Drug Development Overview

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Questions and Answers

What is the average time required for a new drug to go from ideation to market commercialization?

3-5 years

15-20 years

10-14 years (correct)

5-7 years

Which of the following steps is NOT part of the drug development process?

Preclinical studies

Patent application (correct)

Post-marketing surveillance

Clinical trials

What is the primary regulatory authority for drugs in South Africa?

EMA

FDA

SAHPRA (correct)

CDC

What is an Investigational New Drug (IND) primarily used for?

To begin clinical trials Signup and view all the answers

What average cost is associated with research and development for a new drug?

$150 million Signup and view all the answers

What are screening tests used for in drug development?

To select potential compounds Signup and view all the answers

What phase follows clinical trials in the drug development process?

Post-marketing surveillance Signup and view all the answers

Lead finding and lead optimization are important aspects of which stage of drug development?

Preclinical phase Signup and view all the answers

What does the term 'de novo' signify in drug design?

Designing novel compounds from scratch Signup and view all the answers

Which of the following is NOT considered a source of new drug compounds?

Altered genetic material Signup and view all the answers

What characterizes semi-synthetic drugs?

They are derived from natural products and modified. Signup and view all the answers

What is the first step in synthesizing a new drug?

Target selection Signup and view all the answers

What types of conditions have natural products been mainly useful for in drug development?

Infectious diseases and cancer Signup and view all the answers

Which of the following is a benefit of modifying natural compounds in drug development?

Eliminating chemical instability Signup and view all the answers

Which of the following statements about synthetic drugs is accurate?

They are often the most frequent origin for new drugs. Signup and view all the answers

What are drug targets typically composed of?

Functional proteins Signup and view all the answers

What was the initial purpose of developing clonidine?

To treat hypertension Signup and view all the answers

What observation led to the switch of the drug intended for hypertension to treat erectile dysfunction?

Tiny erections in laboratory mice Signup and view all the answers

Who first recognized the potential use of chlorpromazine (CPZ) in psychiatry?

Henri Laborit Signup and view all the answers

What was the effect of CPZ when administered in the dosage of 50 to 100 mg intravenously?

Disinterest without loss of consciousness Signup and view all the answers

What is the aim of preclinical development in drug discovery?

To satisfy requirements for human testing Signup and view all the answers

Which of the following categories does NOT belong to preclinical development?

Clinical trial phase Signup and view all the answers

Why is testing on animals important during preclinical development?

It provides a correlation for drug toxicity in humans Signup and view all the answers

What was one of the applications of CPZ found during Laborit's research?

It helped in artificial hibernation Signup and view all the answers

What aspect does safety pharmacology primarily focus on during drug testing?

Acute hazardous effects of the drug Signup and view all the answers

What is the purpose of preliminary toxicological testing?

To find the maximum non-toxic dose of the drug Signup and view all the answers

In which study is the drug administered for 90 days to monitor changes?

Subacute toxicity study Signup and view all the answers

What is assessed in pharmacokinetic and pharmacodynamic testing?

Relationships between drug exposure and effects Signup and view all the answers

Which of the following is NOT a goal of chemical and pharmaceutical development?

Determining non-toxic animal dosage Signup and view all the answers

What outcomes are observed in an acute toxicity study?

Behavioral changes and LD50 Signup and view all the answers

When is a drug typically administered for 6-24 months in developmental studies?

Chronic toxicity studies Signup and view all the answers

Which of the following parameters is assessed during preclinical pharmacokinetic testing?

Drug's half-life in blood plasma Signup and view all the answers

What characterizes Phase III clinical trials?

They are double-blind and randomized trials conducted on thousands of patients. Signup and view all the answers

Which of the following is typically true about the costs associated with Phase III clinical trials?

They can range from R300 million to R500 million per study. Signup and view all the answers

What is a common challenge faced during Phase III clinical trials?

They can take several years to complete. Signup and view all the answers

What is the primary purpose of submitting a new drug application (NDA)?

To secure licensing for the drug from regulatory authorities. Signup and view all the answers

What is a significant finding about the efficacy of drugs during clinical trial phases?

Some drugs that appear effective in Phase II may show less efficacy in Phase III. Signup and view all the answers

Which of the following best describes the purpose of the dossier submitted for NDA?

It is a detailed compilation of all preclinical and clinical data for the drug. Signup and view all the answers

In terms of patient population, what distinguishes Phase III trials from earlier phases?

Phase III trials typically involve thousands of participants. Signup and view all the answers

What is a potential issue with drug efficacy observed in the different phases of trials?

Efficacy may diminish unexpectedly when transitioning from Phase II to Phase III. Signup and view all the answers

What is the main purpose of developing aromatase inhibitors like anastrozole in breast cancer treatment?

To prevent oestrogen synthesis Signup and view all the answers

What is the primary purpose of high throughput screening (HTS) in drug discovery?

