•Pharmaceutical R&D is being redefined with a race to identify external innovation models.•A large diversity of models are being explored, covering the full R&D value chain.•As these new models ...evolve leading indicators of success will be essential to define those that are most promising.
The pharmaceutical industry continues to face fundamental challenges because of issues with research and development (R&D) productivity and rising customer expectations. To lower R&D costs, move beyond me-too therapies, and create more transformative portfolios, pharmaceutical companies are actively capitalizing on external innovation through precompetitive collaboration with academia, cultivation of biotech start-ups, and proactive licensing and acquisitions. Here, we review the varying innovation strategies used by pharmaceutical companies, compare and contrast these models, and identify the trends in external innovation. We also discuss factors that influence these external innovation models and propose a preliminary set of metrics that could be used as leading indicators of success.
Kidney development occurs in a stereotypic position along the body axis. It begins when a single ureteric bud emerges from the nephric duct in response to GDNF secreted by the adjacent nephrogenic ...mesenchyme. Posterior restriction of
Gdnf expression is considered critical for correct positioning of ureteric bud development. Here we show that mouse mutants lacking either SLIT2 or its receptor ROBO2, molecules known primarily for their function in axon guidance and cell migration, develop supernumerary ureteric buds that remain inappropriately connected to the nephric duct, and that the SLIT2/ROBO2 signal is transduced in the nephrogenic mesenchyme. Furthermore, we show that
Gdnf expression is inappropriately maintained in anterior nephrogenic mesenchyme in these mutants. Thus our data identify an intercellular signaling system that restricts, directly or indirectly, the extent of the
Gdnf expression domain, thereby precisely positioning the site of kidney induction.
Heparan sulfate (HS) is required for morphogen signaling during Drosophila pattern formation, but little is known about its physiological importance in mammalian development. To define the ...developmental role of HS in mammalian species, we conditionally disrupted the HS-polymerizing enzyme EXT1 in the embryonic mouse brain. The EXT1-null brain exhibited patterning defects that are composites of those caused by mutations of multiple HS-binding morphogens. Furthermore, the EXT1-null brain displayed severe guidance errors in major commissural tracts, revealing a pivotal role of HS in midline axon guidance. These findings demonstrate that HS is essential for mammalian brain development.
Commissural axons in vertebrates and insects are initially attracted to the nervous system midline, but once they reach this intermediate target they undergo a dramatic switch, becoming responsive to ...repellent Slit proteins at the midline, which expel them onto the next leg of their trajectory. We have unexpectedly implicated a divergent member of the Robo family, Rig-1 (or Robo3), in preventing premature Slit sensitivity in mammals. Expression of Rig-1 protein by commissural axons is inversely correlated with Slit sensitivity. Removal of Rig-1 results in a total failure of commissural axons to cross. Genetic and in vitro analyses indicate that Rig-1 functions to repress Slit responsiveness similarly to Commissureless (Comm) in Drosophila. Unlike Comm, however, Rig-1 does not produce its effect by downregulating Robo receptors on precrossing commissural axon membranes. These results identify a mechanism for regulating Slit repulsion that helps choreograph the precise switch from attraction to repulsion at a key intermediate axonal target.
Activated partial thromboplastin time (aPTT) and prothrombin time (PT) are clinical tests commonly used to screen for coagulation-factor deficiencies. One genome-wide association study (GWAS) has ...been reported previously for aPTT, but no GWAS has been reported for PT. We conducted a GWAS and meta-analysis to identify genetic loci for aPTT and PT. The GWAS for aPTT was conducted in 9,240 individuals of European ancestry from the Atherosclerosis Risk in Communities (ARIC) study, and the GWAS for PT was conducted in 2,583 participants from the Genetic Study of Three Population Microisolates in South Tyrol (MICROS) and the Lothian Birth Cohorts (LBC) of 1921 and 1936. Replication was assessed in 1,041 to 3,467 individuals. For aPTT, previously reported associations with KNG1, HRG, F11, F12, and ABO were confirmed. A second independent association in ABO was identified and replicated (rs8176704, p = 4.26 × 10−24). Pooling the ARIC and replication data yielded two additional loci in F5 (rs6028, p = 3.22 × 10−9) and AGBL1 (rs2469184, p = 3.61 × 10−8). For PT, significant associations were identified and confirmed in F7 (rs561241, p = 3.71 × 10−56) and PROCR/EDEM2 (rs2295888, p = 5.25 × 10−13). Assessment of existing gene expression and coronary artery disease (CAD) databases identified associations of five of the GWAS loci with altered gene expression and two with CAD. In summary, eight genetic loci that account for ∼29% of the variance in aPTT and two loci that account for ∼14% of the variance in PT were detected and supported by functional data.
During development, retinal ganglion cell (RGC) axons either cross or avoid the midline at the optic chiasm. In
Drosophila, the Slit protein regulates midline axon crossing through repulsion. To ...determine the role of Slit proteins in RGC axon guidance, we disrupted
Slit1 and
Slit2, two of three known mouse
Slit genes. Mice defective in either gene alone exhibited few RGC axon guidance defects, but in double mutant mice a large additional chiasm developed anterior to the true chiasm, many retinal axons projected into the contralateral optic nerve, and some extended ectopically—dorsal and lateral to the chiasm. Our results indicate that Slit proteins repel retinal axons in vivo and cooperate to establish a corridor through which the axons are channeled, thereby helping define the site in the ventral diencephalon where the optic chiasm forms.
