Understanding targeted therapy
Drugs aimed at specific features of cancer cells
The short version
Targeted therapy uses drugs aimed at specific molecules involved in how certain cancer cells grow — such as HER2, or proteins involved in cell division — rather than affecting fast-growing cells more broadly the way chemotherapy does.
Targeted therapy uses drugs designed to interfere with specific molecules involved in how certain cancers grow, rather than acting broadly on all fast-growing cells the way chemotherapy does. Which targeted therapies, if any, apply to you depends on your specific biomarker results.
HER2-targeted therapy
For -positive cancers, drugs like trastuzumab, pertuzumab, and trastuzumab deruxtecan are designed to specifically block or attack cells with excess HER2 protein, often used alongside or after chemotherapy.
CDK4/6 inhibitors
For some hormone-receptor-positive, HER2-negative cancers, a CDK4/6 inhibitor (such as palbociclib, ribociclib, or abemaciclib) may be added to hormone therapy to help slow cell division.
PARP inhibitors
For cancers associated with an inherited BRCA1 or BRCA2 change, a PARP inhibitor (such as olaparib or talazoparib) may be an option, working by interfering with a DNA-repair pathway these cancer cells rely on.
Side effects vary a great deal between these drug classes — they are generally different from classic chemotherapy side effects, and your care team can explain what's specifically expected for the drug you're being offered.
Questions you may want to ask
Am I a candidate for any targeted therapy based on my biomarkers or genetic testing?
How would this be combined with my other treatments?
What side effects are specific to this drug?