11 -Pesticides Biologics Monoclonals

Question 1

Drugs vs. pesticides

Answer 1

• Compounds used in vet intended for use against external organism=can be classified as either a drug OR pesticide
• Authorization for sale is granted by Health Canada
  o Drugs=Veterinary Drug Directorate
  o Pesticides=Pest Management Regulatory Agency
  o *regulations are total different
• *look at if it is a DIN or pest control product (PCP) number

Question 2

What are the primary differences for vets when prescribing/selling drugs and pesticides?

Answer 2

• Can’t LEGALLY use pesticides extralabel!
• Need to have label instructions on in=can NOT dispense a partial package
• *why differences: margin of safety and therapeutic window
  o Pesticides are riskier
• DIN vs PCP (pest control product)

Question 3

Why are veterinary DRUG products that have effects on external arthropods/insects not pesticides?

Answer 3

• Systemic absorption!
• NOT just topical effect

Question 4

Veterinary Pesticide examples

Answer 4

• Advantage (Bayer) = pesticide
• Advantage Multi (Bayer) = DRUG (endoparasiticide)

Question 5

Pesticide formulations

Answer 5

• Usually some type of topical administration
  o Ear tags
  o Collars
  o Immersion baths
  o Topical dusts
  o Shampoos
  o Premises application
• *Occupational exposure risks

Question 6

Veterinary biologics

Answer 6

• Covers vaccines, antitoxins, diagnostic test kits and some antibody formulations used to treat/prevent INFECTIOUS diseases in animals
• Regulated by Health Canda, but under the CFIA

Question 7

‘large molecule’ drugs

Answer 7

• Products that have a larger molecular weight than typical drugs based on chemical API
• Can be small peptides or larger protein

Question 8

Examples of ‘large molecules’ drugs

Answer 8

• Hormones (ex. insulin, GH)
• Colony-stimulating factors (G-CSF)
• Antibodies
• Enzymes

Question 9

‘large molecule’ drugs can be produced by

Answer 9

• Harvesting natural sources (ex. porcine pancreatic enzymes)
• Recombinant technology (ex. derived from bacteria genetically modified to overproduce the protein)
  **generally MUCH more EXPENSIVE to synthesize than traditional (small molecule) drugs

Question 10

Monoclonal antibodies

Answer 10

• Any drug name with ‘vetmab’ at the end
• Antibodies produces synthetically with extremely high specificity for a specific antigen
• Not produced by B cells or plasma cells in the host animal

Question 11

How are mAbs different from ‘regular’ antibodies?

Answer 11

• More precise replicas (a clone of a single antibody)

Question 12

Can the same monoclonal antibody be given to multiple species?

Answer 12

• No, structure of target antigen differs slightly between species
• Ex. Y structure
  o Fab ‘arms’ (antigen binding fragment
  o Fac ‘stems’ (crystallizable structure)

Question 13

What do monoclonal antibodies target?

Answer 13

• All sorts of antigens!
  o Bind to and inactivate the protein/receptor
  o Can lead to apoptosis in certain cases

Question 14

What are some specific targets for mAbs?

Answer 14

• Growth factors
• Cytokines (ex. IL-31)
• Antigens on tumor cells (human mAbs)

Question 15

How are mAbs administered?

Answer 15

• Since they are proteins=parenteral injection (SC in vet med, IV for some humans)
• NOT orally

Question 16

Why can mAbs NOT be administered orally?

Answer 16

• They are proteins!
• *need them intact otherwise they will not work

Question 17

How long is the mAb effect?

Answer 17

• Tends to last one month (low clearance (metabolism))
• Can have chemical moieties attached to decrease the rate of clearance (increase half-life)
  o Ex. PEGylated proteins with Polyethylene Glycol attached

Question 18

Is there a risk of host immune response if mAb is repeatedly administered?

Answer 18

• Not so far