Cell-Based Therapeutics

Question 1

regulated therapies

Answer 1

cultured cells
sorted cells
cells in 3D scaffolds
engineered cells

Question 2

non-regulated therapy example

Answer 2

injecting bone cells into bone

Question 3

criteria to be unregulated
all answers must be YES

Answer 3

1) minimally manipulated
2) homologous use
3) HCT/P combined with device or drug that is sterilizing, preserving, or storage agent?
4) the HCT/P does not have a systemic effect and is not dependent upon the metabolic activity of living cells for its primary function

Question 4

types of cell-based therapies

Answer 4

stem cell products
immunotherapies

Question 5

stem cells and stem cell derived products

Answer 5

do not involve immune cells
stem cell therapy is unspecialized, self-renewal, and pluripotency
example –> stem cell transplantation

Question 6

immunotherapies

Answer 6

involves immune cells
example –> cancer vaccine and cell-based immune therapies (can be naive or gene based); CAR-T

Question 7

components of a CAR-T terapy

Answer 7

CAR –> chimeric antigen receptor (gene)
T –> T cells
cells are removed, genetically engineered, expanded and delivered back to the patient (who are pre-conditioned with chemotherapy to restrain immune response)

Question 8

autologous cell-based therapy

Answer 8

cells from your own body
no graft vs host disease
higher doses feasible
harder to source, immune-compromised

Question 9

allogenic cell-based therapy

Answer 9

cells from a different donor
easier to source, off the shelf
can induce graft vs host disease and/or immune response

Question 10

What are some problems you might think could arise when developing drugs that target a single tumor antigen?

Answer 10

on target, off tumor effects (cells target the correct antigen but one expressed on tissues other than the target cancer, results in severe toxicities)
fratricide (cells target an antigen that is expressed on themselves)

Question 11

What are the main safety issues associated with cell-based gene therapies?

Answer 11

tumor evasion
neurotoxicity due to immune cell activity (potentially fatal)
cytokine release syndrome (CRS)
graft vs host disease
toxicity assocaited with viral genomic DNA (if viral CARs are used)
persist for an extended period and produce a sustained effect –> increases/prolongs ADRs

Question 12

tumor evasion

Answer 12

escape of cancer cells from recognition and killing by immune cells resulting in clinical resistance to treatment
tumor antigens are not recognized by immune response –> poorly immunogenic
tumors are resistant to or inhibit immune cytotoxic responses

Question 13

how to prevent cell persisting /sustained effect

Answer 13

engineering of suicide switches

Question 14

What are two reasons why cell-based therapies have been more successful (and approved by the FDA) for blood cancers, but not solid tumors?

Answer 14

solid tumors –> heterogeneous and have immunosuppressive factors (metabolites, soluble molecules)
immune cells –> infiltration is low, in solid tumors they are dysfunctional

Question 15

What is one way to clinically mitigate or manage cytokine release syndrome?

Answer 15

avoid steroids (could impact CAR-T cells)
antibodies against toxin and cytokines (IL6)
use cells that induce no or limited CRS (NK cell)
through hemofiltration (to filter out cytokine)

Question 16

drug substance

Answer 16

gene vector (engineered molecular component)
example –> CAR or gene

Question 17

drug product

Answer 17

cryopreserved engineered cell (immune cell and gene)
example –> CAR-T/NK cells

Question 18

ADCC

Answer 18

antibody dependent cell-mediated cytotoxicity
when an antibody interacts with CD16 on NK cells to stimulate activation to kill

Question 19

potential risk of cell-based therapies

Answer 19

graft vs host disease disease
cytokine release syndrome

Question 20

graft vs host disease

Answer 20

arise when patients infused with exogenous cells or transplanted with donor tissue recognize these transplants as foreign and react unfavorably

Question 21

cytokine release syndrome

Answer 21

systemic inflammatory response
results in the release of a high number of pro-inflammatory cytokines that attack the patient’s immune system

Question 22

lymphodepletion

Answer 22

chemotherapy to prime patient for cell transfer by weakening the immune system to avoid rejection
the process of removing immunosuppressive subsets of immune cells (like Tregs) from the patient

