Breast cancer treatments are always evolving and improving.

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.


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

In July 2021, pembrolizumab was approved by the FDA to treat early stage triple-negative breast cancer. Keytruda is also approved in combination with chemotherapy for first-line treatment in patients whose cancers have the protein PD-L1 present.

Pembrolizumab works by helping your immune system attack cancer cells.


Trodelvy (sacituzumab govitecan-hziy) was approved by the FDA in April 2020. 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 have an excess of 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 2019, Enhertu (fam-trastuzumab deruxtecan-nxki) has been 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 stops cancer cells from replicating
  • a compound that links the molecules of the other components

Enhertu 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, and have already been treated with two or more types of treatment.


Nerlynx (neratinib), originally approved by the FDA in July 2017 for early stage breast cancer, was approved in February 2020 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 abnormal cells from proliferating in HER2-positive breast cancer cells.


Tukysa (tucatinib) was approved by the FDA in April 2020 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 2020. 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.


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

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 stops 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 docetaxel

Trastuzumab (Herceptin) has been used for many years to treat breast cancer. In June 2020, the FDA approved a new formulation of trastuzumab that combines the medication with docetaxel. Docetaxel 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 2019, 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, or whose tumors express a protein called PD-L1. It is also used in combination with paclitaxel.

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, in that they typically cost less than their branded counterparts.

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 brand drugs.

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)

Pelareorep therapy

A study 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 results 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.

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

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 potential benefit for future treatments. Research is ongoing and new therapies are continually tested.

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 Project released guidelines for improving the quality of life for people undergoing treatment.

The guidelines suggest the following steps:

  • Talk with your healthcare professional about managing pain and side effects from your treatment, such as nausea or fatigue, as well as other potential issues, like sexual health and fertility.
  • If you’re experiencing depression or anxiety, check to see if a therapist or counselor is available at your cancer center, or join a breast cancer support group. Your healthcare team 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 a healthcare professional to see whether you’re eligible.