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1. Introduction and overviews (Suh) 2. Proof of Principle - Cellular model (Tsang) 3. Proof of Principle - Animal model (Tsang) 4. Drug development in pharmaceutical industry (Suh) 5. Anticancer targets and pipelines (Suh) 6. Student seminar 7. Take-home essay 8. Pre-clinical testing (Tsang) 9. Phase I study (Tsang) 10. Case study: Imatinib (Gleevec) (Suh) 11. Invited seminar – institutional review board (5/13, Thu, 9am) 12. 석가탄신일 13~14. Student seminar and current topics 15. Final exam

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- Brief introduction of translational study

- Define a disease and a treatment

- Follow the drug development procedure

- Learn more about individual stages

- Concepts and terminology

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중개연구가 어떻게 시작되었나?

1) Political reason: Tax-payers want to know about the public benefit from scientific investment (국민의 세금으로 지원하는 연구비 사용에 대한 정치적 홍보 효과)

2) Genuine need to facilitate the information flow between scientific discovery and practical application (실패한 신약을 다른 적응증에 대하여 사용 가능. 예: 협심증 치료제 → 발기부전 치료제)

3) Technical advance is not immediately followed by therapeutic achievement (기술 발전 속도 대비 신약 숫자 증가율 저조).

4) Awareness of the discrepancy between animal models and human (사람 질병에 보다 잘 적용되는 동물 모델 개발)

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Molecular target: target identification, target validation (타겟 검증) HTS: high-throughput screening (초고속 스크리닝: 화합물 선별) Hit to lead: hit identification and lead generation

(hit: 활성물질, lead 선도화합물 ) PK: pharmacokinetics (약동력학), PD: pharmacodynamics (약효학) Animal testing: in vivo PK, PD, and toxicology (동물실험, 독성) IND: Investigational New Drug (임상실험 신청) Clinical trial: Phase I, Phase II, and Phase III (sometimes Phase IIa and IIb) NDA: New Drug Application(신약 신청)

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What is a disease? - an abnormal condition of an organism that impairs body function - 유기체의 신체적 기능이 비정상적으로 된 상태

Symptom (증상): - fatigue (피로), anorexia (식욕부진), fever, pain, loss of sight

Sign (징후): - blood cell count, heartbeat, blood pressure, physical exam - skin rash (피부발진) can be both a symptom (observed by a patient) and a sign (observed by a doctor).

Syndrome (증후군): - Presence of one feature alerts the physician the presence of the others - AIDS: acquired immune deficiency syndrome - SARS: severe acute respiratory syndrome

an abnormal experience reported by a patient (subjective)

a medical indication observed by a doctor(objective)

association of several clinical signs and symptoms

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Prevention (예방): - vaccination: polio (소아마비), DTP (디프테리아, 파상풍, 백일해), influenza - antibiotics: anthrax (탄저병, 미국 바이오테러) - antimalaria: chloroquine (말라리아 위험 지역 여행시, 아직 백신 개발중) - cleaning teeth - condom

Treatment (치료): - By matter: drug therapy, gene therapy, hormone therapy, etc. - By energy: chemotherapy, radiotherapy, thermotherapy, etc.

Cure (완치): - cold (감기) : can be cured, but can be caught another time - some cancer and infectious diseases

Remission (진정상태): absence of disease activity of known chronic illness

Relapse (재발): affected by the same disease in the past; "end of remission"

a way to avoid the disease in the first place

alleviates the disease state, and may lead to cure

reverse illness completely to a normal state

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Target is a protein that causes a particular disease state.

- Find a disease. How big is the market? and where?

- Target(s) may be already known.

- If NOT…

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If target(s) of a disease are not already known…

- Genetic and genomic studies from patients give a clue to the suspected gene.

- Studies from knock-out mouse can help understand the role of the gene in the disease.

- Chemical biology and micro-RNA technologies are useful and can support the results.

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Is the protein a viable target?

1) If a new target, (innovative drug)

- The protein exists in human and critical for life? → bacterial and viral proteins are safer to target

- Can it be easily expressed or separated? → in vitro assay possible? or cell-based assay only

- Possible to assay in vitro? (in HTS setting?)

