ISO/TC194/WG15 STRATEGIC APPROACH TO BIOLOGICAL EVALUATION - DRAFT REPORT OF CORE MEETING in BRUSSELS

doc.nr. ISO/TC 194 WG15 Core Group N1
date 1999-01-13
item nr. supersedes document

Secretariat Nederlands Normalisatie-instituut
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Title: CORE GROUP

Secretariat: NNI (Netherlands)

Draft meeting report of December 2, 1998



1. Opening of the meeting


The following ISO/TC 194/WG 15 experts were present Barry Page, Mel Stratmeyer, Akitada Nakamura, Jeremy Tinkler, Victor Dorman-Smith and Jeannette van Loon.

2. Progress of WG 15/TF1 Immunotoxicology


WG 15/TF1 has prepared a draft report: Principles and methods for immunotoxiclogy testing of medical devices. This document is currently being circulated among some experts for comments. A meeting is planned for the end of January/beginning of February to incorporate the comments. The document will than be circulated to a wider group of experts. This document will be presented at the next WG15 meeting in Copenhagen, probably as a draft technical report.


3. Provisional results of the Questionnaire on Experiences with the ISO 10993 series of standards.


In co-operation with TC/194/WG 1 and as discussed at the WG1 meeting in Alexandria, Barbara Krug and Jeannette van Loon have prepared a questionnaire to solicit input from users of the ISO 10993 series of standards. This questionnaire has recently been put on Internet. Dutch experts have been contacted to provide comments on the readability. Some editorial changes will be made and the questionnaire will be send to CEN/TC 206, 1SO/TC 194 and WG15 members, TC's dealing with vertical issues, national standardisation institutes, notified bodies, and authorities. The deadline for response will be 2 months after receipt. The results will give information on the current interpretation of and problems with the current ISO 10993 standards. It will also provide input on the guidance to the format of standards being developed by WG 15/TF2.


4. Progress of WG 15/TF2 Format of ISO 10993 series


WG 15/TF2 has 2 tasks:

a. To prepare a format for guidance on the application of the individual parts of the ISO 10993 series of standards. This should for instance include the background of the development of the standards, limitations of test methods proposed in the standard, how to choose tests out of several choices and how to interpretate the results.

b. To prepare a general guidance document to the ISO 10993 series of standards. This document should give information on the following issues:

. what do we mean by evaluation of biological safety
. what comprises an evaluation
. how do we document the evaluation
. how to include risk aspects

The first type of document can be used by the different WG's to prepare a standard. The second type of document should have a more general character, which gives additional information to the whole ISO 10993 series.

TF2 will continue working on both documents. First drafts are planned to be available at the beginning of April. Ron Brown and David Gott were contacted to give input.


5. Deficiencies in ISO 10993-18 (see letters from Akitada Nakamura and Ron Brown)


Ron Brown has developed a proposal for using a conversion factor (CF) of 10 to estimate toxicologically equivalent doses between oral and parenteral tip, im, sc) exposure (valid for long and short time data). A CF factor of 30 seems to be appropriate when converting oral to iv doses (at least short term).

The proposal states that there would be no need to identify and quantify compounds released from parenteral exposure devices at doses less than 0.1mg/day because such amounts would not be expected to have toxicologically significant effects.

ISO/TC 194/WGs 7, 11 and 14 should discuss the implications for introducing such a threshold within their documents. ISO/TC 194 should recommend that work should be done on development of a threshold for systemic toxicity.

During the ISO/TC 194/WG 14 meeting in London a discussion took place on how to revise the current Part 18 to include risk assessment and clause 5 on Principles for judging Toxicological Equivalency was incorporated. The ISO/TC 194/WG 15 core group generally felt that clause 5 should be an informative Annex (or somewhere else) rather than a normative text. TC 194/WG 15 considers that this clause falls out of the scope of part 18.