Focal recruitment of monocytes and lymphocytes is one of the earliest detectable cellular responses in the formation of lesions of atherosclerosis. This localized accumulation of leukocytes is a ...multistep process in which the endothelium remains intact and may regulate leukocyte recruitment by expressing specific adhesion molecules. To examine the relationship of adhesion molecule expression to initiation factors and the sites of lesion formation, we analyzed the expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and platelet-endothelial cell adhesion molecule-1 (PECAM-1) en face on the aortic endothelium of control mice and homozygous apolipoprotein E-deficient (ApoE -/-) mice that develop complex lesions of atherosclerosis similar to those in humans. In control mice, VCAM-1 staining was weak and limited to sites of altered blood flow. In contrast, in the ApoE -/- mice, VCAM-1 appeared to be localized over the surface of groups of endothelial cells in lesion-prone sites. Expression of VCAM-1 preceded lesion formation, and increased expression above control levels appeared to be correlated with the extent of exposure to plasma cholesterol. Although ICAM-1 was the most prominent adhesion molecule in lesion-prone sites, its expression appeared to be independent of plasma cholesterol levels and was upregulated in both ApoE -/- and control mice. At lesion-prone sites associated with altered blood flow, ICAM-1 was located over the surface of each endothelial cell and on microvilli, whereas VCAM-1 was confined to the cell periphery in non-lesion-prone sites. PECAM-1 was localized at the cell periphery throughout the aorta, and its expression did not appear to be regulated. Thus, the levels, localization, and characteristics of expression of VCAM-1, ICAM-1, and PECAM-1 appear to be differentially regulated. Upregulation of VCAM-1 and ICAM-1 is associated with sites of lesion formation. (Arterioscler Thromb Vasc Biol. 1998;18:842-851.)
We report that Slit proteins, a family of secreted chemorepellents, are crucial for the proper development of several major forebrain tracts. Mice deficient in
Slit2 and, even more so, mice deficient ...in both
Slit1 and
Slit2 show significant axon guidance errors in a variety of pathways, including corticofugal, callosal, and thalamocortical tracts. Analysis of multiple pathways suggests several generalizations regarding the functions of Slit proteins in the brain, which appear to contribute to (1) the maintenance of dorsal position by prevention of axonal growth into ventral regions, (2) the prevention of axonal extension toward and across the midline, and (3) the channeling of axons toward particular regions.
Cholesterol deposition in arterial wall drives atherosclerosis. The key goal of this study was to examine the relationship between plaque cholesterol content and patient characteristics that ...typically associate with disease state and lesion vulnerability. Quantitative assays for free cholesterol, cholesteryl ester, triglyceride, and protein markers in atherosclerotic plaque were established and applied to plaque samples from multiple patients and arterial beds (Carotid and peripheral arteries; 98 lesions in total).
We observed a lower cholesterol level in restenotic than primary peripheral plaque. We observed a trend toward a higher level in symptomatic than asymptomatic carotid plaque. Peripheral plaque from a group of well-managed diabetic patients displayed a weak trend of more free cholesterol deposition than plaque from non-diabetic patients. Plaque triglyceride content exhibited less difference in the same comparisons. We also measured cholesterol in multiple segments within one carotid plaque sample, and found that cholesterol content positively correlated with markers of plaque vulnerability, and negatively correlated with stability markers.
Our results offer important biological validation of cholesterol as a key lipid marker for plaque severity. Results also suggest cholesterol is a more sensitive plaque marker than routine histological staining for neutral lipids.
Thrombin is a central enzyme in hemostasis and thrombosis, and a proven target for anticoagulant therapies. We compared four marketed and representative thrombin inhibitors, heparin, hirudin, ...bivalirudin, and dabigatran, in in-vitro spike-in assays that covered their therapeutic ranges. The assays employed were low tissue factor (1 pmol/l)-triggered thrombin generation assay (TGA) with plasma and 1 : 8000 Recombiplastin-triggered thromboelastography (TEG) with whole blood, with or without tissue plasminogen activator (tPA)-induced fibrinolysis. The three direct thrombin inhibitors (DTIs) prolonged TGA lag time and TEG clotting time (R) with a potency stack-ranking of hirudin > dabigatran ≅ bivalirudin. Heparin had the most steep concentration–response curve for both parameters. In TGA, 1–2 μmol/l dabigatran or hirudin resulted in complete inhibition on peak, slope, and endogenous thrombin potential, whereas bivalirudin had no effect on these parameters up to 10 μmol/l. All three DTIs, but not heparin, displayed a paradoxical increase in peak and slope in the low concentration range. In TEG, whereas all four agents reduced clot strength (maximal amplitude) in synergy with tPA, hirudin was the only DTI that reduced maximal amplitude appreciably without tPA. Dabigatran had the strongest potentiating effect on tPA-induced fibrinolytic activity (Ly30). With regard to the effects on coagulation and clot strength (lag time, R, and maximal amplitude) in the respective therapeutic range, dabigatran elicited the most modest changes. In summary, our observations highlight the distinct features of each agent in thrombin generation, coagulation, and fibrinolysis. The contrasts between the agents are consistent with their known properties and are informative on efforts to define the optimal profiles of new anticoagulants.
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