Treatments

Targeted Therapy: Precision Drugs Guided by Tumour Biology

Targeted therapy uses drugs designed to interfere with specific molecules that drive cancer growth, such as mutated genes or abnormal proteins. Because these drugs act on particular biological targets, they are typically matched to patients whose tumours carry the relevant genetic or molecular feature.

3 min readLast reviewed August 1, 2026Medically reviewed by: GetOnco Medical Review Team

Summary

Targeted therapy uses precision drugs matched to specific molecular changes in a tumour, identified through genetic testing, offering effective options for cancers with known drivers.

Key takeaways

  • Targeted drugs act on specific molecules that drive cancer growth.
  • Genetic or biomarker testing is required to confirm a matching target.
  • Many targeted therapies are oral medications taken daily.
  • Effectiveness depends on the presence of the specific target and can change with resistance.
  • Side effects differ from chemotherapy and relate to the specific pathway blocked.

What it is

Targeted therapies include small-molecule inhibitors and monoclonal antibodies that block specific pathways cancer cells rely on to grow, divide, or spread. Unlike traditional chemotherapy, which affects all rapidly dividing cells, targeted drugs are designed to act more selectively on cancer cells carrying a particular alteration.

What it means for you

If your tumour has a targetable alteration, a matched drug may offer meaningful benefit with a different side-effect profile than chemotherapy. Ongoing monitoring helps detect resistance early so treatment can be adjusted.

Testing

Comprehensive genomic profiling or single-gene tests on tumour tissue or blood identify relevant mutations, fusions, or protein expression. Repeat testing may be recommended if the cancer progresses, to check for new resistance mutations.

Associated cancer types

Targeted therapies are used in lung cancer with EGFR or ALK alterations, breast cancer with HER2 overexpression, colorectal cancer with certain RAS/RAF status, chronic myeloid leukaemia, GIST, and many other cancers with identifiable molecular drivers.

Treatment options

Options include oral kinase inhibitors, monoclonal antibodies given by infusion, and antibody-drug conjugates that combine targeting with a chemotherapy payload. Choice depends on the specific biomarker identified and prior treatments received.

Questions patients ask

  • Does my tumour have a mutation or marker that a targeted therapy could address?
  • What side effects are specific to this targeted drug?
  • How will you monitor whether the treatment is still working over time?
  • What are the signs that resistance might be developing?
  • Will I need repeat biopsies or blood tests during treatment?

Frequently asked questions

How do I find out if targeted therapy will work for my cancer?

Your tumour tissue is tested for specific mutations or proteins; the results determine whether an approved targeted drug matching that alteration is available.

Are targeted therapy side effects milder than chemotherapy?

Often, but not always—side effects depend on the specific drug and pathway involved, and some can still be significant, requiring monitoring.

What happens if targeted therapy stops working?

Tumours can develop resistance over time; repeat biopsy or blood testing can identify new changes and guide the next treatment option.

References

  1. 1.Targeted Therapy to Treat CancerNational Cancer Institute
  2. 2.Personalised MedicineESMO
  3. 3.Targeted Therapy BasicsASCO
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Medically reviewed by:GetOnco Medical Review Team — Oncology-trained clinicians and medical editors

Last reviewed August 1, 2026

Medical disclaimer

Educational information only. GetOnco is software, not a medical provider, and does not diagnose disease or recommend treatments. Always discuss your situation with qualified healthcare professionals.