Phase II randomised discontinuation trial of brivanib in patients with advanced solid tumours

BACKGROUND

Brivanib is a selective inhibitor of vascular endothelial growth factor and fibroblast growth factor (FGF) signalling. We performed a phase II randomised discontinuation trial of brivanib in 7 tumour types (soft-tissue sarcomas [STS], ovarian cancer, breast cancer, pancreatic cancer, non-small-cell lung cancer [NSCLC], gastric/esophageal cancer and transitional cell carcinoma [TCC]).

PATIENTS AND METHODS

During a 12-week open-label lead-in period, patients received brivanib 800 mg daily and were evaluated for FGF2 status by immunohistochemistry. Patients with stable disease at week 12 were randomised to brivanib or placebo. A study steering committee evaluated week 12 response to determine if enrolment in a tumour type would continue. The primary objective was progression-free survival (PFS) for brivanib versus placebo in patients with FGF2-positive tumours.

RESULTS

A total of 595 patients were treated, and stable disease was observed at the week 12 randomisation point in all tumour types. Closure decisions were made for breast cancer, pancreatic cancer, NSCLC, gastric cancer and TCC. Criteria for expansion were met for STS and ovarian cancer. In 53 randomised patients with STS and FGF2-positive tumours, the median PFS was 2.8 months for brivanib and 1.4 months for placebo (hazard ratio [HR]: 0.58, p = 0.08). For all randomised patients with sarcomas, the median PFS was 2.8 months (95% confidence interval [CI]: 1.4-4.0) for those treated with brivanib compared with 1.4 months (95% CI: 1.3-1.6) for placebo (HR = 0.64, 95% CI: 0.38-1.07; p = 0.09). In the 36 randomised patients with ovarian cancer and FGF2-positive tumours, the median PFS was 4.0 (95% CI: 2.6-4.2) months for brivanib and 2.0 months (95% CI: 1.2-2.7) for placebo (HR: 0.56, 95% CI: 0.26-1.22). For all randomised patients with ovarian cancer, the median PFS in those randomised to brivanib was 4.0 months (95% CI: 2.6-4.2) and was 2.0 months (95% CI: 1.2-2.7) in those randomised to placebo (HR = 0.54, 95% CI: 0.25-1.17; p = 0.11).

CONCLUSION

Brivanib demonstrated activity in STS and ovarian cancer with an acceptable safety profile. FGF2 expression, as defined in the protocol, is not a predictive biomarker of the efficacy of brivanib.

First-in-human, phase I study of elisidepsin (PM02734) administered as a 30-min or as a 3-hour intravenous infusion every three weeks in patients with advanced solid tumors

This first-in-human, phase I clinical trial was designed to determine the dose-limiting toxicities (DLTs) and the dose for phase II trials (P2D) of elisidepsin (PM02734) administered as a 30-min or as a 3-h intravenous infusion every 3 weeks (q3wk). Between March 2006 and April 2011, 53 patients with advanced malignant solid tumors were enrolled and treated with elisidepsin on the two different q3wk infusion schedules: 22 (30-min) and 31 (3-h), respectively. Doses evaluated ranged from 0.1 to 1.6 mg/m(2) (30-min q3wk) and from 2.0 to 11.0 mg flat dose (FD) (3-h q3wk). In the 30-min q3wk schedule, transient grade 3/4 increases in hepatic transaminases were the DLT, which appeared at the highest doses tested (from 1.1 to 1.6 mg/m(2)). No DLTs were observed on the 3-h schedule at doses up to 11.0 mg q3wk. Common adverse events were grade 1/2 pruritus, nausea, fatigue and hypersensitivity. Of note, myelotoxicity was not observed. Plasma maximum concentration and total drug exposure increased linearly with dose. Prolonged (≥3 months) disease stabilization was observed in pretreated patients with pleural mesothelioma (n = 1) in the 30-min q3wk arm, and with colorectal adenocarcinoma (n = 3), esophagus adenocarcinoma, endometrium adenocarcinoma, pleural mesothelioma, and head and neck carcinoma (n = 1 each) in the 3-h q3wk arm. In conclusion, elisidepsin doses of 1.1 mg/m(2) (equivalent to a FD of 2.0 mg) and 11.0 mg FD are the dose levels achieved for further phase II trials testing the 30-min q3wk and 3-h q3wk schedules, respectively.

First-in-human phase I study of Lurbinectedin (PM01183) in patients with advanced solid tumors

PURPOSE

Lurbinectedin (PM01183) binds covalently to DNA and has broad activity against tumor cell lines. This first-in-human phase I study evaluated dose-limiting toxicities (DLT) and defined a phase II recommended dose for PM01183 as a 1-hour intravenous infusion every three weeks (q3wk).

