A randomized, placebo-controlled phase III trial of masitinib plus gemcitabine in the treatment of advanced pancreatic cancer

BACKGROUND

Masitinib is a selective oral tyrosine-kinase inhibitor. The efficacy and safety of masitinib combined with gemcitabine was compared against single-agent gemcitabine in patients with advanced pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

Patients with inoperable, chemotherapy-naïve, PDAC were randomized (1 : 1) to receive gemcitabine (1000 mg/m(2)) in combination with either masitinib (9 mg/kg/day) or a placebo. The primary endpoint was overall survival (OS) in the modified intent-to-treat population. Secondary OS analyses aimed to characterize subgroups with poor survival while receiving single-agent gemcitabine with subsequent evaluation of masitinib therapeutic benefit. These prospectively declared subgroups were based on pharmacogenomic data or a baseline characteristic.

RESULTS

Three hundred and fifty-three patients were randomly assigned to receive either masitinib plus gemcitabine (N = 175) or placebo plus gemcitabine (N = 178). Median OS was similar between treatment-arms for the overall population, at respectively, 7.7 and 7.1 months, with a hazard ratio (HR) of 0.89 (95% CI [0.70; 1.13]. Secondary analyses identified two subgroups having a significantly poor survival rate when receiving single-agent gemcitabine; one defined by an overexpression of acyl-CoA oxidase-1 (ACOX1) in blood, and another via a baseline pain intensity threshold (VAS > 20 mm). These subgroups represent a critical unmet medical need as evidenced from median OS of 5.5 months in patients receiving single-agent gemcitabine, and comprise an estimated 63% of patients. A significant treatment effect was observed in these subgroups for masitinib with median OS of 11.7 months in the 'ACOX1' subgroup [HR = 0.23 (0.10; 0.51), P = 0.001], and 8.0 months in the 'pain' subgroup [HR = 0.62 (0.43; 0.89), P = 0.012]. Despite an increased toxicity of the combination as compared with single-agent gemcitabine, side-effects remained manageable.

CONCLUSIONS

The present data warrant initiation of a confirmatory study that may support the use of masitinib plus gemcitabine for treatment of PDAC patients with overexpression of ACOX1 or baseline pain (VAS > 20mm). Masitinib's effect in these subgroups is also supported by biological plausibility and evidence of internal clinical validation.

TRIAL REGISTRATION

ClinicalTrials.gov:NCT00789633.

N0539 phase II trial of fulvestrant and bevacizumab in patients with metastatic breast cancer previously treated with an aromatase inhibitor: a North Central Cancer Treatment Group (now Alliance) trial

BACKGROUND

Based on preclinical studies, the vascular endothelial pathway is an important mechanism for estrogen receptor resistance. We conducted a phase II study of fulvestrant and bevacizumab in patients with aromatase inhibitor pretreated metastatic breast cancer.

PATIENTS AND METHODS

A single-stage phase II study was conducted with these objectives: 6-month progression-free survival (PFS), tumor response, toxic effect, and overall survival. Regimen: 250 mg fulvestrant days 1 and 15 (cycle 1) then day 1 (cycle 2 and beyond) and 10 mg/kg bevacizumab days 1 and 15 of each 4-week cycle.

RESULTS

At interim analysis, 20 eligible patients initiated treatment, 11 were progression free and on treatment at 3 months, not meeting the protocol-specified efficacy requirements (at least 12 of 20). Accrual remained open during interim analysis with 36 patients enrolling before final study closure. Among the 33 eligible patients, the median PFS was 6.2 months [95% confidence interval (CI) 3.6-10.1 months]. Of the 18 with measurable disease, 4 (22%) patients (95% CI 6% to 48%) had a confirmed tumor response (1 complete, 3 partial). The most common grade 3/4 adverse events were hypertension 3 (9%) and headache 3 (9%).

CONCLUSIONS

The fulvestrant/bevacizumab combination is safe and tolerable; however, it did not meet its statistical end point.

