Challenges 2

Question 1

Describe clinical trial progression

Answer 1

Preclinical - lead selection
Phase 1 - safe dose in small number
Phase 2 - first evidence of efficacy (high failure & attrition rates)
Phase 3 - product tested extensively (unexpected but costly failures)

Question 2

Describe a prospective trial

Answer 2

Answer specific question
- Measure cause and effect
- Complete & accurate collection of data
Quick meaningful data

Question 3

Describe study population criteria

Answer 3

Representative sample likely to benefit from treatment
- inclusion criteria define acceptable clinical and demographical features
- Exclusion criteria disqualify patients unlikely to benefit or who may be harmed

Question 4

Describe study sizes

Answer 4

Over-estimate effect - too small trials to achieve results
Under-estimate effect - large and financial failures

Question 5

Describe controlled trials

Answer 5

Standard care, placebo, another treatment
Placebos ethically unsound, deceptive and impede a patient’s right to treatment choice
Elicit response that masks drug effect, lessening power of statistical comparisons

Question 6

Describe randomised trial

Answer 6

Random allocation to groups
- Generation of random sequence
- Implementation without patients or investigators knowledge
- Minimises confounding factors and reduces bias - enable accurate statistical comparisons
- Unethical, conflicting with patient needs

Question 7

Describe double-blinded trial

Answer 7

Mask treatment groups from:
- Investigators
- Participants
- Assessors
- Limited to equivalent treatments
- Unethical and result in patient withdrawals & placebo effects

Question 8

Describe trial endpoints

Answer 8

Objective measure
- Well-defined, reliable, easy to detect and interpret
- Survival, disease exacerbation, clinical event, biomarker of disease
Subjective measure
- Clinical or patient scores
- Better reflect quality of life

Question 9

How can choice contribute to clinical trial failures

Answer 9

• Low % events like survival hard to impact
• biomarkers may not correlate with disease
• Scores provide lower quality data & generate greater placebo effect
• Need alternative treatments leads to study withdrawals

Question 10

How does funding differ across countries

Answer 10

Most OECD countries subsidise medicines for the public
Pharmac in NZ spends less on medicines than other countries
Pharmac funds only 30% of medicines available

Question 11

What are the impacts on medicine efficacy

Answer 11

25% struggle to afford prescription medicines
Costs reduce compliance & -> drug efficacy

Question 12

What factors influence cost of medicines

Answer 12

How many are being manufactured/competitors