Preclinical Development Drugs. Darrin Cowley PhD Executive Director Amgen BioBoot Camp 2015

Transcription

1 Preclinical Development Drugs Darrin Cowley PhD Executive Director Amgen BioBoot Camp 2015

2 Product Development: Development process: File Approval Drug Discovery Preclinical Phase 1 Phase 2 Phase 3 Lifecycle Management It can take 15+ years to develop a new medicine from discovery to approval The preclinical space from discovery to first in human (FIH) on average takes 3-6 years Average cost of research and development is estimated between billion dollars for a program that gets approved

3 Regulations Code of Federal Regulations (CFR) Good Laboratories Practices (GLP): 21 CFR 58 Good Manufacturing Practices (GMP): 21 CFR 211 Apply later in development Biologic Products 21 CFR 600 Additional Standards for Viral Vaccines 21 CFR 630 FDA website (development and approval process) : rocess/default.htm

4 Guidances Product class specific guidance Points to Consider in the Characterization of Cell Lines Used to Produce Biologicals Points to consider in the manufacture and testing of monoclonal antibody products for human use International Conference on Harmonization (ICH) ICH S6: Note for guidance on preclinical safety evaluation of biotechnology derived pharmaceuticals; ICH S8: Note for guidance on immunotoxicity studies for human pharmaceuticals; ICH S9: Note for guidance on non-clinical evaluation for anticancer pharmaceuticals;

5 Documentation Internal Documentation (SOP) Manufacturing Testing Stability Protocols and reports Quality Agreements Contract Development and Manufacturing Nonclinical testing and timelines Clinical Research Organizations (CRO)

6 Majority of Biotech Products Use Living Cells to Produce a Protein Product Insert gene encoding the protein of interest Cells require proper conditions for optimal growth (temp, ph, oxygen, feeds, etc.) Culture and fermentation can take weeks Complex Purification Steps Safe product with desired potency Bar Charts, Inc. 2003

7 How are Protein Therapeutics different from Small Molecule Drugs? May contain intrinsic infectious agents Aseptic techniques required during production (terminal heat or gamma sterilization rarely applied) Usually have heterogeneous composition Numerous process and product-related impurities can occur Change in the manufacturing process can cause change in product composition Exact structure may be unknown (e.g., all possible variants often not fully characterized)

8 Structure of Small Molecule vs. Protein Drugs Proteins have expected: Size, charge, hydrophobicity Correct folding (S-S bonds) Subunits Glycosylation Bioactivity & Unexpected: Aggregation (side effects) Incorrect folding Amino acid modifications ox, deam, cys Truncation, proteolysis Statin ~400 Da Therapeutic protein ~5, ,000 Da

9 From Discovery to Initiation of Testing in Humans Understand the disease Identify a target Identify a lead candidate Define what the product will look like (product quality) and determine how to manufacture it (non-gmp, not for human use) Target product profile Develop analytical methods Perform pre-formulation studies First scale up Choose route of administration Pre-clinical testing in animals (toxicity, bioavailability, PK): determine if the product is safe enough to initiate testing in humans then dose escalation, and if the product exhibits pharmacological activity that justifies further development

10 Planning and Execution Business Patients Needs Compliance Science It all comes down to safety and efficacy

11 Understanding the Disease The only way to be certain that a protein is involved in a given disease is to test the idea in Humans and this is not possible due to safety concerns Understanding the genetics can help predict a possible mechanism or elucidate a potential target To help better understand the impact a target may have on a disease need to better understand the target and any interactions Computer models are becoming much better in predicting structure function and binding If the target protein s structure is known, computer models help predict potential bindings sites

12 Identify a Target Understanding the mechanism of action will help with the development of molecule Human Genome project has provided a lot of new information and the usefulness has yet to be realized Of the approximate 19,000 genes in the human genome, relatively few have known functions Identifying positive leads will be key to successful drug development Most drugs fail because they don t work or they are unsafe Targets where a particular protein elicits a response are typically easier to develop drugs for or against

13 Identify a Lead Candidate There are many different types of cell lines and vehicles Bacterial - Escherichia coli, Pseudomonas Yeast - Pichia pastoris Insect Baculovirus Flu Vaccines chicken eggs Mammalian Chinese hamster ovary (CHO)

14 Identify a Lead Candidate Need to understand what your output will need to be Simple or complex high titer product Soluble or insoluble product Inducible or non-inducible production Isopropyl β-d-1-thiogalactopyranoside (IPTG) induces lac operon tetracycline binds to Tet repressor Specific or non-specific or post-translational modification Glycosylation C and N -terminal modifications Disulfide rearrangements

15 Expression Vectors (Plasmids) Used for transfer of genes from one organism to another Used for production of large amounts of protein Description of origin of the construct Plasmid mapping (e.g., restriction sites, integration sites, promoter, copy number etc.) and stability Sequencing of gene of interest

