Smart Drugs For Cancer - Targeted Therapy
Smart drugs block a specific molecule a cancer depends on, as daily tablets or antibody drips, and they work only when a tumor test finds the target. Imatinib left 83.3 percent of leukemia patients alive at ten years, and in selected solid tumors smart drugs beat chemotherapy. We explain testing, side effects, resistance and the trip.
About This Department
A smart drug is only as smart as the test behind it. With the right target it can turn a fatal cancer into a manageable one.
People call targeted therapy smart drugs. These medicines block a specific molecule a cancer depends on instead of attacking every dividing cell. They come as daily tablets or as antibody drips, and they work only in tumors that carry their target. The first of them showed what is possible. Among patients with chronic myeloid leukemia who started imatinib, 83.3 percent were alive ten years later, in a disease that had killed the majority within a few years. In solid tumors the gains are smaller but real, and every one of them starts with a test on the tumor.
Patients say smart drugs and oncologists say targeted therapy, so the title of this page, Smart Drugs For Cancer - Targeted Therapy, uses both. The name promises more than it delivers. Precision needs a target. This page explains how they work, how the target is found, what the landmark trials showed, what side effects to expect, why they stop working, and how a patient from abroad gets assessed in Istanbul and continue treatment at home.
How a smart drug works
Why smart is a misleading word
Tablets and drips
Two families, two ways of working
Two families
Small molecules, taken as tablets
Small enough to enter the cell, these drugs block the enzyme inside it. Imatinib, osimertinib, crizotinib and the CDK4/6 inhibitors are examples, taken at home once or twice a day for as long as they keep working.
Monoclonal antibodies, given by drip
Too large to enter cells. Antibodies bind the target on the outside, block its signal or flag the cell for the immune system, and trastuzumab for HER2-positive breast cancer is the best known of them. Some carry a chemotherapy payload into the cell, the antibody drug conjugates.
The test comes first
From biopsy to report
What European oncologists recommend
The European Society for Medical Oncology recommends routine sequencing of tumor samples in advanced non-squamous non-small cell lung cancer, prostate cancer, ovarian cancer and bile duct cancer, where large gene panels pay for themselves in treatment choices. In bowel cancer sequencing can replace single-gene tests. Outside these, a broad panel is reasonable if doctor and patient decide together and the patient understands that the chance of finding something useful is low. Mosele and colleagues, Annals of Oncology, 2020.
The drug that proved it
A leukemia that became a chronic conditionIn the IRIS trial, patients with newly diagnosed chronic myeloid leukemia took imatinib, a tablet that blocks the BCR-ABL protein created by a chromosome swap. After a median of 10.9 years, 83.3 percent were alive and 82.8 percent had reached a complete response on chromosome testing. Serious side effects were uncommon and clustered in the first year. Hochhaus and colleagues, New England Journal of Medicine, 2017.
Targets and the drugs that hit them
Common targets
A handful of targets account for most smart drug use today.
This table scrolls sideways on a narrow screen. Swipe or drag to see every column.
| Target | Where it matters most | Example drugs |
|---|---|---|
| HER2 | Breast and stomach cancer | Trastuzumab, pertuzumab, trastuzumab deruxtecan |
| EGFR | Lung cancer with an EGFR mutation | Osimertinib, gefitinib |
| ALK and ROS1 | Lung cancer with a fusion | Alectinib, lorlatinib, crizotinib |
| BRAF V600E | Melanoma, thyroid, bowel and lung cancer | Dabrafenib with trametinib, encorafenib |
| BCR-ABL | Chronic myeloid leukemia | Imatinib, dasatinib, nilotinib |
| CDK4/6 | Hormone receptor positive breast cancer | Palbociclib, ribociclib, abemaciclib |
| VEGF | Bowel, kidney, liver and other cancers | Bevacizumab, sunitinib, lenvatinib |
| NTRK fusions | Many rare cancers | Larotrectinib, entrectinib |
When there is no target
Many tumors carry no change with a matching drug. The negative result still counts. It steers treatment toward chemotherapy, immunotherapy, surgery or radiotherapy, it saves the patient from months on a costly drug that would not have worked, and it stays in the file so that a new trial or a newly approved drug for that change can be matched against it later without testing the tissue again.