Recovery of Salmonella and Escherichia coli from commercial egg shells and effect of translucency on bacterial penetration in eggs

This experiment was conducted to study the prevalence of Salmonella and Escherichia coli (E. coli). from the surface of egg shells, egg shell membranes or pores, and internal contents from unwashed eggs collected from commercial caged layer farms in Australia. Egg shell swabs, shell crush and egg internal contents (yolk and albumen) of an individual egg were processed for bacteriological examination. Salmonella spp. were not detected from any of the egg shell surfaces, egg shell crush or egg internal contents. Thirty five E. coli isolates were isolated from the egg shell surface. Ten E. coli strains were also isolated from shell crush. However, the internal contents of eggs appeared to be sterile. Polymerase chain reaction was performed on forty-five E. coli isolates using primers for heat stable enterotoxin genes A and B (STa and STb) and also for colicin V gene (cvaC). STa gene was detected in four E. coli isolates isolated from egg shell surfaces. All the E. coli isolates were negative for STb and cvaC genes. These data provide useful information regarding the prevalence of virulent E. coli and Salmonella spp. on and in unwashed eggs collected from layer farms. These data also suggest that unwashed eggs collected from caged layer farms are unlikely to be sources of Salmonella outbreaks. Egg shell translucency could be due to changes in the mammillary layer and mamillary cores during the early phases of egg shell formation and has the potential to increase the incidence of microcracks in egg shells, and hence, may be responsible for bacterial penetration. There was a significant correlation between egg shell translucency and egg shell penetration by Salmonella Infantis and E coli. Both strains of bacteria were able to penetrate the translucent egg shells even at very low doses. The penetration, however, was hindered in both translucent and non translucent eggs at 4 degrees C, as compared with room temperature which highlights the importance of storage of eggs at refrigerated temperatures.

N0539 Phase II Trial of Fulvstrant and Bevacizumab in Patients with Metastatic Breast Cancer Previously Treated with an Aromatase Inhibitor: A North Central Cancer Treatment Group Trial

Background: Treatment of aromatase refractory metastatic breast cancer (MBC) is difficult and challenging. Estrogen receptor (ER) resistance causes enhanced expression of the vascular endothelial growth factor (VEGF).Several studies have shown that the ER interacts with the VEGF pathway and is an important mechanism of resistance. Therefore we embarked on a phase II study of fulvestrant, a complete ER suppressor and bevacizumab, a well studied VEGF monoclonal antibody in aromatase refractory MBC patients. Methods: A single stage phase II study with an interim analysis of fulvestrant and bevacizumab was conducted with these objectives: 6 month progression-free survival rate (PFS), tumor response, toxicity, and overall survival. Regimen: fulvestrant 250 mg day1 and 15 (cycle 1) then day 1 (cycle 2 and beyond) and bevacizumab 10mg/kg days 1 and 15 of each 4 weeks is a cycle. Results: At the time of interim analysis, 11/20 evaluable patients achieved 3-month progression-free survival status while remaining on treatment for at least 3 months, not meeting the protocol specified efficacy requirements and thus halting accrual. 36 patients were enrolled from September 2007-December 2008; 33 patients were evaluable. Number of prior metastatic chemotherapy regimens: 0 in 26 patients and 1 in 7 patients. 22 (67%) patients received prior hormonal therapy in the metastatic setting. 18 (55%) had measurable disease. A median of 6 cycles (range 1-19) were administered. 12/33 evaluable patients (95% CI:20-55%) achieved 6-month progression-free survival status while remaining on treatment for a least 6 months. Among 18 patients with measurable disease, 2 (11%) patients CI:1.4-35%) had a confirmed tumor reponse (both PR). Additionally, 2 patients had stable disease for greater than 6 months, for a clinical benefit rate of 22%. Median follow up was 8.5 months (range 1.7-17.5 months). Median progression-free survival was 6.2 months (95% CI:5.4-10.1 months). The 6 -month overall survival rate was 84.8% (95% CI 73.5-98%). The median dose level administered was 250 mg for fulvestrant and 10 mg/kg for bevacizumab for cycles 1-19. The most common grade 3/4 adverse events (AEs) were hypertension 2 (6%), headache pain 2 (6%), and confusion 2 (6%). There was 1 grade 5 central nervous system hemorrhage. 13 (39%) patients experienced a grade 3 non-hematologic AE and 4 (12%) experience a grade 4+ non-hematologic AE. Conclusion: Fulvestrant/bevacizumab is safe and tolerable. Although this regimen did not meet its statistical endpoint, 22% of evaluable patients with aromatase refractory diesease achieved clinical benefit with minimal toxicity.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4096.

Meningioma presenting with transient ischaemic attacks

A case of sphenoid wing meningioma mimicking the presentation of a transient ischaemic attack (TIA) is described. Based on findings from neuroimaging in this case, possible explanations of the mechanism of this uncommon presentation of meningiomas are discussed and the literature is reviewed.

