Abstract 5778: Fragment-based drug discovery of selective inhibitors of fibroblast growth factor receptor (FGFr)

Recent data in a number of tumour types has implicated Fibroblast Growth Factor (FGF) and Fibroblast Growth Factor receptor (FGFr) signalling as being key to the molecular pathology of cancer. This poster will describe fragment based drug discovery using biophysical screening to identify initial fragments. Subsequently, in the fragments-to-leads stage a detailed structural understanding of the binding interactions between the fragment and its target protein utilised X-ray crystallography and NMR. Starting with different fragments allows several lead series to be identified, often by synthesizing only small numbers of compounds.

A fragment screening campaign was conducted against the FGFr-1 to detect very low molecular weight compounds that bound to the hinge region of the kinase. The screening produced several fragment molecules (Molecular Weight <250 Da) which were in the micromolar range and confirmed binding mode in X-ray crystallography. One X-ray hit series that was 120 uM verse FGFr-3 will be described. Several iterations of structure-guided medicinal chemistry led to the identification of a lead compound with 3 nM affinity for FGFr-3, good cell activity and 30-fold selectivity verse VEGFr-2 with good oral activity. The lead was optimised to afford a compound that showed good PK/PD and efficacy.

This poster represents first disclosure of the structure of the lead series and illustrates how a fragment-based drug discovery approach can be efficiently used to discover compounds advanced nanomolar compounds with oral bioavailability.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5778.

Economic evaluation of diagnosing and excluding ectopic pregnancy

BACKGROUND

The diagnosis of ectopic pregnancy in women presenting in early pregnancy is often protracted, relying on costly investigations that are psychologically burdensome to the patient. The aim of this study was to evaluate the financial costs to the health services in Scotland of the current methods used to diagnose and exclude ectopic pregnancy, and compare these with that of a theoretical single diagnostic serum biomarker.

METHODS

We conducted a retrospective cost-description analysis (with and without costs of diagnostic laparoscopy) of the health-care costs incurred by all patients presenting to a large Scottish teaching hospital between June and September 2006 with pain and bleeding in early pregnancy, where ectopic pregnancy was not excluded. Additionally, a cost minimization analysis was performed for the costs of current ectopic pregnancy investigations versus those of a theoretical single diagnostic serum biomarker. This included sensitivity analyses where the biomarker was priced at increasing values and assumed to have less than 100% diagnostic sensitivity and specificity.

RESULTS

About 175 patients were eligible to be included in the analysis. Forty-seven per cent of patients required more than three visits to diagnose or exclude ectopic pregnancy. The total yearly cost for diagnosing and excluding ectopic pregnancy was 197K pound sterling for the hospital stated, and was estimated to be 1364K pound sterling for Scotland overall. Using a theoretical diagnostic serum biomarker we calculated that we could save health services up to 976K pound sterling (lowest saving 251K pound sterling after subanalysis) every year in Scotland.

CONCLUSIONS

Ectopic pregnancy is expensive to diagnose and exclude, and the investigation process is often long and might involve significant psychological morbidity. The development of a single diagnostic serum biomarker would minimize this morbidity and lead to significant savings of up to 1 million pounds per year in Scotland.

A randomized placebo-controlled study of tamoxifen after adjuvant chemotherapy in premenopausal women with early breast cancer (National Cancer Institute of Canada--Clinical Trials Group Trial, MA.12)

BACKGROUND

In the early 1990s, the role of adjuvant tamoxifen in premenopausal women with early breast cancer (EBC) was not established. Similarly, optimum timing relative to adjuvant chemotherapy and efficacy of tamoxifen in hormone receptor-negative tumors were unclear.

PATIENTS AND METHODS

Premenopausal women with EBC, any hormone receptor status, after surgery received standard adjuvant chemotherapy [doxorubicin (adriamycin)/cyclophosphamide, cyclophosphamide/methotrexate/5-fluorouracil, or cyclophosphamide/epirubicin/5-fluorouracil] followed by randomization to tamoxifen or placebo for 5 years. Outcomes were overall survival (OS), disease-free survival (DFS), toxicity, and compliance with therapy.

RESULTS

Median follow-up for 672 women was 9.7 years. Multivariate analysis showed improved DFS [78.2% versus 71.3% at 5 years; hazard ratio (HR) 0.77; P = 0.056] and a trend for improved OS (86.6% versus 82.1% at 5 years; HR 0.78; P = 0.12). There was no evidence of greater benefit for the receptor-positive subgroup. Compliance with treatment was suboptimal in both arms, with 103 (31%) women on tamoxifen and 70 (21%) on placebo-stopping therapy early because of toxicity, refusal, or other choices.

CONCLUSIONS

Adjuvant tamoxifen, given after chemotherapy to premenopausal women with EBC, improved 5-year DFS. Poor compliance may have reduced treatment efficacy.