Question 23

common agent used in lymphodepletion

Answer 23

fludarabine

Question 24

fludarabine

Answer 24

inhibits DNA polymerase (thus synthesis)
immune cells accumulate F-ara-ATP (the active metabolite) –> makes them sensitivite to lymphodepletion
dosed as > 25-40 mg/m^2

Question 25

ADME of cell therapy in comparison to small molecule drugs

Answer 25

cells are not secreted but remain in the system long term --> divide inside recipient

Question 26

challenges with CAR-T manufacturing

Answer 26

sterilization of final product not possible (aseptic processing key) patients are very sick (so they need product quickly) cell variability requirements cannot always be met donor cells cannot always expand optimally, cells are exhausted complex logistics --> freeze/thaw necessary mulitiple times

Question 27

centralized cell therapy manufacturing

Answer 27

PROS --> easier to scale up, central process control and batch records, lower material cost CONS --> complex logistics, longer time to patient, product must be frozen

Question 28

decentralized cell therapy manufacturing

Answer 28

PROS --> quicker, closer to consumer; process is ready for infusion and dose not need to be shipped CONS --> cannot be scaled up; costly

Question 29

cryopreservation

Answer 29

example agent --> DMSO (most commonly used) process of freezing of the cell therapy drug product required as cell therapy products cannot be lyophilized easily enables shipment and storage of the drug product prior to administration

Question 30

Tocilizumab (IL6)

Answer 30

drug commonly use to mitigate cytokine release syndrome

Question 31

extracellular region of CAR

Answer 31

antigen binding domain that binds to cancer cell

Question 32

naive cell therapies

Answer 32

unmodified immune cells (TILs, hematopoietic stem cell transplants) just give cell to patient, no engineering

Question 33

How can immune cells be redirected to attack pathogens?

Answer 33

through engineering synthetic receptors that can recognize antigens present on specific cancers releasing proteins (cytotoxic granules) that kill target cells

Question 34

types and sources of cell-based therapies

Answer 34

peripheral blood core blood cell lines induced pluripotent stem cells

Question 35

peripheral blood characteristics

Answer 35

autologous transfer patient-specific 10% NK/T cells

Question 36

core blood characteristics

Answer 36

allogenic can be cryopreserved 30% NK/T cells

Question 37

cell lines characteristics

Answer 37

commercially available allogenic not like human cells

Question 38

induced pluripotent stem cells characteristics

Answer 38

allogenic through gene editing can be cryopreserved off the shelf

Question 39

types of adoptive cell-based immunotherapies

Answer 39

donor matching native immune cells (activated) TIL (tumor infiltrating lymphocytes) TCR (T-cell receptors) CAR-T or CAR-NK

Question 40

donor matching adoptive cell-based immunotherapies

Answer 40

either haploidentical (half matched so mom, dad, child) or HLA-matched (fully matched so siblings, unrelated, or core blood)

Question 41

native immune cells (activated)

Answer 41

kill cancer without antigen dependent natively expanded outside of the body can be engineered with CARs or infused after expansion without engineering participate in ADCC, T cells do not generally do not cause CRS (unlike T cells) no rejection

Question 42

TIL (tumor infiltrating lymphocytes)

Answer 42

lymphocytes that have infiltrated a tumor and can recognize specific antigens mostly CD8+ T cells which can produce cytokines and mediate tumor killing extracted from the tumor and reinfused back into the patient after expansion

Question 43

how are genes most commonly engineered into cells?

Answer 43

through viruses because they have highest efficiency, are permanent, and potentially toxic

Question 44

basic structure of CAR-T cell therapies

Answer 44

extracellular antigen binding domain, transmembrane domain, and intracellular/costimulatory domain

Question 45

role of extracellular antigen binding domain

Answer 45

bind to cancer cell

Question 46

role of transmembrane domain

Answer 46

anchor and orientation to facilitate interaction with T cell surface proteins

Question 47

role of intracellular/co-stimulatory domains

Answer 47

send cytotoxic/killing/activation signals

Question 48

first two FDA-approved CAR-T cells therapies are targeted against blood cancer

Answer 48

Leukemia Lymphoma

Question 49

how is CRS commonly treated?

Answer 49

with IL-6 antibody