Healthcare costs attributable to diabetes in pregnancy: A cost of illness study in Tasmania, Australia.

AIMS: To estimate the direct costs during the prenatal, delivery and postpartum periods in mothers with diabetes in pregnancy, compared to those without. METHODS: This study used a population-based dataset from 2004 to 2017, including 57,090 people with diabetes and 114,179 people without diabetes in Tasmania, Australia. Based on diagnostic codes, delivery episodes with gestational diabetes mellitus (GDM) were identified and matched with delivery episodes without diabetes in pregnancy. A group of delivery episodes with pre-existing diabetes was identified for comparison. Hospitalisation, emergency department and pathology costs of these groups were calculated and adjusted to 2020-2021 Australian dollars. RESULTS: There were 2774 delivery episodes with GDM, 2774 delivery episodes without diabetes and 237 delivery episodes with pre-existing diabetes identified. Across the 24-month period, the pre-existing diabetes group required the highest costs, totalling $23,536/person. This was followed by the GDM ($13,210/person), and the no diabetes group ($11,167/person). The incremental costs of GDM over the no diabetes group were $890 (95% CI 635; 1160) in the year preceding delivery; $812 (616; 1031) within the delivery period and $341 (110; 582) in the year following delivery (p < 0.05). Within the year preceding delivery, the incremental costs in the prenatal period were $803 (579; 1058) (p < 0.05). Within the year following delivery, the incremental costs in the postpartum period were $137 (55; 238) (p < 0.05). CONCLUSIONS: Our results emphasised the importance of proper management of diabetes in pregnancy in the prenatal and postpartum periods and highlighted the significance of screening and preventative strategies for diabetes in pregnancy.

Island medicine longitudinal cohort study: Rapid rise in chronic kidney disease in rural and remote communities.

AIM: To determine the change in incidence and prevalence of chronic kidney disease (CKD) in rural and remote communities over the last decade. METHODS: We examined the change in age-standardized incidence and prevalence in Tasmania between 2010 and 2020, using a linked dataset that included any adult with a creatinine test taken in a community laboratory during the study period (n = 581 513; 87.8% of the state's adult population). We defined CKD as two measures of eGFR <60 mL/min per 1.73 m2, at least 3 months apart. RESULTS: State-wide age-standardized prevalence of CKD increased by 28% in the decade to 2020, from 516 to 659 per 10 000 population. Prevalence in men increased 31.3% and women 24.8%. The greatest increase in age-standardized prevalence was seen in rural or remote communities with an increase of 36.6% overall, but with considerable variation by community (range + 0.4% to +88.3%). The increase in the actual number of people with CKD in the decade to 2020 was 67%, with the number of women increasing by 58% and men by 79%. CONCLUSION: The age-standardized prevalence of CKD in rural and remote regions has increased considerably over the past decade, likely compounded by limited access to primary and secondary healthcare. These findings highlight the need to ensure healthcare resources are directed to areas of greatest need.

Incremental healthcare expenditure attributable to diabetes mellitus: A cost of illness study in Tasmania, Australia.

AIMS: To quantify the incremental direct medical costs in people with diabetes from the healthcare system perspective; and to identify trends in the incremental costs. METHODS: This was a matched retrospective cohort study based on a linked data set developed for investigating chronic kidney disease in Tasmania, Australia. Using propensity score matching, 51,324 people with diabetes were matched on age, sex and residential area with 102,648 people without diabetes. Direct medical costs (Australian dollars 2020-2021) due to hospitalisation, Emergency Department visits and pathology tests were included. The incremental costs and cost ratios between mean annual costs of people with diabetes and their controls were calculated. RESULTS: On average, people with diabetes had healthcare costs that were almost double their controls ($2427 [95% CI 2322-2543]; ratio 1.87 [95% CI 1.85-1.91]; pooled from 2007-2017). While in the first year of follow-up, the costs of a person with diabetes were $1643 (95% CI 1489-1806); ratio 1.83 (95% CI 1.76-1.92) more than their control, this increased to $2480 (95% CI 2265-2680); ratio 1.69 (95% CI 1.62-1.77) in the final year. Although the incremental costs were higher in older age groups (e.g., ≥70: $2498 [95% CI 2265-2754]; 40-49: $2117 [95% CI 1887-2384]), the cost ratios were higher in younger age groups (≥70: 1.52 [95% CI 1.48-1.56]; 40-49: 2.37 [95% CI 2.25-2.61]). CONCLUSIONS: Given the increasing burden that diabetes imposes, our findings will support policymakers in future planning for diabetes and enable targeting sub-groups with higher long-term costs for possible cost savings for the Tasmanian healthcare system.

