Bevacizumab continuation versus no continuation after first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer: a randomized phase III non-inferiority trial (SAKK 41/06).

BACKGROUND: Chemotherapy plus bevacizumab is a standard option for first-line treatment in metastatic colorectal cancer (mCRC) patients. We assessed whether no continuation is non-inferior to continuation of bevacizumab after completing first-line chemotherapy. PATIENTS AND METHODS: In an open-label, phase III multicentre trial, patients with mCRC without disease progression after 4-6 months of standard first-line chemotherapy plus bevacizumab were randomly assigned to continuing bevacizumab at a standard dose or no treatment. CT scans were done every 6 weeks until disease progression. The primary end point was time to progression (TTP). A non-inferiority limit for hazard ratio (HR) of 0.727 was chosen to detect a difference in TTP of 6 weeks or less, with a one-sided significance level of 10% and a statistical power of 85%. RESULTS: The intention-to-treat population comprised 262 patients: median follow-up was 36.7 months. The median TTP was 4.1 [95% confidence interval (CI) 3.1-5.4] months for bevacizumab continuation versus 2.9 (95% CI 2.8-3.8) months for no continuation; HR 0.74 (95% CI 0.58-0.96). Non-inferiority could not be demonstrated. The median overall survival was 25.4 months for bevacizumab continuation versus 23.8 months (HR 0.83; 95% CI 0.63-1.1; P = 0.2) for no continuation. Severe adverse events were uncommon in the bevacizumab continuation arm. Costs for bevacizumab continuation were estimated to be ∼30,000 USD per patient. CONCLUSIONS: Non-inferiority could not be demonstrated for treatment holidays versus continuing bevacizumab monotheray, after 4-6 months of standard first-line chemotherapy plus bevacizumab. Based on no impact on overall survival and increased treatment costs, bevacizumab as a single agent is of no meaningful therapeutic value. More efficient treatment approaches are needed to maintain control of stabilized disease following induction therapy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, number NCT00544700.

Comparison of carotid arterial resistive indices with intima-media thickness as sonographic markers of atherosclerosis.

UNLABELLED: Background and Purpose-The intima-media thickness (IMT) of the carotid artery is a (morphological) sonographic parameter that depends on the degree of atherosclerosis. In the renal arteries, the value of the (hemodynamic) resistive index (RI) is correlated with the severity of atherosclerosis. In contrast to the well-known IMT, no study has yet applied the carotid RI to estimate generalized atherosclerosis. METHODS: -The SMART atherosclerosis risk score was determined in 157 patients (94 men and 63 women; mean age 63 [range 19 to 80] years) with at least 1 vascular risk factor or a known vascular disease. Duplex sonography of the common carotid (CCA) and internal carotid artery (ICA) was then performed, with determination of IMT and RI. RESULTS: -The mean risk score of all patients was 8.8+/-3.5 (range 1 to 17), the mean IMT value in the CCA was 0.727+/-0.161 mm, the mean RI in CCA was 0.79+/-0.066, and the mean RI in ICA was 0.661+/-0.082. Highly significant correlations were found between the score and IMT CCA and the score and RI ICA (r=0.62, P:<0.0001 and r=0.55, P:<0.0001). The score-RI CCA correlation was much less marked (r=0.354, P:<0.0001). The intraobserver and interobserver agreement was less for IMT than for RI CCA and ICA. The areas under the curve of the receiver operating curves to distinguish between low-risk and high-risk patients resulted in values of 0.86, 0.81, and 0.69 for IMT, RI ICA, and RI CCA, respectively. CONCLUSIONS: -Although RI reflects the atherosclerotic process in an indirect manner, the correlation between the RI ICA and the SMART atherosclerosis score as well as the ability to distinguish between low- and high-risk patients are comparable to those of the well-known IMT.

Transmission of donor illness by stem cell transplantation: should screening be different in older donors?

With increasing donor age, the potential of transmitting diseases from donor to recipient reaches new dimensions. Potentially transmittable diseases from donors include infections, congenital disorders, and acquired illnesses like autoimmune diseases or malignancies of hematological or nonhematological origin. While established nonmalignant or malignant diseases might be easy to discover, early-stage hematological diseases like CML, light-chain multiple myelomas, aleukemic leukemias, occult myelodysplastic syndromes and other malignant and nonmalignant diseases might not be detectable by routine screening but only by invasive, new and/or expensive diagnostic tests. In the following article, we propose recommendations for donor work-up, taking into consideration the age of the donors. In contrast to blood transfusions, stem cells from donors with abnormal findings might still be acceptable for HCT, when no other options are available and life expectancy is limited. This issue is discussed in detail in relation to the available donor and stem cell source. Finally, the recommendations presented here aim at harmonized worldwide work-up for donors to insure high standard quality.