To identify compounds that show activity against a drug target Signup and view all the answers

What does the term 'lead finding' refer to in drug development?

Finding lead compounds with pharmacological activity Signup and view all the answers

Which phase of drug development involves testing a selected compound for efficacy and side effects in humans?

Clinical development Signup and view all the answers

What does the term 'hit' refer to in the context of drug discovery?

A compound that possesses desired activity at a molecular target Signup and view all the answers

Which technology is often used to predict the effectiveness of a potential lead compound?

Computer modeling Signup and view all the answers

What are candidate drug molecules selected based upon in the drug discovery phase?

Their pharmacological properties Signup and view all the answers

What is a typical characteristic of high throughput screening (HTS) in drug development?

It is designed to test large numbers of compounds quickly. Signup and view all the answers

What are 'hits' in the context of drug screening?

Compounds displaying the desired activity at the molecular target Signup and view all the answers

During which stage of drug development are pharmacokinetic and pharmacodynamic analyses typically performed?

Pre-clinical development Signup and view all the answers

What is typically assessed during the clinical trials phase of a new drug development?

Efficacy, side effects, and potential dangers Signup and view all the answers

What role does computational 'prescreening' serve in drug development?

To eliminate compounds with undesirable features Signup and view all the answers

What is one possible drawback of some molecules identified as hits after initial screening?

They may have excessive molecular weight or toxicity. Signup and view all the answers

Which component is not part of the pre-clinical development stage?

Testing in human subjects Signup and view all the answers

What distinguishes the phases of drug development in terms of their typical activities?

Each phase has distinct aims and strategies Signup and view all the answers

What is a major advantage of robot-assisted, high-throughput screening (HTS) in drug discovery?

It speeds up the testing process significantly. Signup and view all the answers

What discovery regarding chlorpromazine (CPZ) did Henri Laborit make during his research?

It produced disinterest without loss of consciousness. Signup and view all the answers

Which aspect of preclinical development involves extensive testing on animals?

Toxicological testing Signup and view all the answers

What led to the reassignment of drug candidates originally intended for treating hypertension to erectile dysfunction?

Observations of an unexpected physiological effect. Signup and view all the answers

What is one of the four main categories of preclinical development?

Pharmacokinetic testing Signup and view all the answers

Which of the following was a notable effect of CPZ when administered at a dosage of 50 to 100 mg?

Minimal sedation with maintained awareness Signup and view all the answers

What was the main reason behind testing chlorpromazine in agitated schizophrenic patients?

It showed promise in reducing agitation. Signup and view all the answers

During preclinical development, why is the correlation between drug toxicity in animals and humans important?

It predicts the drug’s potential side effects. Signup and view all the answers

What role did CPZ have in the context of anesthetic cocktails during its early use?

It helped to lower body temperature. Signup and view all the answers

What is the primary focus of conducting an Ames test in drug development?

To test for mutations in bacterial DNA. Signup and view all the answers

During which study is the drug administered to rodents for their entire lifetime to assess carcinogenic potential?

Chronic toxicity study. Signup and view all the answers

What does the LD50 value represent in drug toxicity research?

The dose that kills half of the animals within a specified period. Signup and view all the answers

What is the significance of performing acute and subacute toxicity studies before starting human clinical trials?

To detect any abnormalities that could affect human safety. Signup and view all the answers

What type of defects are assessed in mutagenesis studies?

Chromosomal breaks and gene mutations. Signup and view all the answers

What typically occurs during the clinical development phases of drug testing?

Initial trials with a small group of healthy volunteers. Signup and view all the answers

What aspect of drug studies might potentially not be revealed until the drug is given to human patients?

Specific adverse reactions due to species differences. Signup and view all the answers

Which statement best describes the role of an Investigational New Drug (IND)?

It initiates clinical trials in human subjects. Signup and view all the answers

What is the main goal of Phase II clinical trials?

To provide a preliminary assessment of drug efficacy and safety in affected individuals Signup and view all the answers

Which aspect is primarily evaluated during Phase I clinical trials?

Pharmacokinetic properties, including half-life and bioavailability Signup and view all the answers

Why might a Phase II clinical trial fail?

It does not demonstrate the expected therapeutic effect Signup and view all the answers

What distinguishes Phase II studies in drug development?

They focus on establishing clinically beneficial pharmacodynamic effects Signup and view all the answers

What is assessed in pharmacodynamics during clinical trials?

The ability of the drug to target specific diseases Signup and view all the answers

How many participants are typically involved in Phase II trials?

Around 100-300 people Signup and view all the answers

What is the objective of assessing tolerability during drug trials?

To identify unpleasant symptoms associated with the drug Signup and view all the answers

What is the purpose of establishing a dosage range during Phase II trials?

