Overview

Breast cancer treatments are always evolving and improving. In 2019, fresh perspectives to approach cancer therapy led to exciting breakthroughs for treatments in research.

Today’s treatments are more targeted and capable of altering the breast cancer disease course while also maintaining your quality of life. In recent years, many therapeutic options have emerged for treating stage 4, or metastatic breast cancer, greatly improving survival rates.

Here’s a list of the newest breast cancer therapies and what’s on the horizon.

Alpelisib

Alpelisib (Piqray) was approved by the U.S. Food and Drug Administration (FDA) in May of 2019. It can be used in combination with fulvestrant (Faslodex) to treat postmenopausal women — as well as men — with a certain type of metastatic breast cancer. The specific type of cancer is called hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer.

Alpelisib is a phosphatidylinositol 3-kinase (PI3K) inhibitor that impedes the growth of tumor cells. This treatment only works for people with PIK3CA mutations. Therefore, you must first take an FDA-approved test to find out if you have this specific mutation.

Talazoparib

The FDA approved talazoparib (Talzenna) in October 2018. Talazoparib is approved to treat locally advanced or metastatic HER2-negative breast cancer in women with a BRCA1 or BRCA2 mutation.

Talazoparib is in a class of drugs called PARP inhibitors. PARP stands for poly ADP-ribose polymerase. PARP inhibitors work by making it harder for cancer cells to survive DNA damage. Talazoparib is taken by mouth as a pill.

Trastuzumab with hyaluronidase

Trastuzumab (Herceptin) has been used for many years to treat breast cancer. The FDA recently approved a new formulation of trastuzumab that combines the medication with hyaluronidase. Hyaluronidase is an enzyme that helps your body use trastuzumab.

The new formulation, known as Herceptin Hylecta, is injected under the skin using a hypodermic needle. The process only takes a few minutes. Herceptin Hylecta is approved to treat both non-metastatic and metastatic breast cancer.

Atezolizumab

In March 2019, the FDA approved atezolizumab (Tecentriq), a new type of drug known as a PD-L1 inhibitor. Atezolizumab is approved for people with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC) whose tumors express a protein called PD-L1. It works by helping the immune system attack cancer cells. It’s often referred to as immunotherapy.

Biosimilars

Biosimilars aren’t necessarily “new” drugs, but they are significantly changing the landscape of breast cancer treatment. A biosimilar is like a generic drug — a copy of a prescription that’s been on the market for a while and has an expired patent. However, unlike generics, biosimilars are copies of biologic drugs, which are large, complex molecules that may contain living material.

Biosimilars go through a rigorous FDA review process and must show no clinically meaningful differences from their reference product. Biosimilar drugs cost less than their branded counterparts. Here are some of the recently approved biosimilars to Herceptin for breast cancer:

  • Ontruzant (trastuzumab-dttb)
  • Herzuma (trastuzumab-pkrb)
  • Kanjinti (trastuzumab-anns)
  • Trazimera (trastuzumab-qyyp)
  • Ogivri (trastuzumab-dkst)

Histone deacetylase (HDAC) inhibitors

HDAC inhibitor drugs block enzymes, called HDAC enzymes, in the cancer growth pathway. One example is tucidinostat, which is currently in phase III testing for advanced hormone receptor-positive breast cancer. Tucidinostat has shown promising results thus far.

CAR-T cell therapies

CAR-T is a revolutionary immunotherapy that researchers say could cure certain types of cancers.

CAR-T, which stands for chimeric antigen receptor T-cell therapy, uses T cells from taken from your blood and genetically alters them to attack cancer. The modified cells are given back to you by infusion.

CAR-T therapies do carry risks. The biggest risk is a condition called cytokine release syndrome, which is a systemic inflammatory response caused by the infused CAR-T cells. Some people experience severe reactions that can lead to death if not quickly treated.

The City of Hope cancer center is currently enrolling people in the very first CAR-T cell therapy trial to focus on HER2-positive breast cancer with brain metastases.

Cancer vaccines

Vaccines can be used to help the immune system fight off cancer cells. A cancer vaccine contains specific molecules often present on tumor cells that can help the immune system better recognize and destroy cancer cells.

In one small study, a HER2-targeted therapeutic cancer vaccine demonstrated clinical benefit in people with metastatic HER2-positive cancers.

The Mayo Clinic is also studying an anti-cancer vaccine that targets HER2-positive breast cancer. The vaccine is intended to be used in combination with trastuzumab following surgery.

Combination therapies

There are hundreds of clinical trials currently being conducted in breast cancer. Many of these trials are evaluating combination therapies of several already approved treatments. Researchers hope that by using a combination of one or more targeted therapies, outcomes can improve.

Treatment for breast cancer depends on the stage of the cancer, as well as several factors like age, genetic mutation status, and family and personal history. Most people need a combination of two or more treatments. Here are some of the available treatments:

  • surgery to remove the cancerous cells in your breast (lumpectomy) or to remove the entire breast (mastectomy)
  • radiation, which uses high energy X-ray beams to stop the spread of the cancer
  • oral hormone treatments, such as tamoxifen
  • trastuzumab if your breast cancer tests positive for excessive HER2 proteins
  • other HER2-targeted therapies, such as pertuzumab (Perjeta), neratinib (Nerlynx), or ado-trastuzumab emtansine (Kadcyla)
  • chemotherapy, such as docetaxel (Taxotere), which is often used alongside other treatments
  • newer drugs called CDK 4/6 inhibitors; these include palbociclib (Ibrance), ribociclib (Kisqali), and abemaciclib (Verzenio), which are approved to treat HR-positive, HER2-negative metastatic breast cancer
  • PARP inhibitors, which are only for people with HER2-negative metastatic breast cancer and who have a BRCA1 or BRCA2 genetic mutation

Every cancer is different, so finding a one-size-fits-all cure is unlikely. However, CAR-T cell therapy is being hailed as the most promising treatment in development today. Of course, some biological challenges still need to be figured out, and there are many years of clinical research ahead.

Gene editing is also showing promise as a possible cure. For it to work, a new gene would have to be introduced to cancer cells that cause them to die off or stop growing. One example of gene editing that’s getting a lot of media attention is the CRISPR system. CRISPR research is still in the early stages. It’s too early to tell if it will be the solution we’re hoping for.

New treatments are found every year for metastatic breast cancer that help improve survival rates. These breakthrough therapies are much safer and more effective. They may be able to replace harsher treatments like chemotherapy. This means that a person’s quality of life during cancer treatment will also improve.

New targeted agents also offer new possibilities for combination therapy. Combination treatments continue to improve survival for most people diagnosed with metastatic breast cancer. If you’re interested in joining a clinical trial to help in the development of new breast cancer therapies, talk to your healthcare provider to see if you’re eligible.