Quality use of medicines in patients with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) affects drug elimination and patients with CKD require appropriate adjustment of renally cleared medications to ensure safe and effective pharmacotherapy. The main objective of this study was to determine the extent of potentially inappropriate prescribing (PIP; defined as the use of a contraindicated medication or inappropriately high dose according to the kidney function) of renally-cleared medications commonly prescribed in Australian primary care, based on two measures of kidney function. A secondary aim was to assess agreement between the two measures. METHODS: Retrospective analysis of routinely collected de-identified Australian general practice patient data (NPS MedicineWise MedicineInsight from January 1, 2013, to June 1, 2016; collected from 329 general practices). All adults (aged ≥18 years) with CKD presenting to general practices across Australia were included in the analysis. Patients were considered to have CKD if they had two or more estimated glomerular filtration rate (eGFR) recorded values < 60 mL/min/1.73m2, and/or two urinary albumin/creatinine ratios ≥3.5 mg/mmol in females (≥2.5 mg/mmol in males) at least 90 days apart. PIP was assessed for 49 commonly prescribed medications using the Cockcroft-Gault (CG) equation/eGFR as per the instructions in the Australian Medicines Handbook. RESULTS: A total of 48,731 patients met the Kidney Health Australia (KHA) definition for CKD and had prescriptions recorded within 90 days of measuring serum creatinine (SCr)/estimated glomerular filtration rate (eGFR). Overall, 28,729 patients were prescribed one or more of the 49 medications of interest. Approximately 35% (n = 9926) of these patients had at least one PIP based on either the Cockcroft-Gault (CG) equation or eGFR (CKD-EPI; CKD-Epidemiology Collaboration Equation). There was good agreement between CG and eGFR while determining the appropriateness of medications, with approximately 97% of the medications classified as appropriate by eGFR also being considered appropriate by the CG equation. CONCLUSION: This study highlights that PIP commonly occurs in primary care patients with CKD and the need for further research to understand why and how this can be minimised. The findings also show that the eGFR provides clinicians a potential alternative to the CG formula when estimating kidney function to guide drug appropriateness and dosing.

Epidemiology of chronic kidney disease in Australian general practice: National Prescribing Service MedicineWise MedicineInsight dataset.

AIM: To describe sociodemographic characteristics and comorbidities of a large cohort of Australian general practice-based patients identified as having chronic kidney disease (CKD), using data from National Prescribing Service (NPS) MedicineWise's MedicineInsight dataset, and compare this dataset to the 2011-2012 Australian Health Survey's (AHS) CKD prevalence estimates. METHODS: This was a cohort study using deidentified, longitudinal, electronic health record data collected from 329 practices and 1 483 416 patients distributed across Australia, from 1 June 2013 until 1 June 2016. Two methods were used to calculate the CKD prevalence. One used the same method as used by the 2011-2012 AHS, based on one estimate of the estimated glomerular filtration rate (eGFR) or albumin/creatinine ratios (ACR). The other defined CKD more rigorously using eGFR or ACR results at least 90 days apart. RESULTS: In 2016, of 1 310 602 active patients, 710 674 (54.2%) did not have an eGFR or ACR test, while 524 961 (40.1%) had an eGFR or ACR test but did not meet AHS criteria for CKD. Age-sex adjusted rates of CKD (compared to AHS) were CKD 1-0.45% (3.9%), CKD 2-0.62% (2.5%), CKD 3a: 3.1% (2.7%), CKD 3b: 1.14% (0.6%), CKD 4-5: 0.41% (0.3%). The CKD cohort defined more rigorously using eGFR and ACR measures >90 days apart, had comorbidities of atrial fibrillation (30.5%), cardiovascular disease (25.0%), diabetes mellitus (17.1%) and hypertension (14.8%). CONCLUSION: The MedicineInsight dataset contains valuable and timely information about Australian patients with CKD, and provides prevalence estimates similar to those from AHS data.

Creating an interactive map visualising the geographic variations of the burden of diabetes to inform policymaking: An example from a cohort study in Tasmania, Australia.