16 Target Product Profile Pre-clinical clone selection and target expression criteria High through put screening assay different clones Plating cells Fed batch growth No purification Small scale Selecting

17 Establishing Initial Target Product Profile Greater emphasis on: Bivariate Fit of Automated Titer (g/l) By Manual Titer (g/l) Day=10 4 Titer 3 Automated Titer (g/l) Linear Fit Linear Fit Manual Titer (g/l) Automated Titer (g/l) = *Manual Titer (g/l) Summary of Fit RSquare RSquare Adj Root Mean Square Error Mean of Response Observations (or Sum Wgts) Analysis of Variance Source Model Error C. Total DF Sum of Squares Parameter Estimates Mean Square F Ratio Prob > F <.0001* Term Estimate Std Error t Ratio Prob> t Cell viability

18 Bench Scale Process Establish research cell bank clones Initial upstream cell culture process development Initial downstream purification process development Chromatography Initial formulation (UF/DF) for drug substance

19 Product Quality Attributes Greater emphasis on product quality parameters that are: Enzymatic processes that are likely to be clone specific: e.g., glycosylation, proteolytic clipping Genetic issues: e.g., mutations, frame shifts, splices Critical to the biological activity of the mab: e.g., ADCC Fucosylation CDC Galactosylation Lesser emphasis on product quality parameters that are: Optimized through purification process development; e.g., host cell protein Chemical mechanisms that are less likely to be clone specific; e.g., oxidation, deamidation, glycation

20 Development of Assays, Formulation Stability What are the critical quality attributes for your molecule Develop fit for purpose analytical assays to detect and monitor the critical quality attributes Develop simple assays to monitor and drive process consistency Develop an initial drug substance formulation Liquid Frozen Establishment of reference standard Frozen -70C

21 Development of Assays, Formulation Stability Formulation development, Initiate drug substance and drug product stability Recommended storage temperature Monitor for product related impurities Accelerated or stressed stability Determine degradation pathway Understand light exposure Data is valuable for temperature excursion investigations Reference standard stability

22 Second Scale Up Clone selection, typically down to 10 or fewer viable candidates Small scale bioreactor production Screen upstream and downstream process to select High titer Low process related impurities Appropriate product quality attributes Eliminate unwanted clones Establish cell bank of remaining clones Freeze banks Make selection of primary clone

23 Preparing for Tox/Animal Studies Scale up production to support Tox and animal studies GLP manufacturing Material should be consistent with smaller scale material

24 Tox/Animal Studies Assessment of critical quality attributes and development of first drug substance and drug product specification(s) Identify stability indicating assays Ensure analytical methods are fit for purpose Initiation of assay qualification

25 Performing Initial Safety Tests General principles Define pharmacological and toxicological effects prior to initiation of human studies. Both in vitro and in vivo studies can be used. Studies are expected to be performed in compliance with Good Laboratory Practices (GLP) Pharmacodynamics/Biological Activity In vitro / Ex vivo Use of cell lines or primary cultures can be useful to examine safety, e.g. cytokine release assays Binding affinity and functional activity studies In vivo PK/PD profile and estimate of clinical dose Short-term toxicity studies incorporating safety pharmacology endpoints

26 Animal Species/Model Selection Choose a relevant species This is a species where the material is pharmacologically active Immunochemical or functional tests can be used to help identify a relevant species The use of non-relevant species may be misleading and should not be used For monoclonal antibodies where no relevant species are available the sponsor should consider The use of knockouts and transgenic animals a clinical plan with very low starting dose and a dose escalation scheme should be discussed with the regulators

27 Dose Administration Administration should be consistent to that proposed for clinical use Consider bioavailability in animal model May need to increase/decrease dose or frequency of administration to account for clearance Immunogenicity should be characterized

28 United States FDA Mission The FDA is responsible for protecting the public health by assuring the safety, efficacy, and security of human and veterinary drugs, biological products, medical devices, our nation s food supply, cosmetics, and products that emit radiation. The FDA is also responsible for advancing the public health by helping to speed innovations that make medicines and foods more effective, safer, and more affordable, and helping the public get the accurate science-based information they need to use medicines and foods to improve their health. Source: FDA Website

29 United States FDA Structure Center for Drug Evaluation & Research (CDER) Center for Biologics Evaluation & Research (CBER) Center for Devices & Radiological Health (CDRH) Center for Food Safety & Applied Nutrition (CFSAN) Vaccines (CBER) National Center for Toxicological Research Office of the Commissioner Office of Regulatory Affairs

30 U.S. Investigational New Drug (IND) Application Submission, Review, & Acknowledgment Approval of Institutional Review Board secured. US IND Application is submitted to FDA. FDA review = 30 days Authorization is implicit unless otherwise notified. IND is amended as new/additional studies are conducted, new protocols are planned, and product development data is collected.

31 Acknowledgments Barry Cherney Chantal Cazeault Andy Spasoff Tim Brown Ingrid Markovic Randy Steiner