At a glance
Targeted therapy is a cancer treatment that uses drugs designed to attack specific molecules inside or on the surface of cancer cells, leaving most healthy cells alone.
Unlike conventional chemotherapy, which kills any rapidly dividing cell, targeted therapy works by blocking the exact signals that tell a cancer cell to grow, divide, or spread. Some drugs block a protein that acts like a stuck "on" switch inside the cancer cell. Others stick to a marker on the cell surface and stop it from receiving growth signals. Because the attack is precise, the side effects are often different from those of chemotherapy, though they are not absent.
Medical Condition
Targeted therapy is used when a patient's cancer has a specific genetic change, protein, or marker that a targeted drug can act on. Before prescribing it, oncologists (cancer specialists) run molecular tests on a tumour sample to confirm the right target is present.
- Non-small cell lung cancer with EGFR, ALK, ROS1, or KRAS mutations (changes in tumour genes)
- Breast cancer that overproduces the HER2 protein (a growth-promoting protein on the cell surface)
- Chronic myeloid leukaemia (a type of blood cancer) driven by the BCR-ABL gene fusion
- Colorectal (bowel) cancer with specific RAS or BRAF mutations
- Melanoma (skin cancer) with a BRAF V600 mutation
- Kidney (renal cell) cancer where certain growth pathways are overactive
- Thyroid cancer with RET or NTRK gene alterations
- Certain lymphomas (cancers of the lymph system) with CD20 or BTK targets
- Ovarian cancer with BRCA gene mutations, where PARP inhibitor drugs are used
Targeted therapy is not suitable for every cancer patient, even if the diagnosis is the same. It is not used when molecular testing finds no matching target in the tumour, when the cancer has already developed resistance to a specific drug, or when the patient's organ function is too poor to clear the drug safely.
- No identifiable driver mutation or target found on testing
- Previous resistance: the cancer stopped responding to the same target drug
- Severe liver or kidney problems that prevent safe drug clearance
- Certain pregnancy situations, depending on the specific drug
Risks & Complications
Targeted therapy has a different side-effect profile from chemotherapy, but risks still exist and vary considerably by drug class.
- Skin rash, dryness, or nail changes, particularly with drugs targeting the EGFR protein
- Diarrhoea or nausea, which can range from mild to disruptive
- Fatigue and general weakness
- High blood pressure, with some drugs that block blood vessel growth (anti-angiogenic agents)
- Liver inflammation (hepatotoxicity), detected through regular blood tests
- Slow or impaired wound healing, especially with anti-angiogenic drugs
- Bleeding or blood-clotting problems
- Heart muscle changes, particularly with HER2-targeting drugs, monitored by periodic heart scans
- Lung inflammation (interstitial pneumonitis), an uncommon but serious reaction
- Drug resistance over time: the cancer can develop new mutations that make the targeted drug less effective
- Rare but serious allergic reactions during infusion (for intravenous drugs given by drip)
Preparation & Procedure
Preparation for targeted therapy begins well before the first dose, with molecular profiling (detailed genetic testing of the tumour) to confirm which target the treatment will address.
For oral targeted drugs taken as tablets or capsules, fasting rules depend on the specific drug. Some must be taken on an empty stomach; others are taken with food. The medical team will give exact instructions. Alcohol is generally best avoided throughout treatment, as it can worsen side effects and affect how the liver processes the drug. Some targeted drugs interact with certain foods, particularly grapefruit, so the prescribing doctor will outline what to avoid.
Several regular medications may need to be paused or adjusted, including blood thinners, antacids, and some supplements. Smoking affects drug metabolism and can reduce treatment effectiveness, so the oncology team will usually address this.
Tests typically run before starting targeted therapy include:
- Biopsy (tissue sample from the tumour) for molecular or genomic profiling, to identify the specific mutation or target
- Blood tests to assess liver and kidney function, full blood count, and clotting
- Heart function scan (echocardiogram or MUGA scan) for drugs known to affect the heart
- Imaging such as CT, MRI, or PET scans to establish a baseline picture of the cancer
- Blood pressure measurement, as a baseline before drugs that affect blood vessels
What happens during treatment depends on the drug type. The general sequence is:
- 1. The oncologist reviews molecular test results and confirms the treatment plan with the patient.
- 2. For oral drugs: the patient collects a prescription and is counselled on when and how to take each dose at home.
- 3. For intravenous (IV) drugs given by drip: the patient arrives at a day-treatment unit, a cannula (a thin plastic tube) is placed in a vein, and the drug is infused slowly over a set period, usually ranging from 30 minutes to several hours.
- 4. Vital signs (blood pressure, heart rate) are monitored during IV infusion for signs of an allergic reaction.
- 5. After the infusion ends, the patient is observed briefly before being allowed to leave.
- 6. Blood tests and imaging are repeated at regular intervals throughout the treatment course to check response and catch side effects early.
