Cancer Pharmacology and Chemotherapy Flashcards

Which targeted therapy is a monoclonal antibody that blocks the HER2 receptor in HER2-positive breast cancer?

Answer: Trastuzumab

Trastuzumab (Herceptin) binds the extracellular domain of HER2, inhibiting downstream proliferative signaling and mediating antibody-dependent cytotoxicity.

Imatinib (Gleevec) revolutionized the treatment of CML by targeting:

Answer: The BCR-ABL tyrosine kinase

Imatinib occupies the ATP-binding site of the BCR-ABL fusion kinase, constitutively produced by the Philadelphia chromosome translocation t(9;22).

Which toxicity is most uniquely associated with bleomycin that limits its cumulative dosing?

Answer: Pulmonary fibrosis

Bleomycin accumulates in lung tissue where the inactivating enzyme bleomycin hydrolase is deficient, leading to dose-dependent pulmonary fibrosis.

VEGF inhibitor bevacizumab carries which unique risk compared to cytotoxic chemotherapy?

Answer: Arterial thromboembolic events, wound healing impairment, and GI perforation

Anti-VEGF therapy impairs angiogenesis needed for wound healing and vascular integrity, increasing risks of arterial thromboembolism, delayed healing, and GI perforation.

PARP inhibitors such as olaparib are most effective in tumors with defects in which repair pathway?

Answer: Homologous recombination (BRCA1/2 mutations)

BRCA1/2-mutated tumors rely solely on PARP-mediated base excision repair; olaparib blocks PARP, causing lethal synthetic lethality in HR-deficient cells.

Checkpoint inhibitors targeting PD-1 (e.g., pembrolizumab) cause a distinctive class of toxicities called:

Answer: Immune-related adverse events (irAEs)

By unleashing T-cell activity, PD-1 inhibitors can cause immune-related adverse events across any organ, including colitis, pneumonitis, hepatitis, and endocrinopathies.