards rice genome scanning by map-based AFLP fingerprinting

Map-based DNA fingerprinting with AFLP markers provides a fast method for scanning the rice genome. Three hundred AFLP markers identified with ten primer combinations were mapped in two rice populations. The genetic maps were aligned and almost full coverage of the rice genome was obtained. The transferability of AFLP markers between indica x japonica and indica x indica crosses was tested. The chromosomes were divided into DNA Fingerprint Linkage Blocks (DFLBs) defined by specific AFLP markers. Using these blocks, the degree of similarity or divergence within specific chromosome regions was calculated for nine varieties. Applications of map-based fingerprinting for biodiversity studies and maker-assisted selection are discussed.

Using remote sensing to predict outbreaks of Oestrus ovis in Namibia

The Directorate of Veterinary Services of the Ministry of Agriculture, Water and Rural Development of Namibia issues warnings to farmers in the south of the country about the likelihood of infestation of small-stock by the nasal bot fly, Oestrus ovis. Farmers can then treat their stock at the most appropriate time. The O. ovis puparia develop at shallow depths in the soil and the timing of emergence is directly dependent on climate conditions, specifically the number of degree-days above a particular threshold soil temperature. Based on temperature measurements from only a few stations scattered throughout the country, the veterinary department warnings lack precision in space and time. This paper presents an attempt to support the programme of warnings with accumulated temperature information from Meteosat satellite images, in order to strengthen predictions of the time of emergence in specific places, and to improve the precision and reliability of warnings given to farmers.

Reducing maternal mortality in St Petersburg

Following the entry of St Petersburg into Europe's Healthy Cities Project in 1991 it was decided that the highest priority should be given to reducing the city's maternal mortality ratio, then standing at approximately 70 deaths per 100,000 live births. Preventing deaths from unsafe, illegal abortion became the main focus of attention. The use of modern contraceptive methods was promoted, information was disseminated to improve the utilization of family planning services, special outreach services for teenagers were established, and providers were given opportunities for education and training. The maternal mortality ratio and the abortion rate have now declined and contraceptive use appears to be increasing. These achievements are attributable in large measure to the commitment of a broad spectrum of St Petersburg society as well as to outside support.

Body mass index, waist circumference, waist-hip ratio, and glucose intolerance in Chinese and Europid adults in Newcastle, UK

OBJECTIVE

To compare the prevalence of glucose intolerance (impaired glucose tolerance and diabetes), and its relationship to body mass index (BMI) and waist-hip ratio in Chinese and Europid adults.

DESIGN

This was a cross sectional study.

SETTING

Newcastle upon Tyne.

SUBJECTS

These comprised Chinese and Europid men and women, aged 25-64 years, and resident in Newcastle upon Tyne, UK.

MAIN OUTCOME MEASURES

Two hour post load plasma glucose concentration, BMI, waist circumference, and waist-hip ratio.

METHODS

Population based samples of Chinese and European adults were recruited. Each subject had a standard WHO oral glucose tolerance test.

RESULTS

Complete data were available for 375 Chinese and 610 Europid subjects. The age adjusted prevalences of glucose intolerance in Chinese and Europid men were 13.0% (p = 0.04). Mean BMIs were lower in Chinese men (23.8 v 26.1) and women (23.5 v 26.1) than in the Europids (p values < 0.001), as were waist circumferences (men, 83.3 cm v 90.8, p < 0.001; women, 77.3 cm v 79.2, p < 0.05). Mean waist-hip ratios were lower in Chinese men (0.90 v 0.91, p = 0.02) but higher in Chinese women (0.84 v 0.78, p < 0.001) compared with Europids. In both Chinese and Europid adults, higher BMI, waist circumference, and waist-hip ratio were associated with glucose intolerance.

CONCLUSIONS

The prevalence of glucose intolerance in Chinese men and women, despite lower BMIs, is similar to or higher than that in local Europid men and women and intermediate between levels found in China and those in Mauritius. It is suggested that an increase in mean BMI to the levels in the Europid population will be associated with a substantial increase in glucose intolerance in Chinese people.