EXPERIMENTAL DESIGN

Thirty-one patients with advanced solid tumors received escalating doses of PM01183 following an accelerated titration design.

RESULTS

PM01183 was safely escalated over 200-fold, from 0.02 to 5.0 mg/m(2). Dose doubling was utilized, requiring 15 patients and nine dose levels to identify DLT. The recommended dose was 4.0 mg/m(2), with one of 15 patients having DLT (grade 4 thrombocytopenia). Clearance was independent of body surface area; thus, a flat dose of 7.0 mg was used during expansion. Myelosuppression, mostly grade 4 neutropenia, occurred in 40% of patients but was transient and manageable, and none was febrile. All other toxicity was mild and fatigue, nausea and vomiting were the most common at the recommended dose. Pharmacokinetic parameters showed high interindividual variation, though linearity was observed. At or above the recommended dose, the myelosuppressive effect was significantly associated with the area under the concentration-time curve from time zero to infinity (white blood cells, P = 0.0007; absolute neutrophil count, P = 0.016). A partial response was observed in one patient with pancreatic adenocarcinoma at the recommended dose.

CONCLUSION

A flat dose of 7.0 mg is the recommended dose for PM01183 as a 1-hour infusion q3wk. This dose is tolerated and active. Severe neutropenia occurred at this dose, although it was transient and with no clinical consequences in this study.

Evaluation of food effect on pharmacokinetics of vismodegib in advanced solid tumor patients

PURPOSE

Vismodegib, an orally bioavailable small-molecule Smoothened inhibitor, is approved for treatment of advanced basal cell carcinoma (BCC). We conducted a pharmacokinetic study of vismodegib in patients with advanced solid tumors to explore the effects of food on drug exposure.

EXPERIMENTAL DESIGN

In part I, patients were randomized to fasting overnight (FO), a high fat meal (HF), or a low fat meal (LF) before a single dose of vismodegib 150 mg. Plasma concentrations of vismodegib were determined by a validated liquid chromatography-tandem mass spectrometry assay. Primary endpoints were C(max) and area under the curve (AUC(0-168)). In part II, patients randomized to FO or HF in part I took vismodegib 150 mg daily after fasting; those randomized to LF took it after a meal. Primary endpoints after two weeks were C(max) and AUC(0-24).

RESULTS

Sixty (22 FO, 20 HF, 18 LF) and 52 (25 fasting, 27 fed) patients were evaluable for primary endpoints in parts I and II, respectively. Mean C(max) and AUC(0-168) after a single dose were higher in HF than FO patients [ratios of geometric means (90% CI) = 1.75 (1.30, 2.34) and 1.74 (1.25, 2.42), respectively]. There were no significant differences in C(max) or AUC(0-24) between fasting and fed groups after daily dosing. The frequencies of drug-related toxicities were similar in both groups.

CONCLUSIONS

A HF meal increases plasma exposure to a single dose of vismodegib, but there are no pharmacokinetic or safety differences between fasting and fed groups at steady-state. Vismodegib may be taken with or without food for daily dosing.

Evaluation of food effect on pharmacokinetics (PK) of GDC-0449 (G) in advanced solid tumor patients

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Background: GDC-0449 (Vismodegib, Genentech), an orally bioavailable small-molecule SMO (Smoothened) inhibitor, was recently approved for advanced basal cell carcinoma (BCC) and is being evaluated in other solid tumors. This study sought to determine whether there is a significant effect of food on the PK of G. Methods: In part I, patients (pts) were randomized 1:1 to fasting overnight (FO) or a high fat meal (HF) before a single dose of G 150 mg. The study was later amended to 1:1:2 randomization to FO, HF or a low fat meal (LF). Plasma concentrations of G were determined by a validated liquid chromatography-tandem mass spectrometry assay. PK endpoints were observed Cmax, observed Tmax, and AUC (0-24 and 0-168 hours). In part II, pts randomized to FO or HF in part I took G 150 mg/day in a fasting state, while pts randomized to LF took G 150 mg/day in a fed state. PK endpoints after two weeks were steady state (ss) Cmax, ss Tmax, and ss AUC (0-24 hours). 60 pts enrolled 10/09-11/11, of which 43 were evaluable for PK: 18 FO; 14 HF; 11 LF. Pt characteristics: Female 53%; median age 59; PS 0: 62%, 1: 38%. Tumor types: 43% colorectal; 17% pancreatic; 40% other. Results: PK data were log-transformed for analysis. AUC (0-168 hours) after a single dose was higher in HF than in FO pts (p = 0.049); ratio of geometric means = 1.46 (90% CI = 1.07-1.99). There was a trend toward higher Cmax after a single dose in HF than in FO pts (p = 0.071); ratio of geometric means = 1.39 (90% CI = 1.03-1.88). There were no significant differences between groups for single dose AUC (0-24 hours) and Tmax. There were no significant differences between fasting and fed groups for ss Cmax, ss Tmax, or ss AUC (0-24 hours). The frequencies of drug-related Grade ≥ 3 toxicities were similar in the fasting and fed groups. There were no objective responses; 11 pts (18%) had stable disease for a median duration of 16 weeks and a maximum of 104 weeks (BCC). Conclusions: A high fat meal increases plasma exposure to a single dose of G, but there are no significant PK or safety differences between fasting and fed groups at ss. GDC-0449 can be taken with or without food for daily dosing. This study design is an efficient way to evaluate the effect of food on oral anti-cancer drugs. Supported by NCI grant 5U01-CA69852-12.