Updated survival analysis of JBR.10: A randomized phase III trial of vinorelbine/cisplatin versus observation in completely resected stage IB and II non-small cell lung cancer (NSCLC)

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Background: JBR.10 was one of a number of phase III trials that established adjuvant cisplatin based chemotherapy as a recommended treatment in completely resected NSCLC . Long-term follow-up of these trials is important to document persistent benefit and potential late toxicities of adjuvant therapy. We report the updated survival data for JBR.10 with more than 9 years median follow up. Methods: Patients with completely resected stage IB (T2N0) or II (T1–2N1) NSCLC were randomized to receive 4 cycles of vinorelbine/cisplatin or observation.. Kaplan-Meier curves were generated for overall (OS) and disease specific survival (DSS). Log-rank test was used to compare survival distribution and to test cause specific hazard. For the competing risk analysis, the Gray test was used to test the difference in cause specific incidences. All efficacy analyses were done on an ITT basis. Results: 482 patients were randomized. Data cut-off for this update was July 2008. Median follow-up is 9.3 years (3.2–13.8 y). 12 patients were lost to follow up, a median 4.9 years from randomization (1.5–12 years). 271 deaths have occurred, 73% due to lung cancer or its treatment. Survival analysis continues to show a benefit for chemotherapy: HR .78 (CI .61-.99, p=.04). The benefit appears to be confined to N1 patients: median OS 6.8 y versus 3.6 y, HR .68 (CI .5-.92, p=.01). N0 patients did not appear to benefit: HR 1.03 (CI .7–1.52, p=.87). Chemotherapy significantly prolonged DSS, HR.73 (CI .55-.97, p=.03) Competing risk analysis showed observation to be associated with significantly higher risk of death from lung cancer (p=.02) with no difference in incidences of death from other causes between arms (p=.62). Conclusions: Prolonged follow-up of patients in the JBR.10 trial continues to show a benefit in survival for adjuvant chemotherapy. This benefit appears to be confined to N1 patients. There was no increase in death from other causes in the chemotherapy arm.

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The surgical treatment of cubital tunnel syndrome: a decision analysis

The objective of our study was to use decision analysis to compare four common surgical treatments for cubital tunnel syndrome: simple decompression of the cubital tunnel, medial epicondylectomy, anterior subcutaneous transposition and anterior submuscular transposition. The variables used for this decision analysis model were based on data from the literature. Extensive sensitivity analyses were carried out to test the impact of the values given to these variables on the outcome of the model. The highest expected utility, 0.973, was associated with simple decompression. The expected utility was 0.969 for subcutaneous transposition and 0.965 for submuscular transposition. Medial epicondylectomy had the lowest expected utility at 0.961. Simple decompression remained the preferred strategy in extensive one-way sensitivity analyses.

Benign hidradenoma: magnetic resonance and ultrasound features of two cases

Tumors of sweat gland origin are rare in the hand but should be considered in the differential diagnosis when certain imaging features are present. We present a case of nodular hidradenoma of the hand, with previously unreported magnetic resonance imaging features, and a further case in the thigh, both with ultrasound and histopathological correlation. The imaging literature of this tumor is reviewed, and its significance is discussed with respect to the current understanding of its malignant potential.

Quality of life (QOL) impact of adjuvant chemotherapy for early stage non-small cell lung cancer (NSCLC): Final analysis of JBR.10 randomized trial

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Background: Adjuvant chemotherapy for early stage NSCLC is now standard of care, but its impact on QOL is not known. We report the final QOL analysis of JBR.10, a North American intergroup randomized trial of adjuvant cisplatin/vinorelbine compared to observation in patients (pts) with completely resected stage IB/II NSCLC (n=482). Methods: QOL, a secondary endpoint of JBR.10, was assessed using the EORTC QLQ-C30 and a trial-specific checklist at baseline, weeks 5 and 9 for those on chemotherapy, and at 3, 6, 9, 12, 18, 24, 30 and 36 months of follow up. A 10-point change in QOL scores from baseline was considered clinically significant. Results: QOL assessment was not mandatory for all pts; 186/242 (76.9%) pts randomized to chemotherapy completed the baseline QOL assessment, compared to 173/240 (72.1%) pts on the observation arm. The overall survival of pts contributing QOL data, and the effect of adjuvant chemotherapy, was not different from the entire study population. Baseline QOL in the two study arms was comparable, with low global QOL scores and a significant symptom burden, especially pain and fatigue, following thoracotomy. A significantly greater proportion of chemotherapy pts experienced worsening symptoms including fatigue (p=0.02), appetite, hair loss, nausea and vomiting. At 6 months, a higher proportion of pts on the observation arm reported improved QOL in the global (p = 0.002), physical (p=0.02) and functional domains, compared to pts on the chemotherapy arm. However, by the 9 month time-point, global QOL of patients on chemotherapy was comparable to QOL of patients on observation, as were the five functional domains. Numbness (change scores: 22 vs 6, p<0.01) and pins & needles in fingers/toes (change scores: 21 vs 5, p<0.01) were the only symptoms that persisted, up to 24 months. Conclusion: Patients on adjuvant chemotherapy experience an initial slower recovery of QOL after thoracotomy, but following completion of treatment reach levels comparable to patients treated with surgery alone, in most aspects of QOL.

