EVITA: a tool for the early EValuation of pharmaceutical Innovations with regard to Therapeutic Advantage

Background

New drugs are generally claimed to represent a therapeutic innovation. However, scientific evidence of a substantial clinical advantage is often lacking. This may be the result of using inadequate control groups or surrogate outcomes only in the clinical trials. In view of this, EVITA was developed as a user-friendly transparent tool for the early evaluation of the additional therapeutic value of a new drug.

Methods

EVITA does not evaluate a new compound per se but in an approved indication in comparison with existing therapeutic strategies. Placebo as a comparator is accepted only in the absence of an established therapy or if employed in an add-on strategy on top. The evaluation attributes rating points to the drug in question, taking into consideration both therapeutic benefit and risk profile. The compound scores positive points for superiority in efficiency and/or adverse effects as demonstrated in randomized controlled trials (RCTs), whilst negative points are awarded for inferiority and/or an unfavorable risk profile. The evaluation follows an algorithm considering the clinical relevance of the outcomes, the strength of the therapeutic effect and the number of RCTs performed. Categories for therapeutic aim and disease severity, although essential parts of the EVITA assessment, are attributed but do not influence the EVITA score which is presented as a color-coded bar graph. In case the available data were unsuitable for an EVITA calculation, a traffic-type yield sign is assigned instead to criticize such practice. The results are presented online http://www.evita-report.de together with all RCTs considered as well as the reasons for excluding a given RCT from the evaluation. This allows for immediate revision in response to justified criticism and simplifies the inclusion of new data.

Results

As examples, four compounds which received approval within the last years were evaluated for one of their clinical indications: lenalidomide, pioglitazone, bupropion and zoledronic acid. Only the first achieved an EVITA score above zero indicating therapeutic advantage.

Conclusions

The strength of EVITA appears to lie in its speedy assessment of the potential therapeutic advantage of a new drug for a given indication. At the same time, this approach draws attention to the typical deficits of data used for drug approval. EVITA is not intended to replace classical health technology assessment reports but rather serves as a screening tool in the sense of horizon scanning.     

Floristic notes from the mountains of Northern Greece Materials for the Mountain Flora of Greece, 7

The authors present an annotated list of rare or otherwise interesting vascular plants collected in the mountains of northern Greece by themselves in 1979 and by Strid and Georgiadou in 1977. The following are apparently new to Greece: Thesium linophyllon L. ssp. montanum (Ehrh. ex. Hoffm.) Čelak., Moehringia pendulo (Waldst. & Kit.) Fenzl, Gypsophila glomerata Pallas ex. Bieb., Dianthus peiraeus Waldst. & Kit. ssp. noeanus (Boiss.) Tutin, Dianthus superbus L., Ranunculus fon–tanus C. Presl, Thlaspi arvense L., Potentilla apennina Ten. ssp. stoianovii Urum. & Jav., Trifolium badium Schreber, Rhamnus pumila Turra, Viola palustris L., Athamanta albanica Alston & Sandwith, Peucedanum oligophyllum ssp. aequiradium (Vandas) Tutin, Vaccinium gaultherioides Bigelow, Galeopsis speciosa Miller, G. bifida Boenn., Melampyrum sylvaticum L., Odontites lutea (L.) Clairv., Sambucus racemosa L., Symphyandra wanneri (Rochel) Heuffel, Galinsoga parviflora Cav., Achillea distans Waldst. & Kit. ex Willd., Centaurea grbavacensis (Rohlena) Stoj. & Acht., C. indurata Janka, Lactuca aurea (Schultz Bip. ex PanČić) Stebbins, Festuca gigantea (L.) Vill., F. pirinica Horvat ex Markgr.–Dannenb., Sparganium minimum (Hartm.) Fries, and Rhynchospora alba (L.) Vahl.     

