Exam 2 Stuffs Flashcards
1
Q
Neutropenia = neutrophil count below ____ cells/mm^2
A
1800
2
Q
2 major dose-limiting side effects of chemo
A
Neutropenia and infection
3
Q
What percentage of circulating erythropoietin is produced by the kidneys?
A
90%
4
Q
What 3 things can have a major impact on neutrophil count and can lead to neutropenia?
A
Chemotherapy
Concomitant therapy
Decreased renal function
5
Q
What is hemostasis?
A
blood clot formation
hemo = blood
stasis = standing still
6
Q
3 steps of hemostasis
A
Formation of the platelet plug
Activation of the clotting cascade
Propagation of the clot
7
Q
Hemophilia A has a deficiency of what factor?
A
VIII (8)
8
Q
Hemophilia B has a deficiency of what factor?
A
IX (9)
9
Q
Another name for erythropoietin?
A
epoetin alpha
10
Q
How many AA residues does erythropoietin (epoetin alpha) have?
A
165
11
Q
What is the MW for erythropoietin (epoetin alpha)?
A
30.4 kDa
12
Q
How many disulfide links does erythropoietin (epoetin alpha) have?
A
2
13
Q
Erythopoietin (epoetin alpha) glycosylated or not?
A
glycosylated
14
Q
Temperature for storage of erythopoietin (epoetin alpha)
A
2-8 degrees Celsius
15
Q
Epogen generic name
A
epoetin
16
Q
Neupogen generic name
A
filgrastim
17
Q
Neupogen glycosylated or not?
A
Non-glycoslylated
18
Q
Filgrastim is a G-CSF - what does this mean?
A
granulocyte colony stimulating factor
19
Q
MW for filgrastim
A
18.8 kDa
20
Q
Which drug is not glycosylated unlike the naturally occurring human G-SCF
A
Filgrastim
21
Q
Vd of Filgrastim
A
150 mL/kg
22
Q
Half-life of Filgrastim
A
3-4 hours
23
Q
In the 1970s, what impact did interferons (IFNs) have on the influenza virus?
A
Interfered with it
24
Q
What kind of molecule are interferons?
A
Pleiotropic cytokines
25
Which drug has diverse immunomodulatory properties?
Interferons
26
IFN alpha comes from ___
leukocytes
27
IFN J comes from ___
fibroblasts
28
IFN psi (greek letter that looks like pitchfork) comes from ___
activated T-lymphocytes
29
What was the first human protein that demonstrated an increase in survival of cancer patients?
Interferons
30
What effects do interferons have?
Antiviral effects
Antitumor effects
Positive effects in multiple sclerosis
31
Pig and human insulin differs by ___ amino acids
1
32
Bovine and human insulin differs by ___ amino acids
3
33
What molecule started as purified extracts from animals?
hormones
34
How many peptide chains do somatotropic hormones have?
1
35
How many peptide chains do glycoprotein hormones have?
2
36
How many peptide chains do pro-opiomelanocortin (POMC) derived hormones have?
1
37
Which types of hormones have the smallest molecular weight?
POMC-derived hormones
38
Which type of hormones have the largest molecular weight?
glycoprotein hormones
39
Which type of hormones have carbohydrates in them?
Glycoprotein hormones
40
What are examples of somatotropic hormones?
```
Growth hormone (GH)
Prolactin (Prl)
Placental lactogen (PL)
```
41
What are examples of glycoprotein hormones?
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Chorionic gonadotropin (CG)
Thyroid-stimulating hormone (TSH)
42
What are examples of POMC-derived hormones?
```
Corticotropin (ACTH)
alpha melanocyte stimulating hormone
beta melanocyte stimulating hormone
beta lipotropin
gamma lipotropin
```
43
What types of hormones were used in the pre-recombinant era?
Somatotropic hormones
Glycoprotein hormone
POMC-derived hormones
44
Downfalls of animal-extracted hormones
Contamination with other animal proteins
Risk of immunological side effects
Not all animal hormones have high homology with the human counterpart
45
Downfalls of human-extracted hormones
```
Scarcity
Safety concerns (creutzfeldt-jakob disease)
```
46
HumulinR/Humalog
| Which is fast-acting?
