Bruno Flamion

Renal biomarker qualification submission: a dialog between the FDA-EMEA and Predictive Safety Testing Consortium

The first formal qualification of safety biomarkers for regulatory decision making marks a milestone in the application of biomarkers to drug development. Following submission of drug toxicity studies and analyses of biomarker performance to the Food and Drug Administration (FDA) and European Medicines Agency (EMEA) by the Predictive Safety Testing Consortiums (PSTC) Nephrotoxicity Working Group, seven renal safety biomarkers have been qualified for limited use in nonclinical and clinical drug development to help guide safety assessments. This was a pilot process, and the experience gained will both facilitate better understanding of how the qualification process will probably evolve and clarify the minimal requirements necessary to evaluate the performance of biomarkers of organ injury within specific contexts.

Bridging the efficacy–effectiveness gap: a regulator's perspective on addressing variability of drug response

Drug regulatory agencies should ensure that the benefits of drugs outweigh their risks, but licensed medicines sometimes do not perform as expected in everyday clinical practice. Failure may relate to lower than anticipated efficacy or a higher than anticipated incidence or severity of adverse effects. Here we show that the problem of benefit–risk is to a considerable degree a problem of variability in drug response. We describe biological and behavioural sources of variability and how these contribute to the long-known efficacy–effectiveness gap. In this context, efficacy describes how a drug performs under conditions of clinical trials, whereas effectiveness describes how it performs under conditions of everyday clinical practice. We argue that a broad range of pre- and post-licensing technologies will need to be harnessed to bridge the efficacy–effectiveness gap. Successful approaches will not be limited to the current notion of pharmacogenomics-based personalized medicines, but will also entail the wider use of electronic health-care tools to improve drug prescribing and patient adherence.

Balancing early market access to new drugs with the need for benefit/risk data: a mounting dilemma

Drug regulatory agencies are increasingly pressed by the challenge of finding the appropriate balance between the need for rapid access to new drugs and the need to ensure comprehensive data on their benefits and risks. This dilemma is not new, but has been made more prominent by recent high-profile drug withdrawals and conflicting demands, including the need to improve the efficiency of drug development on one hand, and the need to avoid exposing patients to unnecessary risks or possibly ineffective treatments on the other. Here, we summarize the current demands by stakeholders and the scientific and regulatory issues at stake, describe existing and emerging regulatory approaches, and speculate on future directions, such as evolution of the current regulatory model from a one-off marketing authorization to a life-cycle approach.

Validation of Real-Time Methylation-Specific PCR to Determine O6-Methylguanine-DNA Methyltransferase Gene Promoter Methylation in Glioma

Epigenetic silencing of the DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) by promoter methylation predicts successful alkylating agent therapy, such as with temozolomide, in glioblastoma patients. Stratified therapy assignment of patients in prospective clinical trials according to tumor MGMT status requires a standardized diagnostic test, suitable for high-throughput analysis of small amounts of formalin-fixed, paraffin-embedded tumor tissue. A direct, real-time methylation-specific PCR (MSP) assay was developed to determine methylation status of the MGMT gene promoter. Assay specificity was obtained by selective amplification of methylated DNA sequences of sodium bisulfite-modified DNA. The copy number of the methylated MGMT promoter, normalized to the beta-actin gene, provides a quantitative test result. We analyzed 134 clinical glioma samples, comparing the new test with the previously validated nested gel-based MSP assay, which yields a binary readout. A cut-off value for the MGMT methylation status was suggested by fitting a bimodal normal mixture model to the real-time results, supporting the hypothesis that there are two distinct populations within the test samples. Comparison of the tests showed high concordance of the results (82/91 [90%]; Cohens kappa = 0.80; 95% confidence interval, 0.82-0.95). The direct, real-time MSP assay was highly reproducible (Pearson correlation 0.996) and showed valid test results for 93% (125/134) of samples compared with 75% (94/125) for the nested, gel-based MSP assay. This high-throughput test provides an important pharmacogenomic tool for individualized management of alkylating agent chemotherapy.

