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.