One target, several drugs
Newer drugs replace older ones for the same target when they work longer, reach the brain or cause fewer side effects. Crizotinib, the first ALK drug, has largely given way to alectinib and lorlatinib in first-line lung cancer. Progress comes fast. A drug that led in one year slips to second choice three years later.
Three trials in solid tumors
Three targets.
What these trials teach
Side effects
Each drug brings its own list.
Different from chemotherapy, and different from each other
When a smart drug stops working
Resistance is expected
Why it happens
A cancer under pressure evolves. The target can mutate so the drug no longer fits, or the cancer switches to another growth signal and leaves the old one behind. In advanced solid tumors this happens sooner or later, within months to a few years for the large majority of patients.
What comes next
Test again. A new biopsy or a blood test for tumor DNA shows how the cancer escaped, and the result points to the next drug, whether a newer generation for the same target, a different targeted drug, or chemotherapy or immunotherapy.
Length of stay, flying, cost and the trip
Tablets or drips
Tablets
One week to start, then homeA first visit of five to seven days covers the consultation, any missing tests and the start of treatment. You can fly home once the plan is set, and the tablets continue at home with blood tests and scans that an oncologist there can arrange from the written plan.
Drips
Every one to four weeksAntibodies are given in a day unit every one to four weeks, depending on the drug, so patients either return for each dose or continue with an oncologist at home. Our coordinator helps plan whichever suits the schedule.
Cost depends first on the drug, paid monthly or per dose for as long as it works, and on whether your own country covers it. Tests, scans and the day-unit time add to it. Published packages in Istanbul cover the consultation, tests, the first review, an interpreter and transfers, and leave out the hotel, flights and the drug supply. The review of your reports is free, and a written plan with figures follows. The coordinator writes in English, Arabic, French, Russian, Serbian, Romanian or Spanish, or arranges an interpreter, sends an appointment confirmation and an invitation letter naming the hospital and the treating doctor ten days before travel, and books the hotel and transfers. Two family members may join consultations, meals come in halal, vegetarian and diabetic versions, a prayer room is on site, and you may request a female doctor at first contact.
At home, and a caution
After you fly home
Follow-up
A plan your own doctor can followOnce you are back home, your oncologist receives the written plan with the drug, dose, blood tests, heart or eye checks where needed and the scan schedule. The coordinator stays reachable on the same WhatsApp number, and clinical questions go to the oncologist who started the treatment.
Smart drugs without a matching test
Europe advises against it outside organized programsGiving a targeted drug because a gene report lists a change, in a cancer where the drug is not approved, is tempting. The European Society for Medical Oncology recommends doing so only within an access program with a formal decision procedure, and a randomized French trial found no benefit from such off-label matching in heavily treated patients. A clinical trial is usually the better route.
Smart Drugs For Cancer - Targeted Therapy FAQ
What are smart drugs for cancer?
Does everyone with cancer benefit from smart drugs?
Are smart drugs better than chemotherapy?
Do smart drugs have side effects?
How long do smart drugs work?
Can I start smart drug treatment in Istanbul and continue at home?
References
- Hochhaus A, Larson RA, Guilhot F, et al. Long-Term Outcomes of Imatinib Treatment for Chronic Myeloid Leukemia. N Engl J Med. 2017;376(10):917-927.
- Slamon DJ, Leyland-Jones B, Shak S, et al. Use of chemotherapy plus a monoclonal antibody against HER2 for metastatic breast cancer that overexpresses HER2. N Engl J Med. 2001;344(11):783-92.
- Chapman PB, Hauschild A, Robert C, et al. Improved survival with vemurafenib in melanoma with BRAF V600E mutation. N Engl J Med. 2011;364(26):2507-16.
- Solomon BJ, Mok T, Kim DW, et al. First-line crizotinib versus chemotherapy in ALK-positive lung cancer. N Engl J Med. 2014;371(23):2167-77.
- Mosele F, Remon J, Mateo J, et al. Recommendations for the use of next-generation sequencing (NGS) for patients with metastatic cancers, a report from the ESMO Precision Medicine Working Group. Ann Oncol. 2020;31(11):1491-1505.
Editor's note
Written by the Biruni Hospital medical editorial team. Reviewed by Prof. Dr. Özcan YILDIZ, Medical Oncology.
Medically reviewed by
Prof. Dr. Özcan YILDIZ
Medical Oncology
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