Actor portrayal

What is ZYDELIG and what sets it apart?

  • It's an oral medication: ZYDELIG (idelalisib) is an FDA-approved medication used to treat relapsed chronic lymphocytic leukemia (CLL)1
  • It works differently: ZYDELIG was approved in 2014 and works by blocking PI3Kδ, a protein that contributes to CLL1-3

ZYDELIG for relapsed CLL

In relapsed CLL, ZYDELIG is used in combination with Rituxan® (rituximab) when CLL comes back after prior cancer treatment and when Rituxan treatment alone may be used due to other health problems. ZYDELIG should not be used as the first medicine to treat people who have been diagnosed with CLL.1

Although CLL is not curable, your doctor can use different therapies or combinations of therapies to slow the growth of your CLL cells and provide you with periods of remission. The ultimate goal of therapy is to help you live longer without your disease getting worse.1,4

How is ZYDELIG thought to work?

ZYDELIG works differently from chemotherapy because it blocks a specific protein in B cells called PI3Kδ. PI3Kδ sends signals to cancerous B cells, telling them to multiply and helping them survive. ZYDELIG blocks these signals, helping to slow the growth of leukemia cells.1-3

Your white blood cell count might go up when you begin treatment with ZYDELIG. Keep in mind the increased count doesn't mean that your ZYDELIG treatment isn't working or that your disease is getting worse. In most cases, this initial rise in white blood cell count decreases over time while you're taking ZYDELIG.1,4

PI3Kδ=phosphatidylinositol 3-kinase.

Proven effective in relapsed CLL1

ZYDELIG was studied in a clinical trial of:
  • 220
    people with relapsed CLL
    who were not able
    to tolerate chemotherapy

At least 50% had been treated with 3 or more prior therapies.

Of the 220 people with relapsed CLL:
  • 84% of those treated with
    ZYDELIG plus Rituxan
    responded to therapy
  • vs
  • 16% of those treated with
    Rituxan alone responded
    to therapy

The main goal, or primary endpoint, of the study was to measure how long people lived without their cancer getting worse while on treatment—also called progression-free survival. In the study, people taking ZYDELIG plus Rituxan had longer progression-free survival (19.4 months) than those taking Rituxan alone (6.5 months).1,3 In addition, 66% of those treated with ZYDELIG plus Rituxan experienced no disease progression at 1 year vs 13% of those treated with Rituxan alone.1,5

The safety profile of ZYDELIG has also been established in people with relapsed CLL.

View the safety profile


Understand your ZYDELIG dose and how to take your medication exactly as prescribed

Learn more

Financial information

Learn more about the financial support offerings that may be available to you while on ZYDELIG® treatment

Call to learn more 1-844-622-2377

ZYDELIG is not indicated and is not recommended for first-line treatment of any patient, including patients with CLL, small lymphocytic lymphoma (SLL), follicular lymphoma (FL), and other indolent non-Hodgkin lymphomas.

ZYDELIG is not indicated and is not recommended in combination with bendamustine and Rituxan, or in combination with Rituxan for the treatment of patients with FL, SLL, and other indolent non-Hodgkin lymphomas.


  1. ZYDELIG® (idelalisib) [Prescribing Information]. Foster City, CA: Gilead Sciences, Inc.; rev February 2022.
  2. Robak P, Robak T. The emerging role of ibrutinib and idelalisib in the treatment of chronic lymphocytic leukemia. J Hematol Transfus. 2013;1(1):1001.
  3. NCI dictionary of cancer terms. National Institute of Health. Accessed September 14, 2023. https://www.cancer.gov/publications/dictionaries/cancer-terms
  4. Someday is today. Leukemia and Lymphoma Society. Updated October 2014. Accessed September 14, 2023. https://www.lls.org/sites/default/files/file_assets/cll.pdf
  5. Data on file. Gilead Sciences, Inc. 2023.