Posterior fossa arachnoid cyst presenting with unilateral tremor

A rare case of unilateral benign essential tremor is presented that responded to surgical excision of a posterior fossa arachnoid cyst.

N0337: Phase II study of capecitabine in combination with vinorelbine and trastuzumab for the first or second treatment of HER2+ metastatic breast cancer

1020

Background: Trastuzumab-containing regimes have dramatically improved outcome of patients with HER2+ breast cancer. Efforts to improve efficacy and tolerability of combination regimens with this monoclonal antibody are important for patient care. Thus, we conducted a multi-institutional phase II study of a triplet combination in patients eligible to receive either first- or second-line treatment for HER2+ metastatic breast cancer (MBC). Methods: A phase II study designed to test that the true confirmed response rate (CRR) was at most 45% versus a true CRR of at least 65% was done (March 2005-June 2008). This design required that at least 25/45 confirmed responses in evaluable patients for the treatment to be considered promising. Patients received capecitabine 825 mg/m2 po (days 1–14), vinorelbine intravenously (IV) 25 mg/m2 days 1 and 8 every 3 weeks and trastuzumab IV 8mg/kg day 1, week 1, and then 6 mg/kg q 3 weeks. Tissue and blood have been collected for future studies on biomarkers. Results: 47 women were accrued, one patient cancelled participation prior to receiving any study drug, and another had a major protocol violation. 45 patients were evaluable and 30 (67%) achieved a confirmed response, (26 patients, 58% had a confirmed partial response and 4 patients, 9% had a confrimed complete response). Median progression free survival was 11.3 months (95% CI 8.4–23.2 months), median overall survival was 27.2 months (95% CI: 26.6-NA months), and among the 30 responders, the median duration of response time was 15.5 months (95% 7.7–26.1 months). The most common grade 3 events include neutropenia 61%, fatigue 13%, skin reaction-hand-foot 11%, and leukopenia 11%. Alopecia was not noted with this regimen. Conclusions: This triplet combination is effective, safe, and is promising in patients with HER2+ MBC. A phase III study should be conducted to compare the best doublet with this triplet combination whether this would lead to better clinical outcomes.

[Table: see text]

A randomised comparison of the single use LMA Flexible with the reusable LMA Flexible in paediatric dental day-case patients

In this study we compared the performance of the single use flexible laryngeal mask airway (LMA Flexible) with the original reusable LMA Flexible in paediatric dento-alveolar day-case surgery. The aim of the study was to determine whether these two supraglottic airway devices were clinically equivalent when used for simple dental extractions in children under general anaesthesia. This randomised comparative trial in 100 healthy children used first attempt airway insertion success as its primary outcome measure. Secondary outcomes included the adequacy of ventilation, incidence of airway obstruction and the requirement for device manipulation and the incidence of adverse airway outcomes during recovery from anaesthesia. No difference was found between the devices in first attempt insertion success rate (94% with reusable LMA Flexible and 90% with single use LMA Flexible, p = 0.358), and ease of insertion was also similar (p = 0.5). Both devices performed equally well during surgery, with no significant differences in episodes of intra-operative airway compromise (p = 0.387), and both the single use and reusable LMA Flexible displayed excellent recovery characteristics, with no occurrences of emergence airway obstruction. No blood was discovered within the inner LMA tube shaft in either device, implying that both protected against tracheobronchial soiling. We conclude therefore that the single use LMA Flexible is an acceptable alternative to the reusable LMA Flexible.

An introduction to Toll-like receptors and their possible role in the initiation of labour

Toll-like receptors (TLR) have emerged as key upstream mediators of inflammation at many tissue sites in humans. Inflammatory processes are involved in the process of parturition suggesting that TLR activity within gestation-associated tissues might have an important role in the initiation and/or maintenance of normal term labour and in various pathological states of pregnancy such as infection-associated preterm labour. Either TLRs or their signalling molecules might be excellent therapeutic targets for prevention of preterm labour.