Challenges with advanced therapy medicinal products and how to meet them

Advanced therapy medicinal products (ATMPs), which include gene therapy medicinal products, somatic cell therapy medicinal products and tissue-engineered products, are at the cutting edge of innovation and offer a major hope for various diseases for which there are limited or no therapeutic options. They have therefore been subject to considerable interest and debate. Following the European regulation on ATMPs, a consolidated regulatory framework for these innovative medicines has recently been established. Central to this framework is the Committee for Advanced Therapies (CAT) at the European Medicines Agency (EMA), comprising a multidisciplinary scientific expert committee, representing all EU member states and European Free Trade Association countries, as well as patient and medical associations. In this article, the CAT discusses some of the typical issues raised by developers of ATMPs, and highlights the opportunities for such companies and research groups to approach the EMA and the CAT as a regulatory advisor during development.

Skeletal and hematological anomalies in HYAL2-deficient mice: a second type of mucopolysaccharidosis IX?

The metabolism of hyaluronan (HA) re lies on HA synthases and hyaluronidases, among which hyaluronidase‐1 (HYAL1) and ‐2 (HYAL2) have been proposed as key actors. Congenital HYAL1 deficiency leads to mucopolysaccharidosis IX (MPS IX), a rare lysosomal storage disorder characterized by joint ab normalities. Knowledge of HYAL2 is limited. This protein displays weak in vitro hyaluronidase activity and acts as a receptor for oncogenic ovine retroviruses. We have generated HYAL2‐deficient mice through a condi tional Cre‐lox system. Hyal2‐/‐ mice are viable and fertile. They exhibit localized congenital defects in frontonasal and vertebral bone formation and suffer from mild thrombocytopenia and chronic, possibly intravascular, hemolysis. In addition, Hyal2‐/‐ mice display 10‐fold increases in plasma levels of HA and 2‐fold increases in plasma hyaluronidase activity. Glo bally, there is no HA accumulation in tissues, including bones, but liver sinusoidal cells seem overloaded with undigested HA. Taken together, these elements dem onstrate for the first time that murine HYAL2 has a physiological activity in vivo that is relevant for cranio vertebral bone formation, maintenance of plasma HA concentrations, and erythrocyte and platelet homeosta sis. In addition, the viability of HYAL2‐deficient mice raises the possibility that a similar defect, defining a new MPS disorder, exists in humans.— Jadin, L., Wu, X., Ding, H., Frost, G. I., Onclinx, C., Triggs‐Raine, B., Flamion, B. Skeletal and hematological anomalies in HYAL2‐deficient mice: a second type of mucopolysaccharidosis IX?. FASEB J. 22, 4316–4326 (2008)

Patient-Reported Outcome Measures in Safety Event Reporting: PROSPER Consortium Guidance