OBJECTIVES: To visualise the geographic variations of diabetes burden and identify areas where targeted interventions are needed. METHODS: Using diagnostic criteria supported by hospital codes, 51,324 people with diabetes were identified from a population-based dataset during 2004-2017 in Tasmania, Australia. An interactive map visualising geographic distribution of diabetes prevalence, mortality rates, and healthcare costs in people with diabetes was generated. The cluster and outlier analysis was performed based on statistical area level 2 (SA2) to identify areas with high (hot spot) and low (cold spot) diabetes burden. RESULTS: There were geographic variations in diabetes burden across Tasmania, with highest age-adjusted prevalence (6.1%), excess cost ($2627), and annual costs per person ($5982) in the West and Northwest. Among 98 SA2 areas, 16 hot spots and 25 cold spots for annual costs, and 10 hot spots and 10 cold spots for diabetes prevalence were identified (p<0.05). 15/16 (94%) and 6/10 (60%) hot spots identified were in the West and Northwest. CONCLUSIONS: We have developed a method to graphically display important diabetes outcomes for different geographical areas. IMPLICATIONS FOR PUBLIC HEALTH: The method presented in our study could be applied to any other diseases, regions, and countries where appropriate data are available to identify areas where interventions are needed to improve diabetes outcomes.

Risk of hospital admission or emergency department presentation due to diabetes complications: a retrospective cohort study in Tasmania, Australia.

Objective To estimate the risk of an emergency department (ED)/inpatient visit due to complications in people with diabetes and compare them to their non-diabetes counterparts. Methods This matched retrospective cohort study used a linked dataset in Tasmania, Australia for the 2004-17 period. People with diabetes (n = 45 378) were matched on age, sex and geographical regions with people without diabetes (n = 90 756) based on propensity score matching. The risk of an ED/inpatient visit related to each complication was estimated using negative binomial regression. Results In people with diabetes, the combined ED and admission rates per 10 000 person-years were considerable, especially for macrovascular complications (ranging from 31.8 (lower extremity amputation) to 205.2 (heart failure)). The adjusted incidence rate ratios of ED/inpatient visits were: retinopathy 59.1 (confidence interval 25.8, 135.7), lower extremity amputation 11.1 (8.8, 14.1), foot ulcer/gangrene 9.5 (8.1, 11.2), nephropathy 7.4 (5.4, 10.1), dialysis 6.5 (3.8, 10.9), transplant 6.3 (2.2, 17.8), vitreous haemorrhage 6.0 (3.7, 9.8), fatal myocardial infarction 3.4 (2.3, 5.1), kidney failure 3.3 (2.3, 4.5), heart failure 2.9 (2.7, 3.1), angina pectoris 2.1 (2.0, 2.3), ischaemic heart disease 2.1 (1.9, 2.3), neuropathy 1.9 (1.7, 2.0), non-fatal myocardial infarction 1.7 (1.6, 1.8), blindness/low vision 1.4 (0.8, 2.5), non-fatal stroke 1.4 (1.3, 1.6), fatal stroke 1.3 (0.9, 2.1) and transient ischaemic attack 1.1 (1.0, 1.2). Conclusions Our results demonstrated the high demand on hospital services due to diabetes complications (especially macrovascular complications) and highlighted the importance of preventing and properly managing microvascular complications. These findings will support future resource allocation to reduce the increasing burden of diabetes in Australia.

Cluster-randomised trial of the Effectiveness of Quality Incentive Payments in General Practice (EQuIP-GP): Prescribing of medicines outcomes.

BACKGROUND: The Effectiveness of Quality Incentive Payments in General Practice (EQuIP-GP) study investigated whether targeted financial incentives promoting access to a preferred general practitioner, post-hospitalisation follow-up and longer consultations, increase patient-perceived relational continuity in primary care. Secondary outcomes included the use of medicines. OBJECTIVE: To evaluate whether introducing a general practice-level service model incorporating enrolment and continuous and graded quality improvement incentives influenced the total prescriptions written and potentially inappropriate prescribing of medicines. METHODS: A 12-month cluster-randomised controlled trial, whereby participating patients within intervention practices were offered enrolment with a preferred general practitioner, a minimum of three longer appointments, and review within seven days of hospital admission or emergency department attendance. Control practice patients received usual care. Differences between intervention and control groups pre-post trial for total prescriptions were analysed, as an indicator of polypharmacy, along with prescriptions for four groups of drugs known to have common quality of medicines issues: antibiotics, benzodiazepines, opioids and proton pump inhibitors (PPIs). RESULTS: A total of 774 patients, aged 18-65 years with a chronic illness or aged over 65 years, from 34 general practices in metropolitan, regional and rural Australia participated. The mean number of medicine prescriptions per month at baseline was 4.19 (SD 3.27) and 4.34 (SD 3.75) in the control and intervention arms, respectively, with no significant between-group differences in changes pre-post trial and also no significant between-group or within-group differences of prescription rates for antibiotics, benzodiazepines, opioids or PPIs. CONCLUSIONS: Total prescribing volume and the use of key medicines were not influenced by quality-linked financial incentives for offering longer consultations and early post-hospital review for enrolled patients.