Translational correlates, including outcome for patients with ER-/PR-/HER2- (triple negative (TNeg)) disease from N0234, a phase II trial of gemcitabine and erlotinib for pts with previously treated metastatic breast cancer (MBC)

1071

Background: N0234 is a phase II trial of gemcitabine at 1000 mg/m2 days 1 and 8 of a 21 day cycle and erlotinib at 150 mg daily in patients with previous therapy with either an anthracycline or a taxane for MBC. A partial response (PR) rate of 17% has been reported (ASCO 2005). Recent information suggests that over-expression of the EGFR pathway is frequent in patients with TNeg MBC. Methods: Tissue and serum were obtained for translational studies of ER, PR, HER2, and proteins related to EGFR pathway on tissue using immunohistochemistry; CK19, mammoglobin, and TTK on circulating tumor cells (CTCs). Markers were evaluated centrally, blinded to patient outcome. Complete data were available in 57 of 59 eligible patients; 20/57 patients (pts) were TNeg. Results: A PR rate of 25% and clinical benefit rate (PR + stable disease > 6 months)of 25% was observed in TNeg pts as compared to a PR rate of 14% (p = 0.30) and clinical benefit rate 22% (p= 0.75) for non-TNeg pts. Median progression free survival 72 days vs 98 days (p=0.13) and overall survival 227 days vs 738 days (p<0.001) were shorter for TNeg pts. Translational results for the EGFR pathway proteins and CTC analysis is forthcoming. Conclusions: The combination of gemcitabine and erlotinib appears to be as active in the non-TNeg and TNeg subset of patients on this trial. TNeg patients had an inferior clinical result, confirming the poor outcome seen in these patients. Data for the remaining biomarkers potentially predictive of activity will be presented. Supported by CA-25224, CA-37404.

[Table: see text]

Patient dose from 3D rotational neurovascular studies

The use of image-guided interventional radiological techniques is increasing in prevalence and complexity. Imaging system developments have helped improve the information available to interventionalists to plan and guide procedures. Information on doses to patients resulting from alternative imaging techniques or protocols is useful for both the process of justifying particular procedures and in optimizing the resultant exposures. Such information is not always available, especially for new or developing imaging techniques. We have undertaken a study of doses to patients associated with two alternative imaging methods for pre-intervention assessment of intracranial aneurysms. In the first technique the aneurysm is assessed from a series of digital subtraction angiography (DSA) runs taken at different imaging projections. The second technique involved acquiring images from one single image run while the imaging system rotated 180 degrees around the patient's head. In this technique, the aneurysm was then evaluated from a 3D reconstruction of the projection images. Effective doses were calculated using a computer model to simulate the exposure geometry and parameters. The mean dose from the DSA protocol used at our centre was 3.4 mSv and from the 3D rotational angiography (RA) technique was 0.20 mSv.

Safety of bevacizumab plus chemotherapy as first-line treatment of patients with metastatic colorectal cancer: Updated results from a large observational registry in the US (BRiTE)

3536

Background: Bevacizumab (BV) prolongs overall survival and progression-free survival when added to standard chemotherapy for patients with metastatic colorectal cancer (mCRC). BRiTE is a large, community-based observational registry of patients with mCRC receiving BV plus first-line chemotherapy. Safety and efficacy information in unselected patients with mCRC are collected. Chemotherapy regimen choice is at the physician’s discretion. Methods: To facilitate and evaluate enrollment of a typical community-based mCRC population, eligibility criteria were minimized. Cohort demographics were consistent with the NCI Surveillance, Epidemiology, and End Results (SEER) database for mCRC. Patients are followed for up to 3 years, and safety data including targeted BV-associated serious adverse events (SAEs) are updated every 3 months (mo). Results are based on descriptive analyses and are not adjusted for propensity of treatment, baseline characteristics, and treatment effects. Results: 1968 patients were enrolled between Feb 2004 and Jun 2005. Median study follow-up was 10 mo by Nov 4, 2005. SAEs were reported in 12.0% of patients including gastrointestinal perforation (GIP) (1.7%), postoperative bleeding/wound healing complications (1.2%), arterial thromboembolic events (ATE) (2.1%), and grade 3–4 bleeding (1.9%). 3.2% of patients discontinued BV due to a BV-related toxicity, most commonly bleeding. For patients with the respective event(s), median time to first event was 2.1 mo for GIP, 3.5 mo for ATE and 4.0 mo for grade 3–4 bleeding. 8.9% of patients with no history of hypertension (HTN) developed HTN requiring medication and 6.2% of patients who had HTN requiring medication at baseline experienced worsening of their HTN while on study treatment. Conclusions: In this unselected population of patients with mCRC, the safety profile of BV plus various chemotherapy regimens appears consistent with that observed in the pivotal BV trial. Overall discontinuation of BV due to a BV-related toxicity was uncommon. In this large community-based observational registry, no new BV associated safety issues have been identified.

