Metastatic Breast Cancer Treatments and Breakthroughs of 2020

Breast cancer treatments are always evolving and improving.

In 2019 and 2020, fresh perspectives to approaching cancer therapy led to exciting breakthroughs for treatments in research.

Today’s treatments are more targeted and capable of altering the course of breast cancer while also maintaining 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.

New Treatment for Breast Cancer


Trodelvy (sacituzumab govitecan-hziy) was approved by the Food and Drug Administration (FDA) in April 2020Trusted Source. It can be used to treat metastatic triple-negative breast cancer that hasn’t responded to at least two other treatments.

Triple-negative means the cancer cells test negative on three factors: They don’t have estrogen or progesterone receptors, and they don’t overexpress a protein called HER2.

This type of breast cancer is difficult to treat. It spreads faster than other types.

Trodelvy is an antibody drug conjugate. That means it targets the chemotherapy drug into the cancer cell and helps spare healthy tissue more than traditional chemotherapy.


Approved by the FDA in December 2019Trusted Source, Enhertu (fam-trastuzumab deruxtecan-nxki) has been very effective in treating HER2-positive breast cancer that’s metastasized (spread) or can’t be removed with surgery.

Enhertu has three components:

  • fam-trastuzumab, an anti-HER2 medication
  • DXd, a topoisomerase I inhibitor that disrupts the ability of cancer cells to replicate
  • a compound that links the molecules of the other components

This antibody drug conjugate is for use by adults who have had at least two other treatments for HER2-positive breast cancer that’s metastasized or can’t be removed with surgery.


Nerlynx (neratinib), originally approved by the FDA in July 2017Trusted Source for early stage breast cancer, was approved in February 2020Trusted Source for metastatic cancer in combination with the chemotherapy drug capecitabine.

It’s for use in adults who have had at least two other treatments for HER2-positive cancer.

Nerlynx is a tyrosine kinase inhibitor. This is a class of drugs that works by stopping the abnormal cell proliferation in HER2-positive breast cancer cells.


Tukysa (tucatinib) was approved by the FDA in April 2020Trusted Source to be used in combination with the chemotherapy drugs trastuzumab and capecitabine.

It’s intended for adults with advanced metastatic HER2-positive breast cancer, including cancer that’s spread to the brain and is difficult to treat.

This drug is a tyrosine kinase inhibitor. It blocks an area of the HER2 gene in cancer cells, stopping the cells from growing and spreading.


This combination injection of pertuzumab, trastuzumab, and hyaluronidase-zzxf was approved by the FDA in June 2020Trusted Source. It works by binding to HER2 sites and stopping cancer cell growth.

A health professional can administer a Phesgo injection in your home. It’s for use in combination with chemotherapy by adults with early or metastasized HER2-positive breast cancer.


Already approved by the FDA to treat many types of cancers that have a large number of gene mutations in the cancer cells, pembrolizumab (Keytruda) has been studied for the treatment of metastatic triple-negative breast cancer.

Pembrolizumab is a checkpoint inhibitor. It works by helping your immune system attack cancer cells.


Alpelisib (Piqray) was approved by the FDA in May 2019Trusted Source.

It can be used in combination with fulvestrant (Faslodex) to treat postmenopausal people with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer.

Alpelisib is a phosphatidylinositol 3-kinase (PI3K) inhibitor. It impedes the growth of tumor cells.

This treatment only works for people with PIK3CA gene mutations. Therefore, you must first take an FDA-approved test to find out whether you have this specific mutation.


The FDA approved talazoparib (Talzenna) in October 2018. Talazoparib is approved to treat locally advanced or metastatic HER2-negative breast cancer in people 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. In June 2020Trusted Source, the FDA 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.

Hylecta is approved to treat both nonmetastatic and metastatic breast cancer.


In March 2019Trusted Source, the FDA approved atezolizumab (Tecentriq), a new type of drug known as a PD-L1 inhibitor.

Atezolizumab is approved for people with locally advanced or metastatic triple-negative breast cancer (TNBC) that can’t be surgically removed, 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 and is given together with chemotherapy for TNBC.


Biosimilars aren’t necessarily “new” drugs, but they’re significantly changing the landscape of breast cancer treatment.

A biosimilar is similar to 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. They 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)

Emerging and Breakthrough Therapies

Pelareorep therapy

A studyTrusted Source called BRACELET-2 is determining whether pelareorep, an immuno-oncolytic virus (IOV) drug that destroys cancer cells, is more effective in combination with the chemotherapy drugs paclitaxel and avelumab for treating local or metastasized HER2-negative breast cancer.

Histone deacetylase (HDAC) inhibitors

HDAC inhibitor drugs block enzymes, called HDAC enzymes, in the cancer growth pathway. One example is tucidinostat. It’s currently in phase 3 testing for advanced hormone receptor-positive breast cancer.

Tucidinostat has shown promising resultsTrusted Source thus far.

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.

Many vaccines are currently being researched.

According to early data presented at a cancer conference in 2018, a HER2-targeted therapeutic cancer vaccine demonstrated clinical benefit in people with metastatic HER2-positive cancers.

The Mayo Clinic is also studying an anticancer 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 for 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.

Current Treatments

Treatment for breast cancer depends on the stage of the cancer and several other factors, like age, genetic mutation status, and medical history.

Most cases of breast cancer 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 and aromatase inhibitors
  • trastuzumab if the breast cancer tests positive for excessive HER2 proteins
  • other HER2-targeted therapies, such as pertuzumab (Perjeta), neratinib (Nerlynx), or ado-trastuzumab emtansine (Kadcyla)
  • newer drugs called CDK 4/6 inhibitors that are approved to treat HR-positive, HER2-negative metastatic breast cancer; they include palbociclib (Ibrance), ribociclib (Kisqali), and abemaciclib (Verzenio)
  • tyrosine kinase inhibitors that treat HER2-positive metastatic breast cancer, including neratinib (Nerlynx), lapatinib (Tykerb), and tucatinib (Tuksya)
  • PARP inhibitors, which are only for people with HER2-negative metastatic breast cancer and who have a BRCA1 or BRCA2 genetic mutation
  • zoledronic acid (Zometa) and denosumab (Xgeva) can help prevent skeletal-related events, such as fractures and spinal cord compression, for breast cancer that’s spread to the bones

Are We Close to a Cure?

Every cancer is different, so finding a one-size-fits-all cure is unlikely anytime soon.

Research is targeting various methods, including gene editing, that have the potential to prove beneficial in future treatments. Research is ongoing and new therapies are continually tested.

Quality of Life

While living with metastatic breast cancer, there are ways to help improve your physical, emotional, and financial well-being.

In 2018, the Metastatic Breast Cancer Collateral Damage ProjectTrusted Source released guidelines for improving the quality of life for people undergoing treatment.

Based on these guidelines, it’s important to take the following steps:

  • Talk with your healthcare provider about managing pain and any side effects from your treatment, such as nausea or feeling fatigued, as well as other potential issues, like sexual health and fertility.
  • If you’re experiencing depression or anxiety, see a therapist or counselor, or join a breast cancer support group. Your healthcare provider may have recommendations.
  • For help covering the cost of your treatment, talk with a financial counselor about assistance programs.


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 with a metastatic breast cancer diagnosis.

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 whether you’re eligible.

Last medically reviewed on December 3, 2020

Posted in: Medical/Science, Research, Treatment