An Introduction to the Regulatory and Nonclinical Aspects of the Nonclinical Development of Antibody Drug Conjugates.

Antibody drug conjugates (ADCs) are promising therapies currently in development for oncology with unique and challenging regulatory and scientific considerations. While there are currently no regulatory guidelines specific for the nonclinical development of ADCs, there are harmonized international guidelines (e.g., ICHS6(R1), ICHM3(R2), ICHS9) that apply to ADCs and provide a framework for their complex development with issues that apply to both small and large molecules. The regulatory and scientific perspectives on ADCs are evolving due to both the advances in ADC technology and a better understanding of the safety and efficacy of ADCs in clinical development. This paper introduces the key scientific and regulatory aspects of the nonclinical development of ADCs, discusses important regulatory and scientific issues in the nonclinical to clinical dose translation of ADCs, and introduces new concepts in the areas of pharmacokinetic/pharmacodynamic (PK/PD) modeling and simulation.

Cytokines: The Good, the Bad, and the Deadly.

Over the past 30 years, the world of pharmaceutical toxicology has seen an explosion in the area of cytokines. An overview of the many aspects of cytokine safety evaluation currently in progress and evolving strategies for evaluating these important entities was presented at this symposium. Cytokines play a broad role to help the immune system respond to diseases, and drugs which modulate their effect have led to some amazing therapies. Cytokines may be "good" when stimulating the immune system to fight a foreign pathogen or attack tumors. Other "good" cytokine effects include reduction of an immune response, for example interferon ß reduction of neuron inflammation in patients with multiple sclerosis. They may be "bad" when their expression causes inflammatory diseases, such as the role of tumor necrosis factor α in rheumatoid arthritis or asthma and Crohn's disease. Therapeutic modulation of cytokine expression can help the "good" cytokines to generate or quench the immune system and block the "bad" cytokines to prevent damaging inflammatory events. However, care must be exercised, as some antibody therapeutics can cause "ugly" cytokine release which can be deadly. Well-designed toxicology studies should incorporate careful assessment of cytokine modulation that will allow effective therapies to treat unmet needs. This symposium discussed lessons learned in cytokine toxicology using case studies and suggested future directions.

The development of therapeutic monoclonal antibodies: overview of the nonclinical safety assessment.

Monoclonal antibodies (mAbs) represent a class of biotechnology-derived therapeutics for use in the treatment of various disease indications such as oncology, autoimmune, cardiovascular, and metabolic disorders. Monoclonal antibodies are immunoglobulin (Ig) proteins engineered to bind to specific antigens with high specificity. The concepts reviewed in this paper include 1) the regulatory procedures and guidelines that apply to mAbs, 2) the types of toxicology studies applicable to mAbs, and 3) the scientific challenges, such as the selection of a relevant animal species and the development of anti-drug antibodies, that can arise due to the unique properties of mAbs.