Two drug interaction studies of sirolimus in combination with sorafenib or sunitinib in patients with advanced malignancies

PURPOSE

Sirolimus is the prototypical mTOR inhibitor. Sorafenib and sunitinib are small molecule inhibitors of multiple kinases including VEGF receptor (VEGFR) kinases. These agents have different mechanisms of action, providing a strong rationale for combination.

EXPERIMENTAL DESIGN

Patients with advanced cancer were assigned to receive either sirolimus or the VEGFR inhibitor alone for a 2-week lead-in period, followed by combination therapy. The primary end point of each trial was to determine whether a drug interaction exists between sirolimus and either sorafenib or sunitinib, as defined by a difference in C(max) for each drug alone compared with its C(max) during combination therapy.

RESULTS

The sorafenib and sunitinib trials enrolled 34 and 23 patients, respectively. There were no clinically significant differences in C(max) for any of the drugs alone compared with the C(max) during combination therapy. Toxicity profiles were similar to those expected for each drug alone. One patient with adrenal cortical cancer had a partial response to sirolimus and sunitnib.

CONCLUSIONS

Sirolimus can be safely combined with sorafenib or sunitinib. Our trial design is feasible and informative in screening for potential drug-drug interactions, using a relatively small number of patients and limited pharmacokinetic sampling.

The quinoxaline anti-tumor agent (R+)XK469 inhibits neuroblastoma tumor growth

The quinoxaline anti-tumor agent (R+)XK469 mediates its effects by topoisomerase IIB inhibition. This report describes a 14-year old with relapsed neuroblastoma who experienced disease stabilization for 14 months while receiving (R+)XK469 monotherapy. Due to this favorable response, laboratory studies were undertaken to determine efficacy in the preclinical setting. (R+)XK469 inhibited proliferation, caused G(2) cell cycle arrest of neuroblastoma cells in vitro, and inhibited growth of neuroblastoma xenograft tumors. These preclinical results, coupled with the favorable clinical response, demonstrate that (R+)XK469 and similar anti-tumor agents may be effective in the treatment of high-risk neuroblastoma and warrant further testing.

Abstract 2774: Complete results from a phase Ia dose-escalation and dose-expansion study of single-agent MetMAb, a monovalent antagonist antibody to the receptor MET, administered intravenously in patients with locally advanced or metastatic solid tumors

COMPLETE RESULTS FROM A PHASE Ia DOSE-ESCALATION AND DOSE-EXPANSION STUDY OF SINGLE-AGENT MetMAb, A MONOVALENT ANTAGONIST ANTIBODY TO THE RECEPTOR MET, ADMINISTERED INTRAVENOUSLY IN PATIENTS WITH LOCALLY ADVANCED OR METASTATIC SOLID TUMORS

Background: The receptor tyrosine kinase Met and/or its ligand, the hepatocyte growth factor (HGF), are frequently over-expressed in cancers and their levels are closely related to cancer progression and prognosis. Aberrant activation of HGF/Met pathway can enhance invasion, proliferation, and survival. MetMAb was uniquely engineered as a recombinant, humanized, monovalent (one-armed) monoclonal antibody to act as an antagonist of HGF-induced Met signaling.

Materials and Methods: This was a 3+3 open label, Phase Ia, dose escalation study in patients with advanced solid malignancies and consisted of two stages: a dose escalation stage, which tested 1, 4, 10, 20 and 30 mg/kg doses of MetMAb, and an expansion stage, which tested a recommended phase 2 dose (RP2D) of 15 mg/kg of MetMAb. Patients received MetMAb IV every 21 days. Pre- and post- dose serum was collected for evaluation of pharmacodynamic (PD) biomarkers that could be affected by inhibition of Met signaling. In addition, archival tissue was obtained for exploratory diagnostic assessments.