Efficient mobilization of PBSC with vinorelbine/G-CSF in patients with malignant lymphoma.

High-dose chemotherapy (HDT) and hematopoietic SCT are effective in patients with relapsing or refractory malignant lymphoma. Collection of sufficient numbers of stem cells is a prerequisite for such a therapy. In a pilot trial, we evaluated the feasibility of stem cell mobilization with vinorelbine/G-CSF in patients with lymphoma, a regimen allowing precise timing and harvesting of sufficient stem cells in myeloma patients. Forty-five patients with lymphoma received vinorelbine 35 mg/m(2) i.v. on day 1 and G-CSF 10 microg/kg/day s.c., divided in two daily doses from day 4 until collection. Stem cell collection was successfully performed in 43 patients (96%) with a median of 3.6 x 10(6) CD34(+) cells/kg (range: 1.4-16) in the collected product. In 28 patients (62%), the first stem cell apheresis was performed on day 8, and for 28 patients a sufficient stem cell yield was reached with one apheresis only. All 43 patients underwent high-dose chemotherapy with BEAM and auto-SCT with hematological recovery on time and without unexpected toxicity. In conclusion, vinorelbine/G-CSF allows accurate timing and safe harvesting of sufficient stem cells in patients with malignant lymphoma.

Weekly paclitaxel and carboplatin combination chemotherapy in patients with advanced squamous cell carcinoma of the head and neck.

BACKGROUND: The combination of paclitaxel and carboplatin is active in the treatment of squamous cell carcinoma of the head and neck (SCCHN). However, considerable toxicity develops with 3-weekly drug administration. Treatment on a weekly basis may allow for a higher dose intensity with less adverse effects. PATIENTS AND METHODS: Enrolled in this study were 31 patients with locally advanced, metastatic or relapsed SCCHN, most of them pretreated. They received weekly i.v. infusions of 80 mg/m(2) paclitaxel over 1 h combined with carboplatin at an area under the concentration time curve of 2 mg/ml/min over 30 min. RESULTS: The overall response rate was 52% with 1 complete response and 16 partial responses. Median progression-free survival was 5.4 months, median overall survival 12.8 months. Grade 3/4 hematologic adverse events occurred in 7 patients and grade 3 peripheral neuropathy in one. 10 patients required dose reduction or treatment delay due to neutropenia, thrombocytopenia or neuropathy. CONCLUSIONS: Weekly administration of paclitaxel and carboplatin appears to be safe and efficacious in patients with advanced, metastatic or recurrent SCCHN.

[Neonatal alloimmune thrombocytopenia due to a rare anti-HPA-1b antibody]. / Neonatale Alloimmunthrombozytopenie durch einen Antikörper gegen das selten immunogene HPA-1b.

Foetal and neonatal alloimmune thrombocytopenia is caused by transplacental transfer of antibodies directed against platelet antigens and affects approximately 1 in 1000-2500 neonates. Clinically relevant complications are the intracranial haemorrhages that occur in 10-20% of cases. 20 platelet antigen systems are currently known. However, immunisation is most frequently seen against two of these (HPA-1a and HPA-5b). Treatment options include transfusion of compatible or, if these are not available while urgently needed, random donor platelets, intravenous immunoglobulin, and steroids. We report on a case of neonatal alloimmune thrombocytopenia due to an anti-HPA-1b antibody in the third pregnancy of a 31-year-old Caucasoid woman. The infant was treated with repeated maternal and random donor platelet transfusions and with a single dose of intravenous immunoglobulin.

Silencing of RNA polymerases II and III-dependent transcription by the KRAB protein domain of KOX1, a Krüppel-type zinc finger factor.

