Cancer 2 Flashcards
Name a drug that targets EGRF mutation [2]
Gefitinib or erlotinib
Tyrosine kinase receptors:
Name 4 key antibody targets that are GF receptors and / ligands
Epidermal growth factor receptor (EGFR)
HER2 (no ligand)
HER2/3 (ligand: HER2 can bind to HER3 – activates different pathway)
Vascular endothelial growth factor (VEGF)
State difference in antibody and small molecule kinase inhibitors
Antibodies:
* high selectivity
* targets are often restricted to the cell surface
* require intravenous or subcutaneous dosing because of their large molecular weight
* Can be conjugated to cytoxic drugs
Small molecule kinase inhibitors:
* vary in selectivity
* Oral
* Bind- ATP binding sites
* Can potentially bind a wider range of extracellular and intracellular targets (> one kinase)
Describe the mechanism of antibodies [2] and SMKI [1]
Antibody:
* Produce antibodies that target extracellular part of tyrosine kinase receptor
* Inhibits ligand binding or causes the ligand to bind in an area that doesn’t cause dimerization
SMKI:
* Binds to ATP binding pocket & intracellular-P cant occur
State the overall three mechanisms of monoclonal antibodies [3]
Killing tumour cell directly
Killing tumour cells via an immune-mediated mechanism
Vascular or stromal ablation: VEGF antagonsim
Describe mechansim of trastuzumab emtansine (Kadcycla)?
Kadycycla is formed from the conjugate binding of Herceptin with DM1, which is an anti-microtubule agent
Drug is taken up by lysosome.
Within the lysosome: herceptin and DM1 dissociate and are released into cell
DM1 attacks cell tubule
What is first line treatment of HER2-positive breast cancer? [3]
Pertuzumab (HER2/HER3 blocker), in combination with trastuzumab (HER2 blocker) and docetaxel
What is second line treatment of HER2-positive breast cancer? [2]
Trastuzumab - emtansine (Kadcycla)
What is third line treatment of HER2-positive breast cancer? [2]
Trastuzumab-deruxtecan
Describe overall mechanism of Small Molecule Tyrosine Kinase Inhibitors (e.g. Tarceva)
Tarceva has similar structure to ATP
Binds to ATP binding pocket in the cell membrane causes competitive inhibition in ATP binding pocket-inhibit function of kinases
Explain what a second generation tyrosine kinase inhibitor is [1]
Name a second gen tyrosine kinase inhibitor for EGFR in NSCLC [1]
Drug for the new mutation of the tyrosine kinase receptor
Mutations associated with drug resistance to erlotinib so Osimertinib prescribed (fits the new ATP binding site)
Monoclonal antibodies and cancer therapy mechanisms:
Explain how killing tumour cells directly via monoclonal antibodies works [4]
- Inhibit ligand binding
- Or possible delivery of toxic payload
- Signalling blocked
- Apoptosis induced
Monoclonal antibodies and cancer therapy mechanisms:
Explain how killing tumour cells directly via an immune-mediated mechanism works [3]
- Induction of phagocytosis
- Complement-dependent cytotoxicity (CDC)
- Antibody-dependent cell cytotoxicity (ADCC)
Monoclonal antibodies and cancer therapy mechanisms:
Explain how killing tumour cells directly via vascular or stromal ablation works [1]
VEGF antagonism
Cetuximab inhibits which receptor:
HER2
HER2/HER3
EGFR
VEGF
Cetuximab inhibits which receptor:
HER2
HER2/HER3
EGFR
VEGF
Name a small molecule tyrosine kinase Inhibitors [1]
Tarceva
(Erlotinib)
Name three pathways that are targets for kinase inhibitors [3]
- Transcription
- Receptor tyrosine kinase signalling
- Proto oncogenes
How does HER2 resistance occur?
As tumours develop they acquire mutations.
With HER2: becomes truncated: extracellular part becomes truncated.
As a result, kinase activity is switched off (doesn’t need receptor activation to switch on intracellular pathway).
As a result Herceptin stops working as there is no binding sit
Name a AE of targeting VEGF [1] and EGFR [1]
VEGF: High blood pressure
EGFR: Slow wound healing and blood clotting
This rash comes from which cancer drug? [1]
Trastuzumab - rash