Advertisement

Genotoxicity Testing of API

  • L. L. Custer
  • M. W. Powley

Abstract

Fortunately the frequency of mutagenic drug candidates recognized in early drug development is very low because positive Ames bacterial mutagenicity test results usually have severe ramifications with APIs dropped from further development. While negative results in the appropriate follow-up tests (e.g., mouse carcinogenicity studies) could enable progression of API development, pragmatically the cost and long duration required for these tests means that most pharmaceutical companies drop mutagenic APIs from development and quickly move on to another drug candidate.

Positive in vitro mammalian genotoxicity tests are far more frequently encountered but most times do not prevent further development of an API. When positive in vitro mammalian genotoxicity test results are obtained, follow-up studies in complementary in vitro or in vivo assays are quickly conducted to understand the biological relevance of the initial positive response. In the majority of cases the additional testing allows the sponsor to demonstrate lack of biological relevance or establish a safety threshold (generally ≥10×) based on exposures in animals at the no observed genotoxic effect level (NOGEL) relative to highest clinical exposure. For all these reasons, follow-up testing in response to an in vitro mammalian cell positive test is generally pursued and often results in continued development of the API.

This chapter focuses on genotoxicity testing strategies and includes case studies where follow-up studies were used to effectively de-risk positive in vitro genotoxicity test results. The regulatory guidelines (e.g., ICH S2(R1)) dictating which tests are required and which follow-up tests are acceptable are also presented. Because the regulatory guidelines list acceptable follow-up tests with little to no guidance on how to select them, this chapter provides recommendations on how to design the most appropriate follow-up testing strategy.

Keywords

Genotoxicity Ames bacterial mutagenicity test DNA damage Clastogenicity ICH S2(R1) No-observed genotoxic effect level (NOGEL) 