J. Lang will be asked to reconsider how to proceed with ISO/DIS 10993-18 in view of these comments.


6. Requirements for biological evaluation in horizontal and vertical standards.


For the evaluation of biological safety of specific product groups more/other biological evaluation tests might be necessary. The problem is often that within the groups working on vertical standards not enough expertise is present on biological evaluation. So there is a strong need for more effective liaisons between ISO/TC 194 and vertical TC's and the knowledge within those TC's that they can make use of the expertise within ISO/TC 194.

Jeannette van Loon will contact the Chair of ISO/TC 194, Wolfgang Muller-Lierheim on his progress in meeting with the Chairpersons of ISO/TC's dealing with vertical subjects. As discussed at the plenary session at the last ISO/TC 194 meeting, Dr. Muller-Lierheim will discuss biocompatibility testing according to ISO 10993 and how to incorporate more specific requirements for biocompatibility testing in vertical standards when this is necessary. Akitada Nakamura mentioned that in Japan during a revision of a vertical standard a clause was included on biological evaluation according to the Japanese standards (which are comparable with the ISO 10993 series).


7. General items


There is a list of standards recognised by the FDA. This list does not contain all the ISO 10993 standards. Acceptance depends on a technical assessment of each standard and this includes the confidence of the reviewers in the standards. The fact that specific standards are used and how often they are used plays an essential role.

Within ISO/TC 210 a standard has been prepared on risk management. Developments in the ISO 10993 standards should be in alignment with developments in clauses on risk analysis, risk management and quality assurance. At the moment no reference is made to the ISO 10993 series in the risk management document. There was a reference made in the EN 1441. This should be aligned.


8. Further actions


* TF1 will work further on the draft report. Comments from experts will be collected. The document will be presented during the next ISO/TC 194 meeting in Denmark in May 1999.

* The questionnaire will be distributed to CEN/TC 206, ISO/TC 194 and ISO/TC 194/WG15 members, TC's dealing with vertical issues, national standardisation institutes, notified bodies, and authorities. Results will be presented at the ISO/TC 194 meeting in Denmark in May 1999.

* Jeannette van Loon will contact Wolfgang Muller-Lierheim on his progress to inform TC's, dealing with vertical subjects, about biocompatibility testing according to ISO 10993 and how to incorporate requirements on biocompatibility testing in vertical standards.

* TF2 will continue to prepare a guidance on the format of individual standards and a guidance document which gives information on issues like what do we mean by evaluation of biological safety, what comprises an evaluation, how do we document the evaluation and how to include risk aspects.

* ISO/TC 194 should recommend that work should be done on the development of a threshold for systemic toxicity.

* J. Lang will be asked to reconsider some aspects of ISO/DIS 10993-18. Clause 5 should be an informative Annex rather than a normative clause. A discussion on this should be initiated in WG14 (in co-operation with WG11 and 7).

* A liaison should be created between ISO/TC 194 and ISO/TC 210 to align the content of the ISO 10993 series and the standards written on risk analysis, risk management and quality assurance.


9. Place and date of next meeting


The next meeting of the WG15 core group will take place in Copenhagen (half a day) before the meeting of the whole WG15 (half a day). The core group will collect the results from the TF's and define further steps. This will be presented to the whole WG15. The final decisions and recommendations will be presented to ISO/TC 194.


10. Closure


The meeting was closed at 16:00h.

The following documents were handed out during the meeting:

. (Draft) Questionnaire on experiences with the ISO 10993 series of standards
* Report of ISO/TC 194 WG15 TF1 Immunotoxicology " Principles and methods for immunotoxicology testing of medical devices".
* Modifications to the list of recognised standards, Federal register/vol.63, no. 200/October 16, 1998
* Brief minutes of ISO/TC 194 WG14 in London 12, 13 October 1998.
* Letters from Akitada Nakamura and Ron Brown: Chemical characterisation.
* Slides: progress report for WG15: Risk Assessment-Based Approach for systemic Toxicity Evaluation.