IA et données de santé : regards croisés sur les droits, devoirs et responsabilités des personnes publiques

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Phase 3 trials of ixekizumab in moderate-to-severe plaque psoriasis

BACKGROUND Two phase 3 trials (UNCOVER-2 and UNCOVER-3) showed that at 12 weeks of treatment, ixekizumab, a monoclonal antibody against interleukin-17A, was superior to placebo and etanercept in the treatment of moderate-to-severe psoriasis. We report the 60-week data from the UNCOVER-2 and UNCOVER-3 trials, as well as 12-week and 60-week data from a third phase 3 trial, UNCOVER-1. METHODS We randomly assigned 1296 patients in the UNCOVER-1 trial, 1224 patients in the UNCOVER-2 trial, and 1346 patients in the UNCOVER-3 trial to receive subcutaneous injections of placebo (placebo group), 80 mg of ixekizumab every 2 weeks after a starting dose of 160 mg (2-wk dosing group), or 80 mg of ixekizumab every 4 weeks after a starting dose of 160 mg (4-wk dosing group). Additional cohorts in the UNCOVER-2 and UNCOVER-3 trials were randomly assigned to receive 50 mg of etanercept twice weekly. At week 12 in the UNCOVER-3 trial, the patients entered a long-term extension period during which they received 80 mg of ixekizumab every 4 weeks through week 60; at week 12 in the UNCOVER-1 and UNCOVER-2 trials, the patients who had a response to ixekizumab (defined as a static Physicians Global Assessment [sPGA] score of 0 [clear] or 1 [minimal psoriasis]) were randomly reassigned to receive placebo, 80 mg of ixekizumab every 4 weeks, or 80 mg of ixekizumab every 12 weeks through week 60. Coprimary end points were the percentage of patients who had a score on the sPGA of 0 or 1 and a 75% or greater reduction from baseline in Psoriasis Area and Severity Index (PASI 75) at week 12. RESULTS In the UNCOVER-1 trial, at week 12, the patients had better responses to ixekizumab than to placebo; in the 2-wk dosing group, 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; in the 4-wk dosing group, the respective rates were 76.4% and 82.6%; and in the placebo group, the rates were 3.2% and 3.9% (P<0.001 for all comparisons of ixekizumab with placebo). In the UNCOVER-1 and UNCOVER-2 trials, among the patients who were randomly reassigned at week 12 to receive 80 mg of ixekizumab every 4 weeks, 80 mg of ixekizumab every 12 weeks, or placebo, an sPGA score of 0 or 1 was maintained by 73.8%, 39.0%, and 7.0% of the patients, respectively. Patients in the UNCOVER-3 trial received continuous treatment of ixekizumab from weeks 0 through 60, and at week 60, at least 73% had an sPGA score of 0 or 1 and at least 80% had a PASI 75 response. Adverse events reported during ixekizumab use included neutropenia, candidal infections, and inflammatory bowel disease. CONCLUSIONS In three phase 3 trials involving patients with psoriasis, ixekizumab was effective through 60 weeks of treatment. As with any treatment, the benefits need to be weighed against the risks of adverse events. The efficacy and safety of ixekizumab beyond 60 weeks of treatment are not yet known

Cryo-EM study of an archaeal 30S initiation complex gives insights into evolution of translation initiation

International audienceArchaeal translation initiation occurs within a macromolecular complex containing the small ribosomal subunit (30S) bound to mRNA, initiation factors aIF1, aIF1A and the ternary complex aIF2:GDPNP:Met-tRNAiMet. Here, we determine the cryo-EM structure of a 30S:mRNA:aIF1A:aIF2:GTP:Met-tRNAiMet complex from Pyrococcus abyssi at 3.2 Å resolution. It highlights archaeal features in ribosomal proteins and rRNA modifications. We find an aS21 protein, at the location of eS21 in eukaryotic ribosomes. Moreover, we identify an N-terminal extension of archaeal eL41 contacting the P site. We characterize 34 N4-acetylcytidines distributed throughout 16S rRNA, likely contributing to hyperthermostability. Without aIF1, the 30S head is stabilized and initiator tRNA is tightly bound to the P site. A network of interactions involving tRNA, mRNA, rRNA modified nucleotides and C-terminal tails of uS9, uS13 and uS19 is observed. Universal features and domain-specific idiosyncrasies of translation initiation are discussed in light of ribosomal structures from representatives of each domain of life

