Idelalisib (trade name: Zydelig) has been approved in Germany since September 2014 for the treatment of follicular lymphoma or chronic lymphatic leukemia in the following forms:

  • Follow-up treatment for adults with follicular lymphoma that has not responded to two previous treatments.
  • Follow-up treatment for adults with chronic lymphatic leukemia who have been treated unsuccessfully in the past.
  • Initial treatment for adults with chronic lymphatic leukemia and certain genetic traits (17p deletion or TP53 mutation) who cannot have chemoimmunotherapy. 17p deletion means that a particular gene segment is missing, while a TP53 mutation means that a specific gene is defective.

Idealisib is approved as monotherapy for the treatment of follicular lymphoma. The drug is combined with rituximab in the treatment of chronic lymphatic leukemia. Rituximab is an antibody used in cancer therapy that affects the immune system.

Non-Hodgin lymphomas are a group of cancer diseases of the lymphatic system in which usually white blood cells (lymphocytes) or their precursors are mutated and multiply uncontrollably. These mutated lymphocytes can spread through the body via lymph vessels. If this type of cancer reaches an advanced stage it may also spread to organs such as the liver, spleen or bone marrow.

Depending on the type of lymphocyte mutation, non-Hodgkin lymphoma is classified as either B-cell or T-cell non-Hodgkin lymphoma..

Follicular lymphoma is a common kind of B-cell non-Hodgkin lymphoma. The word "follicular" refers to the parts of the lymph nodes that produce B-lymphocytes from precursor cells.

Chronic lymphatic leukemia is usually categorized as a B-cell non-Hodgkin lymphoma. It causes B-lymphocytes to stop protecting the body and instead to start spreading through the blood, bone marrow, and lymphatic system.

Idelalisib is a drug that specifically targets the cancer cells and slows their growth.


The drug is taken twice a day in tablet form (150 milligrams).

Other treatments

People with follicular lymphoma who have been treated unsuccessfully twice can receive Best Supportive Care. This kind of treatment needs to be individually tailored to individual needs. It also aims to relieve symptoms like disease-related anemia or loss of appetite, and improve overall quality of life.

There are a number of therapy options available for chronic lymphatic leukemia, depending on how the condition develops and how severe it is. These treatments include chemotherapy in combination with rituximab or individual supportive treatment.


In 2014, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) examined the advantages and disadvantages of idelalisib compared with the standard therapies available for treating follicular lymphoma or chronic lymphatic leukemia.

The manufacturer did not provide any suitable data to make these comparisons, so it is not clear whether idelalisib offers any advantages.

More information

This information summarizes the most important results of a review produced by the Institute for Quality and Efficiency in Health Care (IQWiG, Germany). The review was commissioned by the German Federal Joint Committee (G-BA) as part of the "early benefit assessment of medications." On the basis of this review and the hearings received, G-BA passed a resolution on the added benefit of idelalisib (Zydelig).