What are targeted therapies?
Targeted therapies refer to the kind of medication, which, when injected into the human body or taken orally, can target specific genes, proteins and tissue environments that contribute to cancer growth and survival. Primarily, targeted therapies are highly focused and cause much fewer side effects as compared to standard chemotherapy since they do not cause much damage to healthy living cells.
However, not all types of cancer tumors have the same targets (genes/protein receptors). To identify the right targeted therapy that works for a specific patient, further testing becomes necessary to identify tumor-specific factors. Specific molecular targets today may lead to more effective targeted therapeutic treatments.
Targeted therapies in the treatment of HER2-positive breast cancer patients
Hormonal therapies were the first type of targeted therapies for breast cancer. Read more on other treatment options for breast cancer. Moreover, after the discovery of the HER2 receptor, HER2-targeted therapies came into existence. These include:
This is for the treatment of non-metastatic and metastatic HER2-positive breast cancer. Patients with stage 1 to stage 3 breast cancer can receive a trastuzumab-based regimen. This includes a combination of trastuzumab with chemotherapy, followed by the completion of one year of adjuvant (post-surgical) trastuzumab. Furthermore, in metastatic HER2/neu receptor-positive patients, doctors recommend it in a combination or as an individual drug.
This is a neoadjuvant (pre-surgical) treatment for HER2-positive breast cancer, in combination with trastuzumab and chemotherapy.
Ado-trastuzumab emtansine (or T-DM1)
T-DM1 is a combination of trastuzumab, linked to a type of chemotherapy. This allows trastuzumab to increase the absorption of chemotherapy drugs into the cancer cells while reducing the chemotherapy absorbed by healthy cells. Besides, doctors are now studying the effects of T-DM on early breast cancer (a drug in the treatment of metastatic breast cancer.)
This is an orally administered drug used in in the treatment of advanced or metastatic breast cancer, where the tumor expresses HER2. Doctors recommend it in combination with standard chemotherapy.
This is an oral drug, used in the treatment of early-stage HER2-positive breast cancer. Usually, doctors recommend it after 12 months of being on trastuzumab.
This is an oral drug which inhibits the cyclin-dependent kinases CDK4 and CDK6. It treats ER/PR positive and HER2 negative metastatic breast cancer patients, along with Letrozole or Fulvestrant.
Bone modifying drugs
Metastatic breast cancer spreads to the bones, making them weaker, causing osteoporosis, and sometimes breaking them. Bone modifying drugs target and block bone destruction and to help in strengthening a patient’s skeletal structure after bone metastasis. Moreover, they help prevent cancer from distant recurrence (with bone metastasis).
Currently, there are two types of bone modifying drugs:
- Bisphosphonates – These work by targeting and blocking osteoclasts – the type of cancer cells that destroy the bone structure.
- RANK ligand inhibitors – These are also osteoclast-targeted therapies that can help in strengthening bone density in metastatic breast cancer patients. (e.g. Denosumab)