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Tamoxifen (T) compared to placebo (P), after adjuvant chemotherapy (CT), in premenopausal women with early breast cancer (EBC): Interim results of NCIC-CTG MA.12

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Background: In the early 1990’s, the role of adjuvant T in premenopausal women with EBC had not been clearly established. The efficacy of adjuvant T in hormone receptor (H) negative EBC was unclear. Methods: Eligible premenopausal women with node (N) +ve/high risk N -ve EBC, any H status, post surgery, received standard adjuvant CT (AC ×4, CMF ×6, CEF x6) then were randomized to T (20 mg/day) or P for 5 yrs. Overall survival (OS), disease-free survival (DFS) and toxicity/compliance were evaluated. Original sample size was 800 pts but based on slow accrual was reduced to 660. Mortality rate is lower than anticipated, and Data Safety Monitoring Committee approved reporting results after second interim analysis (152 deaths). Results: 1993–2000, 672 women randomized, median follow-up 8.4 yrs. For T vs P, 5 yr OS 87% vs 82% [Hazard Ratio HR 0.81 (95% CI 0.58–1.12), p = 0.19] and 5 yr DFS 78% vs 71% [HR 0.79 (95% CI 0.61–1.03), p = 0.09]. HR for OS (0.87 vs 0.78, p = 0.71) and DFS (0.79 vs 0.77, p = 0.87) were not significantly different for H +ve and H -ve tumors respectively. Compliance with T/P was suboptimal, 29% women stopping treatment within 2 yrs, and only 53% completing 5 yrs. Conclusions: Current results show only a trend towards improved DFS for premenopausal women with EBC who receive T after adjuvant CT. Other studies of similar design have shown improved DFS, but not OS, and meta-analysis may be more informative. Issues affecting results (slow accrual, improved outcomes for EBC, poor compliance, additional therapies) will be discussed.

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Beyond the rhetoric: what do we mean by a 'model of care'?

BACKGROUND

Contemporary health care systems are constantly challenged to revise traditional methods of health care delivery. These challenges are multifaceted and stem from: (1) novel pharmacological and non-pharmacological treatments; (2) changes in consumer demands and expectations; (3) fiscal and resource constraints; (4) changes in societal demographics in particular the ageing of society; (5) an increasing burden of chronic disease; (6) documentation of limitations in traditional health care delivery; (7) increased emphasis on transparency, accountability, evidence-based practice (EBP) and clinical governance structures; and (8) the increasing cultural diversity of the community. These challenges provoke discussion of potential alternative models of care, with scant reference to defining what constitutes a model of care.

AIM

This paper aims to define what is meant by the term 'model of care' and document the pragmatic systems and processes necessary to develop, plan, implement and evaluate novel models of care delivery.

METHODS

Searches of electronic databases, the reference lists of published materials, policy documents and the Internet were conducted using key words including 'model*', 'framework*', 'models, theoretical' and 'nursing models, theoretical'. The collated material was then analysed and synthesised into this review.

RESULTS

This review determined that in addition to key conceptual and theoretical perspectives, quality improvement theory (eg. collaborative methodology), project management methods and change management theory inform both pragmatic and conceptual elements of a model of care. Crucial elements in changing health care delivery through the development of innovative models of care include the planning, development, implementation, evaluation and assessment of the sustainability of the new model. Regardless of whether change in health care delivery is attempted on a micro basis (eg. ward level) or macro basis (eg. national or state system) in order to achieve sustainable, effective and efficient changes a well-planned, systematic process is essential.

DOTS implementation in a middle-income country: development and evaluation of a novel approach

BACKGROUND

DOTS is widely accepted as the most cost-effective strategy for tuberculosis (TB) control. However, there is little published information regarding methods for implementation in middle-income countries.

METHODS

Over 3 years, the Canadian Lung Association assisted the Ecuadorian TB programme to implement DOTS for over half the nation's total population. A multilevel strategy developed by a team of Ecuadorian health professionals provided initial, in-service, replica and reinforcement training at the local level, and training at national level for specialist physicians, specialist societies and medical schools. Evaluation was based on international guidelines for case finding, treatment and laboratory quality control, and costs of all implementation activities.