Results: We present here the complete results from the Phase Ia study, in which 34 patients were treated with MetMAb as a single-agent – 21 patients in the dose-escalation phase and 13 patients in the expansion stage. MetMAb was generally well tolerated at all dose-cohorts up to the maximum administered dose (MAD) of 30 mg/kg. No Gr4 drug-related toxicities were observed. One Gr3 and dose-limiting toxicity (DLT) of pyrexia was observed at 4 mg/kg; other Gr3 drug-related toxicities included: abdominal pain, increased aspartate aminotransferase, hyponatremia and peripheral edema. In the dose expansion stage, the most frequent drug-related toxicities included fatigue (39%) and peripheral edema (54%). An objective complete response was observed in one patient with gastric carcinoma after 4 cycles of treatment (and patient continues to exhibit no evidence of disease); analysis of the patient's archived tumor showed findings characteristic of an HGF/cMet autocrine tumor. At the RP2D, MetMAb has a half-life and clearance approximating 11 days and 7 (±2.0) mL/day/kg, respectively.

Conclusions: This Phase Ia study represents a first in human trial of a monovalent antibody. MetMAb, when administered as a single-agent, is generally safe and well tolerated. The combination of MetMAb plus bevacizumab is being investigated, and a Phase II study testing MetMAb in combination with erlotinib in NSCLC is currently ongoing.

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 2774.

Phase I and pharmacokinetic (PK) study of PTK787/ZK222584 (PTK/ZK) plus capecitabine (cape) in patients (Pts) with advanced cancer

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Background: PTK/ZK is a small molecule inhibitor of the vascular endothelial growth factor receptor family. Cape is a standard treatment for pts with breast and colon cancer, tumors for which angiogenesis inhibition is beneficial. Therefore, we conducted a phase I study of the combination to determine the maximally tolerated doses (MTD), toxicities and PK interactions. Methods: Eligible pts had advanced cancer with no standard treatment option, Karnofsky performance status (KPS) > 70, and normal organ function. Pts with bone marrow or CNS involvement or who had more than 4 prior chemotherapy regimens were excluded. A dose escalation (dosesc) phase was conducted to determine the MTD followed by a dose expansion (dosexp) phase to assess PK interactions. PTK/ZK was given as a single oral daily doser without interruption and cape was given orally twice daily for 14 of 21 days. Results to Date: 43 pts (30 male, 13 female), median age 61 y (34–78 y) and median KPS 95 (70–100) were enrolled in the dosesc phase. 37 had prior chemotherapy; 5 had radiation only. Diagnoses included colorectal cancer (10), head/neck (7), sarcoma (5), renal (4), stomach/pancreas (3 each) and others (11). 29/43 pts were evaluable for MTD determination and received a total of 145 cycles. Doses of PTK/ZK-cape (mg-mg/m2) were: 750/2,500; 1,000/2,500; 750/2,000; 1,000/2,000; 1,250/2,000. DLT occurred in 1/6 pts (gr 3 fatigue) at 750/2,500; 2/2 pts (≥gr 3 fatigue, hypertension [HTN]) at 1,000/2,500; 0/3 pts at 750/2,000; 2/12 pts (≥ gr 3 dizziness, HTN and seizure) at 1,000/2,000 and in 1/6 (gr 3 proteinuria) pts at 1,250/2,000. 1,250 mg was the highest PTK/ZK dose planned. Other common toxicities in the dosesc phase were hand-foot syndrome (HFS, 93%) and HTN (28%). In the dosexp phase 26 pts (14 M, 12 F) have thus far received 73 cycles at the MTD (1,250/2,000). Median age is 65 y (26–79 y) and median KPS is 80 (70–100). 28/73 cycles were delayed or interrupted for toxicity with gr ≥3 toxicities (# cycles): HFS (7), fatigue (5), increased LFTs (5), HTN (3), DVT/PE (4). 23 pts (17 in dosesc and 6 in dosexp) had response or stable disease longer than 12 weeks. Final results and PK data will be presented. Conclusion: PTK/ZK and cape can be combined without unexpected toxicities.

No significant financial relationships to disclose.

Outcome analysis of vesicoamniotic shunting in a comprehensive population

PURPOSE

Prenatal detection of obstructive uropathy is used widely and vesicoamniotic shunting is the accepted procedure in well-defined cases. We present outcomes of vesicoamniotic shunting in a consecutive series from a coordinated prenatal-postnatal treatment program.

MATERIALS AND METHODS

From 1989 to 1998 bladder obstruction was identified in 89 fetuses at a multidisciplinary prenatal high risk clinic. Prenatal intervention was considered in cases of bilateral hydronephrosis associated with evidence of bladder outlet obstruction and oligohydramnios.