Humalog (lispro)
47
HumulinR/Humalog
| Which is regular insulin?
HumalinR
48
Difference between human insulin and insulin lispro
2 amino acid difference
| Lys and Pro AA's are switched (aka why it was named was it was)
49
HumalinN
| Long-acting or fast-acting?
Long-acting
50
Humalog Mix 75/25
| Long-acting or fast-acting?
Both!
51
Insulin Glargine
| Long-acting or fast acting?
Long-acting
52
Amino acid difference between insulin glargine and human insulin?
3 amino acids
53
NPH insulin
| Long-acting or fast acting?
Long-acting
54
MOA of NPH insulin
suspension that gradually dissolves and absorbs into the body from the formulation
55
MOA of insulin glargine
solution that precipitates upon injection and forms a depot
56
NPH or insulin glargine
| Has a peak on the glucose utilization rate graph
NPH
57
NPH or insulin glargine
| Does not have a peak on the glucose utilization rate graph
glargine (steady absorption)
58
Isoelectric point definition
pH value at which a protein has no net charge
| aka is "zwitterionic"
59
At what point is the solubility of a protein at its minimum
isoelectric point
60
Why does insulin glargine precipitate when injected?
It is least soluble in the neutral pH, so it precipitates into a hexamer under physiological conditions
61
What pH is native insulin least soluble?
5.4
62
What pH is insulin glargine least soluble?
7
63
Insulin in solution exists in equilibrium between what 3 configurations? Why is it like this?
monomer
dimer
hexamer
This helps to maintain stability of the protein
64
What ion is in the middle of a hexamer of insulin, stabilizing it?
zinc
65
Which insulin configuration is the most vulnerable to unfolding and denaturation?
monomer
66
Which insulin configuration acts at the receptor site?
monomer
67
Which insulin configuration is the most stable?
Hexamer
68
What ion serves as an anchor in the formation of the insulin hexamer formation and stabilizes insulin?
zinc
69
What pH is insulin glargine formated at?
4
70
How long does it take for the insulin glargine depot to dissolve?
~24 hours
71
Importance of enzymes
- biologic catalysts
- capable of accelerating chemical rate reactions by a million-fold
- they are proteins
- essential for viability of cells and tissues
72
How many enzymatic reactions have been reported and how many proteins with enzymatic activity have been reported?
over 1,000
| over 10,000
73
Deficient enzyme activity in metabolic pathways may produce what?
clinical symptoms
74
What can adenosine deamidase be used to treat?
severe combined immunodeficiency
75
what can glucocerebrosidase be used to treat?
gaucher's disease (glycolipids in lysosomes)
76
What can DNAse be used to treat?
Cystic fibrosis
77
What molecule consists of four chains of amino acids joined by disulfide bonds
antibodies
78
another name for antibodies
immunoglobulins
79
variable region of an antibody
Fab
80
constant (fixed) region of an antibody
Fc
81
What region of the antibody determines what class the antibody is from?
Fc region
82
What are the different classes of antibodies?
```
IgG
IgM
IgD
IgA
IgE
```
83
True or false
| Fc region of all antibodies of a certain class (e.g. IgG, IgM, etc) are the same
True
84
Which antibodies exist only as monomers?
IgG
IgE
IgD
85
Which antibody exists as a pentamer?
IgM
86
IgM has a _____ located in the middle of the pentamer
J chain
87
What is a J chain
polypeptide joined to the IgM pentamer by disulfide bonds
88
Which antibody exists as a monomer or dimer (in excreted fluids)
IgA
89
How does the Fab region of an antibody bind to an antigenic determinant
selectively
90
What is antibody specificity
When an antibody coded for one antigenic determinant will bind to that determinant and no other
91
Another term for antibody specificity
lock-and-key
92
What is the first immunoglobulin made to fight a new infection?
IgM
93
What immunoglobulin is produced that is more specific for the infecting antigen?
