Targeted cancer therapies are treatments that target specific characteristics of cancer cells, such as a protein that tells the cancer cells to grow in a rapid or abnormal way. They are generally more precise than chemotherapy in targeting cancer cells and therefore less likely to harm normal, healthy cells. Targeted therapies can be used:
- Before surgery in conjunction with chemotherapy to reduce the size of breast cancer and prevent early spread of cancer to other parts of the body
- After breast cancer surgery (with or without chemotherapy) to reduce the rate of cancer returning back in the future and enhance the rate of cure
- when breast cancer has already spread (metastatic or stage 4) to achieve control and prevent further spread.
Targeted therapies are divided into the following main groups:
Drugs that target (stop) protein called HER-2:
About 1 in 4 breast cancer patients have a high number of Her-2 protein on their cancer cell surfaces encouraging their cancer cells to grow and divide. The fact that someone has Her-2 positive breast cancer is bad news and good news at the same time. On one hand, Her-2 positive breast cancer tends to be more aggressive than Her-2 negative breast cancer. On the other hand, we now have many effective drugs that can be used to switch Her-2 off and stop its effect on cancer cells. The main anti-Her2 drugs are:
Trastuzumab: (tras-TOO-zoo-mab): it is also called Herceptin.
Used after breast surgery as an adjuvant therapy to enhance chances of cure. It can also be used before breast surgery to reduce the size of the cancer and stop early spread to other organs outside the breast and lymph nodes. In stage 4 breast cancer, it is used to control cancer and achieve remission from the disease. Herceptin is given subcutaneously (injection under the skin) or intravenously (injection into the blood) once every 3 weeks with or without chemotherapy. Patients on Herceptin should not get pregnant because Herceptin can harm the unborn baby.
Ado-trastuzumab emtansine: also known as T-DM1 or Kadcyla.
Kadcyle is a combination of Herceptin and a chemotherapy medicine emtansine. It is used in patients with stage 4 breast cancer that has already been treated with Herceptin and a chemo drug called Docetaxel. It is also for these patients if the breast cancer has come back after adjuvant therapy.
Pertuzumab (per-TOO-zoo-mab) Perjeta:
It is usually given in stage 4 breast cancer in combination with Herceptin and Docetaxel chemotherapy in patients who have not been treated before for their stage 4 cancer. It has also been approved recently for high-risk non-stage 4 breast cancer before surgery to shrink the cancer and reduce the risk of cancer recurrence in the future.
Lapatinib (luh-PA-tih-nib) Tykerb
It is used to treat Her-2 positive and stage 4 breast cancer in combination with a chemotherapy drug called Capecitabine when the cancer has not responded to previous chemotherapy.
Neratinib (neh-RA-tih-nib) Nerlynx
It can be used in non-stage 4 breast cancer as an extended therapy after 12 months of adjuvant Herceptin.
Drugs that target (stop) protein called mTOR:
Everolimus (eh-veh-ROH-lih-mus) Afinitor
It is used in postmenopausal patients with stage 4 breast cancer in combination with Hormone therapy Exemestane when breast cancer has not responded to other treatments. against hormone-receptor-positive breast cancers that have stopped responding to Arimidex or Femara by stopping the cancer cells from getting the energy they need.
Drugs that inhibit enzymes called CDK (called CDK4/6 inhibitors)
This group of drugs are suitable for patients with stage 4 breast cancer that is sensitive to hormones AND do not have the Her-2 protein (HER-2 negative)
Palbociclib: (PAL-boh-SY-klib) Ibrance
This is a drug that has been approved to treat postmenopausal women with stage 4 breast cancer in combination with hormone therapy in patients who have not treated before with hormones. Palbociclib can also be used with a drug called Fulvestrant if breast cancer has not responded to previous hormone therapy.
Ribociclib: (RY-boh-SY-klib) Kisqali
It is licensed to treat postmenopausal women with stage 4 breast cancer in combination with hormone therapy in patients who have not treated before with hormones.
Abemaciclib (uh-BEH-muh-SY-klib) Versenio
Abemaciclib can be used in combination with Fulvestrant if breast cancer has not responded to previous hormone therapy. It is also used on its own to treat breast cancer that has not responded to previous hormones or chemotherapy.