2) If an old target, (me-too drug)

- Are there drugs in market, or in pipelines? (How many?)

- If not, what was the problem?

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Use of 96-well or 396-well plates for screening

Robotic automated system

Employ a compound library (10,000 ~ 100,000)

Quick and dirty: Primary hit compounds are re-synthesized and go through a manual secondary assay.

→ Commercial library may be impure, unstable, or incorrect.

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Build a focused library. → compound derivatives from a hit scaffold

Use of 96-well plates to synthesize diverse compounds

Robotic automated system

Synthesized compounds are applied to secondary assay.

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Medicinal chemists (의약 화학자) draw a compound structure and find a way to synthesize the compound from available precursors.

Sometimes, small change of the structure is useful.

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Medicinal chemists prepare compounds for biological evaluation, that, if active, could serve as lead compounds.

  1950~1980: - Medicinal chemists relied primarily on data from in vivo testing. - They were often the project leaders.

  1980~present: - Emerging technologies, vast information, and complex biology demand multidisciplinary collaboration in drug development.

- high-throughput in vitro screnning - large compound library - combinatorial technology - defined molecular targets (rational design) - structure-based drug design

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  in vitro test - enzyme assay, selectivity - cell-based assay

  Pharmacological test (ADME) - stability (microsomal assay, hepatocyte assay) - permeability: in (transporter) and out (Pgp) - drug interaction (metabolism, protein binding) - plasma protein binding (albumin, globulin, etc.)

  Physical property of the chemical - Lipinski's rule of five - m.w. < 500, LogP < 5, H-bond donor <5

  in vivo test - functional test, secondary test

  Toxicity test - Ames test (mutagenesis) - hERG (sudden cardiac death)

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PK: What the body does to the drug (약동력학)

ADME Absorption (흡수), Administration (투약) - depends on permeability, route of administration Distribution (분포) - route of administration Metabolism (대사) - first pass effect (liver), in vivo stability Excretion (배설) - metabolic modification can speed up excretion.

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by mouth: orally, p.o. (per os), (경구투여)

intravenous: into a vein, iv (정맥주사)

subcutaneous: under the skin, sc (피하주사)

intraperitoneal: injection into the peritoneum, ip (복강주사)

topical: skin patch, inhalation (흡입), eye drop, nose spray, etc.

Each route has advantages and disadvantages.

- Ease of administration (투여의 용이성)

- Efficiency of absorption (흡수 정도)

- Half-life (metabolism and excretion)

- Side effects

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- Bioavailability (F): fraction of an administered drug that reaches the systemic circulation. Absolute bioavailability takes the ratio of the fraction between non-intravenous and intravenous administration.

AUC: Area under the curve

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- Walter Straub (1874-1944) "There is only a quantitative difference between a drug and a poison"

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- Potency: amount (dose) of a drug to produce a given therapeutic effect

. Drug A is more potent than Drug B.

. The same effect can be achieved by smaller amount of Drug A than Drug B

. Measured by EC50: effective concentration at half the maximum effect

- Efficacy: capacity of a drug to produce an effect

. Intrinsic activity, maximum functional response

. Drug A is more efficacious than Drug B.

high dose (large amount)

low dose (small amount)

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Affinity measures the degree of binding between a drug and its receptor.

Efficacy measure the biological signal of the receptor upon drug binding.

Affinity: binding of the drug to the receptor Efficacy: effect of the drug when bound to the receptor

Example: 1. Which drug is more potent? 2. Which drug is more efficacious?

약효 (%)

100

0

50

용량 (mg) 1 10 100

Morphine Codeine

Aspirin

Log 10[drug]

Frac

tiona

l res

pons

e 1.0

0.5

EC50

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-7 -6 -5 -4

Res

pons

e

Full Agonist: E = 100

Partial Agonist: 0 < E < 100

Antagonist: E = 0

log (dose)

Inverse agonist: E < 0

E: % efficacy relative to endogenous ligand

Super agonist: E > 100 실제 우리 몸속에서 만들어진 리간드에 의한 효과를 100% 라고 할때,

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1. enzyme activity

2. cell-based activity

3. selectivity

4. metabolism (CLp)

5. bioavailability

6. drug interaction

Nature Rev. Drug Discov. 3, 853-862 (2004)

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- Examine the efficacy and the toxicity.

