How it is administered

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

How it works

Idelalisib is a targeted therapy known as a kinase inhibitor. It works by blocking a specific enzyme called PI3Kδ (phosphatidylinositol 3-kinase delta), which is found in normal and malignant B-cells. This enzyme plays a role in the survival, proliferation, and movement of B-cells, which are a type of white blood cell often involved in chronic lymphocytic leukemia (CLL).

By inhibiting PI3Kδ, idelalisib disrupts signals that help cancerous B-cells grow and survive. This leads to cancer cell death (apoptosis) and reduces the ability of these cells to move to and remain in places like lymph nodes and bone marrow. This targeted action helps slow the progression of CLL and can shrink lymph nodes and reduce symptoms.

Who Should take it

Idelalisib is indicated for adults with relapsed chronic lymphocytic leukemia (CLL) who cannot tolerate standard chemoimmunotherapy due to other health conditions. It is used in combination with rituximab, another medication that targets B-cells. Idelalisib is not recommended as a first-line treatment for CLL or for other types of blood cancers unless specifically directed by your doctor.

This medication is especially considered for patients who have already received other treatments and whose disease has come back (relapsed), and for whom rituximab alone would be considered appropriate due to co-morbidities.

Who should not take it

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

It is also not recommended for use in pregnant women, as it may cause harm to an unborn baby. Women who are breastfeeding should not use idelalisib. Patients with severe liver problems or active, serious infections should discuss the risks with their healthcare provider before starting this medication.

Commonly used with

Idelalisib is most commonly used in combination with rituximab for the treatment of relapsed CLL. Rituximab is a monoclonal antibody that also targets B-cells, and using these medications together can improve treatment outcomes.

Idelalisib is not recommended in combination with bendamustine and rituximab, or with other therapies for first-line treatment of CLL or other indolent non-Hodgkin lymphomas.

Commonly tested with

In clinical studies, idelalisib has been tested in combination with rituximab for relapsed CLL. It has also been studied with ofatumumab and with bendamustine plus rituximab, but these combinations are not currently recommended due to safety concerns.

The main evidence for its use in CLL comes from trials where it was combined with rituximab in patients who had previously received other treatments.