The Patient-Reported Outcomes Safety Event Reporting (PROSPER) Consortium was convened to improve safety reporting by better incorporating the perspective of the patient. PROSPER comprises industry, regulatory authority, academic, private sector and patient representatives who are interested in the area of patient-reported outcomes of adverse events (PRO-AEs). It has developed guidance on PRO-AE data, including the benefits of wider use and approaches for data capture and analysis. Patient-reported outcomes (PROs) encompass the full range of self-reporting, rather than only patient reports collected by clinicians using validated instruments. In recent years, PROs have become increasingly important across the spectrum of healthcare and life sciences. Patient-centred models of care are integrating shared decision making and PROs at the point of care; comparative effectiveness research seeks to include patients as participatory stakeholders; and industry is expanding its involvement with patients and patient groups as part of the drug development process and safety monitoring. Additionally, recent pharmacovigilance legislation from regulatory authorities in the EU and the USA calls for the inclusion of patient-reported information in benefit–risk assessment of pharmaceutical products. For patients, technological advancements have made it easier to be an active participant in one’s healthcare. Simplified internet search capabilities, electronic and personal health records, digital mobile devices, and PRO-enabled patient online communities are just a few examples of tools that allow patients to gain increased knowledge about conditions, symptoms, treatment options and side effects. Despite these changes and increased attention on the perceived value of PROs, their full potential has yet to be realised in pharmacovigilance. Current safety reporting and risk assessment processes remain heavily dependent on healthcare professionals, though there are known limitations such as under-reporting and discordant perspectives between patient reports and clinician perceptions of adverse outcomes. PROSPER seeks to support the wider use of PRO-AEs. The scope of this guidance document, which was completed between July 2011 and March 2013, considered a host of domains related to PRO-AEs, including definitions and suitable taxonomies, the range of datasets that could be used, data collection mechanisms, and suitable analytical methodologies. PROSPER offers an innovative framework to differentiate patient populations. This framework considers populations that are prespecified (such as those in clinical trials, prospective observational studies and some registries) and non-prespecified populations (such as those in claims databases, PRO-enabled online patient networks, and social websites in general). While the main focus of this guidance is on post-approval PRO-AEs from both prespecified and non-prespecified population groups, PROSPER has also considered pre-approval, prespecified populations. The ultimate aim of this guidance is to ensure that the patient ‘voice’ and perspective feed appropriately into collection of safety data. The guidance also covers a minimum core dataset for use by industry or regulators to structure PRO-AEs (accessible in the online appendix) and how data, once collected, might be evaluated to better inform on the safe and effective use of medicinal products. Structured collection of such patient data can be considered both a means to an end (improving patient safety) as well as an end in itself (expressing the patient viewpoint). The members of the PROSPER Consortium therefore direct this PRO-AE guidance to multiple stakeholders in drug safety, including industry, regulators, prescribers and patients. The use of this document across the entirety of the drug development life cycle will help to better define the benefit–risk profile of new and existing medicines. Because of the clinical relevance of ‘real-world’ data, PROs have the potential to contribute important new knowledge about the benefits and risks of medicinal products, communicated through the voice of the patient.

Two Novel Functions of Hyaluronidase-2 (Hyal2) Are Formation of the Glycocalyx and Control of CD44-ERM Interactions

It has long been predicted that the members of the hyaluronidase enzyme family have important non-enzymatic functions. However, their nature remains a mystery. The metabolism of hyaluronan (HA), their major enzymatic substrate, is also enigmatic. To examine the function of Hyal2, a glycosylphosphatidylinositol-anchored hyaluronidase with intrinsically weak enzymatic activity, we have compared stably transfected rat fibroblastic BB16 cell lines with various levels of expression of Hyal2. These cell lines continue to express exclusively the standard form (CD44s) of the main HA receptor, CD44. Hyal2, CD44, and one of its main intracellular partners, ezrin-radixin-moesin (ERM), were found to co-immunoprecipitate. Functionally, Hyal2 overexpression was linked to loss of the glycocalyx, the HA-rich pericellular coat. This effect could be mimicked by exposure of BB16 cells either to Streptomyces hyaluronidase, to HA synthesis inhibitors, or to HA oligosaccharides. This led to shedding of CD44, separation of CD44 from ERM, reduction in baseline level of ERM activation, and markedly decreased cell motility (50% reduction in a wound healing assay). The effects of Hyal2 on the pericellular coat and on CD44-ERM interactions were inhibited by treatment with the Na+/H+ exchanger-1 inhibitor ethyl-N-isopropylamiloride. We surmise that Hyal2, through direct interactions with CD44 and possibly some pericellular hyaluronidase activity requiring acidic foci, suppresses the formation or the stability of the glycocalyx, modulates ERM-related cytoskeletal interactions, and diminishes cell motility. These effects may be relevant to the purported in vivo tumor-suppressive activity of Hyal2.

