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Robert Combes

Publications and source records attributed to Robert Combes.

34 records · Page 2Linked to original sources
PubMed2005

The need for a formal invalidation process for animal and non-animal tests.

A plethora of regulations require that many chemicals and chemical products are tested for efficacy and/or toxicity. When permitted to operate effectively and without bias, the ECVAM/ICCVAM/OECD validation process can be used to independently establish that new animal and non-animal test procedures are sufficiently relevant and reliable for their stated purposes and should be considered for regulatory use. However, the validation process is under threat because of vested interests of various kinds, and it is clear that many currently-accepted animal tests and candidate animal and non-animal tests do not, and could never, meet the agreed criteria for necessity, test development, prevalidation, validation and acceptance. We therefore need an invalidation process to parallel and protect the validation process, so that such methods could be independently reviewed and declared irrelevant and/or unreliable for their claimed purposes. An additional advantage of such a process would be that valuable resources would no longer be wasted in attempts to secure the acceptance of inherently inadequate tests.

Animal Use Alternatives↗
PubMed2005

Intelligent testing strategies for chemicals testing -- a case of more haste, less speed?

The prospects for using (Q)SAR modelling, read-across (chemical) and other non-animal approaches as part of integrated testing strategies for chemical risk assessment, within the framework of the EU REACH legislation, are considered. The potential advantages and limitations of (Q)SAR modelling and read-across methods for chemical regulatory risk assessment are reviewed. It is concluded that it would be premature to base a testing strategy on chemical-based computational modelling approaches, until such time as criteria to validate them for their reliability and relevance by using independent and transparent procedures, have been agreed. This is mainly because of inherent problems in validating and accepting (Q)SARs for regulatory use in ways that are analogous to those that have been developed and applied for in vitro tests. Until this issue has been resolved, it is recommended that testing strategies should be developed which comprise the integrated use of computational and read-across approaches. These should be applied in a cautious and judicious way, in association with available tissue culture methods, and in conjunction with metabolism and biokinetic studies. Such strategies should be intelligently applied by being driven by exposure information (based on bioavailability, not merely on production volume) and hazard information needs, in preference to a tick-box approach. In the meantime, there should be increased efforts to develop improved (Q)SARs, expert systems and new in vitro methods, and, in particular, ways to expedite their validation and acceptance must be found and prospectively agreed with all major stakeholders.

Animal Testing Alternatives↗
PubMed2004

Optimising the design of preliminary toxicity studies for pharmaceutical safety testing in the dog.

A working party, comprising two animal welfare organisations and some 12 pharmaceutical companies in Europe, was established to minimise the use of the dog in safety testing. As first step, the participants defined the major objectives of preliminary dose-range finding/MTD toxicity studies in non-rodents, defined the principles and requirements for this study type and agreed on a proposal for an optimised study design, based on collective experience of conducting such studies in industry, involving an evaluation of 100 individual study data sets. The suggested study design is explained and described, and reflects current best practice in the pharmaceutical industry in Europe. The implementation of such an optimised design is believed to result in a reduction in the overall numbers of animals used for this purpose, without jeopardising the scientific rationale and usefulness of the studies for informing the conduct of later regulatory studies.

Animal Testing Alternatives↗
PubMed2002

The establishment of a network of European human research tissue banks.

This is a report of a workshop held on the establishment of human research tissue banking which was held in Levi, Finland 21-24 March 2002. There were 21 participants from 7 European countries. This meeting was attended by representatives from academia, research tissue banks and from the Biotech and Pharmaceutical Industries. The principal aim of the workshop was to find a way to progress the recommendations from ECVAM workshop 44 (ATLA 29, 125-134, 2001) and ECVAM workshop 32 (ATLA 26, 763-777, 1998). The workshop represented the first unofficial meeting of the European Network of Research Tissue Banks (ENRTB) steering group. It is expected that in the period preceding the next workshop the ENRTB steering group will co-ordinate the ethical, legislative and organisational aspects of research tissue banking. Key issues dealt with by the Levi workshop included the practical aspects of sharing expertise and experiences across the different European members. Such collaboration between research tissue banks and end users of such material seeks to ultimately enable shared access to human tissue for medical and pharmaco-toxicological research while maintaining strict adherence to differences in legal and ethical aspects related to the use of human tissue in individual countries.

