Stakeholders' expectations of precision medicine: A qualitative study to identify areas of (mis)alignment

Background and Aims

To sustainably address challenges in implementing precision medicine (PM), coordinated efforts of different stakeholders are required. Understanding their expectations represents a first key step toward aligning on future actions and strategies. Here, we aimed to explore the expectations of different stakeholders from themselves and each other regarding PM.

Methods

This collaborative qualitative study was initiated by the global multistakeholder consortium From Testing to Targeted Treatments (FT3). Structured interviews were conducted with participants from five stakeholder groups: patients/patient advocates, healthcare providers (HCPs), researchers, policymakers/regulators/payers and industry representatives. A broad reach across geography, roles, experiences, and disease areas was sought. Results were analyzed by grounded theory methodology.

Results

All stakeholders stated that optimal implementation of PM can only be achieved through collaboration; industry representatives were the biggest promoters of collaboration. Stakeholders agreed that PM should be implemented focusing on the patient's best interest; HCPs were seen as important gatekeepers for PM by interacting directly with patients, and policymakers/payers were perceived as the most important drivers of access to PM. Areas of misalignment included the role of industry in clinical trial design and in access to PM (perceived as important by patients, HCPs and policymakers but not by industry representatives), and the stakeholders responsible for elaborating guidelines on PM use (patients indicated policymakers, while researchers indicated themselves). Priorities for optimal PM implementation and suggested actions included the need for enhancing high-level policy focus, improving genomic literacy, optimizing the health technology assessment for PM, advocating for equitable access, promoting collaboration between industry and other stakeholder groups and development of reliable research standards.

Conclusion

Stakeholder expectations revealed in this study suggested that no stakeholder group can drive change on its own; a global, multistakeholder collaborative approach that brings together current programs and best practices to support universal access to PM is needed.

How can we deliver on the promise of precision medicine in oncology and beyond? A practical roadmap for action

Background

Precision medicine (PM) is a form of personalized medicine that recognizes that individuals with the same condition may have different underlying factors and uses molecular information to provide tailored treatments. This approach can improve treatment outcomes and transform lives through favorable risk/benefit ratios, avoidance of ineffective interventions, and possible cost savings, as evidenced in the field of lung cancer and other oncology/therapeutic settings, including cardiac disease, diabetes, and rare diseases. However, the potential benefits of PM have yet to be fully realized.

Discussion

There are many barriers to the implementation of PM in clinical practice, including fragmentation of the PM landscape, siloed approaches to address shared challenges, unwarranted variation in availability and access to PM, lack of standardization, and limited understanding of patients' experience and needs throughout the PM pathway. We believe that a diverse, intersectoral multistakeholder collaboration, with three main pillars of activity: generation of data to demonstrate the benefit of PM, education to support informed decision-making, and addressing barriers across the patient pathway, is necessary to reach the shared goal of making PM an accessible and sustainable reality. Besides healthcare providers, researchers, policymakers/regulators/payers, and industry representatives, patients in particular must be equal partners and should be central to the PM approach-from early research through to clinical trials and approval of new treatments-to ensure it represents their entire experience and identifies barriers, solutions, and opportunities at the point of delivery.

Conclusion

We propose a practical and iterative roadmap to advance PM and call for all stakeholders across the healthcare system to employ a collaborative, cocreated, patient-centered methodology to close gaps and fully realize the potential of PM.

Primary stability of tibial components in TKA: in vitro comparison of two cementing techniques

In spite of improvements in cementing technique, migration of tibial component remains a problem in total knee arthroplasty. This study compares the primary stability of tibial components using two different cementing techniques with roentgen stereophotogrammetric analysis (RSA) in vitro. A total of 20 tibia specimens were matched into two groups, 10 specimens per group. Cementing technique was randomized to each group. In the first group only the base and in the second group the base and stem were cemented. The implants and the tibial metaphysis were marked with markers for the RSA analysis. All specimens were tested with an axial load of 2,000 N for 1,000 and 10,000 cycles and RSA analysis was performed. Endpoints for radiosterometric analysis were maximum total point motion, maximum subsidence, lift off, rotation and translation along the x-, y-, and z-axes. After 1,000 and 10,000 cycles, no significant differences could be found, but two tibial components of the surface cementing group showed a migration of more than 2 mm defined as failure compared to six failed tibial components in the full cementing group (P = 0.068). This higher number of failed arthroplasties in the fully cemented prosthesis group demonstrates a disadvantageous load distribution in the tibia apophysis which can cause an early component loosening.

Rolling circle amplification for scoring single nucleotide polymorphisms

The analysis of the genetic basis of phenotypic traits is moving towards the complex diseases prevalent in wealthy populations. There is an increasing requirement for the detection of different types of sequence variation, particularly single-nucleotide polymorphisms (SNPs). SNPs occur about once every 100 to 300 bases. High-density SNP maps will help to identify the multiple genes associated with complex diseases such as cancer, diabetes, vascular disease, and some forms of mental illness.

