Pink Sheet is part of Pharma Intelligence UK Limited

This site is operated by Pharma Intelligence UK Limited, a company registered in England and Wales with company number 13787459 whose registered office is 5 Howick Place, London SW1P 1WG. The Pharma Intelligence group is owned by Caerus Topco S.à r.l. and all copyright resides with the group.

This copy is for your personal, non-commercial use. For high-quality copies or electronic reprints for distribution to colleagues or customers, please call +44 (0) 20 3377 3183

Printed By

UsernamePublicRestriction

CARCINOGENICITY THRESHOLD DETERMINATIONS ON A CASE-BY-CASE BASIS

Executive Summary

CARCINOGENICITY THRESHOLD DETERMINATIONS ON A CASE-BY-CASE BASIS should be recognized as an appropriate approach to the assessment of chemical carcinogens, PMA maintained in recent comments on the White House Office of Science & Technology Policy (OSTP) draft document on carcinogenicity evaluation. PMA said that while OSTP does not make "any conclusive statements regarding the existence of or lack of existence of thresholds," it "fails to acknowledge that solid experimental evidence exists to demonstrate that a few chemicals do produce cancer in animals by mechanism involving a threshold." The assn. cited the food additive selenium as having a recognized threshold for carcinogenicity. FDA "concluded that selenium's capacity to induce liver damage at excessively high doses may be associated with a higher incidence of liver cancer but that such capacity does not warrant its classification as a carcinogen at nutritionally-required levels," PMA commented. Since at least one regulatory agency has acknowledged that "for at least some chemicals thresholds do exist," PMA said, it is "important to state this fact and to allow scientists the flexibility of case-by-case analysis as to whether the concept applies to a particular substance." OSTP published a draft document of its review of the science and associated principles of chemical carcinogens in the May 22 Federal Register. The purpose of the document is to "articulate a view of carcinogenesis that scientists generally hold in common today," and to derive a series of principles "that can be used to establish specific guidelines for assessing carcinogenic risk," OSTP explained. One of OSTP's principles states that "agents found carcinogenic in animal studies . . . are considered suspect human carcinogens." PMA stated that, as currently worded, "the principle could be misconstrued to imply that, once a chemical is associated with cancer in animals, it must forever be considered a suspect human carcinogen." The assn. recommended the principle be revised to state "agents found carcinogenic in animal studies . . . should be further evaluated for their potential carcinogenicity in humans, thus permitting a more definitive classification." With respect to high dosing in long-term animal studies, PMA said that while OSTP's document "contains strong inferences that excessive dosage can confuse interpretation, little attention is given to the fact that the animal model can be so disrupted by overdosage that the findings may have no application to the test animal itself in a normal physiological state and certainly none to man." The assn. recommended that test doses exceeding human exposure levels be considered appropriate "as long as the doses are not so excessive that the data are confounded."

You may also be interested in...



Part D Discount Liability Coming Into Focus: CMS Releases Drug Cost Data

Newly released Medicare Part D data sheds light on the sales hit that branded pharmaceutical manufacturers will face when the coverage gap discount program gets under way in 2011

FDA Skin Infections Guidance Spurs Debate On Endpoint Relevance

FDA appears headed for a showdown with clinicians and the pharmaceutical industry over the proposed new clinical trial endpoints for acute bacterial skin and skin structure infections, the guidance's approach for justifying a non-inferiority margin and proposed changes in the types of patients that should be enrolled in trials

Shire Hopes To Sow Future Deals With $50M Venture Fund

Specialty drug maker Shire has quietly begun scouting deals with a brand-new $50 million venture fund, the latest of several in-house investment arms to launch with their parent company's pipelines, not profits, as the measure of their worth

Latest Headlines
See All
UsernamePublicRestriction

Register

PS007011

Ask The Analyst

Ask the Analyst is free for subscribers.  Submit your question and one of our analysts will be in touch.

Your question has been successfully sent to the email address below and we will get back as soon as possible. my@email.address.

All fields are required.

Please make sure all fields are completed.

Please make sure you have filled out all fields

Please make sure you have filled out all fields

Please enter a valid e-mail address

Please enter a valid Phone Number

Ask your question to our analysts

Cancel