Costs of major complications in people with and without diabetes in Tasmania, Australia.

Objective We set out to estimate healthcare costs of diabetes complications in the year of first occurrence and the second year, and to quantify the incremental costs of diabetes versus non-diabetes related to each complication. Methods In this cohort study, people with diabetes (n = 45 378) and their age/sex propensity score matched controls (n = 90 756) were identified from a linked dataset in Tasmania, Australia between 2004 and 2017. Direct costs (including hospital, emergency room visits and pathology costs) were calculated from the healthcare system perspective and expressed in 2020 Australian dollars. The average-per-patient costs and the incremental costs in people with diabetes were calculated for each complication. Results First-year costs when the complications occurred were: dialysis $78 152 (95% CI 71 095, 85 858), lower extremity amputations $63 575 (58 290, 68 688), kidney transplant $48 487 (33 862, 68 283), non-fatal myocardial infarction $30 827 (29 558, 32 197), foot ulcer/gangrene $29 803 (27 183, 32 675), ischaemic heart disease $29 160 (26 962, 31 457), non-fatal stroke $27 782 (26 285, 29 354), heart failure $27 379 (25 968, 28 966), kidney failure $24 904 (19 799, 32 557), angina pectoris $18 430 (17 147, 19 791), neuropathy $15 637 (14 265, 17 108), nephropathy $15 133 (12 285, 18 595), retinopathy $14 775 (11 798, 19 199), transient ischaemic attack $13 905 (12 529, 15 536), vitreous hemorrhage $13 405 (10 241, 17 321), and blindness/low vision $12 941 (8164, 19 080). The second-year costs ranged from 16% (ischaemic heart disease) to 74% (dialysis) of first-year costs. Complication costs were 109-275% higher than in people without diabetes. Conclusions Diabetes complications are costly, and the costs are higher in people with diabetes than without diabetes. Our results can be used to populate diabetes simulation models and will support policy analyses to reduce the burden of diabetes.

Chronic Kidney Disease in Tasmania: Protocol for a Data Linkage Study.

BACKGROUND: Chronic kidney disease (CKD) is a significant and growing health burden globally. Tasmania has the highest state prevalence for non-Indigenous Australians and it has consistently had the lowest incidence and prevalence of dialysis in Australia. OBJECTIVE: To examine the gap between the high community prevalence of CKD in Tasmania and the low use of dialysis. METHODS: This is a retrospective cohort study using linked data from 5 health and 2 pathology data sets from the island state of Tasmania, Australia. The study population consists of any person (all ages including children) who had a blood measurement of creatinine with the included pathology providers between January 1, 2004, and December 31, 2017. This study population (N=460,737) includes within it a CKD cohort, which was detected via pathology or documentation of kidney replacement therapy (KRT; dialysis or kidney transplant). Kidney function (estimated glomerular filtration rate [eGFR]) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. Individuals with 2 measures of eGFR<60 mL/min/1.73 m2, at least 90 days apart, were identified as having CKD and were included in the CKD cohort. Individuals treated with dialysis or transplant were identified from the Australia and New Zealand Dialysis and Transplant Registry. RESULTS: The study population consisted of 460,737 people (n=245,573 [53.30%] female, mean age 47.4 years) who were Tasmanian residents aged 18 years and older and were followed for a median of 7.8 years. During the later 5 years of the study period, 86.79% (355,622/409,729) of Tasmanian adults were represented. The CKD cohort consisted of 56,438 people (ie, 12.25% of the study population; 53.87% (30,405/56,438) female, mean age 69.9 years) followed for a median of 10.4 years with 56,039 detected via eGFR and 399 people detected via documentation of KRT. Approximately half (227,433/460,737, 49.36%) of the study population and the majority of the CKD cohort (41,448/56,438, 73.44%) had an admission episode. Of the 55,366 deaths recorded in the study population, 45.10% (24,970/55,366) had CKD. CONCLUSIONS: Whole-of-population approaches to examine CKD in the community can be achieved by data linkage. Over this 14-year period, CKD affected 12.25% (56,438/460,737) of Tasmanian adult residents and was present in 45.10% (24,970/55,366) of deaths. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/20160.

