Clinical Epidemiology Drug Development I Preclinical Development

Transcription

1 IBE Clinical Epidemiology Drug Development I Preclinical Development Sascha Tillmanns, MSc, Medical Director s.tillmanns@online.de Clinical/Preclinical Development, SuppreMol GmbH

2 Agenda Scope Introduction Preclinical overview Assay development Preclinical efficacy Toxicological evaluation Pharmacokinetics (PK) and toxicokinetics (TK) The no observed adverse effect level (NOAEL) and no effect level (NOEL) Minimum anticipated biological effect level (MABEL) Maximum recommended starting dose (MRSD) Example: Preclinical development for a receptor protein Drug Development I 2

3 Abbreviations AUC c max CMC CMO CRO DLT DRF EMA FDA FiH GLP ICH IMP IP MABEL Area under the concentration-time curve Maximum concentration Chemistry, manufacturing, controls Contract manufacturing organisation Contract research organisation Dose limiting toxicity Dose range finder European medicinal agency Food and drug administration First-in-Human Good laboratory practice International conference on harmonisation Investigational medicinal product Investigational product Minimum anticipated biological effect level (N)ADA NOAEL NOEL PD PK TK t max (Neutralising) anti-drug antibodies No observed adverse effect level No observed effect level Pharmacodynamics Pharmacokinetics Toxicokinetics Time at maximum concentration Drug Development I 3

4 Scope The presentation will focus on preclinical development parts necessary (critical path) prior to the first clinical study (First in Human [FiH] clinical trial) in healthy subjects or patients It is based on the real development of a receptor molecule (FcγRIIB) for the treatment of autoimmune diseases such as rheumatoid arthritis Additional preclinical or nonclinical investigations can be performed later in parallel to the clinical development, e.g: phase III investigational medicinal product (IMP) upscaling, carcinogenicity studies, male fertility or long term toxicity studies in animals Drug Development I 4

5 Scope Small Molecules Source: Rais, PharmUZ 6/2012 (41) Biologics Acetylsalicylic acid Insulin Monoclonal Antibody ( 180 Da) ( 5,800 Da) ( 150 kda) Prior to entering the preclinical development phase, the investigational product (IP) has been optimised through lead optimisation in the research phase The presentation will focus on the development of biological drugs (e.g. antibodies, fab fragments, receptor molecules) and less on small molecules Drug Development I 5

6 Scope Small Molecules Source: Rais, PharmUZ 6/2012 (41) Biologics Acetylsalicylic acid Insulin Monoclonal Antibody ( 180 Da) ( 5,800 Da) ( 150 kda) Prior to entering the preclinical development phase, the investigational product (IP) has been optimised through lead optimisation in the research phase The presentation will focus on the development of biological drugs (e.g. antibodies, fab fragments, receptor molecules) and less on small molecules Drug Development I 6

7 Introduction From 250 products entering preclinics, only 1 to 2 receive market approval Question: Reasons for failure? Source: en.wikibooks.org Drug Development I 7

8 Introduction Source: en.wikibooks.org From 250 products entering preclinics, only 1 to 2 receive market approval Reasons for failure are: Toxicity Lack of efficacy Pharmacokinetics Gender effect Production costs Drug Development I 8

9 Preclinical Overview Phase Ia/Ib Dose Escalation FiM Clinical Trial Drug Development I 9

10 Preclinical Overview Assay Development - IP Bioassay for PK - ADA/NADA Assay Phase Ia/Ib Dose Escalation FiM Clinical Trial Drug Development I 10

11 Preclinical Overview Assay Development - IP Bioassay for PK - ADA/NADA Assay Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models Drug Development I 11

12 Preclinical Overview Assay Development - IP Bioassay for PK - ADA/NADA Assay Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL Drug Development I 12

13 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies Assay Development - IP Bioassay for PK - ADA/NADA Assay Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL Drug Development I 13

14 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL Drug Development I 14

15 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay MRSD and Dosing Steps Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL Drug Development I 15

16 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay MRSD and Dosing Steps Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL IP Lab Scale Toxicological Relevant IP IMP for Human Use Drug Development I 16

17 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay MRSD and Dosing Steps Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL IP Lab Scale Toxicological Relevant IP IMP for Human Use Drug Development I 17

18 In-vitro Binding Studies and Assays In-vitro binding studies (e.g. with ELISA) as first step to characterise IP binding affinity to the target Antibody concentration [ng/ml] Adopted from source: abdserotec.com Drug Development I 18