- PK and toxicology go hand in hand.

6마리 쥐에 대하여 ip 투여 BALB/c nude mouse 18 days bid: bis in die (twice a day) 15mpk: 15 mg per kg of mouse

Check tumor size and body weight

대조군 6마리 모두 종양생성 처치군 3마리만 종양생성

처치군 1마리 사망 조직병리 분석 및 부검

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- Test safety and efficacy for health intervention (therapy)

- Design 1. Blind: Subjects do not know which treatments they receive

- Double-blind: Doctors do not know then, either.

2. Placebo-controlled: fake-treatment

3. Randomized: Each subject is randomly assigned to receive either the treatment or placebo-control.

IRB: Institutional Review Board

-Ethics board that regulates research using human subjects.

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Phase 0: a micro group (10 to 15 subjects) to get preliminary PK information

Phase I: a small group (20 to 100 subjects) to get PK information - Health volunteers - Dose escalation: tolerance, therapeutic range

Phase II: 20 to 300 subjects to get efficacy information - Patients - Some trials combine Phase I and II, and some have separate IIA and IIB. - IIA: assess dosing requirement - IIB: study efficacy

Phase III: 300 to 3000 or more subjects to get efficacy and side effects - Varying patient groups by sex, age, and other health conditions

Phase IV: - Detect any rare or long-term side effect, and drug misuse. - Approved drug can be pulled out of the market.

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  Discovery: 1-2 yrs, $1-3 million, < 1 % success probability   Preclinical: 3-5 yrs, $3-5 million, 5 %   Manufacturing: 1-2 yrs, $1-2 million, 7 %   IND: 3-6 months, $0.5-1 million, 10 %   Phase I: 1-2 yrs, $1-3 million, 15~25 %   Phase II: 2-3 yrs, $3-6 million, 35~45 %   Phase III: 3-4 yrs, $10-20 million, 65 %   FDA: 1-3 yrs, $4-8 million, 75 %   Phase IV: After market surveillence

* In total: 12-21.5 yrs, $23.5-$48 million ** costs estimated for biotech companies; factor of 5 for Big Pharma *** Reported costs of $ 800~900 million include failed drugs.

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- SBDD: Structure-based drug design

- Virtual screening: screening compounds in silico

- Cheminformatics: mining compound database

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Regulatory Affairs

Project Management

Clinical Research

Process Development

Methods Development

Analytical Chemistry

Discovery

Patents & Trademarks

Preclinical Research

Quality Assurance

Quality Control

Manufacturing Formulation

Development

Sales & Marketing

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- RA: Regulatory Affairs . Documentation works with government

- QA: Quality Assurance . Improve and stabilize the manufacturing process (불량품 예방)

- QC: Quality Control . Keep the quality of manufactured drugs (불량품 제거)

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RA

1. 최적의 개발계획 수립 및 일정 관리 - 관련규정 완전 이해, 정보수집 - 규정변화 예측 및 대응전략 마련

3. 개발 자료의 Quality 확보 및 관리 - GLP/GMP/GCP Compliance - 모든 자료의 문서화 및 보관/관리 (Document Control)

2. 허가기관과의 지속적인 Communication

- 개발 중 regulatory issue 해결 - 허가기관과의 개발 결과 논의/개발 방향 합의 (Pre-IND, End of Phase II, Pre-NDA Meetings)

4. 허가자료의 작성, 검토 및 제출 - IND/NDA, CTX/MAA, DMF - 기시법/안유심, 조건부 품목허가 - 신규물질의 유해성심사, 생산허가

• 효율적인 개발을 통한 신약의 조기 상품화 성공

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•  전임상 / 임상용 샘플의 품질보증 (GMP)

•  안전성 시험의 신뢰성 보증 (GLP)

•  임상시험의 신뢰성 보증 (GCP)

•  FDA / ICH / OECD등의 Regulation 및 Guideline 적용

•  사람 / 시설 / 시스템에 대한 Training / Audit / Review

•  SOP / Protocol / Report / Batch Record / QA Certificate등의 Documentation

GMP/GLP/GCP & Documentation

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분석결과의 신뢰성: GMP & Documentation