RESULTS

Indications for prenatal shunting were present in 12 patients (13%), and 9 underwent vesicoamniotic shunt insertion between weeks 20 and 28 of gestation. None of the prenatal procedures was associated with preterm labor, chorioamnionitis or urine chemistry values greater than cutoff threshold on bladder tap. Shunts were extruded from 2 fetuses, which required sequential insertion. After prenatal intervention 1 patient elected pregnancy termination and the others proceeded to term. Two neonates died at birth, and 6 survived. The underlying urological diagnosis was posterior urethral valves in 4 newborns, urethral atresia in 1, and prune belly variant and urethral atresia in 1. Of the patients 3 had relatively normal renal function, 2 had severe renal insufficiency and 1 had mild renal impairment. Five newborns are voiding freely and 1 underwent bladder reconstruction and is on intermittent catheterization. None of the patients had pulmonary problems at last followup.

CONCLUSIONS

Although vesicoamniotic shunting is effective in reversing oligohydramnios, its ability to achieve sustainable good renal function in infancy is variable. No specific prenatal parameters were effective in predicting eventual good renal function. Pulmonary function cannot be assured with restoration of amniotic fluid.

Polyuria and proteinuria in cystinosis have no impact on renal transplantation. A report of the North American Pediatric Renal Transplant Cooperative Study

Because cystinotic patients are polyuric and may have severe proteinuria, each of which is a potential risk factor for graft thrombosis, preemptive transplantation for them is questionable. The objectives of this study were to characterize the changes in urine volume and protein excretion at various stages of cystinosis, determine whether there is serologic evidence of hypercoagulability, and review the clinical experience in renal transplantation in cystinotic children. The records of cystinotic patients followed at the Montreal Children's Hospital between 1992 and 1998 were reviewed. Urinary volume, protein excretion, and coagulation markers were collected to determine the glomerular filtration rate (GFR) >50 ml/min/1.73 m2, <20 ml/min/1.73 m2, before and after starting dialysis. In addition, graft failure and graft thrombosis rates were obtained from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database. Urinary volume and protein excretion remained elevated throughout different phases of the disease. Coagulation factors were within normal limits for all patients. In the NAPRTCS database there were four thromboses among the 114 patients transplanted cystinotic patients. All these occurred in cadaveric grafts and only one occurred after preemptive transplantation. Despite polyuria and severe proteinuria, children with cystinosis do not appear to be at an increased risk of graft failure or graft thrombosis.

The natural history of neonatal vesicoureteral reflux associated with antenatal hydronephrosis

PURPOSE

In an attempt to evaluate the natural history of neonatal vesicoureteral reflux, patients with antenatal history of hydronephrosis and documented reflux in the first 30 days of life were analyzed.

MATERIALS AND METHODS

Between 1993 and 1998, 260 patients with a history of antenatal hydronephrosis were referred for evaluation. Of these patients 31 were diagnosed with unilateral or bilateral refluxing renal units (54 renal units). Patients were treated with a prospective plan of observational therapy and prophylactic antibiotics, and resolution rate was calculated in patients with adequate followup. Reflux grade was correlated with postnatal ultrasonographic findings, urinary tract infections and differential renal function. Outcome analysis of 34 high grade (III to V) refluxing renal units using the Kaplan-Meier survival curves was undertaken with the end point being complete resolution or improvement. Three patients with vesicostomy and 2 who underwent ureteral reimplantation were excluded from analysis.

RESULTS

Reflux was grade I in 5% (33% males), II in 15% (62% males), III in 32% (71% males), IV in 18% (90% males) and V in 30% (100% males) of the patients. Postnatal ultrasound findings correlated poorly with the presence and degree of vesicoureteral reflux. Of 17 patients followed for at least 14 months (average followup 20) there was complete resolution in 60% with grade III, 50% with grade IV and 28% with grade V reflux. Using the Kaplan-Meier estimate there was a 50% chance of improvement (decrease in reflux grade by at least 2 grades) in high grade reflux by age 16 months. Urinary tract infections developed in 8 patients (26%) while on antibiotics. Of 46 renal units in 23 patients evaluated with a renal scan before urinary tract infection, 12 had less than 35% function.

CONCLUSIONS

A normal postnatal ultrasound should not be a basis for excluding the use of cystography. Our Kaplan-Meier estimate shows that high grade reflux does improve and may resolve spontaneously. In addition, renal scarring may be seen with high and low grade reflux in the absence of urinary tract infection but high grade reflux is associated with a higher incidence of infection.

