Talazoparib (Talzenna) is a targeted therapy for treating breast cancer. Find out when it's used, how it works and possible side effects.

1. What is talazoparib?

Talazoparib is a targeted therapy. Targeted therapy is the name given to a group of drugs that block the growth and spread of cancer. They target and interfere with processes in the cells that help cancer grow.  

Talazoparib belongs to a group of drugs called PARP inhibitors.

Talazoparib is the drug’s non-branded name. The brand name is Talzenna.

2. Who might be offered talazoparib?

You may be offered talazoparib if you have HER2-negative breast cancer that has spread to another part of the body (secondary breast cancer), or that can’t be removed by surgery, and you have an inherited altered BRCA gene.

You should already have had:

  • Chemotherapy with an anthracycline or a taxane, or both, unless these treatments are not suitable and
  • Hormone therapy if your breast cancer is hormone receptor positive, unless this is not suitable

3. How talazoparib works

Talazoparib is a PARP inhibitor. PARP stands for poly-ADP ribose polymerase. This is a protein that helps cells repair themselves if they become damaged. PARP inhibitors stop the PARP from repairing cancer cells.

There are 2 inherited altered genes that increase the risk of breast cancer developing, called BRCA1 and BRCA2. Cancer cells with faulty BRCA genes are less able to repair themselves if they become damaged. PARP inhibitors can also help block the cancer cells from repairing themselves, so they get too damaged to survive.

4. How to take talazoparib

Talazoparib is taken as a capsule once a day. The capsule should be swallowed whole, not opened, crushed, broken, or chewed.

It can be taken with or without food.

You’ll have talazoparib for as long as your treatment team feels you’re benefitting from the drug, and any side effects are manageable.

5. Side effects of talazoparib

Like any drug, talazoparib can cause side effects.

Everyone reacts differently to drugs and some people have more side effects than others. These side effects can usually be managed and they won’t affect everyone who takes the drug.

This information does not list all the possible side effects. If you have any questions about side effects, whether they are listed below or not, talk to your treatment team.

You should be given a 24-hour contact number or told who to contact if you feel unwell or are concerned about side effects at any time, including at night or at the weekend.

Common side effects

Effects on the blood

Talazoparib can temporarily affect the number of blood cells in the body.

You’ll have regular blood tests to check your blood count. Blood is made up of red cells, white cells and platelets. If the number of blood cells is too low, your next treatment may be delayed or the dose reduced.

Risk of infection

Not having enough white blood cells (neutropenia) can increase the risk of getting an infection.

Signs of an infection

Your treatment team may give you guidelines to follow for reporting signs of an infection. But generally you should contact your hospital immediately if you experience any of the following:  

  • A high temperature (over 37.5°C) or low temperature (under 36°C), or whatever your treatment team has advised  
  • Suddenly feeling unwell, even with a normal temperature  
  • Symptoms of an infection, for example a sore throat, a cough, a need to pass urine frequently or feeling cold or shivery 
Anaemia

Having too few red blood cells is called anaemia. If you feel particularly tired, breathless or dizzy, let your treatment team know.

Bruising and bleeding

Talazoparib can reduce the number of platelets, which help the blood to clot. You may bruise more easily, have nosebleeds or your gums may bleed when brushing your teeth. Tell your treatment team if you have any of these symptoms.

Nausea and vomiting

You may feel sick (nausea) and be sick (vomit) at times during your treatment.

If nausea and vomiting affect you, let someone in your treatment team know. You should be able to have anti-sickness drugs to help. 

Try to eat small regular meals if possible and drink regularly.

Extreme tiredness

Cancer-related fatigue is extreme tiredness that doesn’t go away with rest or sleep. It’s a very common side effect of breast cancer treatment and may affect you physically and emotionally. 

Fatigue has many causes, from the emotional impact of a diagnosis to side effects of treatment or growth and spread of the cancer. Fatigue may affect how you cope with your cancer and its treatment. It can also make everyday activities harder and affect your quality of life. 

