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Flashcards in Targeted Therapy Deck (51)
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What does "MAB" mean in the spelling of a medication?

Monoclonal antibody; target will be a cell surface receptor that activates a signaling cascade leading to proliferation


Drug names that end in "ib" indicate what?

The drug is an inhibitor agent of tyrosine kinase receptors



A monoclonal antibody drug

Target: Binds to and down-regulates HER-2 receptor

Effect: Cell cycle arrest

Cancer: Breast cancer


Which drug binds to and down-regulates the HER-2 receptor?



Which drug prevents dimerization of the HER-2 and HER-3 receptors, thereby preventing HER-2 from phosphorylation HER-3? What cascade does it prevent?





Monoclonal antibody drug

Target: HER-2 and HER-3

Effect: Recall that HER-2 dimerizes with and phosphorylates HER-3, and they then promote the PI3K cascade. Pertuzumab prevents formation of the heterodimer.

Cancer: Breast cancer



These drug types contain in their structure both an antibody and a cytotoxic agent. In Sweatman's example, they are binding the EGFR.

1) Antibody action finds the receptor
2) Delivery of a cytotoxic agent to the tumor target, thus minimizing distribution of the native drug throughout the body.



A monoclonal antibody drug

Target: Binds CTLA-4 so that the tumor cell cannot send its B7 to bind. Normally, if B7 binds CTLA-4, the T-cell gets the message that it need to activate and proliferate. Because this antibody drug takes up the CTLA-4 binding site, the only other one open for B7 is CD28, which activates the T-cell, perhaps giving it a chance to attack tumor cells.

Cancer: Melanoma

Interesting note: This drug was the first to utilize active immunotherapy, as opposed to the suppression tactic.


Which drug binds the CTLA-4 receptor on T-cells to prevent B7 (CD80/86) from binding?




A monoclonal antibody drug

Target: Binds to the surface of the transmembrane protein CD20, which is found on precursor and mature B-cells. Recall that CD20 regulates early steps in the activation process for cell cycle initiation and differentiation.

Effect: Binding of the antibody drug produces rapid and sustained depletion of B-cells, lasting for several months. ADCC, apoptosis, and CDC

Cancer: Chronic lymphocytic leukemia and non-Hodgkin's lymphoma


VEGFR pathway normally activated with whom and when?

This pathway is activated in large, solid tumors that are beginning to outgrow their vascular supply. Because the cancer needs increased blood supply to spread, the VEGFR is a great target for monoclonal antibody drugs.


Hypoxia inducible factor-1 (HIF-1) in times of oxygen deprivation

In times of oxygen deprivation, VHL (Von Hippel Lindau) allows this molecule to translocate to the nucleus to promote up-regulation and expression of VEGF and PDGF, which then promotes angiogenesis.

The ultimate result is metastatic tumor spread, proliferation, and survival.


HIF-1 in times of plentiful oxygen

When oxygen levels are sufficient, any HIF-1 produced is sent by VHL (Von Hippel Lindau) to the 26s proteasome complex for degradation.


General Characteristics of MABs

(Route of admin, immunoglobulin on which they're based, general target)

Administered by injection

Large protein structures

Based on IgG

Traditionally target classical proliferative cell surface targets

Ipilimumab, which you'll recall targets CTLA-4, is the first drug to take the approach of immune system activation.


Adverse effects of monoclonal antibodies

Recall that we're targeting mammalian targets, and that these targets, while OVERexpressed in tumor cells, are regularly expressed in non-tumor cells; thus, we see things like:

1) Cardiovascular problems, including CHF and HTN

2) Depletion of cell populations in blood where target is expressed in component of this tissue

3) Infusion related reactions, like anaphylaxis, angioedema, and pulmonary toxicity. To mitigate this issue, give antihistamines and/or corticosteroids.



A monoclonal antibody drug

Target: EGFR-1, HER-1

Effect: Apoptosis, ADCC of cell



A monoclonal antibody drug

Target: EGFR-1, HER-1

Effect: Apoptosis, ADCC


Which two drugs target EGFR-1 , HER-1? Their killing mechanisms?

Cetuximab and Panitumumab

ADCC and apoptosis



Target: VEGF

Effect: Prevents angiogenesis and neovascularization


Which drug targets VEGF to prevent angiogenesis by tumor cells?




Target: CD20

Effect: Apoptosis, ADCC, CDC

Cancer: chronic lymphocytic leukemia


Which drugs target CD20?

Rituximab and Ofatumumab


The ATP-binding site of tyrosine kinases is highly ___________.



T3151 of the ATP binding site

When a tyrosine kinase inhibitor drug is given to a patient, response is initially great…but then we see resistant clones emerge. This is largely due to a mutation in T3151, which prevents binding of first-generation drugs.


Solution drug for the problems that a mutation in T3151 causes?

Ponatinib, a later generation of tyrosine kinase inhibitor.


Whisper in my ear the sweet nothings about tyrosine kinase inhibitors. The good, the bad, the ugly. I want to know it all.

Target binding site?


What do they look like?

How are they taken and metabolized?

They bind in the ol' highly conserved ATP binding domain of the tyrosine kinase receptor

Resistance follows an initial successful response to the drugs; accomplished by kinase over-expression and binding site mutations.

Mutations impact drug binding but do not inactivate kinase function

Small, orally active drugs

Bioavailability can vary depending on food and CYP3A4

The potential for drug-drug interaction is very real.


What do mutations in the ATP binding site of the tyrosine kinase receptor do to the therapeutic window and the dose-response curve?

They change or diminish the therapeutic window, possibly making it impossible to achieve adequate clinical effect without initiating significant adverse effects caused by "off target" actions.

They shift the dose response curve to the right


Are there certain body parts that are especially affected by TKR inhibitors?

Yeah. Make sure to check your patient's thyroid function, bone density, PTH, and vitamin D

If he's a diabetic, monitor blood glucose

If it's a she, warn her about fetal development

If it's a kid, make sure it's growing right, complete with puberty


List some adverse effects of tyrosine kinase inhibitors

Usual uncomfortable effects like N/V, fatigue, and rash

QT prolongation

Blood dyscrasia (this means dat blood fucked)

hand-foot syndrome

Basically anybody who takes these meds is going to look super hawt.




non-small-cell lung carcinoma