[Table: see text]

Risk factors for gastrointestinal perforations in patients with metastatic colorectal cancer receiving bevacizumab plus chemotherapy

3535

Background: Bevacizumab (BV) prolongs overall survival and progression-free survival when added to standard chemotherapy in patients (pts) with metastatic colorectal cancer (mCRC). BRiTE is a large, community-based observational registry of pts with mCRC receiving BV plus first-line chemotherapy (CT). Incidence rate, temporal pattern, and potential risk factors associated with gastrointestinal perforation (GIP) were explored. Methods: Baseline patient characteristics (BC), including prospectively identified potential risk factors for GIP, were collected at study entry. Safety data were collected every 3 months (mo). Logistic regression models, adjusted and unadjusted for treatment assignment, were used to identify BC potentially associated with GIP. Results: 1968 pts were enrolled between Feb 2004 and Jun 2005. Median study follow-up was 10 mo as of Nov 4, 2005. GIPs were observed in 34 pts (1.7%). For pts with GIP, median time to first event was 2.1 mo; the majority of events were non-fatal and occurred within the first 3 mo after starting BV. BC including GI medical history (chronic aspirin or NSAID use, peptic ulcer disease, diverticulosis) were similar in pts with or without GIP and with earlier or later GIP onset (≤ or >3 mo from start of BV). Although adjusted models did not show any significant BC, GIP rates were numerically higher in pts with primary tumor intact (2.6%) vs. resected (1.6%). Furthermore, univariate analyses revealed a significant difference between intact (2.3%) and resected (0.8%) primary tumor for earlier GIP (≤3 mo from start of BV). The majority of pts with GIP had at least one of the following: acute diverticulitis, intra-abdominal abscess, gastrointestinal obstruction, tumor at GIP site, abdominal carcinomatosis, prior abdominal or pelvic radiation therapy. Conclusions: Preliminary analyses indicate the incidence of GIP in this large, community-based observational registry is similar to that previously reported in phase III mCRC trials with BV. No associations between specific BCs and an increased risk of GIP were identified. Patients with primary tumor intact were more likely to incur a GIP within the first 3 mo of starting BV and CT.

[Table: see text]

Efficacy of bevacizumab plus chemotherapy as first-line treatment of patients with metastatic colorectal cancer: Updated results from a large observational registry in the US (BRiTE)

3537

Background: Bevacizumab (BV) prolongs overall survival and progression-free survival (PFS) when added to standard chemotherapy (CT) in patients with metastatic colorectal cancer (mCRC). BRiTE is a large, community-based observational registry of patients with mCRC receiving BV plus first-line CT. Safety and efficacy information in unselected patients with mCRC are collected. Chemotherapy regimen choice is at the physician’s discretion. Methods: 1968 patients receiving BV plus first-line CT were enrolled at 248 sites in 49 states between Feb 2004 and Jun 2005. Patients are followed for up to 3 years, with data reporting every 3 months (mo) including disease status as assessed by investigator using his/her method of choice. Patients were grouped twice by CT. Cox regression models, adjusted and unadjusted for treatment assignment, were used to identify baseline characteristics (BC) and differential chemotherapy effects on PFS. Results: Cohort demographics were consistent with the NCI Surveillance, Epidemiology, and End Results (SEER) database for mCRC. Median study follow-up was 10 months by Nov 4, 2005. CT regimens included FOLFOX (55.8%), FOLFIRI (14.1%), and IFL (9.7%). Based on observed progression events (n=800) or deaths (n=123), projected median PFS is 11.3 mo (95% CI: 10.4–11.7). Median PFS was comparable in patients treated with CT regimen based on irinotecan (11.3 mo), oxaliplatin (11.4 mo), or neither (10.2 mo) (CT Grouping 1); or 5FU infusion (11.5 mo), 5-FU bolus (9.7 mo), or capecitabine (11.6 mo) (CT Grouping 2). Significant BC in adjusted and unadjusted models are ECOG performance status (PS), primary disease site, and albumin, with no significant difference among CT regimens. Conclusions: This large, community-based registry included a patient population with demographics consistent with the SEER database for mCRC. Preliminary median PFS of 11.3 mo compares favorably to that reported in the pivotal trial. Median PFS appears to be comparable for all CTs when combined with BV. Higher baseline albumin, PS of 0, and primary disease site of rectum were associated with improved outcome.