IgG
94
mab naming
| a
rat
95
mab naming
| axo
rat/mouse
96
mab naming
| e
hamster
97
mab naming
| i
primate
98
mab naming
| o
mouse
99
mab naming
| u
human
100
mab naming
| xi
chimeric
101
mab naming
| xizu
chimeric-humanized
102
mab naming
| zu
humanized
103
Antibody half-life in circulation
days
104
What are among the most stable natural proteins?
Antibodies
105
Most proteins have a half-life of ___
minutes
106
Stability of IgG is comparable to what?
serum albumin
107
How are therapeutic antibodies administered?
Subcutaneously (so they are high in concentration)
108
Implications of therapeutic antibodies
- pharmacokinetics
| - difficulty and pain associated with administration
109
Antibodies are big or small?
BIG (>100 kD)
110
Antibodies are mainly absorbed into what?
lymphatic system
111
Molecules with MW <5 kD are absorbed into what?
Capillaries
112
Molecules with MW >100 kD are absorbed into what?
Lymphatic system
113
Liposomes and nanoparticles up to 200 nm are absorbed into what?
lymphatic drainage
114
As the concentration of mabs increases so does ___
viscosity
115
therapeutic mabs are usually ____ concentration
high
| >100 mg/mL
116
What does the high viscosity of mabs cause during administration?
difficulty in syringability
long administration times
increased pain perception upon administration
117
Biopharmaceutical definition
biologic produced by a living system that has been genetically engineered
118
Examples of biopharmaceuticals
mab's
therapeutic proteins
vaccines
119
What are biopharmaceuticals composed of?
proteins
glycans
polyneucleotides and lipids
120
Which antibodies have the lowest immunogenic risk of generating anti-therapeutic antibodies (ATAs)?
Fully humanized mab's
121
Which antibodies have the highest immunogenic risk of generating anti-therapeutic antibodies (ATAs)?
murine (mouse) mab's
122
Which buffer has a large pKa range?
Phosphate (2.1, 7.2, 12.4)
123
What are examples of protein stabilizers?
sucrose
trehalose
mannitol
sorbitol
124
Why is freezing a stress to biologics?
Proteins interact with the surface of ice, which loosens the native structure
125
Biologicals (like peptides and proteins) are stable or unstable molecules?
unstable!
126
What structure of a protein involves amino acid sequence and all covalent modifications, except disulfide bonds
Primary structure
127
What structure of a protein results from hydrogen bonding, electrostatic interactions, van der waals forces, etc?
Secondary structure
128
What structure of a protein results from intramolecular interactions?
Tertiary structure
129
What protein structure involves inter-molecular interactions between more than one protein chain?
Quaternary structure
130
Examples of covalent bonds
Peptide bonds of backbone
| Disulfide bonds
131
Examples of electrostatic interactions
charge-charge
charge-dipole
dipole-dipole
*HYDROGEN BONDING*
132
Polar interaction examples
aromatic-aromatic
| oxygen or sulfer-aromatic
133
Polar interactions are strong or weak?
Weak
134
Hydrophobic interactions usually occur where?
core of proteins
135
What are hydropphobic interactions driven by?
unfavorable interactions with water
136
What type of interaction is van der waal forces?
hydrophobic
137
What does solvation require?
hydration
138
Definition of physical instability
changing in the physical structure of the protein that can occur through several different pathways
139
Pathways of physical instability
Denaturation
Aggregation
Precipitation
Surface adsorption
140
What is degradation of the globular protein structure - unfolding
denaturation
141
what is it called when proteins clump into inactive multimeric units by association of hydrophobic surfaces, or other attractive forces for association?
Aggregation
142
What is macroscopic aggregation into large particulates called?
Precipitation
143
What is it called when a protein adsorbs on the surface of a glass vial and denatures?
surface adsorption
144
Synthesis for large peptides is ___ and ___ to perform in large quantities
expensive
| difficult
145
True or false
| Proteins can be readily produced by cells
True! They are natural products
146
What allows for mass production of protein?
