Skip to Content


Active Substance: idelalisib
Common Name: idelalisib
ATC Code: L01XX47
Marketing Authorisation Holder: Gilead Sciences International Ltd
Active Substance: idelalisib
Status: Authorised
Authorisation Date: 2014-09-18
Therapeutic Area: Lymphoma, Non-Hodgkin Leukemia, Lymphocytic, Chronic, B-Cell
Pharmacotherapeutic Group: Antineoplastic agents, other antineoplastic agents

Therapeutic Indication

Zydelig is indicated in combination with rituximab for the treatment of adult patients with chronic lymphocytic leukaemia (CLL):

  • who have received at least one prior therapy, or
  • as first line treatment in the presence of 17p deletion or TP53 mutation in patients unsuitable for chemo-immunotherapy.

Zydelig is indicated as monotherapy for the treatment of adult patients with follicular lymphoma (FL) that is refractory to two prior lines of treatment.

What is Zydelig and what is it used for?

Zydelig is a cancer medicine that is used to treat two types of blood cancer: chronic lymphocytic leukaemia (a cancer of a type of white blood cells called B lymphocytes) and follicular lymphoma (one of another group of cancers that affect B lymphocytes).

In chronic lymphocytic leukaemia, Zydelig is used in combination with another medicine (rituximab) in patients who have received at least one previous treatment and in patients who have genetic mutations in their cancer cells called 17p deletion or TP53 mutation that make them unsuitable for treatment with a combination of chemotherapy medicines and immunotherapy (treatments that stimulate the immune system to kill cancer cells).

In follicular lymphoma, Zydelig is used in patients whose disease has not responded to two previous treatments.

Zydelig contains the active substance idelalisib.

How is Zydelig used?

Zydelig can only be obtained with a prescription and treatment should be prescribed by a doctor experienced in using cancer medicines.

Zydelig is available as 100 mg and 150 mg tablets. The recommended dose is 150 mg twice a day, and treatment should be continued for as long as the patient improves or remains stable and the side effects are tolerable. If the patient experiences severe side effects, treatment must be stopped and can be re-started at a lower dose of 100 mg twice a day.

For more information, see the summary of product characteristics (also part of the EPAR).

How does Zydelig work?

The active substance in Zydelig, idelalisib, blocks the effects of an enzyme called PI3K-delta. This enzyme plays a role in the growth, migration and survival of white blood cells but is overactive in blood cancers, where it enables the survival of the cancer cells. By targeting this enzyme and blocking its effects, idelalisib causes death of the cancer cells, thereby delaying or stopping the progression of the cancer.

What benefits of Zydelig have been shown in studies?

In a main study of 220 patients with previously treated chronic lymphocytic leukaemia, Zydelig was shown to be more effective at treating the cancer than placebo (a dummy treatment) when both were given in combination with another medicine rituximab: 75% of patients taking Zydelig had an improvement in their disease compared with 15% of patients taking placebo. Zydelig was also more effective than placebo in the subgroup of patients who had a specific genetic mutation in their cancer cells that makes them unsuitable for chemo-immunotherapy.

Another main study evaluated Zydelig in patients with different lymphomas, including 72 patients with follicular lymphoma that had failed two previous treatments. Zydelig was shown to be effective, with 54% of patients with follicular lymphoma having either a complete or partial response to treatment.

What are the risks associated with Zydelig?

The most common side effects with Zydelig (which may affect more than 1 in 10 people) are infections, neutropenia (low levels of neutrophils, a type of white blood cell), diarrhoea, increased liver enzymes in blood, rash, fever and increased blood fat levels.

Based on studies in animals, Zydelig may be harmful to the unborn child. Zydelig is therefore not recommended during pregnancy, and women taking the medicine should use a reliable method of contraception to avoid becoming pregnant during treatment and for 1 month after treatment. It is also not known whether Zydelig can make hormonal contraceptives less effective. Women and their partners should therefore also use a barrier method of contraception such as condoms.

For the full list of all side effects and restrictions, see the package leaflet.

Why is Zydelig approved?

The Agency’s Committee for Medicinal Products for Human Use (CHMP) noted that available data from the main studies, which were still ongoing at the time of the evaluation, showed high response rates with Zydelig in patients with chronic lymphocytic leukaemia and follicular lymphoma. It was also effective in chronic lymphocytic leukaemia patients who have the 17p deletion or TP53 mutation that makes them unsuitable for chemo-immunotherapy.

In addition, the safety of the medicine was considered acceptable. The Committee therefore concluded that Zydelig’s benefits are greater than its risks and recommended that it be approved for use in the EU.

What measures are being taken to ensure the safe and effective use of Zydelig?

A risk management plan has been developed to ensure that Zydelig is used as safely as possible. Based on this plan, safety information has been included in the summary of product characteristics and the package leaflet for Zydelig, including the appropriate precautions to be followed by healthcare professionals and patients.

In addition, the company will also provide final results of the ongoing main studies of Zydelig in patients with chronic lymphocytic leukaemia and follicular lymphoma.

Other information about Zydelig

The European Commission granted a marketing authorisation valid throughout the European Union for Zydelig on 18 September 2014.

For more information about treatment with Zydelig, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist.

Source: European Medicines Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.