RESULTS

By January 2004, DOTS training had been provided to 1954 health professionals and 199 smear microscopy technicians, and DOTS was implemented in all 496 health facilities. Case detection activities at the local level increased substantially. Cure and treatment completion improved to 83% of new cases. Overall concordance of laboratory quality control readings was 98.7%. The total cost of DOTS implementation was US dollar 3 049 585.

CONCLUSIONS

To achieve international targets for TB control, DOTS implementation in a middle-income country required intensive training at the local level and at multiple other levels.

Evaluation of abnormal uterine bleeding: comparison of three outpatient procedures within cohorts defined by age and menopausal status

OBJECTIVES

To compare three outpatient methods of endometrial evaluation in terms of performance, patient acceptability and cost-effectiveness.

DESIGN

Pragmatic unblinded trial randomised separately within three groups determined by risk of endometrial cancer.

SETTING

The gynaecology outpatient clinic of a large city hospital in Edinburgh, Scotland.

PARTICIPANTS

Women referred for investigation and management of abnormal bleeding between January 1999 and May 2001.

INTERVENTIONS

Investigations were: blind biopsy alone, hysteroscopy with biopsy, ultrasound evaluation including transvaginal ultrasound, and, in the low-risk group, the option of no investigation. Within this design, two devices for obtaining endometrial biopsy were compared, the Pipelle sampler and the Tao brush.

MAIN OUTCOME MEASURES

Successful (informative) completion of the investigation, acceptability of the investigation method to women, women's satisfaction with clinic care in the short term and at 10 months and 2 years of follow-up, and cost-effectiveness to the end of investigation.

RESULTS

Minor adverse events (e.g. shock, patient distress) did not occur for ultrasound, but occurred in 16% and 10% of women for hysteroscopy and biopsy procedures respectively. Pipelle biopsy provided an acceptable endometrial sample for 79% of moderate-risk women, but only 43% of high-risk women. The Tao brush gave similar performance in moderate-risk women (77%), but was more successful than the Pipelle sampler in postmenopausal (high-risk) women (72%). There were significantly more successful visualizations for ultrasound than for hysteroscopy in both the low-risk and the moderate-risk group, and a similar but non-significant trend in the high-risk group. Ultrasound was significantly better than hysteroscopy at detecting fibroids, but hysteroscopy significantly better for polyps. At the 10-month follow-up, high-risk women who had been investigated by hysteroscopy (with biopsy) had the most positive views of their clinic experience, but this effect had largely disappeared by 24 months. In the moderate-risk group, the subgroup randomised to biopsy alone gave the most negative responses about their clinic experience and health now. Women wishing they had more investigation comprised 22% of moderate-risk women and 38% of low-risk women, but only 14% of postmenopausal women. At follow-up the moderate-risk women (with menstrual bleeding problems), compared with postmenopausal women, had much worse ratings for clinic experience and health now. Resource use tended to be higher in the moderate- and low-risk women. There was minimal difference in cost-effectiveness between investigation options in the high-risk group, with the option involving hysteroscopy being marginally better than ultrasound. The most cost-effective investigation in the moderate-risk group was biopsy alone and in the low-risk group ultrasound.

CONCLUSIONS

Decision-making about investigation would be clarified if postmenopausal women were studied separately from premenopausal women with menstrual bleeding problems. For postmenopausal women exclusion of cancer is a main objective, so once investigation has been completed discharge follows, but in the woman with abnormal menstrual bleeding, even if serious pathology is excluded, the original presenting symptoms require management. About 60% of premenopausal women with abnormal bleeding reported that their symptoms were not 'much improved' at 10 months. Research is needed to understand this phenomenon, and to explore ways to integrate patient factors into optimising evaluation and treatment. The significance of benign pathologies in this group also requires clarification. Given the relatively small differences observed in cost-effectiveness, there is justification for allowing other issues (such as clinician preferences and women's perspectives) to influence decisions as to the investigation method. There is scope to make better use of patient factors to inform decisions as to the most efficient and acceptable method of investigation for an individual woman. Additional analyses, using data available as a result of this study, will contribute to this agenda.

Stop TB-Halte à la Tuberculose-Canada: engaging industrialised nations in the challenge to meet global targets

The Stop TB Partnership has engaged the 22 high-burden countries in a drive toward the goal of finding 70% of cases and curing 85% by 2005. Traditional partners, aid agencies and governments of industrialised nations have joined the Partnership, but the broader range of civil society remains outside the discourse, risking disinterest on the part of the donor community. Stop TB-Halte à la Tuberculose-Canada was organised to engage new partners to support the Canadian government's commitment to the goal of reducing poverty and diseases of poverty, including tuberculosis, by 50% by 2010. The successes and challenges are explored, and the possibility raised that having a Stop TB movement in every country will ensure that support is sustained and goals of global tuberculosis control reached.