Multiple unilateral renal cysts in two children

We report two children who presented with multiple renal cysts involving only one kidney and in whom there was no family history of renal disease and who did not have syndromes known to be associated with renal cystic disease. This unilateral involvement may represent a distinct entity, which has only been previously described in three cases; however, long-term follow-up will be needed to confirm this hypothesis. We illustrate the sonographic and computed tomographic findings, and the differential diagnosis is discussed.

Non-mydriatic fundus photography: a viable alternative to fundoscopy for identification of diabetic retinopathy in an Aboriginal population in rural Western Australia?

PURPOSE

To evaluate the Canon CR5-45NM non-mydriatic fundus camera (Canon, Kanagawa, Japan) for identifying retinopathy and the need for laser treatment in a population of Aboriginal patients with diabetes mellitus in rural Western Australia.

METHODS

Diabetic Aboriginal patients were photographed through undilated pupils using a Canon CR5-45NM non-mydriatic fundus camera, after which ophthalmoscopy was performed using indirect ophthalmoscopy through dilated pupils. The examining ophthalmologist recorded the presence of retinopathy and the need for laser treatment. A proportion of patients were rephotographed through dilated pupils. Photographs were reviewed by a second ophthalmologist who evaluated the quality of the image, the presence of retinopathy and the need for laser treatment. Results of fundus photographs and ophthalmoscopy were compared.

RESULTS

Three hundred and twenty-eight eyes in 164 Aboriginal patients were examined. The mean patient age was 48.2 years (range 16-81 years) and the mean duration of diabetes was 7.5 years (range 1-35 years). Seventy-four eyes (22.6%) were diagnosed with retinopathy using combined examination techniques, 44 (59.5%) of which were identified by ophthalmoscopy and 55 (74.3%) by photography. Thirty-five eyes were deemed to need treatment, 18 (51.4%) of which were identified by ophthalmoscopy and 30 (85.7%) by photography. Kappa coefficient measurement for agreement for presence of retinopathy and need for referral was 0.41 and 0.53, respectively. Photograph quality was significantly improved following pupil dilation.

CONCLUSIONS

The Canon CR5-45NM non-mydriatic fundus camera was relatively good at identifying diabetic retinopathy and could usefully be applied within a screening programme for treatable disease within this population.

Peritoneal membrane transport function in children receiving long-term dialysis

Accurate characterization of peritoneal solute transport capacity in children has been hampered by a lack of standardized test mechanics and small patient numbers. A standardized peritoneal equilibration test was used to study 95 pediatric patients (mean age, 9.9 +/- 5.6 yr) receiving chronic peritoneal dialysis at 14 centers. Patients were divided into four age groups (< 1, 1 to 3, 4 to 11, 12 to 19 yr) for analysis. Each patient received a 4-h peritoneal equilibration test with an exchange volume of 1100 mL/m2 per body surface area. Dialysate to plasma (D/P) ratios for creatinine (C) and urea (U) and the ratio of dialysate glucose (G) to initial dialysate glucose concentration (D/D0) were determined. Mass transfer area coefficients (MTAC) were calculated for the three solutes and potassium (P). The mean (+/- SD) 4-h D/P ratios for C and U were 0.64 +/- 0.13 and 0.82 +/- 0.09, respectively. The mean 4-h D/D0 for G was 0.33 +/- 0.10. D/P and D/D0 ratio results were similar across age groups. Normalized (for body surface area) mean MTAC (+/- SD) values were as follows: C, 10.66 +/- 3.74; G, 12.93 +/- 5.02; U, 18.43 +/- 4.02; and P, 14.02 +/- 3.94. Whereas a comparison of the normalized MTAC values across age groups with an analysis of variance showed significant age group differences only for glucose (P = 0.001) and potassium (P = 0.036), analysis by quadratic regression demonstrated a nonlinear decrease with age for C (P = 0.016), G (P < 0.001), and P (P = 0.034). In summary, evaluation of D/P and D/D0 ratios obtained from a large group of children in a standardized manner reveals values that are similar across the pediatric age range and not unlike the results obtained in adults. In contrast, normalized MTAC values of young children are greater than the values of older children, possibly as a result of maturational changes in the peritoneal membrane or differences in the effective peritoneal membrane surface area.

Ultrasound findings in juvenile nephronophthisis

The ultrasound finding of renal medullary cysts associated with increased echogenicity has been suggested to be diagnostic of juvenile nephronophthisis. The lack of cysts in several of our patients with juvenile nephronophthisis lead us to review the ultrasound findings at presentation in our patient population. Of 11 children with the diagnosis of juvenile nephronophthisis, 10 demonstrated increased echogenicity with loss of corticomedullary differentiation on initial ultrasound. Only 2 children had a single cyst each. On follow-up ultrasound, 2, 4.5, and 7 years later, 3 patients developed visible renal cysts. We conclude that at presentation the ultrasound finding consistent with the diagnosis of juvenile nephronophthisis is most often that of hyperechogenic kidneys without cysts; namely the lack of cysts does not rule out the diagnosis of juvenile nephronophthisis.