[Table: see text]

Idiopathic spinal epidural lipomatosis

We report a rare case of paraparesis caused by thoracic spinal epidural lipomatosis in a female patient who did not have any recognized predisposing factor for this condition.

Normal skull suture variant mimicking intentional injury

A presumed skull fracture might be a variant of a normal skull suture, especially when bilateral

Cutaneous metastasis from glioblastoma

A rare case of glioblastoma with isolated cutaneous metastasis adjacent to the scar site is described. Its pathogenesis and clinical significance are discussed.

Symptomatic intraspinal pneumocoele resulting from closed head injury

Intraspinal pneumocoele is rarely associated with closed head injury. We describe a case of intra-spinal pneumocoele following a closed head injury. We believe this to be the first case presenting with radicular symptoms.

Delayed post-surgical development of dural arteriovenous fistula after cervical meningocele repair

A 34-year-old female patient presented with an intracranial subarachnoid hemorrhage and was found to have a dural arteriovenous fistula at the site of previous cervical meningocele repair. Subsequent occlusion was achieved with endovascular embolization. To our knowledge, the phenomenon of the development of a spinal dural fistula at the site of a meningocele repair has not been recorded before.

Assessment of distortion in a three-dimensional rotational angiography system

The purpose of this project was to determine the degree of geometrical distortion in a three-dimensional (3D) image volume generated by a digital fluorography system with rotational image acquisition capabilities. 3D imaging is a valuable adjunct in neuroangiography for visualization and measurement of cerebral aneurysms and for determination of the optimum projection for intervention. To enable spatially accurate 3D reconstruction the system must correct for geometrical distortion in the image intensifier television system as well as for deviations in gantry motion. 3D volumes were reconstructed from 100 X-ray projections acquired over a 180 degrees arc over a period of 8 s. A phantom was constructed to assess geometrical distortion in the three dimensions. The phantom consisted of 1 mm diameter ball bearings embedded in Perspex in a cubic lattice configuration. The ball bearings were placed at 20 mm intervals over a 140 mm cubic volume. Distortion was assessed by taking measurements between points of known separation and using a differential distortion measurement. The maximum error in the 3D location of objects was found to be 1.4 mm, while the differential distortion was found to range from -1.0% to +2.3%. The 3D images were found to have negligible visual distortion, enabling subjective assessments to be made with confidence to aid intervention.

Sustained response to open-label venlafaxine in drug-resistant major depression

The aim of this study was to evaluate the response to venlafaxine in patients with treatment-resistant depression during an extension phase of an open-label study of venlafaxine. After completing the initial 8 weeks of the study, patients could continue venlafaxine treatment for an additional period of up to 10 months. Efficacy results are given for 149 patients with treatment-resistant depression. Response was defined as a 50% reduction in scores on the Montgomery-Asberg Depression Rating Scale (MADRS); 69% were responders after 8 weeks of treatment in the initial study phase, and 73% were responders at their final extension-phase visit. The mean MADRS score was 32.8 before treatment, 12.9 by 8 weeks, and 10.8 at the final extension visit. There was a statistically significant reduction of 2.1 MADRS units from entry into the extension phase to the final extension visit. At extension entry, 36.7% patients were in remission, as defined by a MADRS score of less than 12, whereas at the final extension visit, this had increased to 49%. Improvement in Clinical Global Impressions Scale scores (both patient and physician ratings) was maintained throughout the extension period, with 88% of patients reporting some improvement (75% with "very much" or "much") and 92% of doctors noting some improvement in patients (79% with "very much" or "much") at the last extension visit. The safety profile during the extension phase of the study was similar to that found in the initial phase and in other studies. The most common study events were somnolence (21%), headache (18%), insomnia (16%), sweating (16%), constipation (14%), dry mouth (11%), nausea (10%), and dizziness (10%). Patients with resistant depression that was treated with venlafaxine maintained their response for up to 10 months after an 8-week phase of treatment and showed some evidence of further improvement.