Transfecting a gene into a cell
147
Advantages of recombinant protein production
Relatively inexpensive process
Ease of maintaining cell cultures
Relies on well defined molecular and cellular biology
148
Where are biologics generated from?
biological source
149
Different pathways of biologic production
Microbial
Mammalian
Plant
Gene therapy
150
What do human proteins often have?
Post-translational modifications (PTMs)
151
True or false
| Bacteria provide post tranlational modification
False!
152
What can be used to generate post translationally modified protein?
Chinese Hamster Ovary (CHO)
COS
Baby hamster kidney cells
Yeast cells
153
What can post-translational modification be important in?
Immunogenicity
| Pharmacodynamics
154
What is a fusion tag?
When a peptide/protein epitopes are added to a protein
| ***sequence must not be similar to that of the cell
155
What do fusion tags do?
Can help with immunopurification
156
Affinity purification concepts in relation to fusion tags
- you have to make sure the epitope tag does not interfere with protein function
- since the tag is foreign, it may induce immunogenic response in humans
- Enzyme cleavage sites before the tag can enable removal of epitope
157
Does E.coli add Post translational modifications?
No
158
The generation of proteins at a larger quantity requires what 2 things?
vectors
| appropriate cell models for functional yields
159
Some proteins require difficult purification steps which can affect what?
yield
160
What is one way to improve purification through affinity chromatography?
epitope tagging
161
True or false
| The protein must be in the native form after it is purified?
True
162
After protein purification, why is the protein so unstable?
It is out of its cellular environment
163
What should be included in formulations that proteins are stabilized in?
as little as possible!
Buffering agents
essential excipients
protein
164
What do polyols do to help stabilize biosimilars?
they have multiple alcohol moeities that create preferential hydration
165
What do metal chelators do to help stabilize biosimilars
bind metals that might cause oxidative stress or induce instability due to metal binding to the protein
166
What do amino acids do to help stabilize biosimilars?
they can be added to act in a case by case manner to increase stability
167
What do surfactants do to help stabilize biosimilars?
in low concentrations can increase solubility and prevent film formation
Can be toxic in pediatric indications!!!
168
What do phospholipids and fatty acids do to help stabilize biosimilars?
They can stabilize proteins through stoichiometric binding or by forming liposomal liek structures
169
What do antioxidants do to help stabilize biosimilars?
they can be used to prevent oxidative damage to met, protect disulfide bonds, and potentially stabilize a protein
170
What does albumin do to help stabilize biosimilars?
possesses fairly high stability
Can prevent aggregation and surface adsorption on glass
Bad - Can carry blood born pathogens and prions
171
Buffer capacity definition
magnitude of the resistance to pH changes that a buffer exerts
172
Protein formulations require ____ buffer capacities to resist pH changes
HIGH
pH can affect both chemical and physical stability!
173
Immunogenicity definition
property of being able to evoke a humoral or cell-mediated immune response
Includes both antigens and allergens
174
Immunogenic reaction examples
-Severe allergic or anaphylactic response
Reduction of efficacy
-induction of autoimmunity to endogenous proteins
175
True or false
| The relationship between antibody formation adn clinical outcome is always direct and quantative
FALSE
176
True or false
The risk and benefit of antibody formation on the drug’s safety, efficacy and PK/PD parameters must be assessed and weighed against the benefits of therapy.
True
177
True or false
| Immunogenicity is a risk that needs to be evaluated with biologics
True
178
True or False
| Immune responses will be product and indication dependent
True
179
True or False
| Immunogenicity may affect efficacy
True
180
True or False
| Immunogenicity is predictable
False!
181
Immunogenicity can often result in ______ effects on the patients
Little to no
182
Biosimilar drug issues
Cellular and expression system critical
Post-translational modification
Cell extraction of protein is required
Cell purification is required
183
Stability of biosimilar drug issues
Physical/structural instability
Chemical instability
Enzymatic stability
184
Formulation issues with biosimilar drugs
Excipient choice depends on the route of administration and is carefully optimized for clinical use
185
True or false
| Immunogenicity is very important
True
186
How should biosimilars be handled
VERY CAREFULLY