Aftercare
Targeted therapy is usually an ongoing, outpatient treatment rather than a one-time procedure, so aftercare is woven into the entire treatment course rather than a single recovery period.
- Monitoring: regular blood tests, usually every few weeks, to check liver and kidney function, blood counts, and drug levels where relevant
- Heart monitoring: repeat echocardiograms (heart scans) for patients on HER2-targeting or certain other drugs, typically every few months
- Imaging: CT or MRI scans at intervals (often every two to three months) to assess whether the cancer is responding
- Skin care: for patients with skin rash or dryness, the dermatology team may recommend specific moisturisers and sun protection; severe rash can sometimes require a dose adjustment
- Blood pressure: home or clinic monitoring if the drug is known to raise blood pressure, with medication added if needed
- Diarrhoea management: dietary adjustments and, if severe, medical treatment; the oncologist adjusts the dose if the problem is prolonged
- Activity: most patients can continue light daily activities; the level of restriction depends on how well the drug is tolerated
- Wound care: patients on anti-angiogenic drugs are advised to avoid elective surgery during treatment because of slow healing; any planned procedures should be discussed with the oncologist first
- Medication review: all new prescriptions, over-the-counter drugs, and supplements should be cleared with the oncologist, as drug interactions are common with targeted agents
- Follow-up if resistance develops: if scans show the cancer is growing again, the oncologist may arrange repeat molecular testing to look for new mutations and consider switching to a different targeted drug or another treatment type
Cost & What Determines It
The cost of targeted therapy varies widely because it depends on the specific drug prescribed, how long treatment lasts, and the setting in which it is delivered, all of which differ greatly from one patient to the next.
- Drug type and class: some targeted drugs are significantly more expensive than others, and newer agents tend to cost more than older ones
- Treatment duration: targeted therapy is usually taken for months to years, so the total drug cost accumulates over time rather than being a single charge
- Cancer type, stage, and molecular profile: more complex or advanced cases may require higher doses, combination regimens, or more frequent monitoring
- Route of administration: intravenous drugs given in a clinic carry nursing, pharmacy preparation, and facility fees that oral drugs taken at home do not
- Hospital class and country: private hospitals in major medical travel destinations charge differently from public or semi-public hospitals, and prices differ significantly between countries
- Molecular testing: genomic profiling tests used to identify the right target can be expensive and are sometimes billed separately from the treatment itself
- Imaging and monitoring scans: repeated CT, MRI, or PET scans throughout treatment add to the total cost
- Management of side effects: additional medications, dermatology consultations, or blood pressure drugs needed during treatment are usually billed separately
- Accommodation and travel: for patients travelling abroad, stays can be lengthy given the ongoing nature of the therapy
Hospital packages for targeted therapy, where offered, often include the drug cost for a defined number of cycles, intravenous infusion nursing fees, and scheduled blood tests. Imaging scans, molecular profiling, consultations with specialists outside oncology, and drugs for managing side effects are typically charged on top. Oral targeted drugs are usually dispensed by the hospital pharmacy and billed separately from any package.
BPJS Kesehatan and most Indonesian private insurance policies do not cover cancer treatment received abroad, which means patients travelling overseas for targeted therapy generally pay out of pocket or rely on international private health insurance that explicitly covers treatment outside Indonesia. Before travelling, asking the hospital for a detailed written cost estimate covering the full expected treatment course, not just the first cycle, is the most practical way to plan finances and avoid unexpected bills.
Frequently Asked Questions
How many sessions of targeted therapy will I need?
The number of sessions varies depending on the type of cancer, the specific drug used, and how well your body responds to treatment. Some patients take an oral tablet daily at home, while others receive an infusion at the clinic every few weeks. Your oncologist will set the schedule after reviewing your test results and adjusting it over time based on how the cancer is responding.
What does targeted therapy feel like, and what are the side effects?
Most people tolerate targeted therapy better than traditional chemotherapy, but side effects are still possible and differ depending on which part of the cancer cell the drug is designed to block. Common experiences include skin rashes, fatigue, nausea, or diarrhea. Your care team will monitor you regularly and can adjust your treatment plan to help manage any discomfort.
How soon will I know if targeted therapy is working?
Doctors usually check whether the treatment is working after a few weeks to a few months, using scans or blood tests to look for changes in the tumor. Some patients notice symptom improvement earlier, but a scan gives a clearer picture of what is happening inside the body. Your oncologist will explain what the results mean and whether any changes to your plan are needed.
How much does targeted therapy cost?
The cost depends on several factors specific to your situation, including which drug or combination of drugs is prescribed, how long treatment continues, the class of hospital you choose, and whether regular monitoring tests are included. Because these factors are different for every patient, a written estimate from the hospital after your initial consultation is the most reliable way to understand what to expect.
This page is general information, not a substitute for medical advice. Every case is different. Your doctor decides what is right for you.
