Zydelig

(Idelalisib)

The active ingredient in Zydelig is idelalisib. It works by selectively inhibiting phosphoinositide 3-kinase inhibitor (PI3K-delta), an enzyme that plays a key role in the survival, proliferation, and migration of B-cells. By blocking PI3K-δ signalling, Zydelig disrupts pathways that cancerous B-cells rely on to grow and avoid apoptosis, leading to reduced tumor cell survival. It is used mainly in certain B-cell malignancies, such as chronic lymphocytic leukaemia and indolent non-Hodgkin lymphoma.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labelling, Instructions for Use, and Medication Guide before using Zydelig. However, the following is a synopsis of the general guidelines for the use of Zydelig:

• Zydelig is taken by mouth as a tablet.
• It is usually taken twice daily, with or without food.
• Tablets should be swallowed whole and not crushed, broken, or chewed.
• Take the medication at the same time each day to maintain consistent levels in the body.
• If a missed dose is remembered within six hours, take it as soon as possible. If more than six hours have passed, skip the missed dose and take the next dose at the regular time.
• Do not take two doses at the same time.
• Treatment may be stopped or adjusted based on side effects, blood test results, or disease response.

Some mild or common side effects of Zydelig seen in clinical trials include:

• Fatigue.
• Fever.
• Diarrhea.
• Cough.
• Mild abdominal pain.
• Neutropenia or low neutrophil and white blood cell counts increase infection risk.
• Lung inflammation, such as pneumonitis.

Some individuals may experience serious side effects while using Zydelig. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Severe diarrhea or colitis that may be persistent or bloody.
• Liver problems, including increased AST and ALT levels, hepatitis, or hepatotoxicity.
• Serious infections, including Pneumocystis jirovecii pneumonia or other opportunistic infections.
• Intestinal perforation with severe abdominal pain.
• Severe skin reactions, including toxic epidermal necrolysis.
• Serious allergic reactions or anaphylaxis.

These are not all of the possible side effects of Zydelig. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the U.S. Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Zydelig, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including:

• Liver disease or abnormal liver enzyme levels.
• A history of lung disease or breathing problems.
• Current or past serious infections.
• Low blood cell counts or bone marrow abnormalities.
• Gastrointestinal conditions that may increase the risk of colitis or intestinal perforation.
• Frequent blood tests are required to monitor liver function, white blood cell counts, and overall safety during treatment.

Boxed Warning

Zydelig has a boxed warning due to the risk of severe and life-threatening toxicities. These include fatal and serious hepatotoxicity, severe diarrhea and colitis, pneumonitis, intestinal perforation, and serious infections. Close monitoring and prompt management of symptoms are required. Treatment may need to be interrupted or permanently discontinued if these reactions occur.

There are no absolute contraindications listed for Zydelig. However, it should not be used in patients who have had severe hypersensitivity or adverse reactions to idelalisib or any component of the formulation.

Response times vary between individuals. In clinical trials involving patients with relapsed chronic lymphocytic leukemia, small lymphocytic lymphoma, and follicular lymphoma, some patients showed improvement in lymph node size and blood counts within weeks. Full response may take longer and depends on disease type, prior treatments, and overall health.

When Zydelig is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• Strong CYP3A inhibitors or inducers may increase the toxicity or reduce the effectiveness of idelalisib.
• Rituximab, bendamustine, cyclophosphamide, or ofatumumab may increase the risk of infections or hematologic abnormalities when used together.
• Live vaccines should be avoided due to immune system suppression.

Zydelig is available as:

Oral tablets containing idelalisib.

The specific dose and schedule are determined by the healthcare provider based on the condition being treated and patient tolerance.

It should be stored at room temperature, away from the reach of children or pets.

Zydelig is manufactured by Gilead Sciences.

No. There is currently no generic version of Zydelig available.

Do not stop taking Zydelig unless directed by your healthcare provider. Treatment may be paused, reduced, or permanently stopped if serious side effects occur or if blood test abnormalities develop. Always follow medical advice when discontinuing therapy.

Zydelig may cause harm to an unborn baby. Females who can become pregnant should use effective contraception during treatment with Zydelig and for at least 1 month after their last dose. Males with female partners who can become pregnant should use effective contraception during treatment and for 3 months after their last dose.

Breastfeeding is not recommended during treatment with Zydelig and for at least 1 month after the last dose because of the potential risk to the infant.