Use of β3-methionine as an amino acid substrate of Escherichia coli methionyl-tRNA synthetase

International audiencePolypeptides containing β-amino acids are attractive tools for the design of novel proteins having unique properties of medical or industrial interest. Incorporation of β-amino acids in vivo requires the development of efficient aminoacyl-tRNA synthetases specific of these non-canonical amino acids. Here, we have performed a detailed structural and biochemical study of the recognition and use of β3-Met by Escherichia coli methionyl-tRNA synthetase (MetRS). We show that MetRS binds β3-Met with a 24-fold lower affinity but catalyzes the esterification of the non-canonical amino acid onto tRNA with a rate lowered by three orders of magnitude. Accurate measurements of the catalytic parameters required careful consideration of the presence of contaminating α-Met in β3-Met commercial samples. The 1.45 Å crystal structure of the MetRS: β3-Met complex shows that β3-Met binds the enzyme essentially like α-Met, but the carboxylate moiety is mobile and not adequately positioned to react with ATP for aminoacyl adenylate formation. This study provides structural and biochemical bases for engineering MetRS with improved β3-Met aminoacylation capabilities

A systematic review of regulatory and educational interventions to reduce the burden associated with the prescriptions of sedative-hypnotics in adults treated for sleep disorders

<div><p>Background</p><p>The burden of Sedative-Hypnotics (SHs) has been known since the 1980s. Yet, their consumption remains high. A systematic review of the literature should help to assess efficient interventions to improve the appropriate use of SHs in sleep disorders.</p><p>Objectives</p><p>To identify and assess regulatory and educational interventions designed to improve the appropriate use of SHs for insomnia treatment.</p><p>Methods</p><p>We conducted a systematic review of the literature according to PRISMA guidelines. A systematic search covering the period 1980–2015 was carried out in Medline, Web of Science, Embase and PsycInfo. We included studies reporting the implementation of regulatory or educational strategies directed towards patients and/or healthcare professionals to improve the appropriate use of SHs to treat insomnia in the community, hospitals and nursing homes.</p><p>Results</p><p>Thirty-one studies were included: 23 assessed educational interventions (recommendations by mail/email, computer alerts, meetings, mass media campaigns, prescription profile), 8 assessed regulatory interventions (prescription rule restriction, end of reimbursement). The most recent was implemented in 2009. Restrictive prescription rules were effective to reduce the consumption of targeted SHs but led to a switch to other non-recommended SHs. Among educational interventions, only 3 studies out of 7 reported positive results of mono-faceted interventions; whereas, 13 out of the 16 multi-faceted interventions were reported as efficient: particularly, the active involvement of healthcare professionals and patients and the spread of information through mass media were successful. The risk of bias was high for 24 studies (mainly due to the design), moderate for 3 studies and weak for 4 studies.</p><p>Conclusion</p><p>Educational multifaceted studies are presented as the most efficient. But further better designed studies are needed to make evidence-based results more generalizable.</p></div

Sedative-hypnotic initiation and renewal at discharge in hospitalized older patients: an observational study

Abstract Background Sedative-hypnotics (SHs) are widely used in France but there are no available data addressing their prescription specifically in hospitalized older patients. The objective is thus to determine the cumulative incidence of sedative-hypnotic (SH) medications initialized during a hospital stay of older patients, the proportion of SH renewal at discharge among these patients and to study associated risk factors. Methods We conducted a retrospective observational study in six internal medicine units and six acute geriatric units in eight hospitals (France). We included 1194 inpatients aged 65 and older without SH medications prior to hospitalization. Data were obtained from patients’ electronic pharmaceutical records. Primary outcome was the cumulative incidence of SH initiation in the study units. Secondary outcomes were the proportion of SH renewal at discharge and risk factors for SH initiation and renewal at discharge (patient characteristics, hospital organization). A Cox regression model was used to study risk factors for SH initiation. A mixed effects logistic regression was used to study risk factors for SH renewal at discharge. Results SH initiation occurred in 21.5% of participants 20 days after admission. SH renewal at discharge occurred in 38.7% of patients who had initiated it during their stay and were discharged home and in 56.0% of patients discharged to rehabilitation facilities. Neither patients’ characteristics nor hospital organization patterns was associated with SH initiation. SH initiation after the first six days after admission was associated with a lower risk of SH renewal in patients discharged to rehabilitation facilities (OR = 0.19, 95% CI: [0.04–0.80]). Conclusions Hospitalization is a period at risk for SH initiation. The implementation of interventions promoting good use of SHs is thus of first importance in hospitals. Specific attention should be paid to patients discharged to rehabilitation facilities

Bevacizumab/docetaxel association is more efficient than docetaxel alone in reducing breast and prostate cancer cell growth: a new paradigm for understanding the therapeutic effect of combined treatment.