Force-induced bidirectional stepping of cytoplasmic dynein

Cytoplasmic dynein is a minus-end-directed microtubule motor whose mechanism of movement remains poorly understood. Here, we use optical tweezers to examine the force-dependent stepping behavior of yeast cytoplasmic dynein. We find that dynein primarily advances in 8 nm increments but takes other sized steps (4-24 nm) as well. An opposing force induces more frequent backward stepping by dynein, and the motor walks backward toward the microtubule plus end at loads above its stall force of 7 pN. Remarkably, in the absence of ATP, dynein steps processively along microtubules under an external load, with less force required for minus-end- than for plus-end-directed movement. This nucleotide-independent walking reveals that force alone can drive repetitive microtubule detachment-attachment cycles of dynein's motor domains. These results suggest a model for how dynein's two motor domains coordinate their activities during normal processive motility and provide new clues for understanding dynein-based motility in living cells.     

Predators induce egg retention in prey

To prevent predation on their eggs, prey often avoid patches occupied by predators. As a result, they need to delay oviposition until they reach predator-free patches. Because many species allocate energy to egg production in a continuous fashion, it is not clear what kind of mechanism prey use to delay oviposition. We used females of the phytoseiid mite Neoseiulus cucumeris to study these mechanisms. Females were placed in patches with pollen, a food source they use for egg production, and they were exposed to another phytoseiid mite, Iphiseius degenerans, which is an intraguild predator of N. cucumeris juveniles. We found that the oviposition of N. cucumeris females on patches with the predator was lower than on patches without the predator. Cues left by the intraguild predator were not sufficient to elicit such behaviour. Females of N. cucumeris reduced oviposition when exposed to the predator by retaining the egg inside their body, resulting in a lower developmental rate once these eggs were laid. Hence, females are capable of retaining eggs, but the development of these eggs continues inside the mother’s body. In this way, females gain some time to search for less risky oviposition sites.     

Lower Permian Bryozoa from Ellesmere Island (Canada)

A collection of fossils sampled during the 1898–1902 expedition of theFram to the Canadian Arctic Islands includes abundant bryozoans from the Lower Permian (Artinskian) Great Bear Cape Formation of Ellesmere Island. From this material a new genus with one new species —Nansenopora peculiaris n. gen., n. sp. — as well as three new species —Streblotrypella arctica n. sp.,Phragmophera patricki n. sp. andKallodictyon spinatum n. sp. — are described. Furthermore, the speciesUlrichotrypa ramulosa Bassler, 1929 is reported for the first time from the Lower Permian of the Arctic region.     

Endothelin-1 and pancreatic islet vasculature: studies in vivo and on isolated, vascularly perfused pancreatic islets

Endothelin-1 (ET-1) is a potent endothelium-derived vasoconstrictor, which also stimulates insulin release. The aim of the present study was to evaluate whether exogenously administered ET-1 affected pancreatic islet blood flow in vivo in rats and the islet arteriolar reactivity in vitro in mice. Furthermore, we aimed to determine the ET-receptor subtype that was involved in such responses. When applying a microsphere technique for measurements of islet blood perfusion in vivo, we found that ET-1 (5 nmol/kg) consistently and markedly decreased total pancreatic and especially islet blood flow, despite having only minor effects on blood pressure. Neither endothelin A (ET(A)) receptor (BQ-123) nor endothelin-B (ET(B)) receptor (BQ-788) antagonists, alone or in combination, could prevent this reduction in blood flow. To avoid confounding interactions in vivo, we also examined the arteriolar vascular reactivity in isolated, perfused mouse islets. In the latter preparation, we demonstrated a dose-dependent constriction in response to ET-1. Administration of BQ-123 prevented this, whereas BQ-788 induced a right shift in the response. In conclusion, the pancreatic islet vasculature is highly sensitive to exogenous ET-1, which mediates its effect mainly through ET(A) receptors.     