Medication Prescribing Quality in Australian Primary Care Patients with Chronic Kidney Disease.

Background: Australian patients with chronic kidney disease (CKD) are routinely managed in general practices with multiple medications. However, no nationally representative study has evaluated the quality of prescribing in these patients. The objective of this study was to examine the quality of prescribing in patients with CKD using nationally representative primary care data obtained from the NPS MedicineWise's dataset, MedicineInsight. Methods: A cross-sectional analysis of general practice data for patients aged 18 years or older with CKD was performed from 1 February 2016 to 1 June 2016. The study examined the proportion of patients with CKD who met a set of 16 published indicators in two categories: (1) potentially appropriate prescribing of antihypertensives, renin-angiotensin system (RAS) inhibitors, phosphate binders, and statins; and (2) potentially inappropriate prescribing of nephrotoxic medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), at least two RAS inhibitors, triple therapy (an NSAID, a RAS inhibitor and a diuretic), high-dose digoxin, and metformin. The proportion of patients meeting each quality indicator was stratified using clinical and demographic characteristics. Results: A total of 44,259 patients (24,165 (54.6%) female; 25,562 (57.8%) estimated glomerular filtration (eGFR) 45-59 mL/1.73 m2) with CKD stages 3-5 were included. Nearly one-third of patients had diabetes and were more likely to have their blood pressure and albumin-to-creatinine ratio monitored than those without diabetes. Potentially appropriate prescribing of antihypertensives was achieved in 79.9% of hypertensive patients with CKD stages 4-5. The prescribing indicators for RAS inhibitors in patients with microalbuminuria and diabetes and in patients with macroalbuminuria were achieved in 69.9% and 62.3% of patients, respectively. Only 40.8% of patients with CKD and aged between 50 and 65 years were prescribed statin therapy. The prescribing of a RAS inhibitor plus a diuretic was less commonly achieved, with the indicator met in 20.6% for patients with microalbuminuria and diabetes and 20.4% for patients with macroalbuminuria. Potentially inappropriate prescribing of NSAIDs, metformin, and at least two RAS inhibitors were apparent in 14.3%, 14.1%, and 7.6%, respectively. Potentially inappropriate prescribing tended to be more likely in patients aged ≥65 years, living in regional or remote areas, or with socio-economic indexes for areas (SEIFA) score ≤ 3. Conclusions: We identified areas for possible improvement in the prescribing of RAS inhibitors and statins, as well as deprescribing of NSAIDs and metformin in Australian general practice patients with CKD.

Radiation dosimetry of beta-amyloid tracers 11C-PiB and 18F-BAY94-9172.

UNLABELLED: Beta-amyloid (Abeta) imaging has great potential to aid in the diagnosis of Alzheimer disease and the development of therapeutics. The radiation dosimetry of Abeta radioligands may influence their application; therefore, we calculated and compared the effective doses (EDs) of 11C-PiB and a new 18F-labeled ligand, 18F-BAY94-9172. METHODS: Attenuation-corrected whole-body scans were performed at 0, 15, 30, 45, and 60 min after injection of 350+/-28 MBq (mean+/-SD) of 11C-PiB in 6 subjects and at 0, 20, 60, 120, and 180 min after injection of 319+/-27 MBq of 18F-BAY94-9172 in 3 subjects. Coregistered CT was used to define volumes of interest (VOIs) on the PET images. The source organs were the brain, lungs, liver, kidneys, spleen, and vertebrae. The VOIs for the contents of the gallbladder, urinary bladder, lower large intestine, upper large intestine, and small intestine were also defined. Total activity in each organ at each time point was calculated by use of reference organ volumes. The resultant time-activity curves were fitted with constrained exponential fits, and cumulated activities were determined. A dynamic bladder voiding model was used. The OLINDA/EXM program was used to calculate the whole-body EDs from the acquired data. RESULTS: For 11C-PiB, the highest absorbed doses were in the gallbladder wall (44.80+/-29.30 microGy/MBq), urinary bladder wall (26.30+/-8.50 microGy/MBq), liver (19.88+/-3.58 microGy/MBq), and kidneys (12.92+/-3.37 microGy/MBq). The ED was 5.29+/-0.66 microSv/MBq. For 18F-BAY94-9172, the highest doses were also in the gallbladder wall (132.40+/-43.40 microGy/MBq), urinary bladder wall (24.77+/-7.36 microGy/MBq), and liver (39.07+/-8.31 microGy/MBq). The ED was 14.67+/-1.39 microSv/MBq. CONCLUSION: The estimated organ doses for 11C-PiB were comparable to those reported in earlier research. With the doses used in published studies (300-700 MBq), the EDs would range from 1.6 to 3.7 mSv. The ED of 18F-BAY94-9172 was 30% lower than that of 18F-FDG and, at the published dose of 300 MBq, would yield an ED of 4.4 mSv. The dosimetry of both Abeta radioligands is suitable for clinical and research applications.