Bevacizumab (Bvz), a Vascular Endothelial Growth Factor (VEGF)-targeted humanised monoclonal antibody, provides clinical benefit in combination with docetaxel (DXL), a microtubule-stabilising agent, in the treatment of metastatic breast and prostate cancers. Since VEGF and their receptors are expressed by tumour cells, we hypothesised that Bvz, in addition to its impact on neo-vascularisation, could have an impact on tumour cells and enhance the DXL activity. Hence, we studied the effect of DXL and Bvz on metastatic breast (MDA MB-231) and prostate (PC3) cancer cells lines. Bvz alone did not decrease cell proliferation but in combination with DXL, Bvz enhanced the anti-proliferative activity of DXL. Other anti-angiogenic factors Sunitinib, Sorafenib and Gefitinib enhanced the anti-proliferative effect of DXL. qPCR experiments showed that DXL significantly increased the VEGF and VEGF receptor 2 (VEGF-R2) mRNA levels. Activation of VEGF and VEGF-R2 promoters demonstrated that enhanced mRNA levels are partly due to transcriptional activation. ELISA assays showed that DXL induced accumulation of cytoplasmic VEGF but decreased extracellular levels by 39% (MDA) and 48% (PC3). Cell surface localisation of VEGF-R2 was increased by DXL alone, but decreased after combined treatment of DXL plus Bvz. Abnormal expression of VEGF-R2 was also shown on breast and prostate tumour samples reinforcing the results obtained on cellular models. In conclusion, DXL and Bvz in combination decreased extracellular VEGF and VEGF-R2 levels at the plasma membrane thereby blocking an important growth/survival loop. Thus, the combined therapeutic impact of Bvz and DXL observed in clinical trials is associated with enhanced anti-proliferative activity and inhibition of the vascular network

CONSTITUTIVE ERK ACTIVITY INDUCES DOWN-REGULATION OF TRISTETRAPROLIN, A MAJOR PROTEIN CONTROLLING INTERLEUKIN8/CXCL8 mRNA STABILITY IN MELANOMA CELLS.

International audienceMost melanoma cells are characterized by the V600E mutation in B-Raf kinase. This mutation leads to increased expression of Interleukin (CXCL8) which plays a key role in cell growth and angiogenesis. Thus, CXCL8 appears to be an interesting therapeutic target. Hence, we performed vaccination of mice with GST-CXCL8 which results in a reduced incidence of syngenic B16 melanoma cell xenograft tumors. We next addressed the molecular mechanisms responsible for aberrant CXCL8 expression in melanoma. The CXCL8 mRNA contains multiples AU-rich sequences (AREs) that modulate mRNA stability through the binding of Tristetraprolin (TTP). Melanoma cell lines express very low TTP levels. We therefore hypothesized that the very low endogenous levels of TTP present in different melanoma cell lines might be responsible for the relative stability of CXCL8 mRNAs. We show that TTP is actively degraded by the proteasome and that ERK inhibition results in TTP accumulation. Conditional expression of TTP in A375 melanoma cells leads to CXCL8 mRNA destabilization via its 3'UTR and TTP over-expression reduces its production. In contrast, down-regulation of TTP by sh-RNA results in up-regulation of CXCL8 mRNA. Maintaining high TTP levels in melanoma cells decreases cell proliferation and autophagy and induces apoptosis. Sorafenib, a therapeutic agent targeting Raf kinases, decreases CXCL8 expression in melanoma cells through re-expression of TTP. We conclude that loss of TTP represents a key event in the establishment of melanomas through constitutive expression of CXCL8, which constitutes a potent therapeutic target

Representation of study results as a function of study design, type of intervention and risk of bias.

<p>Bold text: Randomized Controlled Trials. Italics: type of intervention.</p

PRISMA flow diagram for the systematic review of regulatory and educational interventions to reduce the burden associated with the prescriptions of sedative-hypnotics in adults treated for sleep disorders.

<p>PRISMA flow diagram for the systematic review of regulatory and educational interventions to reduce the burden associated with the prescriptions of sedative-hypnotics in adults treated for sleep disorders.</p