19 In-vitro Binding Studies and Assays 100% 40,000 In-vitro binding studies (e.g. with ELISA) as first step to characterise IP binding affinity to the target K d = 7 ng/ml Antibody concentration [ng/ml] Adopted from source: abdserotec.com Drug Development I 19

20 In-vitro Binding Studies and Assays IP bioassay for quantification and pharmacokinetic (PK) analysis for human and animal samples Anti-drug antibody (ADA) assay to assess potential immunogenicity Neutralising anti-drug antibody (NADA) assay to investigate limitations to IP treatment duration and cross-reactivity to endogenous targets Cell based human full blood assays to investigate IP activity on targets such as: activation markers, mediator release, cell depletion Cell based assay useful to determine IP potency for IMP release in clinical trials Drug Development I 20

21 Animal Efficacy Studies with Human IP Animal efficacy disease models are usually the next step to establish the pharmacodynamic (PD) effect of the IP Most of the efficacy disease models are established in mice Usually, PD animal models do not support determination of the no observed adverse effect level (NOAEL) but are useful for determination of the minimum anticipated biological effect level (MABEL) Standard animal disease models can be used if IP intended for human use has at least some cross-reactivity to the equivalent animal target Optimal study design would include different IP dosages, determination of IP levels with PK analysis with satellite animals Drug Development I 21

22 Animal Efficacy Studies with Human IP Inclusion of competitor IP with well-known activity in this disease model Toxicological evaluations including clinical signs, histopathology, immunogenicity, etc. Disease models commercially available but usually performed by academic institutions under non-good laboratory practice (non-glp) For the efficacy transfer to the human target, usually a factor needs to be considered for the lesser binding activity in animals Drug Development I 22

23 Animal Efficacy Studies with Surrogate For some targets, the cross-reactivity of the human IP to the equivalent animal target is negligible or the target is not expressed at all in animals For these targets, standard animal models with the human IP is not useful Instead, the use of a surrogate IP or humanised animals with additional disease model should be considered Drug Development I 23

24 Animal Efficacy Studies with Surrogate A surrogate IP is developed to express a certain binding affinity to the animal target which is comparable to the human IP format to the human target With a suitable surrogate IP, standard animal disease models can be used Surrogate IP cannot be used, if there is no equivalent target present in animals Surrogate IP does not present the human IP format and the use could mask some additional pharmacological properties Drug Development I 24

25 Efficacy Studies in Humanised Animals If the target is not present in animals, human cell-based studies or humanised animals with human IP are an alternative Humanised animal models are able to mimic to some extend human binding characteristics, immunological pathways and on-target effects Normally low animal numbers, non-glp and the degree of humanisation varies from animal to animal Establishment of additional disease model problematic Drug Development I 25

26 Toxicology and Safety Pharmacology Expensive step after positive efficacy results Normally requires toxicology and safety pharmacology studies in two species under GLP International conference on harmonisation (ICH) guideline M3 (R2) on non-clinical safety studies for the conduct of human clinical trials and marketing authorisation for pharmaceuticals, December 2009 However, due to lack of cross-reactivity of biotech-derived IPs, to an equivalent target, standard tox program is not always feasible ICH guideline S6 (R1): Preclinical Safety Evaluation of Biotechnology Derived Pharmaceuticals, June Drug Development I 26

27 Toxicology and Safety Pharmacology Similar to the preclinical efficacy, they are 3 possibilities to generate relevant preclinical toxicology data prior to the start of FiH clinical trials Standard GLP toxicology studies in up to 2 species with the human IP conducted by a commercial contract research organisation (CRO) GLP toxicology studies in up to 2 species with a surrogate IP conducted by a commercial CRO Toxicology evaluations in humanised animals with the human IP usually performed in collaboration with academic institutions under non-glp Drug Development I 27

28 Standard GLP Toxicology Useful if human IP format is characterised by a reasonable equivalent target in one ore more animal species GLP In small molecules usually rats and dogs are used For biotech IPs, quite often mice (PD studies) and (still) cynomolgus monkeys are evaluated Adequate IP exposure (c max, AUC) in mice compared to human applications often difficult to achieve due to higher IP metabolism IP exposure to be considered also for safety margin Drug Development I 28

29 Standard GLP Toxicology Dose frequency and duration in tox studies should at least cover 1:1 the intended human IP application in clinical trials (not sufficient for market approval) Prior to the GLP main part of the study, usually a non-glp dose range finder (DRF) pilot is performed before to determine a safe dose range for the main study Example: minimum and maximum intended toxicological dose over 2 weeks in a limited number of animals Drug Development I 29