Inhibition of PDK-1 activity causes a reduction in cell proliferation and survival

3-Phosphoinositide-dependent kinase-1 (PDK-1) was identified by its ability to phosphorylate and activate protein kinase B (PKB) in vitro [1,2] and can phosphorylate and activate additional protein kinases in the AGC family in vitro [3-6]. Its role in vivo has, however, only begun to be addressed. We used antisense oligonucleotides directed against PDK-1 expression to explore the role of PDK-1 in human glioblastoma cells (U87-MG), which express a mutant PTEN allele. Reduction in PDK-1 levels resulted in inhibition of PKB activity, and a reduction in phosphorylation on Thr308 and Ser473 of PKB. p70 S6 kinase (p70(S6K)) activity was also reduced. Cell proliferation was dramatically inhibited following treatment with PDK-1 antisense oligonucleotides, due to a combination of decreased cell doubling and an increase in apoptosis. This is in contrast to direct inhibition of phosphoinositide 3-OH kinase (PI 3-kinase), which results in G1 arrest with no effect on apoptosis. This study confirms both PKB and p70(S6K) as in vivo substrates for PDK-1. The effect of acute PDK-1 loss on cell proliferation and survival suggests the involvement of PI 3-kinase dependent and independent signaling events, and implicates PDK-1 as a potential therapeutic target for human neoplasms.

Continuous intravenous diltiazem infusion for short-term ventricular rate control in children

Intravenous diltiazem was administered to 10 pediatric patients with primary atrial tachyarrhythmias with rapid ventricular response. Rapid, consistent, and safe temporary ventricular rate control was obtained in all patients given this medication.

Rho GTPase control of protein kinase C-related protein kinase activation by 3-phosphoinositide-dependent protein kinase

The protein kinase C-related protein kinases (PRKs) have been shown to be under the control of the Rho GTPases and influenced by autophosphorylation. In analyzing the relationship between these inputs, it is shown that activation in vitro and in vivo involves the activation loop phosphorylation of PRK1/2 by 3-phosphoinositide-dependent protein kinase-1 (PDK1). Rho overexpression in cultured cells is shown to increase the activation loop phosphorylation of endogenous PRKs and is demonstrated to influence this process by controlling the ability of PRKs to bind to PDK1. The interaction of PRK1/2 with PDK1 is shown to be dependent upon Rho. Direct demonstration of ternary (Rho.PRK.PDK1) complex formation in situ is provided by the observation that PDK1 is recruited to RhoB-containing endosomes only if PRK is coexpressed. Furthermore, this in vivo complex is maintained after phosphoinositide 3-kinase inhibition. The control of PRKs by PDK1 thus evidences a novel strategy of substrate-directed control involving GTPases.

A phase II trial of 200% ProMACE-CytaBOM in patients with previously untreated aggressive lymphomas: analysis of response, toxicity, and dose intensity

We showed in a phase I trial that the maximum tolerated dose of the ProMACE-CytaBOM regimen in patients with aggressive lymphoma was 200% (Gordon et al, J Clin Oncol 14:1275, 1996). Based on these observations, we initiated a phase II trial designed to determine response, toxicity, and dose intensity using this regimen. We analyzed 74 patients with advanced-stage (III or IV) or bulky stage II aggressive lymphoma. The overall complete response rate was 69% (72% in evaluable patients). With a median follow-up of 4.5 years, the median survival has not yet been reached. The 4-year survival rate is 73% (95% confidence interval [CI] 62, 83%) and no difference was observed among International Prognostic Index (IPI) groups. The 4-year disease-free survival was 71% (95% CI 58, 84%) with no statistical difference between patients with IPI 0 to 1 versus 2 to 4. The toxicity was acceptable, though the grade 4 hematologic toxicity rate for this regimen was 100%. Grade 4 nonhematologic toxicity was 36%. Three cases of either myelodysplastic syndrome or acute leukemia occurred at 7 months, 3.4 years, and 4.2 years after registration. Cytogenic analysis was available in two cases, showing inv(16) without French American British classification (FAB) M4 EO histology in one patient and a 5q-syndrome in the other. These data suggest that 200% ProMACE-CytaBOM with either granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF results in a high complete remission rate and a disease-free survival comparable to any prior risk-based analysis in aggressive lymphoma. Before using this regimen in general practice, phase III clinical trials should be conducted.

Intravenous urography in urinary tract surveillance in carcinoma of the bladder

AIMS

The need for intravenous urography (IVU) in upper tract surveillance for primary transitional cell carcinoma (TCC) of the bladder is contentious. We reviewed our intensive screening policy in the follow-up of these patients to ascertain if such a policy is required and if specific groups could be identified to rationalise this protocol.