A phase I biodistribution and pharmacokinetic trial of humanized monoclonal antibody Hu3s193 in patients with advanced epithelial cancers that express the Lewis-Y antigen.

PURPOSE: We report a first-in-man trial of a humanized antibody (hu3S193) against the Le(y) antigen. EXPERIMENTAL DESIGN: Patients with advanced Le(y)-positive cancers received four infusions of hu3S193 at weekly intervals, with four dose levels (5, 10, 20, and 40 mg/m(2)). The first infusion of hu3S193 was trace labeled with Indium-111, and biodistribution, pharmacokinetics, tumor uptake, and immune response were evaluated in all patients. RESULTS: A total of 15 patients (7 male/8 female; age range, 42-76 years; 6 breast, 8 colorectal cancer, and 1 non-small-cell lung cancer) were entered into the study. Transient grade 1 to 2 nausea and vomiting was observed following infusion of hu3S193 at the 40 mg/m(2) dose level only. There was one episode of dose-limiting toxicity with self-limiting Common Toxicity Criteria grade 3 elevated alkaline phosphatase observed in one patient with extensive liver metastases. The biodistribution of (111)In-hu3S193 showed no evidence of any consistent normal tissue uptake, and (111)In-hu3S193 uptake was observed in cutaneous, lymph node, and hepatic metastases. Hu3S193 displayed a long serum half-life (T(1/2)beta = 189.63 +/- 62.17 h). Clinical responses consisted of 4 patients with stable disease and 11 patients with progressive disease, although one patient experienced a 89% decrease in a lymph node mass, and one patient experienced inflammatory symptoms in cutaneous metastases, suggestive of a biological effect of hu3S193. No immune responses (human anti-human antibody) to hu3S193 were observed. CONCLUSION: Hu3S193 is well tolerated and selectively targets tumors, and the long half-life and biological function in vivo of this antibody makes it an attractive potential therapy for patients with Le(y)-expressing cancers.

A pilot study of monoclonal antibody cG250 and low dose subcutaneous IL-2 in patients with advanced renal cell carcinoma.

The chimeric monoclonal antibody cG250 recognizes the CAIX/MN antigen. cG250 induces antibody-dependent cellular cytotoxicity (ADCC) responses in vitro that can be enhanced by IL-2. We studied the effects of adding daily low-dose subcutaneous IL-2 to cG250 for treatment of clear cell renal cell carcinoma (RCC). The primary endpoints of the trial were toxicity and immunological effects (human anti-chimeric antibodies [HACA], ADCC, natural killer [NK] and lymphokine-activated killer cell [LAK] activity); secondary endpoints were cG250 biodistribution and pharmacokinetics (PK) and tumour response rates. Eligible patients had unresectable metastatic or locally advanced clear cell RCC with measurable or evaluable disease. Nine patients were treated with six doses of cG250 (10 mg/m(2)/week, first and fifth doses trace-labelled with (131)I), and 1.25 x 10(6) IU/m(2)/day IL-2 for six weeks. Treatment was generally well tolerated with no adverse events attributable to cG250. Two patients required a 50% dose reduction of IL-2 due to toxicity. No HACA was detected. (131)I-labeled cG250 showed excellent targeting of tumour deposits. (131)I cG250 PK: T(1/2)alpha 20.16 +/- 6.59 h, T(1/2)beta 126.21 +/- 34.04 h, CL 39.67 +/- 23.06 mL/h, Cmax 5.12 +/- 0.86 microg/mL, V(1) 3.88 +/- 1.05 L. IL-2 did not affect cG250 PK. A trend for increased percentage of circulating CD3-/CD16+CD56+ NK cells was observed. Some patients showed enhanced ADCC or LAK activity. No antitumour responses were observed. In conclusion, weekly cG250 with daily low-dose subcutaneous IL-2 is well tolerated. IL-2 does not influence cG250 biodistribution or increase HACA.