30 Standard GLP Toxicology In the main part, a common way is to start with a 28-day weekly dosing tox study including: Male and female mice 3 different IP dosages and placebo Clinical signs/symptoms Immunological evaluation Histopathology Toxicokinetic (TK) evaluation Drug Development I 30

31 Standard GLP Toxicology TK evaluations represent PK assessment under toxicological levels The figure here represents IP plasma concentrations of three different dosages Question: What could be the application form? Drug Development I 31

32 Standard GLP Toxicology TK evaluations represent PK assessment under toxicological levels The figure here represents IP plasma concentrations of three different dosages Application form is i.v Drug Development I 32

33 Standard GLP Toxicology The maximum serum concentrations c max increase approximately linear c max = 100 mg/l for 200 mg/kg c max = 40 mg/l for 100 mg/kg c max = 20 mg/l for 50 mg/kg The time at the maximum conc. (t max ) is zero (always for i.v. drugs) t max = 0h Drug Development I 33

34 Standard GLP Toxicology Drug exposure is represented by c max and AUC AUC is the area under the concentration - time curve AUC 0-t can be calculated manually by the trapezoid rule Drug Development I 34

35 Standard GLP Toxicology Drug exposure is represented by c max and AUC AUC is the area under the concentration - time curve AUC 0-t can be calculated manually by the trapezoid rule Drug Development I 35

36 Standard GLP Toxicology Drug exposure is represented by c max and AUC AUC 0-t = ca. 400 mg*h/l for 200 mg/kg AUC is the area under the concentration - time curve AUC 0-t can be calculated manually by the trapezoid rule Drug Development I 36

37 Standard GLP Toxicology Additional important PK/TK parameters are the area under the concentration time curve until infinity (AUC 0-inf ), trough level (c 0 ) and the terminal half-life (t 1/2 ) An additional recovery period of at least 2 weeks with satellite animals is recommended The dosages used in the DRF and main study should be based on preclinical efficacy experience, resulting in an anticipated human dose range with an adequate safety margin Example: expected human dose: xmg/kg, toxicology dosages: placebo, 5*xmg/kg, 30*xmg/kg and 100*xmg/kg The need to perform single dose tox and safety pharmacology studies (ECG, behaviour) according to ICH guidelines is normally integrated into the multiple tox studies Drug Development I 37

38 Standard GLP Toxicology Appearance of (N)ADAs should be evaluated, their presence could cause irrelevant side effects to the foreign protein or limit IP administration All results from the toxicological evaluations will be summarised into the NOAEL Drug Development I 38

39 NOAEL NOAEL determination is one of the most important outcomes in standard GLP toxicity studies It defines the dose level where no adverse effects can be observed However, for quite a few biotech IPs, even the highest dose does not lead to a NOAEL NOAEL is different from the no observed effect level (NOEL), which defines a dose level where no pharmacological effect can be observed at all Drug Development I 39

40 NOAEL Appropriate conversion of the dose level into the human dose with additional safety margin leads to the maximum recommended starting dose (MRSD) in FiH clinical trials Food and drug administration (FDA) guidance for industry: estimating the maximum safe starting dose in initial clinical trials for therapeutics in adult healthy volunteers, July 2005 The MRSD determination based on the NOAEL is valid for all IPs not falling under the European medicines agency (EMA) risk mitigation guideline, requiring the MABEL for dose selection Drug Development I 40

41 MABEL In 2006, administration of a T-cell-activating IP (agonistic anti-cd28 antibody TGN1412, TeGenero) to six healthy volunteers in a phase I clinical trial led to severe side effects (multiple organ dysfunction) caused by a cytokine storm Suntharalingam G et al., Cytokine Storm in a Phase 1 Trial of the Anti-CD- 28 Monoclonal Antibody TGN1412. N Engl J Med 2006;355: The initial dose of TGN1412 was estimated based on the NOAEL observed in nonclinical cynomolgus studies and a safety margin of 500x The observed effects of TGN1412 in humans were not anticipated from nonclinical data Drug Development I 41

42 MABEL It is assumed that different toxicological on-target effects of TGN1412 based on differences of CD28 extracellular domains and inhibitory signalling molecules in cynomolgus and humans were responsible for the effect As a consequence, the EMA published a guideline on the MABEL approach for potential high-risk products EMA guideline: Strategies to identify and mitigate risks for first-in-human medicinal products, EMEA/CHMP/SWP28367/07, July 2007 The TeGenero case had major influence on current FiH study design for IPs with a new/risky mode of action: MRSD calculation based on MABEL Drug Development I 42