A single-site mutant and revertants arising in vivo define early steps in the pathogenesis of Venezuelan equine encephalitis virus

The early stages of Venezuelan equine encephalitis virus (VEE) pathogenesis in the mouse model have been examined using a genetic approach. Disease progression of a molecularly cloned single-site mutant was compared with that of the parental virus to determine the step in the VEE pathogenetic sequence at which the mutant was blocked. Assuming that such a block constitutes a genetic screen, isolates from different tissues thought to be distal to the block in the VEE pathogenetic sequence were analyzed to determine the pathogenetic step at which revertants of the mutant were selected. Directed mutation and analysis of reversion in vivo provide two powerful genetic tools for the dissection of the wild-type VEE pathogenetic sequence. Virus from the parental virulent clone, V3000, first replicated in the draining lymph node after subcutaneous inoculation in the left rear footpad. Movement of a cloned avirulent mutant, V3010 (E2 76 Glu to Lys), to the draining lymph node was impaired, replication in the node was delayed, and spread beyond the draining lymph node was sporadic. Serum, contralateral lymph node, spleen, and brain isolates from V3010 inoculated animals were invariably revertant with respect to sequence at E2 76 and/or virulence in mice. Revertants isolated from serum and contralateral lymph node retained the V3010 E2 Lys 76 mutation but also contained a second-site mutation, Glu to Lys at E2 116. Modification of the V3010 clone by addition of the second-site mutation at E2 116 produced a virus that bypassed the V3010 block at the draining lymph node but that did not possess full wild-type capacity for replication in the central nervous system or for induction of mortality. A control construct containing only the E2 116 reverting mutation on the V3000 background was identical to V3000 in terms of early pathogenetic steps and virulence. Therefore, analysis of mutant replication and reversion in vivo suggested (1) that the earliest steps in VEE pathogenesis are transit to the draining lymph node and replication at that site, (2) that the mutation in V3010 impairs transit to the draining lymph node and blocks dissemination to other tissues, and (3) that reversion can overcome the block without restoring full virulence.

The influence of fluorescent dye structure on the electrophoretic mobility of end-labeled DNA

Over the past 10 years, fluorescent end-labeling of DNA fragments has evolved into the preferred method of DNA detection for a wide variety of applications, including DNA sequencing and PCR fragment analysis. One of the advantages inherent in fluorescent detection methods is the ability to perform multi-color analyses. Unfortunately, labeling DNA fragments with different fluorescent tags generally induces disparate relative electrophoretic mobilities for the fragments. Mobility-shift corrections must therefore be applied to the electrophoretic data to compensate for these effects. These corrections may lead to increased errors in the estimation of DNA fragment sizes and reduced confidence in DNA sequence information. Here, we present a systematic study of the relationship between dye structure and the resultant electrophoretic mobility of end-labeled DNA fragments. We have used a cyanine dye family as a paradigm and high-resolution capillary array electrophoresis (CAE) as the instrumentation platform. Our goals are to develop a general understanding of the effects of dyes on DNA electrophoretic mobility and to synthesize a family of DNA end-labels that impart identically matched mobility influences on DNA fragments. Such matched sets could be used in DNA sequencing and fragment sizing applications on capillary electrophoresis instrumentation.

A novel organotypic long-term culture of the rat hippocampus on substrate-integrated multielectrode arrays

Spatiotemporally coordinated activity of neural networks is crucial for brain functioning. To understand the basis of physiological information processing and pathological states, simultaneous multisite long-term recording is a prerequisite. In a multidisciplinary approach we developed a novel system of organotypically cultured rat hippocampal slices on a planar 60-microelectrode array (MEA). This biohybrid system allowed cultivation for 4 weeks. Methods known from semiconductor production were employed to fabricate and characterize the MEA. Simultaneous extracellular recording of local field potentials (LFPs) and spike activity at 60 sites under sterile conditions allowed the analysis of network activity with high spatiotemporal resolution. To our knowledge this is the first realization of hippocampus cultured organotypically on multi-microelectrode arrays for simultaneous recording and electrical stimulation. This biohybrid system promises to become a powerful tool for drug discovery and for the analysis of neural networks, of synaptic plasticity, and of pathophysiological conditions such as ischemia and epilepsy.