Lack of correlation of hypoxic cell fraction and angiogenesis with glucose metabolic rate in non-small cell lung cancer assessed by 18F-Fluoromisonidazole and 18F-FDG PET.

UNLABELLED: PET offers a noninvasive means to assess neoplasms, in view of its sensitivity and accuracy in staging tumors and potentially in monitoring treatment response. The aim of this study was to evaluate newly diagnosed non-small cell lung cancer (NSCLC) for the presence of hypoxia, as indicated by the uptake of (18)F-Fluoromisonidazole ((18)F-FMISO), and to examine the relationship of hypoxia to the uptake of (18)F-FDG, microvessel density, and other molecular markers of hypoxia. METHODS: Twenty-one patients with suspected or biopsy-proven NSCLC were enrolled prospectively in this study. All patients had PET studies with (18)F-FMISO and (18)F-FDG. Seventeen patients subsequently underwent surgery, with analysis performed for tumor markers of angiogenesis and hypoxia. RESULTS: In the 17 patients with resectable NSCLC (13 men, 4 women; age range, 51-77 y), the mean (18)F-FMISO uptake in tumor was significantly lower than that of (18)F-FDG uptake (P < 0.0001) and showed no correlation with (18)F-FDG uptake (r = 0.26). The mean (95% confidence interval [CI]) (18)F-FMISO SUV(max) (maximum standardized uptake value) was 1.20 [0.95-1.45] compared with the mean [95% CI] (18)F-FDG SUV(max) of 5.99 [4.62-7.35]. The correlation between (18)F-FMISO uptake, (18)F-FDG uptake, and tumor markers of hypoxia and angiogenesis was poor. A weakly positive correlation between (18)F-FMISO and (18)F-FDG uptake and Ki67 was found. CONCLUSION: The hypoxic cell fraction of primary NSCLC is consistently low, and there is no significant correlation in NSCLC between hypoxia and glucose metabolism in NSCLC assessed by (18)F-FDG. These findings have direct implications in understanding the role of angiogenesis and hypoxia in NSCLC biology.

Pharmacodynamic analysis of tumour perfusion assessed by 15O-water-PET imaging during treatment with sunitinib malate in patients with advanced malignancies.

BACKGROUND: We evaluated pharmacodynamic changes in tumour perfusion using positron emission tomography (PET) imaging with 15O-water to assess biological response to sunitinib, a multitargeted tyrosine kinase inhibitor. METHODS: Patients with advanced malignancies received sunitinib 50 mg/day orally, once daily for 4 weeks on treatment, followed by 2 weeks off treatment, in repeated 6-week cycles. Quantitative measurement of tumour perfusion was assessed using 15O-water-PET at baseline and after 2 weeks of treatment. At least one reference tumour lesion was included in the fields of view and assessed at both time points. Patients also underwent 18 F-fluorodeoxyglucose (FDG)-PET imaging at baseline and after 2 and 4 weeks of treatment. Radiological response of the reference tumour lesion and overall radiological response were assessed at week 12. Serum pharmacokinetic and biomarker analyses were also performed. RESULTS: Data were available for seven patients. Compared with baseline, all patients experienced a decrease in reference tumour blood flow ranging from 20 % to 85 % and also a reduction in the FDG standard uptake value ranging from 29 % to 67 %. Six patients experienced a partial metabolic response based on FDG-PET criteria. Four patients had stable disease defined by radiological response (Response Evaluation Criteria in Solid Tumors) lasting between 4 and 12 cycles. An association between perfusion change and clinical benefit, and biomarker levels including vascular endothelial growth factor was observed. CONCLUSION: Administering sunitinib to patients with advanced malignancies is associated with early biological responses, including decreased blood flow in secondary tumour deposits.

Immuno-PET quantitation of de2-7 epidermal growth factor receptor expression in glioma using 124I-IMP-R4-labeled antibody ch806.

