What is the difference between targeted therapy and immunotherapy?

Targeted therapy blocks a specific mutation within the tumour. Immunotherapy activates the immune system to attack cancer cells broadly. Biomarker and PD-L1 testing determine which is appropriate.

Is targeted therapy better than chemotherapy for lung cancer?

For patients with an actionable mutation, targeted therapy produces longer progression-free survival and fewer severe side effects. For patients without such a mutation, chemo or immunotherapy is the standard.

How do I know if I am eligible for targeted therapy?

Through biomarker testing, a biopsy tests the tumour’s genetic profile. All NSCLC patients should be tested at diagnosis. Your oncologist will discuss whether a targeted drug matches your mutation.

Can targeted therapy cure lung cancer?

For most patients with advanced NSCLC, targeted therapy controls the disease rather than curing it. For earlier-stage disease, surgery followed by adjuvant targeted therapy can achieve long-term remission.

How long do patients take targeted therapy?

As long as the drug is working and side effects are manageable, ranging from months to several years. Treatment continues until imaging shows disease progression.

Targeted Therapy for Lung Cancer

What Is Targeted Therapy for Lung Cancer?

Targeted therapy blocks the specific genetic mutations driving a cancer to grow. Unlike chemotherapy - which attacks all rapidly dividing cells - targeted drugs act precisely on what is wrong with the cancer cell. Most are taken as daily oral tablets, allowing treatment from home. Targeted therapy only works if your tumour carries a specific, actionable mutation, confirmed through biomarker testing before treatment begins.

Who Is Eligible for Targeted Therapy?

Biomarker Testing Is the First Step

All NSCLC patients should be tested for biomarkers before treatment begins using a tissue biopsy or liquid biopsy. Next-generation sequencing (NGS), which screens for multiple mutations at once, is the preferred method. Around 40-50% of NSCLC patients have a targetable biomarker. Those without one are typically treated with chemotherapy, immunotherapy, or a combination.

Targeted Therapy in NSCLC vs SCLC

Targeted therapy is primarily used in NSCLC (~85% of lung cancers), where specific gene mutations or fusions can be directly blocked. SCLC is harder to treat this way - its genetic changes are less targetable. Antibody-drug conjugates (ADCs) are an emerging approach for SCLC currently in clinical trials.

Targetable Gene Mutations in Lung Cancer

The following mutations are currently covered by FDA-approved targeted therapies for NSCLC:

EGFR (10-15% of NSCLC cases) - more common in never-smokers and Asian patients
KRAS G12C - common in patients with a smoking history; together with EGFR, accounts for ~40% of NSCLC alterations
ALK rearrangement (~5% of cases)
ROS1, MET exon 14, RET fusion, BRAF V600E, HER2, and NTRK fusions (each present in smaller subsets)

Your oncologist will identify which mutation your tumour carries and recommend the appropriate drug.

Types of Targeted Therapy Drugs

The most commonly used class is tyrosine kinase inhibitors (TKIs) - oral tablets that block the signalling pathways cancer cells use to grow. Key approved drugs include osimertinib (EGFR), alectinib (ALK), sotorasib and adagrasib (KRAS G12C), tepotinib (MET exon 14), selpercatinib (RET fusion), and dabrafenib plus trametinib (BRAF V600E).

Antibody-drug conjugates (ADCs) are a newer class that deliver chemotherapy directly to cancer cells via a targeting antibody. Trastuzumab deruxtecan (Enhertu) is approved for HER2-mutated NSCLC, and ADCs are under active investigation for SCLC.

When Is Targeted Therapy Used?

Targeted therapy was originally developed for advanced, metastatic NSCLC - but its use has expanded significantly. It is now used across earlier stages as well:

Stage IV (metastatic) NSCLC - first-line treatment for patients with an actionable mutation, often without chemotherapy
After surgery (adjuvant) - osimertinib is approved for EGFR-mutated NSCLC; alectinib for ALK-positive NSCLC from Stage IB-IIIA
Before surgery (neoadjuvant) - increasingly used in appropriate early-stage cases as clinical evidence grows

Side Effects of Targeted Therapy

Because targeted drugs act more selectively on cancer cells, they tend to cause fewer severe side effects than chemotherapy. Common side effects include skin rash or dryness, nail changes, mild diarrhoea, fatigue, and liver enzyme changes monitored through blood tests. A serious but less common risk is pneumonitis - lung inflammation - which requires prompt attention if breathlessness develops. Newer generations of targeted drugs are increasingly specific; osimertinib, for example, causes significantly fewer side effects than the original EGFR inhibitors. Dose adjustments can be made if side effects are difficult to manage.

What Happens When Targeted Therapy Stops Working?

Over time, cancer cells can develop resistance - new mutations that allow the tumour to grow despite the drug. When this happens, a repeat biopsy or liquid biopsy identifies the resistance mechanism. Further options include next-generation TKIs, alternative targeted drugs, chemotherapy, immunotherapy, or a clinical trial.

Conclusion

Targeted therapy has changed the way many lung cancers are treated by focusing on the specific mutations that drive tumour growth. It often causes fewer side effects than traditional treatments. However, it only works if the tumour has the right biomarker, which is why testing is important before starting treatment. As research continues, targeted therapies are helping more patients access effective and personalised care.