How to define responders in osteoarthritis

Abstract Background: Osteoarthritis is a clinical syndrome of failure of the joint accompanied by varying degrees of joint pain, functional limitation, and reduced quality of life due to deterioration of articular cartilage and involvement of other joint structures. Scope: Regulatory agencies require relevant clinical benefit on symptoms and structure modification for registration of a new therapy as a disease-modifying osteoarthritis drug (DMOAD). An international Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and International Osteoporosis Foundation was convened to explore the current burden of osteoarthritis, review current regulatory guidelines for the conduct of clinical trials, and examine the concept of responder analyses for improving drug evaluation in osteoarthritis. Findings: The ESCEO considers that the major challenges in DMOAD development are the absence of a precise definition of the disease, particularly in the early stages, and the lack of consensus on how to detect structural changes and link them to clinically meaningful endpoints. Responder criteria should help identify progression of disease and be clinically meaningful. The ideal criterion should be sensitive to change over time and should predict disease progression and outcomes such as joint replacement. Conclusion: The ESCEO considers that, for knee osteoarthritis, clinical trial data indicate that radiographic joint space narrowing >0.5 mm over 2 or 3 years might be a reliable surrogate measure for total joint replacement. On-going research using techniques such as magnetic resonance imaging and biochemical markers may allow the identification of these patients earlier in the disease process.

The regulatory landscape for actively personalized cancer immunotherapies.

volume 31 NumBeR 10 oCToBeR 2013 nature biotechnology genes known to be commonly mutated in patients, such as TP53, KRAS or the VonHippel-Lindau (VHL) gene10,11. Recent advances in whole-genome sequencing that make individual tumor genomes available within days at affordable cost now expand the aforementioned approach to a new level and reach far beyond a restricted set of predefined antigen libraries or a few known mutated genes12. Complete de novo synthesis of multitarget vaccines directed against the immunogenic mutanome of individual patients allows, for the first time, the comprehensive exploitation of highly immunogenic epitopes not covered by central immune tolerance. Identification of tumor-specific nonsynonymous mutations in individual tumors is achieved by novel, massively parallel, next-generation sequencing technology. Based on a list of tumor-specific mutations, a standardized selection process defines the set of mutations to be included in the vaccine. This could be achieved by applying computer-based prediction tools13, determining naturally presented mutated peptides based on elution of human leukocyte antigen–restricted peptides and subsequent peptide sequencing by mass spectrometry14 or testing patients for pre-existing immunity against identified mutated epitopes. Finally, a small fraction of tumor-specific mutated antigens are selected for the vaccine. Such actively personalized vaccines do not add new markers, but merely enrich antigens that are also present in vaccine formats, such as tumor-cell lysates that have frequently been used clinically in the past. Addressing regulatory challenges associated with APVACs and their possible solutions requires a differentiated look at quality, preclinical and clinical aspects. Quality attributes of APVACs targeting the mutanome need to be prospectively defined as for any medicine, which will be feasible when using vaccine formats, such as synthetic peptides or RNA that can be well characterized. Because of the ‘on demand’ production of APVACs and the variability of APVACS that might be associated with varying stabilities, the generation of stability data as normally required for well-defined products will be challenging. Nevertheless, the same principles as for autologous cellular therapies might be applied, by performing real-time stability studies on a defined number of batches and then assigning the established shelf life to all subsequent batches manufactured by the same manufacturing process (extrapolation). Unfortunately animal models are not useful for establishing 19. Dugoff, L. N. Engl. J. Med. 367, 2249–2251 (2012). 20. Kranz, E. Methods Mol. Biol. 111, 259–267 (1999). 21. Tran Thanh Van, K. et al. Adv. Biochem. Eng. 18, 151–171 (1980). 22. Henry, Y. et al. Euphytica 79, 45–58 (1994). 23. Bairu, M.W. et al. Plant Growth Regul. 63, 147–173 (2011). 24. Mulcahy, D.L. et al. Sex. Plant Reprod. 9, 353–356 (1996).