UNLABELLED: Overexpression, activation, and mutations of the epidermal growth factor receptor (EGFR) are commonly found in solid tumors. The aim of this study was to develop a PET-based method for detecting the constitutively active mutant de2-7 EGFR, which is associated with disease progression and resistance to chemotherapy and radiotherapy in glioma. METHODS: The chimeric antibody ch806, which selectively binds an epitope of the EGFR that is exposed only on overexpressed, mutant, or ligand-activated forms of the receptor, was conjugated to the radiohalogen (124)I via the residualizing ligand IMP-R4, and in vitro properties were characterized. In vivo biodistribution and small-animal PET studies were performed in BALB/c nude mice bearing U87MG.de2-7 glioma xenografts. Imaging results were correlated with measured tumor uptake of the radioconjugate. RESULTS: (124)I-IMP-R4-ch806 had an immunoreactivity of 78.3% and was stable for 7 d when incubated in serum in vitro. The biodistribution analysis of (124)I-IMP-R4-ch806 demonstrated a maximal uptake of 30.95 +/- 6.01 percentage injected dose per gram (%ID/g) in U87MG.de2-7 xenografts at 48 h after injection, with prolonged tumor retention (6.07 +/- 0.80 %ID/g at 216 h after injection). The tumor-to-blood ratio increased from 0.44 at 4 h after injection to a maximum of 4.70 at 168 h after injection. PET of (124)I-IMP-R4-ch806 biodistribution was able to clearly detect the U87MG.de2-7 tumors at 24 h after injection and for at least 168 h after injection. Correlation between tumor PET image quantitation of (124)I-IMP-R4-ch806 and %ID/g determined from resected tissues (r = 0.9350) was excellent. CONCLUSION: These results show that immuno-PET with (124)I-IMP-R4-ch806 is feasible and allows noninvasive quantitation of de2-7 EGFR expression in vivo.

Phase I biodistribution and pharmacokinetic study of Lewis Y-targeting immunoconjugate CMD-193 in patients with advanced epithelial cancers.

PURPOSE: This phase I study explored the biodistribution and pharmacokinetics of the immunoconjugate CMD-193 [a humanized anti-Lewis Y (Le(y)) antibody conjugated with calicheamicin in patients with advanced cancers expressing the Le(y) antigen. EXPERIMENTAL DESIGN: The primary objectives were to determine biodistribution and pharmacokinetics of CMD-193. Secondary objectives included response rates and change in tumor metabolism. Patients with progressive, measurable, and Le(y) positive malignancies were eligible for enrollment in one of two dose cohorts, 1.0 and 2.6 mg/m(2). The first cycle was trace labeled with (111)In for biodistribution assessment using gamma camera imaging. Subsequent cycles were administered every 3 weeks up to a maximum of six cycles, depending on toxicity and response. Pharmacokinetic analysis was based on radioassay and ELISA. RESULTS: Nine patients were enrolled in the study. Biodistribution images showed initial blood pool activity, followed by markedly increased hepatic uptake by day 2, and fast blood clearance in all patients. There was low uptake in tumor in all patients. The overall T(1/2)beta of (111)In-CMD-193 was 102.88 +/- 35.67 hours, with no statistically significant difference between the two dose levels. One patient had a partial metabolic response on (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG PET) after four cycles, but no radiological responses were observed. Myelosuppression and effects on liver function were the most significant adverse effects. CONCLUSIONS: CMD-193 shows rapid blood clearance and increased hepatic uptake compared with prior studies of the parental antibody hu3S193. These results highlight the importance of biodistribution and pharmacodynamic assessment in early phase studies of new biologics to assist in clinical development.

A phase I clinical trial with monoclonal antibody ch806 targeting transitional state and mutant epidermal growth factor receptors.

An array of cell-surface antigens expressed by human cancers have been identified as targets for antibody-based therapies. The great majority of these antibodies do not have specificity for cancer but recognize antigens expressed on a range of normal cell types (differentiation antigens). Over the past two decades, our group has analyzed thousands of mouse monoclonal antibodies for cancer specificity and identified a battery of antibodies with limited representation on normal human cells. The most tumor-specific of these antibodies is 806, an antibody that detects a unique epitope on the epidermal growth factor receptor (EGFR) that is exposed only on overexpressed, mutant, or ligand-activated forms of the receptor in cancer. In vitro immunohistochemical specificity analysis shows little or no detectable 806 reactivity with normal tissues, even those with high levels of wild-type (wt)EGFR expression. Preclinical studies have demonstrated that 806 specifically targets a subset of EGFR expressed on tumor cells, and has significant anti-tumor effects on human tumor xenografts, primarily through abrogation of signaling pathways. The present clinical study was designed to examine the in vivo specificity of a chimeric form of mAb 806 (ch806) in a tumor targeting/biodistribution/pharmacokinetic analysis in patients with diverse tumor types. ch806 showed excellent targeting of tumor sites in all patients, no evidence of normal tissue uptake, and no significant toxicity. These in vitro and in vivo characteristics of ch806 distinguish it from all other antibodies targeting EGFR.