Identification of a peptide methionine sulphoxide reductase gene in an oleosin promoter from Brassica napus

A bidirectional promoter can be defined operationally as a short segment of DNA that regulates divergent transcription. In an attempt to investigate whether the intergenic region between the oleosin and a second open reading frame (ORFII) in Brassica napus (L.) is a divergent promoter, and also to characterize the ORFII, cDNA clones homologous to ORFII were isolated from a leaf cDNA library. A representative cDNA (clone D) of one of the two classes identified was identical, in DNA sequence, to the genomic ORFII. The second representative cDNA (clone O) was 97% identical at the nucleotide level to the genomic ORFII. The predicted amino acid sequence of the cDNA clones each exhibit homology with the peptide methionine sulphoxide reductase (PMSR) of Escherichia coli. The gene structure of ORFII was elucidated and the relative positions of the oleosin, ORFII, and the intergenic promoter region were determined. This confirms that the B. napus oleosin-ORFII intergenic region has divergent promoter activity. Consequently this is the first such plant nuclear divergent promoter identified. RFLP-mapping results showed that all four ORFII genes are linked to four of the six copies of the oleosin genes. This suggested that the bidirectional promoter locus is conserved within the B. napus genome. The ORFII gene product is targeted to the chloroplast, which is consistent with previous data indicating the presence of PMSR activity in the chloroplast. The over-expressed recombinant fusion protein (minus the transitpeptide) showed the capability to reduce peptide methionine sulphoxide residues in vitro, indicating PMSR activity. This study demonstrates that ORFII is transcribed and encodes a plant PMSR, and is the first example of the isolation of a eukaryotic PMSR gene.

Comparative analysis of sequences at the 5' end of the human and mouse apolipoprotein B genes

A comparison was made between the DNA sequences in two regions of the mouse and the human apolipoprotein B genes: the 5'-flanking sequence and the region between the first exon and the second intron. Considerable homology was observed, particularly in the immediate 5' region and in the second intron. Because promoter and enhancer elements have been previously localized to these regions in the human apolipoprotein B gene, it is proposed that regions of conserved base sequence delineate binding regions for regulatory proteins. In some cases, contiguous regions of homology are longer than expected for regions designed as recognition sites for individual nuclear proteins, and may define regions recognizable by a cluster of interacting proteins. Both the human and mouse genes contain repetitive elements and a hypervariable dinucleotide repeat.

DNA sequence of the human apolipoprotein B gene

The sequence of the human apolipoprotein B gene comprises 43 kb divided into 29 exons, one of which is unusually long and contains 7572 bp. Comparison of the gene sequence with four complete and three partial cDNA sequences published elsewhere reveals a total of 60 nucleotide substitutions and 39 amino acid substitutions and one small deletion in the signal peptide.

Identification of surface-exposed segments of apolipoprotein B-100 in the LDL particle

The isolation and amino acid sequence of eleven peptides liberated by tryptic treatment from surface-exposed regions of apolipoprotein B-100 in the native low-density lipoprotein particle are described. These peptides represent eight segments in the sequence of the B-100 protein, one of which was localised to the amino-terminal thrombolytic fragment T4 (1297 amino acids), four to the T3 fragment (2052 residues) and three to the carboxylterminal fragment T2 (1287 residues). An exposed segment was identified on each side of the T2/T3 cleavage site, in close proximity to two segments enriched in basic amino acids (residues 3147-3157 and 3359-3367 respectively). The surface exposure of this region is consistent with its contribution to the putative apo-B,E receptor binding domain. Four of the eight tryptic segments contribute to regions of proline-rich clusters. Homology between the sequence of the tryptic peptides and those predicted by cDNA cloning was complete.

RFLP for the human apolipoprotein B gene: II;EcoRI

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RFLP for the human apolipoprotein B gene: III;EcoRV

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RFLP for the human apolipoprotein B gene: I;BamHI

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RFLP for the human apolipoprotein B gene: IV;MspI

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RFLP for the human apolipoprotein B gene: V;XbaI

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On-Column Periodate Reaction Method for Analysis of Ephedrine Sulfate in Solid Dosage Forms: Collaborative Study

Seven laboratories collaboratively studied a method for the quantitative ultraviolet (UV) determination of ephedrine sulfate in solid dosage forms. Ephedrine is separated from water-soluble impurities and strong acids by elution from a weakly basic Celite column, and further cleaned up by retention on a weakly acidic column while the weak acids, weak bases, and organic-soluble neutrals are eluted. Ephedrine is eluted from the column after neutralization with NH3 and is converted to benzaldehyde via an on-column periodate reaction. The samples collaboratively studied consisted of 3 synthetic preparations of known ephedrine sulfate concentrations and 2 commercial preparations containing ephedrine sulfate. One commercial sample was submitted as a blind duplicate. Recoveries for the synthetic preparations averaged 101.7, 101.2, and 100.5% for mixtures containing 7.93, 9.35, and 6.85% ephedrine sulfate, respectively. The means and standard deviations for the commercial preparations were 24.72 ± 0.376 mg/dosage unit for the preparation labeled to contain 25 mg/dosage unit, and 22.46 ± 0.643 and 22.29 ± 0.339 mg/dosage unit for the blind duplicate labeled to contain 24 mg/dosage unit. The method has been adopted as official first action.