If you have fatigue, tell your GP or treatment team so you can be fully assessed and offered advice on how to manage your energy levels.

Find out more about managing fatigue.

Dizziness

Talazoparib may cause dizziness. If you feel dizzy, avoid driving. If dizziness carries on, speak to your treatment team or GP.

Diarrhoea

If you have diarrhoea, drink plenty of fluids. Your treatment team or GP can prescribe drugs to help.

Contact your specialist chemotherapy team if you have diarrhoea 4 or more times in 24 hours.

Hair thinning or hair loss

Hair thinning and hair loss is common when receiving talazoparib.

Find out more about hair loss.

Other common side effects

Other common side effects of talazoparib include:

  • Tummy pain
  • Headaches
  • Loss of appetite

Less common side effects

Less common side effects of talazoparib include:

  • Sore mouth
  • Heartburn or indigestion
  • Changes in how things taste

Rare side effects

Serious problems with the bone marrow

Rarely, talazoparib may cause serious problems with the bone marrow such as myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML).

6. Other important information

Allergic reaction 

If you have an allergic reaction to talazoparib, it’s more likely to happen the first time you have the treatment. 

Symptoms include flushing, skin rash, itching, back pain, shortness of breath, faintness, fever or chills.

Blood clots

People with breast cancer have a higher risk of blood clots such as a DVT (deep vein thrombosis).

If you have a DVT, there’s a risk part of the blood clot could break away and travel to the lung. This is known as a pulmonary embolism (PE).  

Blood clots can be life-threatening and should be treated quickly. 

Blood clot symptoms

Contact your treatment team or go to your local A&E department straight away if you have any of the following symptoms: 

  • Pain, redness/discolouration of the skin, heat and swelling of the arm or leg
  • Swelling, redness or tenderness where a central line is inserted to give chemotherapy, for example in the arm, chest area or up into the neck
  • Shortness of breath
  • Pain or tightness in the chest
  • Unexplained cough or coughing up blood

Find out more about blood clots.

Medicines and food to avoid when having talazoparib

There are some drugs you shouldn’t take with talazoparib, so it’s important to tell your treatment team about any prescribed or over-the-counter medicines you are taking.

It’s also important to ask your treatment team before taking any herbal medicines or supplements, such as St John’s wort, or food supplements containing large amounts of curcumin while you are taking talazoparib. Curcumin is found in turmeric root, but using spices in cooking is not likely to cause a problem.

Sex and contraception

It’s important not to get pregnant when having talazoparib, as it may be harmful to a developing baby.

Some women can still become pregnant even if their periods are irregular or have stopped. Your treatment team will advise you to use 2 methods of effective contraception during treatment and for 7 months after the last dose.

Men who have a female sexual partner who is pregnant or could become pregnant should use condoms while taking talazoparib and for at least 4 months after the last dose. Your partner should also use an additional method of effective contraception.

If you or your partner could become pregnant, talk to your treatment team about the most suitable methods of contraception for you.

Fertility

We don’t fully know the impact of talazoparib on fertility.

If you were diagnosed with locally advanced or secondary breast cancer before you started or completed a family, you may be concerned about your fertility. Depending on your diagnosis and treatment, you may be advised not to get pregnant.

You can talk to your treatment team about any possible fertility preservation options before starting treatment.

You can always call our helpline to discuss any concerns with one of our nurses.

Breastfeeding

You shouldn’t breastfeed while having talazoparib, or for at least 1 month after the last dose. This is because there’s a risk the drugs could be passed on through breast milk.

Travel and vaccinations

If you’re planning a holiday or need to travel overseas, check with your treatment team first. 

You should not have any live vaccines while you’re having treatment.

For more information about vaccines, including COVID-19 and flu vaccines, see our information on vaccines and breast cancer.

7. Further information

If you'd like more information on talazoparib or just want to talk things through, our nurses are ready to listen on our free helpline.

Find out more about our support services.

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Quality assurance

This information was published in January 2024. We will revise it in January 2027.

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