Drug Approval Process Flashcards
How does the approval of cancer drugs differ from other types of drugs?
- They can be approved on the basis of Surrogate end products (made up goals)
- They don’t have to cure cancer they just have to stop it
Why might data for the side effects of drugs be incomplete?
- Average amount of time used to determine drug side effects is 6 months so you don’t get an idea of the long term side effects of taking a drug
What kind of patients are used in phase I clinical trials?
Phase I trials
T or F: many trials don’t compare the drug to a gold standard and just use a placebo instead
True, they don’t want you to know that the new drug is worse than the old drug
What is an orphan drug?
Drug that would be used by so few patients that is would never be made if it weren’t for FDA help (incentive)
**Any drug for a target of less than 200,000 ppl
T or F: OTCs reduce cost, but the cost then shifts from the HMO to the consumer.
True
What Milestones in drug regulation were met in:
- 1906
- 1938
- 1962
1906:
- Drugs were no longer allowed to be mislabed or adulterated (PURITY was the goal)
1938:
- Required SAFETY in addition to Purity
1962:
- Drugs need to be EFFECTIVE, SAFE, and PURE
What group of drugs is approved solely on the basis of animal testing?
Anti-Bioterrism Drugs
Why should you be very cautious about prescribing a new drug?
1/5 of approved drugs will be pulled from the market due to toxicity issues
What are the 4 general phases of making a drug?
In vitro studies (0-2 years):
- A library of similar compounds is made and tested
Animal Testing (2-4 years): - Efficacy Selectivity we just want to see if it works in animals
Clinical Testing (4-8 years): - Clinical Testing (phase 0 - phase 3)
Marketing:
- Phase 4 “trials”
After what phase can drugs fill out their new drug application?
After clinical Testing - this takes 8-9 years to get to this point meaning it only has 11-12 years left before generics can compete.
What happens during phase 0 of the clinical trials?
Drugs in this day and age have a defined target and we want to see how well it hits that target
**Measure relationship between dose and target
How many chemical entries are submitted to get 1 drug candidate?
- what are the variations exist among these entries?
5,000 to 10,000 entries to get one drug
- Change pks, metabolism, solubility, route of delivery etc.
Before moving to human trials what is the goal?
- Keep it simple and cheap
- Use less animals
- Keep the amount of drug that needs to be synthesized down to a minimum
What is the difference for 1st in class drugs and Follower drugs as far as targeting to specific receptors goes?
First in Class drugs:
- we look more at outcome - is the patient getting corrected to the right phenotype
Follower Drugs:
- We start looking at How well the Drug is binding to the RECEPTOR
How have drug companies changed their minds about potency and efficacy?
- what do they now do to ensure drugs work?
Old Way:
- Make a compound with the highest potency and wait until off on animal trials to look at pharacokinetics
New Way:
- Use RAPID ADME-TOX assays to assess solubility, Absoption (artificial membranes), and Metabolism (Hepatocytes or Microsomes)
How can we look at how much a molecule will interfere with CYPs without using an animal?
Put 3-5 compounds on an HPLC column loaded with CYP proteins to see what drugs interact most strongly
What are Herg Channels?
- how do we test for interactions here?
Herg Channels are the K+ channels of the Heart
- Terfenadine was a drug put on the market before this testing was done and had to be pulled back off (Costed the company tons of money)
What is the general trend if you’re trying to determine any sort of toxicity or carcinogenicity in the drug you’re trying to get approved?
- Time needed for tests?
- You need to Test it in 2 different species
Acute Toxicity - (2 diff. routes)
Sub-Acute Toxicity - (1-3 months of dosing)
Chronic Toxicity - (more than 6 months of dosing)
Carcinogenicity - (2 years)
Mutagenicity - done with an Ames test in a rat (so I guess only one species needed)
How long does the FDA have to review paperwork for a drug once its sent in?
30 days
aka IRB application approval
When is the only time you’ll see sick patients in a Phase I clinical trial?
If its a cancer drug
*Cancer patients who have failed other treatments may are allowed to enter these trials
Phase I clinical Trial:
- Purpose?
- People used?
- Size?
Purpose:
- Find the Minimum Toxic Dose
People Used:
- Healthy adult volunteers
Size:
- Small 10-15 adults (or 20-100 according to his chart)
Phase II clinical Trials:
- Purpose?
- Dosing?
- People used?
- Size?
Purpose:
- See if it fixes the illness in humans, Try to figure out dosing and pharacokinetics in humans
Dosing:
- START at the Minimum Toxic Dose from the First trial
People Used:
- People affected by the disease of interest
Size:
100-200 patients
**Note if it doesn’t work in the first 14 pts. Statistics say that there is more than a 95% chance that the drug won’t work
Phase III clinical Trials:
- Purpose?
- Dosing?
- People Used?
- Size?
Purpose:
- Compare the drug to a placebo and see if it works
- Eliminate any bias
(this stage is make or break, do benefits outweigh risks?)
Size:
1000-6000 pts.