METHODS

Review of the clinical and radiological data on 174 patients with a diagnosis of primary TCC of the bladder attending a teaching hospital urology department.

RESULTS

Eight upper tract 'lesions' were identified: six TCC and two false-positive examinations using IVU. No link was demonstrable between upper tract recurrence and tumour stage, grade or multiplicity at diagnosis. All had recurrent bladder tumour but four of the six upper tract tumours occurred at 72 months or later. Twenty-nine patients over the study period developed either a dilated pelvi-calyceal system or a non-functioning kidney detected on IVU.

CONCLUSIONS

Upper tract TCC can present late and patients with early bladder recurrence and those who do not show a reduction in bladder tumour number at follow-up cystoscopy are most at risk. IVU can probably be safely abandoned in those without local recurrence at 24 months. IVU is sensitive but not specific for upper tract tumour but also yields other relevant clinical information concerning the renal tract. Screening for upper tract metachronous disease should therefore be confined to those with recurrent transitional cell carcinoma of the bladder.

Safety and single-dose pharmacokinetics of abacavir (1592U89) in human immunodeficiency virus type 1-infected children

Abacavir (formerly 1592U89) is a potent 2'-deoxyguanosine analog reverse transcriptase inhibitor that has been demonstrated to have a favorable safety profile in initial clinical trials with adults with human immunodeficiency virus (HIV) type 1 infection. A phase I study was conducted to evaluate the pharmacokinetics and safety of abacavir following the administration of two single oral doses (4 and 8 mg/kg of body weight) to 22 HIV-infected children ages 3 months to 13 years. Plasma was collected for analysis at predose and at 0.5, 1, 1.5, 2, 2.5, 3, 5, and 8 h after the administration of each dose. Plasma abacavir concentrations were determined by high-performance liquid chromatography, and data were analyzed by noncompartmental methods. Abacavir was well tolerated by all subjects. The single abacavir-related adverse event was rash, which occurred in 2 of 22 subjects. After administration of the oral solution, abacavir was rapidly absorbed, with the time to the peak concentration in plasma occurring within 1.5 h postdosing. Pharmacokinetic parameter estimates were comparable among the different age groups for each dose level. The mean maximum concentration in plasma (Cmax) and the mean area under the curve from time zero to infinity (AUC0-infinity) increased by 16 and 45% more than predicted, respectively, as the abacavir dose was doubled from 4 to 8 mg/kg (Cmax increased from 1.69 to 3.94 micrograms/ml, and AUC0-infinity increased from 2.82 to 8.09 micrograms.h/ml). Abacavir was rapidly eliminated, with a mean elimination half-life of 0.98 to 1.13 h. The mean apparent clearance from plasma decreased from 27.35 to 18.88 ml/min/kg as the dose increased. Neither body surface area nor creatinine clearance were correlated with pharmacokinetic estimates at either dose. The extent of exposure to abacavir appears to be slightly lower in children than in adults, with the comparable unit doses being based on body weight. In conclusion, this study showed that abacavir is safe and well tolerated in children when it is administered as a single oral dose of 4 or 8 mg/kg.

Human immunodeficiency virus protease inhibitors serve as substrates for multidrug transporter proteins MDR1 and MRP1 but retain antiviral efficacy in cell lines expressing these transporters

The human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs)-saquinavir, ritonavir, nelfinavir, and indinavir-interact with the ABC-type multidrug transporter proteins MDR1 and MRP1 in CEM T-lymphocytic cell lines. Calcein fluorescence was significantly enhanced in MDR1(+) CEM/VBL100 and MRP1(+) CEM/VM-1-5 cells incubated in the presence of various HIV PIs and calcein acetoxymethyl ester. HIV PIs also enhanced the cytotoxic activity of doxorubicin, a known substrate for MDR1 and MRP1, in both VBL100 and VM-1-5 CEM lines. Saquinavir, ritonavir, and nelfinavir enhanced doxorubicin toxicity in CEM/VBL100 cells by approximately three- to sevenfold. Saquinavir and ritonavir also enhanced doxorubicin toxicity in CEM/VM-1-5 cells. HIV-1 replication was effectively inhibited by the various PIs in all of the cell lines, and the 90% inhibitory concentration for a given compound was comparable between the different cell types. Therefore, overexpression of MDR1 or MRP1 by T lymphocytes is not likely to limit the antiviral efficacy of HIV PI therapy.