43 MABEL Sequential randomisation of subjects Direct access to an intensive care unit in case of emergency Implementation of a data safety monitoring board (DSMB) The MABEL and subsequently the MRSD calculation should be based on a series of relevant in-vitro, ex-vivo and animal disease models to investigate the anticipated minimum human dose which causes the first biological (on-target) effect (e.g. 10% of the maximum effect) in the most appropriate/sensitive model Usually an additional safety margin (e.g. 10x less) for the MRSD needs to be applied for the use in FiH clinical trials Drug Development I 43

44 Toxicology Evaluation with IP Surrogate Equivalent to the use in PD studies, if human IP does not bind to an equivalent animal target, or target is not expressed The model provides supportive information on the expected ontarget effects in humans Disadvantage: the surrogate does not represent the human IP format Normally, additional tox studies with human IP necessary to investigate additional toxicological off-target effects Drug Development I 44

45 Humanised Animals for Toxicology Can be used if the target is not expressed in animals or/and no IP surrogate is available In these animals, parts of the human immune system is transferred (Bcells, T-cells, macrophages, etc.) to mice, expressing now the human target and parts of the downstream immunological response Humanised animals are commercially available but these studies are normally conducted in academic institutions under non-glp Disadvantage: The individual degree of the humanised immune status makes it difficult to obtain consistent data over a larger number of animals However, it might be the only way to obtain relevant toxicity data for an IP which shows a promising anticipated mode of action in patients Drug Development I 45

46 Preclinical Overview Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay MRSD and Dosing Steps Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL IP Lab Scale Toxicological Relevant IP - CMO IMP for Human Use - CMO Drug Development I 46

47 MRSD One of the most important tasks in preclinical development is to determine and justify a first safe human dose or maximum recommended starting dose (MRSD) for the FiH clinical trial FDA guidance for industry: estimating the maximum safe starting dose in initial clinical trials for therapeutics in adult healthy volunteers, July 2005 The MRSD calculation for investigational drugs may be based on: NOAEL from GLP toxicity animal studies in rodents and non-rodents (direct and via human equivalent dose [HED]) MABEL from animal efficacy data MABEL from ex-vivo human blood assay The most appropriate/sensitive approach including an appropriate safety factor should be used for the initial dose in humans Drug Development I 47

48 Dosing Steps and Maximum Dose The FiH clinical trial will most likely include an escalating dose scheme with the MRSD in the first cohort Human dose-response curves can be estimated from pre-clinical efficacy models with different IP dosages Dose steps should be only moderate to avoid inadequate dose increase causing intolerable side effects Exemption: oncology trials Each dosing step in FIH clinical trials should be controlled by a DSMB Maximum dose in FiH clinical trials is dependent on the occurrence of dose limiting toxicities (DLTs) Drug Development I 48

49 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL MRSD based on direct NOAEL conversion from toxicity animal studies with a receptor protein blocking cell-standing Fcγ receptors Drug Development I 49

50 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL Standard safety pharmacological package including respiratory- and cardiovascular function tests in rats and cynomolgus monkeys NOAEL approach mainly based on acute- and two 28-day toxicity studies in mice and cynomolgus monkeys NOAEL achieved in both species with highest dose of 3.0 mg/kg per week Drug Development I 50

51 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL The highest dose was limited to the receptor concentration and feasible injection volume in animals Using the mg/kg approach and a simple 10x safety margin, the MRSD in humans would be: 3.0 mg/kg/10 = 300 µg/kg per week for 4 weeks The NOEL was not achieved due to the formation of ADAs in mice and cynomolgus Drug Development I 51

52 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL/HED MRSD based on NOAEL via HED from toxicity animal studies with the receptor protein This approach is based on the HED in mg/kg based on the body surface ratio between the animal and humans some oncology drugs use directly the surface as dosing, e.g. mg/m 2, without conversion, e.g. B-cell depleting drug rituximab Conversion factors for different species are listed in the FDA guidance on MSRD NOAEL for mice and cynomolgus monkeys is 3.0 mg/kg/week Conversion factors for a 60 kg human based on mice and cynomolgus monkeys is 0.08 and 0.32, respectively Drug Development I 52

53 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL/HED Source: FDA Guidance for Industry: Estimating the Maximum Safe Starting Dose in Initial Clinical Trials for Therapeutics in Adult Healthy Volunteers, July Drug Development I 53

54 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL/HED Source: FDA Guidance for Industry: Estimating the Maximum Safe Starting Dose in Initial Clinical Trials for Therapeutics in Adult Healthy Volunteers, July Drug Development I 54