References

  1. 1.
    Escobar PA, Kemper RA, Tarca J, Nicolette J, Kenyon M, Glowienke S et al (2013) Bacterial mutagenicity screening in the pharmaceutical industry. Mutat Res 752(2):99–118CrossRefPubMedGoogle Scholar
  2. 2.
    Khandoudi N, Porte P, Chtourou S, Nesslany F, Marzin D, Le Curieux F (2009) The presence of arginine may be a source of false positive results in the Ames test. Mutat Res 679(1–2):65–71CrossRefPubMedGoogle Scholar
  3. 3.
    Thompson C, Morley P, Kirkland D, Proudlock R (2005) Modified bacterial mutation test procedures for evaluation of peptides and amino acid-containing material. Mutagenesis 20(5):345–350CrossRefPubMedGoogle Scholar
  4. 4.
    Glatt H, Oesch F (1985) Mutagenicity of cysteine and penicillamine and its enantiomeric selectivity. Biochem Pharmacol 34(20):3725–3728CrossRefPubMedGoogle Scholar
  5. 5.
    Aeschbacher HU, Finot PA, Wolleb U (1983) Interactions of histidine-containing test substances and extraction methods with the Ames mutagenicity test. Mutat Res 113(2):103–116CrossRefPubMedGoogle Scholar
  6. 6.
    OECD (2013) Test No. 488: Transgenic rodent somatic and germ cell gene mutation assays, OECD guidelines for the testing of chemicals, section 4. OECD Publishing, Paris. doi:http://dx.doi.org/10.1787/9789264203907-en
  7. 7.
    Special issue of environmental molecular & mutagenesis focused on the Pig-a gene mutation assay (2011) 52(9):681–794Google Scholar
  8. 8.
    Kirkland D, Pfuhler S, Tweats D, Aardema M, Corvi R, Darroudi F, Elhajouji A, Glatt H, Hastwell P, Hayashi M, Kasper P, Kirchner S, Lynch A, Marzin D, Maurici D, Meunier J-R, Muller L, Nohynek G, Parry J, Parry E, Thybaud V, Tice R, van Benthem J, Vanparys P, White P (2007) How to reduce false positive results when undertaking in vitro genotoxicity testing and thus avoid unnecessary follow-up animal tests: Report of an ECVAM Workshop. Mutat Res 628:31–55CrossRefPubMedGoogle Scholar
  9. 9.
    Scott D, Galloway SM, Marshall RR, Ishidate M, Brusick D, Ashby J, Myhr BC (1991) Genotoxicity under extreme culture conditions. A report from ICPEMC task group 9. Mutat Res 257:147–204CrossRefPubMedGoogle Scholar
  10. 10.
    Lorge E, Moore MM, Clements J, O’Donovan M, Fellows M, Honma M, Kohara A, Galloway S, Armstrong MJ, Sutter A, Thybaud V, Gollapudi B, Aardema MJ, Tanir JY (2015) Standardized cell sources and recommendations for good cell culture practices in genotoxicity testing. Mutat Res (in preparation)Google Scholar
  11. 11.
    Parry JM, Parry EM, Boumer R, Doherty A, Ellard S, O’Donovan J et al (1996) The detection and evaluation of aneugenic chemicals. Mutat Res 353(1–2):11–46CrossRefPubMedGoogle Scholar
  12. 12.
    Schuler M, Muehlbauer P, Guzzie P, Eastmond DA (1999) Noscapine hydrochloride disrupts the mitotic spindle in mammalian cells and induces aneuploidy as well as polyploidy in cultured human lymphocytes. Mutagenesis 14(1):51–56CrossRefPubMedGoogle Scholar
  13. 13.
    Rao CV, Yamada HY, Yao Y, Dai W (2009) Enhanced genomic instabilities caused by deregulated microtubule dynamics and chromosome segregation: a perspective from genetic studies in mice. Carcinogenesis 30(9):1469–1474PubMedCentralCrossRefPubMedGoogle Scholar
  14. 14.
    Kirkland DJ, Aardema M, Banduhn N, Carmichael P, Fautz R, Meunier J-R, Pfuhler S (2007) In vitro approaches to develop weight of evidence (WoE) and mode of action (MoA) discussions with positive in vitro genotoxicity results. Mutagenesis 22:161–175CrossRefPubMedGoogle Scholar
  15. 15.
    Thybaud V, Aardema M, Casciano D, Dellarco V, Embry MR, Gollapudi BB, Hayashi M, Holsapple MP, Jacobson-Kram D, Kasper P, MacGregor JT, Rees R (2007) Relevance and follow-up of positive results in in vitro genetic toxicity assays: an ILSI-HESI initiative. Mutat Res 633(2):67–79CrossRefPubMedGoogle Scholar
  16. 16.
    Dearfield KL, Thybaud V, Cimino MC, Custer L, Czich A, Harvey JS, Hester S, Kim JH, Kirkland D, Levy DD, Lorge E, Moore MM, Ouedraogo-Arras G, Schuler M, Suter W, Sweder K, Tarlo K, van Benthem J, van Goethem F, Witt KL (2011) Follow-up actions from positive results of in vitro genetic toxicity testing. Environ Mol Mutagen 52(3):177–204CrossRefPubMedGoogle Scholar
  17. 17.
    Asanami S, Shimono K (1997) High body temperature induces micronuclei in mouse bone marrow. Mutat Res 390(1–2):79–83CrossRefPubMedGoogle Scholar
  18. 18.
    Asanami S, Shimono K (1997) Hypothermia induces micronuclei in mouse bone marrow cells. Mutat Res 393(1–2):91–98CrossRefPubMedGoogle Scholar
  19. 19.
    Asanami S, Shimono K (2000) Effects of chemically- and environmentally-induced hypothermia on micronucleus induction in rats. Mutat Res 471(1–2):81–86CrossRefPubMedGoogle Scholar
  20. 20.
    Asanami S, Shimono K (2009) Species-level differences between mice and rats in regards to micronucleus induction with the hypothermia-inducing drug haloperidol. Mutat Res 676(1–2):102–105CrossRefPubMedGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Drug Safety EvaluationBristol-Myers SquibbNew BrunswickUSA
  2. 2.U.S. Food and Drug AdministrationCenter for Drug Evaluation and ResearchSilver SpringUSA

Personalised recommendations