Journal Article↗
PubMedDate not supplied

An overall strategy for the testing of chemicals for human hazard and risk assessment under the EU REACH system.

In its White Paper, "Strategy for a Future Chemicals Policy," published in 2001, the European Commission (EC) proposed the REACH (Registration, Evaluation and Authorisation of CHemicals) system to deal with both existing and new chemical substances. This system is based on a top-down approach to toxicity testing, in which the degree of toxicity information required is dictated primarily by production volume (tonnage). If testing is to be based on traditional methods, very large numbers of laboratory animals could be needed in response to the REACH system, causing ethical, scientific and logistical problems that would be incompatible with the time-schedule envisaged for testing. The EC has emphasised the need to minimise animal use, but has failed to produce a comprehensive strategy for doing so. The present document provides an overall scheme for predictive toxicity testing, whereby the non-animal methods identified and discussed in a recent and comprehensive ECVAM document, could be used in a tiered approach to provide a rapid and scientifically justified basis for the risk assessment of chemicals for their toxic effects in humans. The scheme starts with a preliminary risk assessment process (involving available information on hazard and exposure), followed by testing, based on physicochemical properties and (Q)SAR approaches. (Q)SAR analyses are used in conjunction with expert system and biokinetic modelling, and information on metabolism and identification of the principal metabolites in humans. The resulting information is then combined with production levels and patterns of use to assess potential human exposure. The nature and extent of any further testing should be based strictly on the need to fill essential information gaps in order to generate adequate risk assessments, and should rely on non-animal methods, as far as possible. The scheme also includes a feedback loop, so that new information is used to improve the predictivity of computational expert systems. Several recommendations are made, the most important of which is that the European Union (EU) should actively promote the improvement and validation of (Q)SAR models and expert systems, and computer-based methods for biokinetic modelling, since these offer the most realistic and most economical solution to the need to test large numbers of chemicals.

Cytochrome P-450 Enzyme System↗
PubMedDate not supplied

A critical assessment of the European Commission's proposals for the risk assessment and registration of chemical substances in the European Union.

In May, 2003, the European Commission published detailed proposals relating to its 2001 White Paper - Strategy for a Future Chemicals Policy. The White Paper described a new registration system called the REACH (Registration, Evaluation and Authorisation of Chemicals) system, for both new and existing chemicals. Subsequently, these detailed proposals were available for an eight-week consultation period for stakeholders to voice their views and concerns. In this paper, we describe our reactions to the Commission's more-detailed proposals. These include the creation of a European Chemicals Agency to implement the REACH system in conjunction with Competent Authorities (CAs) in Member States and the Commission itself. Unfortunately, many of our concerns and suggestions, previously voiced and shared with several other key stakeholders, remain unanswered, but are as relevant as when the White Paper was published. In particular, we are concerned about the lack of a clear and coherent strategy. There is no guidance for registrants on intelligent testing to maximise the use of non-animal approaches to safety testing, based on a combination of factors for estimating exposure levels, rather than mainly on production volumes. We are also concerned about the absence of a clear programme for the development, improvement and validation of new alternative methods, in conjunction with the Commission's own unit, the European Centre for the Validation of Alternative Methods, as well as other organisations with relevant expertise and experience, including FRAME. Finally, we explain why such measures should be introduced, together with clearer guidelines for the respective roles of the Agency, the CAs and the Commission in implementing and harmonising the REACH system at the European Union and Member State levels. A series of recommendations are made, to improve the situation and to improve the risk assessment process.

Animal Use Alternatives↗