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Information about Venclyxto▼

What is it and what is it used for?

Venclyxto is a medicine for treating a blood cancer known as chronic lymphocytic leukaemia (CLL) when other treatments have failed or are unsuitable.

In patients with particular genetic changes (17p deletion or TP53 mutation) that make them unsuitable for chemo-immunotherapy, Venclyxto is used when medicines known as B‑cell receptor pathway inhibitors (ibrutinib and idelalisib) are not suitable or have failed.

In patients who do not have these genetic changes, Venclyxto is used after treatments with chemo-immunotherapy and a B‑cell receptor pathway inhibitor has failed.

Because the number of patients with CLL is low, the disease is considered ‘rare’, and Venclyxto was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 6 December 2012.

How Venclyxto works
The active substance in Venclyxto, venetoclax, attaches to a protein called Bcl-2. This protein is present in high amounts in CLL cancer cells, where it helps the cells survive for longer in the body and makes them resistant to cancer medicines. By attaching to Bcl-2 and blocking its actions, venetoclax causes the death of cancer cells and thereby slows the progression of the disease.

How Venclyxto is used
Venclyxto is available as tablets to be taken by mouth once a day with a meal. The starting dose is 20 mg daily and the dose is gradually increased over 5 weeks to 400 mg. The patient should stay on treatment for a long as the patient improves or remains stable and the side effects are tolerable. If the patient experiences certain side effects, treatment may be stopped temporarily or the dose reduced.

Venclyxto should be started and supervised by a doctor with experience of cancer medicines and can only be obtained with a prescription.

What are the benefits?

A high proportion of patients respond to Venclyxto after other treatments have failed or are unsuitable.Studies showed patients with particular genetic mutations (17p deletion or TP53 mutations) that make them unsuitable for chemo-immunotherapy responding well to treatment. In addition, a high response rate was seen in patients whose previous treatment with ibrutinib or idelalisib failed.

Regarding safety, the medicine’s side effects are considered acceptable. Although there is a risk of tumour lysis syndrome, a complication that occurs when the cancer cells are being destroyed too quickly, this risk can be contained through preventive measures, such as increasing the dose gradually or reducing the dose, if needed.

The European Medicine Agency noted that although a small number of patients have been studied so far Venclyxto's benefits outweigh its risks and recommended its approval in the EU.

Venclyxto has been given ‘conditional approval’. This means that there is more evidence to come about the medicine. Every year, the European Medicines Agency will review any new information that becomes available and this summary will be updated as necessary.

What are main side effects?

The most common side effects with Venclyxto (seen in more than 1 in 5 people) are:
  • reduced neutrophils (a type of white blood cell)
  • diarrhoea
  • nausea
  • anaemia (low red blood cell counts)
  • nose and throat infection
  • tiredness
  • high levels of phosphate in the blood
  • vomiting
  • constipation.
The most common serious side effects (seen in more than 2 in 100 people) are:
  • pneumonia (lung infection)
  • fever associated with reduced neutrophils
  • tumour lysis syndrome (a complication caused by breakdown of cancer cells)
For the full list of side effects reported with Venclyxto, see the package leaflet.

Who should avoid taking it?

Venclyxto must not be used with medicines known as ‘strong CYP3A inhibitors’ during the early stages of treatment and must also not be used with St. John’s wort (a herbal preparation used to treat anxiety and depression).

What studies have been done?

Studies have shown that a high proportion of patients have their cancer cells partially or completely cleared following treatment with Venclyxto.

In a main study of 107 previously treated patients with CLL and 17p deletion, 75% responded partially or completely to Venclyxto. In another study of 64 patients with or without 17p deletion or TP53 mutation, the response rate was 67%. Patients in this second study had all previously taken B‑cell receptor pathway inhibitors.

Can patients be prescribed this medicine?

NICE have approved Venclyxto as an option for NHS patients in England for use within the Cancer Drugs Fund, as an option for treating chronic lymphocytic leukaemia, that is, in adults:
  • with a 17p deletion or TP53 mutation and when a B‑cell receptor pathway inhibitor is unsuitable, or whose disease has progressed after a B‑cell receptor pathway inhibitor or
  • without a 17p deletion or TP53 mutation, and whose disease has progressed after both chemo‑immunotherapy and a B‑cell receptor pathway inhibitor
The Scottish Medicines Consortium have approved Venclyxto for use in combination with rituximab for the treatment of adult patients with chronic lymphocytic leukaemia (CLL) who have received at least one prior therapy.
Progression-free survival was significantly longer in the venetoclax plus rituximab group compared with chemoimmunotherapy in a phase III study of patients with relapsed or refractory CLL.

This means that Venclyxto is available as an option for patients being treated by NHS Scotland.


Venclyxto was first made available in the EU in 2016. It is manufactured by AbbVie.

EMA website for Venclyxto
NICE website
SMC website
Accessed on 13/08/19
Links available in External Resources
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Reporting of suspected adverse reactions

Reporting suspected adverse reactions (side effects) after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals or patients are asked to report any suspected adverse reactions via the Yellow Card Scheme at or search for MHRA Yellow Card in the Google Play or Apple App Store.

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. We cannot provide individual medical advice. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.

For the full list of side effects and restrictions, see the package leaflet (link to package leaflet available in External Resources).