Molecular and structural basis for redox regulation of beta-actin

An essential consequence of growth factor-mediated signal transduction is the generation of intracellular H₂O₂. It operates as a second messenger in the control of actin microfilament dynamics, causing rapid and dramatic changes in the morphology and motile activity of stimulated cells. Little is understood about the molecular mechanisms causing these changes in the actin system. Here, it is shown that H₂O₂ acts directly upon several levels of this system, and some of the mechanistic effects are detailed. We describe the impact of oxidation on the polymerizability of non-muscle β/γ-actin and compare with that of muscle α-actin. Oxidation of β/γ-actin can cause a complete loss of polymerizability, crucially, reversible by the thioredoxin system. Further, oxidation of the actin impedes its interaction with profilin and causes depolymerization of filamentous actin. The effects of oxidation are critically dependent on the nucleotide state and the concentration of Ca²⁺. We have determined the crystal structure of oxidized β-actin to a resolution of 2.6 Å. The arrangement in the crystal implies an antiparallel homodimer connected by an intermolecular disulfide bond involving cysteine 374. Our data indicate that this dimer forms under non-polymerizing and oxidizing conditions. We identify oxidation of cysteine 272 in the crystallized actin dimer, likely to a cysteine sulfinic acid. In β/γ-actin, this is the cysteine residue most reactive towards H₂O₂ in solution, and we suggest plausible structural determinants for its reactivity. No other oxidative modification was obvious in the structure, highlighting the specificity of the oxidation by H₂O₂. Possible consequences of the observed effects in a cellular context and their potential relevance are discussed.     

Quantification of the elevated rate of domain rearrangements in metazoa

Most eukaryotic proteins consist of multiple domains created through gene fusions or internal duplications. The most frequent change of a domain architecture (DA) is insertion or deletion of a domain at the N or C terminus. Still, the mechanisms underlying the evolution of multidomain proteins are not very well studied.Here, we have studied the evolution of multidomain architectures (MDA), guided by evolutionary information in the form of a phylogenetic tree. Our results show that Pfam domain families and MDAs have been created with comparable rates (0.1-1 per million years (My)). The major changes in DA evolution have occurred in the process of multicellularization and within the metazoan lineage. In contrast, creation of domains seems to have been frequent already in the early evolution. Furthermore, most of the architectures have been created from older domains or architectures, whereas novel domains are mainly found in single-domain proteins. However, a particular group of exon-bordering domains may have contributed to the rapid evolution of novel multidomain proteins in metazoan organisms. Finally, MDAs have evolved predominantly through insertions of domains, whereas domain deletions are less common.In conclusion, the rate of creation of multidomain proteins has accelerated in the metazoan lineage, which may partly be explained by the frequent insertion of exon-bordering domains into new architectures. However, our results indicate that other factors have contributed as well.     

Identification of NCAM-binding peptides promoting neurite outgrowth via a heterotrimeric G-protein-coupled pathway

A combinatorial library of undecapeptides was produced and utilized for the isolation of peptide binding to the fibronectin type 3 modules (F3I–F3II) of the neural cell adhesion molecule (NCAM). The isolated peptides were sequenced and produced as dendrimers. Two of the peptides (denoted ENFIN2 and ENFIN11) were confirmed to bind to F3I–F3II of NCAM by surface plasmon resonance. The peptides induced neurite outgrowth in primary cerebellar neurons and PC12E2 cells, but had no apparent neuroprotective properties. NCAM is known to activate different intracellular pathways, including signaling through the fibroblast growth factor receptor, the Src-related non-receptor tyrosine kinase Fyn, and heterotrimeric G-proteins. Interestingly, neurite outgrowth stimulated by ENFIN2 and ENFIN11 was independent of signaling through fibroblast growth factor receptor and Fyn, but could be inhibited with pertussis toxin, an inhibitor of certain heterotrimeric G-proteins. Neurite outgrowth induced by trans- homophilic NCAM was unaffected by the peptides, whereas knockdown of NCAM completely abrogated ENFIN2- and ENFIN11-induced neuritogenesis. These observations suggest that ENFIN2 and ENFIN11 induce neurite outgrowth in an NCAM-dependent manner through G-protein-coupled signal transduction pathways. Thus, ENFIN2 and ENFIN11 may be valuable for exploring this particular type of NCAM-mediated signaling.