55 Example: Preclinical Development for a Receptor Protein MRSD from NOAEL/HED Using the body surface approach, the HED would be 0.08*3.0 mg/kg = 240 µg/week from mice and 0.32*3.0 mg/kg = 960 µg/kg/week from cynomolgus monkeys Applying a 10x safety factor to the HED from the most sensitive species result in a MRSD of 24 µg/kg/week for 4 weeks However, it could be also argued that cynomolgus monkeys would be more relevant for MRSD calculation Drug Development I 55

56 Example: Preclinical Development for a Receptor Protein MRSD from MABEL MRSD based on MABEL from animal PD data In-vitro binding studies of the receptor protein with human and mouse IgG revealed a 3-fold less binding affinity for mouse IgG As a consequence, a 3-fold safety factor has to be applied Due to limited budget, no clear dose-response curves of the IP in autoimmune animal studies were established Results from the acute primary immune thrombocytopenia (ITP) animal model revealed a first biological effect for 1.0 mg/kg IP in mice Data from the collagen-induced arthritis (CIA) animal model suggested a first biological effect for 1.5 mg/kg IP in mice Drug Development I 56

57 Example: Preclinical Development for a Receptor Protein MRSD from MABEL Acute ITP mouse model, 20 µg IP CIA mouse model 4 x IP IP (n=15) Control (n=13) PBS 10 µg IP 30 µg IP 100 µg IP A fixed dose of 20 µg IP leads to an inhibition of a induced platelet depletion in the ITP model Several IP dosages were used in the CIA mouse model In comparison to the control (PBS), 30 and 100 µg IP lead to an improvement of the CIA clinical score Drug Development I 57

58 Example: Preclinical Development for a Receptor Protein MRSD from MABEL Taken the differences in binding affinity (3x) and the most sensitive animal PD model (1.0 mg/kg) into account, the expected MABEL would be approximately mg/kg or 333 µg/kg IP Applying a further 10-fold safety factor, the MRSD in humans would be 30 µg/kg IP (rounded) Drug Development I 58

59 Example: Preclinical Development for a Receptor Protein MRSD Summary Model Approach Dose MRSD based on 1/10 Nonclinical GLP toxicity studies NOAEL (direct) 30 mg/kg/week 3 mg/kg/week Drug Development I 59

60 Example: Preclinical Development for a Receptor Protein MRSD Summary Model Approach Dose MRSD based on 1/10 Nonclinical GLP toxicity studies Nonclinical GLP toxicity studies NOAEL (direct) 30 mg/kg/week 3 mg/kg/week NOAEL (HED) 240 µg/kg/week 24 µg/kg/week Drug Development I 60

61 Example: Preclinical Development for a Receptor Protein MRSD Summary Model Approach Dose MRSD based on 1/10 Nonclinical GLP toxicity studies Nonclinical GLP toxicity studies Preclinical animal models NOAEL (direct) 30 mg/kg/week 3 mg/kg/week NOAEL (HED) 240 µg/kg/week 24 µg/kg/week MABEL 300 µg/kg 30 µg/kg Drug Development I 61

62 Example: Preclinical Development for a Receptor Protein MRSD Summary Model Approach Dose MRSD based on 1/10 Nonclinical GLP toxicity studies Nonclinical GLP toxicity studies Preclinical animal models Human full blood ex-vivo NOAEL (direct) 30 mg/kg/week 3 mg/kg/week NOAEL (HED) 240 µg/kg/week 24 µg/kg/week MABEL 300 µg/kg 30 µg/kg MABEL 225 µg/kg 22 µg/kg Drug Development I 62

63 Example: Preclinical Development for a Receptor Protein MRSD Summary Model Approach Dose MRSD based on 1/10 Nonclinical GLP toxicity studies Nonclinical GLP toxicity studies Preclinical animal models Human full blood ex-vivo NOAEL (direct) 30 mg/kg/week 3 mg/kg/week NOAEL (HED) 240 µg/kg/week 24 µg/kg/week MABEL 300 µg/kg 30 µg/kg MABEL 225 µg/kg 22 µg/kg First human dose cohort with 20 to 30 µg/kg IP Drug Development I 63

64 Summary Toxicological Evaluation - GLP Single/Multiple Toxicology Studies NOAEL Assay Development - IP Bioassay for PK - ADA/NADA Assay MRSD and Dosing Steps Phase Ia/Ib Dose Escalation FiM Clinical Trial Preclinical Efficacy - In-vitro Binding Studies - Cell-based Assays - Animal Disease Models MABEL IP Lab Scale Toxicological Relevant IP IMP for Human Use Drug Development I 64

65 Drug Development I 65