The relationship between intraperitoneal volume and solute transport in pediatric patients. Pediatric Peritoneal Dialysis Study Consortium

A multicenter study was conducted to determine the relationship between intraperitoneal volume and solute (e.g., urea, creatinine) transport as determined by the dialysate to plasma (D/P) ratio and mass transfer area coefficient (MTAC). Two 4-h peritoneal equilibration tests were conducted on each of 12 pediatric peritoneal dialysis patients (mean age, 10.8 yr; range, 0.2 to 19.2 yr). One test exchange volume was 900 mL/m2 body surface area (BSA), and the other was 1,100 mL/m2 BSA. Dialysate samples were collected at 0, 30, 60, 120, 180, and 240 min. Blood samples were drawn at 0 and 240 min. Solute equilibration was significantly more rapid with the 900 mL/m2 BSA exchange volume than with the 1,100 mL/m2 exchange volume when evaluated by the D/P ratio. In contrast, no differences in solute transport were noted with either exchange volume when assessed with the MTAC. In conclusion, solute D/P ratios vary with changes in the intraperitoneal volume, necessitating the use of a standardized exchange volume for the reliable interpretation of evaluations such as the peritoneal equilibration tests. In contrast, the use of the MTAC allows for an accurate assessment of solute transport over a wide range of exchange volumes.

Renal replacement therapy after repair of congenital heart disease in children. A comparison of hemofiltration and peritoneal dialysis

The development of renal failure necessitating peritoneal dialysis after cardiac operations is associated with a reported mortality greater than 50%. Improved fluid removal and nutritional support have been reported with the use of continuous arteriovenous hemofiltration and continuous venovenous hemofiltration techniques. We have compared our experience with all three techniques in managing children who required renal replacement therapy after cardiac operations in terms of efficacy (fluid removal, calorie intake, and clearance of urea and creatinine), complications, and outcome. Over a 5-year period renal replacement therapy was initiated in 42 children, and in 34 of them it was successfully established for more than a 24-hour period: 17 were managed with peritoneal dialysis, 8 with continuous arteriovenous hemofiltration, and 9 with continuous venovenous hemofiltration. A net negative fluid balance was achieved in only 6 (35%) patients treated with peritoneal dialysis compared with 50% of those treated with continuous venovenous hemofiltration and 89% of those treated with continuous venovenous hemofiltration. In terms of nutritional support, calorie intake increased by 43% after peritoneal dialysis was started compared with 515% and 409% in the arteriovenous and venovenous hemofiltration groups, respectively, (p < 0.005). The serum urea levels fell by 36% (p = 0.02) and 39% (p = 0.005) compared with pre-therapy levels with arteriovenous and venovenous hemofiltration, respectively, and the creatinine content was reduced by 19% and 33% (p = 0.003). Neither parameter was reduced in the peritoneal dialysis group. We conclude that the use of hemofiltration as a renal replacement therapy after surgical correction of congenital heart disease offers significant advantages over the more traditional approach of peritoneal dialysis. In addition, we suggest that a more aggressive approach to the management of fluid overload and nutritional depletion with hemofiltration may result in a decrease in the very high mortality seen in renal failure after cardiac operations.

Continuous arteriovenous hemofiltration after cardiac operations in infants and children

Acute renal insufficiency after cardiopulmonary bypass can lead to a significant morbidity from fluid overload and electrolyte disturbance, impede pulmonary gas exchange, and postpone weaning from mechanical ventilation. The limitations placed on free water intake result in severe restriction of nutrition while diuretic therapy causes electrolyte imbalance. Artificial renal support either in the form of peritoneal dialysis or hemodialysis may be complicated by sepsis and hemodynamic instability. We reviewed our experience with the use of continuous arteriovenous hemofiltration, an extracorporeal technique for removal of solutes, toxins, and water in critically ill patients with cardiac failure complicated by acute renal insufficiency and hemodynamic instability after cardiopulmonary bypass. Ten infants and children with renal insufficiency caused by low cardiac output had continuous arteriovenous hemofiltration instituted for indications including sepsis, volume overload, oliguria for more than 24 hours nonresponsive to diuretic therapy, and the need for hyperalimentation. All were supported by mechanical ventilation and receiving high-dose inotropic support. Arterial and venous vascular access was successfully obtained by cannulation of the femoral artery and vein in nine patients. Anticoagulation of the circuit was achieved with heparin infusion (6 to 20 micrograms/kg/hr) and monitored by measurement of activated clotting time. The continuous arteriovenous hemofiltration circuit was replaced if there was clot formation, or at 3 days after placement. Dialysis solution (Dianeal) 1.5% or 0.5% was infused as prefilter dilution. With the use of continuous arteriovenous hemofiltration, 20 to 100 m/hr of ultrafiltrate was removed, which allowed correction of hypervolemia, and caloric intake increased from 13.5 kcal/kg/day to 79.5 kcal/kg/day. Continuous arteriovenous hemofiltration was maintained between 5 hours and 8 days and was well tolerated in all patients. Serum urea and creatinine levels declined during continuous arteriovenous hemofiltration. We conclude that continuous arteriovenous hemofiltration is a safe and effective method for fluid and electrolyte homeostasis and that it thus allows hyperalimentation in infants and children after cardiac operations.