To create a dosage regimen for Phase III studies Signup and view all the answers

Study Notes

Drug Development

Drug development is a highly regulated process that can take 10-14 years and cost an average of $150 million per drug.
South Africa's regulatory authority for drugs is SAHPRA (South African Health Products Regulatory Authority).
SAHPRA assesses applications for new drugs before they can be registered and sold in South Africa.

Drug Development Phases

Investigational New Drug (IND): This phase marks the beginning of human testing and requires approval from authorities like the FDA in the USA.
New Drug Application (NDA): Once clinical trials are completed, an NDA is submitted to regulatory agencies for approval to market the drug.

Origins of New Drug Compounds

Natural Products: These compounds are naturally occurring, often derived from fungi or plants, and have yielded significant therapeutic agents like penicillin, streptomycin, and vincristine.
Semi-Synthetic Drugs: Derived from natural products, but modified to improve properties such as chemical stability, oral absorption, or reduce unwanted effects.
Synthetic Drugs (De Novo Drug Design): Most frequent origin for new drugs, these are designed from scratch by computer algorithms, aiming to fit a set of constraints and generate novel molecular entities.

Phases of Drug Discovery

Preclinical Development: Extensive animal testing is conducted to assess the drug's safety and efficacy before testing in humans.
- Safety Pharmacology: Evaluates acute, subacute, and chronic toxicity by testing the drug's impact on behavior, physiology, and tissue samples.
- Preliminary Toxicological Testing: Animal studies determine the maximum non-toxic dose and assess genotoxicity.
- Pharmacokinetic and Pharmacodynamic Testing: Determines how the drug is absorbed, distributed, metabolized, and excreted (ADME) in laboratory animals.
- Chemical and Pharmaceutical Development: Evaluates the feasibility of large-scale synthesis and purification, assesses stability under various conditions, and develops suitable clinical formulations.

Clinical Development

Phase I (Safety): First human trials with a small group (20-80 individuals) to assess safety, dosage, and identify possible side effects.
Phase II (Efficacy): The drug's effectiveness and dose range are evaluated in a larger group (100-300 individuals).
Phase III (Confirmation): Large-scale, randomized controlled trials with thousands of participants across multiple centers to confirm effectiveness, assess long-term safety, and establish appropriate labelling instructions.

Regulatory Approval

New Drug Application (NDA): Once Phase III trials are completed, a detailed NDA is submitted to SAHPRA for licensing.
Drug Dossier: The NDA includes comprehensive preclinical and clinical data, proposed labelling, and intended clinical indications.

Costs of Drug Development

Preclinical Studies: Cost approximately R15-20 million per compound.
Phase I Clinical Studies: Cost around R5-10 million per study.
Phase II Clinical Studies: Cost around R50-100 million per study.
Phase III Clinical Studies: Cost can range from R300-500 million per study.

New Drug Development

Drug discovery involves identifying potential drug molecules based on their pharmacological properties.
Pre-clinical development involves testing the drug in non-human subjects.
- This includes toxicity testing, pharmacokinetic/pharmacodynamic analysis, and formulation studies.
Clinical development involves human testing of the drug.
- The drug is tested for efficacy, side effects, and potential dangers in volunteers and patients.

Stages of Drug Development

High Throughput Screening (HTS) is a process used during drug discovery to screen a large library of compounds against a specific drug target.
- HTS involves testing compounds directly against the drug target and often uses robot-assisted techniques to speed up the process.
- Hits are compounds that display the desired activity at the molecular target.
Preclinical Development is designed to ensure a drug is ready to be tested in humans.
- This involves extensive testing on animals.
Pharmacokinetic studies are conducted to understand how a drug is absorbed, distributed, metabolized, and excreted (ADME) in the body.
Clinical development involves testing the drug in human subjects.
- Phase I trials are performed on a small group of healthy volunteers to assess toxicity, tolerability, and pharmacokinetic properties.
- Phase II trials are performed on a group of patients with the target disease to assess the drug's efficacy and safety, and to establish a dosage range.
- Phase III trials are large-scale, controlled studies that are designed to confirm the drug's efficacy and safety in a larger population.

Synthetic Drugs

Lead finding is the initial stage of synthetic drug development where researchers identify compounds with the desired pharmacological activity and suitability for further modification.
Compound libraries are collections of synthetic compounds used in screening processes.
High throughput screening (HTS) involves the screening of the entire compound library directly against the drug target.
- HTS is designed to run in plates with a high capacity (384 wells or more) to test large numbers of compounds quickly.
- HTS is often used in drug discovery to identify potential "hits."
Computational prescreening is used to eliminate compounds from the library that are likely to be ineffective or toxic.

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Description

This quiz provides insights into the intricate process of drug development, highlighting the phases, regulatory bodies, and origins of new drug compounds. It covers essential concepts including the roles of SAHPRA and the FDA, as well as the distinctions between natural and semi-synthetic drugs.