How it is administered

Idelalisib is taken by mouth as a tablet. The recommended dose is 150 mg twice daily, with or without food. Tablets should be swallowed whole and not crushed or chewed. If a dose is missed by less than 6 hours, it should be taken as soon as possible; if more than 6 hours, skip the missed dose and take the next one at the usual time.

How it works

Idelalisib works by inhibiting a specific enzyme called phosphatidylinositol 3-kinase delta (PI3Kδ), which is found in normal and malignant B-cells. This enzyme is involved in cell signaling pathways that help B-cells survive, grow, and move to different parts of the body. By blocking PI3Kδ, idelalisib disrupts these pathways, leading to the death of cancerous B-cells and slowing their growth.

Idelalisib also interferes with signals that help B-cells travel and stay in the lymph nodes and bone marrow. This action further reduces the ability of cancer cells to survive and spread. Its effects are particularly important in blood cancers like chronic lymphocytic leukemia (CLL), where abnormal B-cells accumulate and cause disease.

Who Should take it

Idelalisib is indicated for adults with relapsed chronic lymphocytic leukemia (CLL) who cannot tolerate standard chemoimmunotherapy due to other health problems. It is used in combination with rituximab for these patients.

It is not recommended for first-line treatment of CLL or for patients with small lymphocytic lymphoma (SLL), follicular lymphoma (FL), or other indolent non-Hodgkin lymphomas. It should only be used when other therapies are not suitable, and always under the guidance of a healthcare provider experienced in treating blood cancers.

Who should not take it

Idelalisib should not be taken by patients who have had serious hypersensitivity reactions to idelalisib, including anaphylaxis, or those with a history of toxic epidermal necrolysis with any drug.

It should also be avoided in patients who are pregnant, as it may cause harm to an unborn baby. Patients with severe liver problems or those who have experienced severe skin reactions, severe diarrhea, or intestinal perforation while on idelalisib should not continue this medication. Always inform your doctor of your full medical history before starting idelalisib.

Commonly used with

Idelalisib is most commonly used in combination with rituximab for the treatment of relapsed CLL. Rituximab is a monoclonal antibody that targets B-cells and is often used alongside other therapies in blood cancers.

It is not recommended to be used with bendamustine and rituximab or with rituximab for the treatment of follicular lymphoma, SLL, or other indolent non-Hodgkin lymphomas.

Commonly tested with

Idelalisib has been tested in clinical trials in combination with rituximab, ofatumumab, and bendamustine (with rituximab) for the treatment of blood cancers. However, its approved use is specifically in combination with rituximab for relapsed CLL.

Other combinations, especially with bendamustine and rituximab or with rituximab for indolent lymphomas, are not recommended due to increased risks of serious and fatal side effects.