The so-called KRAB domain, which is present in about one third of the vertebrate Kruppel-type zinc finger factors, has previously been shown to inhibit transcription in cis when tethered to promoter regions. Here we analyze this effect with fusions of the KRAB domain derived from KOX1/ZNF10 zinc finger protein to the heterologous DNA binding domains of both LexA and GAL4 factors. In transfected human cells, repression of reporter gene transcription is observed not only from proximal promoter positions, but also when KRAB is tethered to DNA at a remote position more than 1.8 kb downstream of the initiation site of transcription. Furthermore, KRAB-mediated silencing over short and long distances is not restricted to RNA polymerase II, since transcription by RNA polymerase III is also repressed. However, transcription by RNA polymerase I and by phage T7 RNA polymerase in mammalian cells are not significantly influenced by the KRAB domain. These latter results may indicate that repression by the KRAB domain, at least under our assay conditions, involves specific inhibition of some component(s) of RNA polymerase II and III transcription, rather than inducing some gross physical alteration of template chromatin structure.

A novel mitochondrial tRNA(Phe) mutation inhibiting anticodon stem formation associated with a muscle disease.

We have identified a novel mitochondrial (mt) DNA mutation in the tRNA(Phe)-gene in a patient with an isolated mitochondrial myopathy. This T to C transition at position 618 disrupts a strictly conserved base pair within the anticodon stem of tRNA(Phe). Computer analysis showed that the affected base pair is essential for anticodon stem formation of tRNA(Phe). The mutant mtDNA was heteroplasmic in skeletal muscle (95% mutant) and peripheral blood cells (20% mutant) from the patient but was undetectable in blood cells from his healthy sister. The patient presented with ragged red fibers and reduced activities of complex I and complex III in skeletal muscle. The T618C mutation described here is the second found in this region. Both mutations affect the same base pair of the tRNA(Phe) anticodon stem substantiating the pathogenic nature of both mutations.

Transcriptional repression by RING finger protein TIF1 beta that interacts with the KRAB repressor domain of KOX1.

Many of the vertebrate zinc finger factors of the Kruppel type (C2H2 zinc fingers) contain in their N-terminus a conserved sequence referred to as the KRAB (Kruppel-associated box) domain that, when tethered to DNA, efficiently represses transcription. Using the yeast two-hybrid system, we have isolated an 835 amino acid RING finger (C3HC4 zinc finger) protein, TIF1 beta (also named KAP-1), that specifically interacts with the KRAB domain of the human zinc finger factor KOX1/ZNF10. TIF1 beta, TIF1 alpha, PML and efp belong to a characteristic subgroup of RING finger proteins that contain one or two other Cys/His-rich clusters (B boxes) and a putative coiled-coil in addition to the classical C3HC4 RING finger motif (RBCC configuration). Like TIF1 alpha, TIF1 beta also contains an additional Cys/His cluster (PHD finger) and a bromo-related domain. When tethered to DNA, TIF1 beta can repress transcription in transiently transfected mammalian cells both from promoter-proximal and remote (enhancer) positions, similarly to the KRAB domain itself. We propose that TIF1 beta is a mediator of the transcriptional repression exerted by the KRAB domain.

A serine/arginine-rich nuclear matrix cyclophilin interacts with the C-terminal domain of RNA polymerase II.

The largest subunit of RNA polymerase II shows a striking difference in the degree of phosphorylation, depending on its functional state: initiating and elongating polymerases are unphosphorylated and highly phosphorylated respectively. Phosphorylation mostly occurs at the C-terminal domain (CTD), which consists of a repetitive heptapeptide structure. Using the yeast two-hybrid system, we have selected for mammalian proteins that interact with the phosphorylated CTD of mammalian RNA polymerase II. A prominent isolate, designated SRcyp/CASP10, specifically interacts with the CTD not only in vivo but also in vitro . It contains a serine/arginine-rich (SR) domain, similar to that found in the SR protein family of pre-mRNA splicing factors, which is required for interaction with the CTD. Most remarkably, the N-terminal region of SRcyp includes a peptidyl-prolyl cis - trans isomerase domain characteristic of immunophilins/cyclophilins (Cyp), a protein family implicated in protein folding, assembly and transport. SRcyp is a nuclear protein with a characteristic distribution in large irregularly shaped nuclear speckles and co-localizes perfectly with the SR domain-containing splicing factor SC35. Recent independent investigations have provided complementary data, such as an association of the phosphorylated form of RNA polymerase II with the nuclear speckles, impaired splicing in a CTD deletion background and inhibition of in vitro splicing by CTD peptides. Taken together, these data indicate that factors directly or indirectly involved in splicing are associated with the elongating RNA polymerases, from where they might translocate to the nascent transcripts to ensure efficient splicing, concomitant with transcription.