Iphosphamide-induced nephrotoxicity in children

The nephrotoxic potential of iphosphamide was evaluated in a retrospective analysis of all children receiving the drug at The Hospital for Sick Children in Toronto. The 25 children exhibiting nephrotoxicity did not receive more cycles or higher doses per square metre than the 78 with normal renal function. Similarly, the two groups received comparable doses and number of cycles of sodium 2-mercaptoethanesulphonate, and had similar rates of exposure to nephrotoxic drugs (except for cis-platinum). Children exhibiting nephrotoxicity were significantly younger (78.1 +/- 64.1 months) than those having normal kidney function (103.8 +/- 66.6 months) (P less than 0.05). Children exhibiting nephrotoxicity were more likely to have received cis-platinum prior to the iphosphamide (10/25, 40%) than those with normal renal function (14/73, 18%) (P less than 0.05). Nephrotoxicity was associated with a significant effect on growth. Careful follow-up of renal function should take place in children receiving iphosphamide, with special attention paid to children younger than 5 years of age and those who have received cis-platinum.

Personalized versus usual care of previously uncontrolled hypertensive patients: an exploratory analysis

This study was conducted to explore whether the quality of provider care may contribute to blood pressure reduction and whether other factors related to the treatment of hypertension may explain decline in blood pressure. In the study, 46 uncontrolled (greater than or equal to 140/90 mm Hg), medically treated hypertensive patients who received more personalized care differed significantly in the magnitude of blood pressure reduction from 36 usual-care patients (10/7 vs 2/2 mm Hg means for systolic and diastolic blood pressure reduction, respectively). About twice as many experimental patients as controls were reclassified as having "controlled" blood pressure, and this difference reached statistical significance. A multiple regression analysis for personalized-care subjects showed that no dynamic variables were related to blood pressure changes. It was postulated that more personalized care may have accounted for the significant difference between groups in blood pressure reduction. Similar personalized monitoring services might be important additions to usual medical care in order to control blood pressure more fully in high-risk hypertensive patients.

Minimal lesion disease followed by membranous glomerulonephropathy in two children with nephrotic syndrome

Two children with nephrotic syndrome are described whose clinical course, initial response to steroids, and renal biopsies were consistent with a diagnosis of minimal lesion disease (MLD). Both children subsequently became resistant to steroids and repeat renal biopsies 7 and 8 years after initial biopsies showed membranous glomerulonephropathy (MGN). Explanations are suggested which may account for the occurrence of MLD followed by MGN in a single patient. These cases illustrate the necessity of performing repeat renal biopsies in patients with nephrotic syndrome if the clinical behavior and response to steroids are not typical for MLD.

Nephrotic syndrome and diffuse mesangial proliferative glomerulonephritis in children

The clinical course, response to therapy, and outcome were analyzed in 25 children with nephrotic syndrome associated with moderate to severe mesangial cell proliferation. The conditions of more than two thirds of the patients (16/23) failed to respond to prednisone therapy, and renal insufficiency or failure developed in 13. Our data suggest an association between response to therapy and degree of mesangial cell proliferation. Persistent nephrotic syndrome was associated with slow deterioration of renal function.

Evaluation of an educational program on compliance with medication regimens in pediatric patients with renal transplants

An educational program was initiated in an attempt to improve compliance in taking medications among pediatric renal transplant patients. Compliance was assessed by pill counts and by knowledge about medications by interview and questionnaire before, during, and after a six-month study period. Forty-three percent of the population was initially found to be in some way noncompliant with medication regimens, and 19% remained so after extensive counseling and instruction. Factors associated with noncompliance were adolescence, female sex, and family instability. Compliance was associated with direct parental involvement and voluntary maintenance of medication calendars. Although knowledge about drugs significantly improved, there was no correlation with compliance; motivational factors appeared to be of greater importance.