The primary objective of this study is to evaluate overall response rate (ORR) following treatment with idelalisib plus rituximab in participants with previously untreated chronic lymphocytic leukemia (CLL) with 17p deletion.

An increased rate of deaths and serious adverse events (SAEs) among participants with front-line CLL and early-line indolent non-Hodgkin lymphoma (iNHL) treated with idelalisib in combination with standard therapies was observed by the independent data monitoring committee (DMC) during regular review of 3 Gilead Phase 3 studies. Gilead reviewed the unblinded data and terminated those studies in agreement with the DMC recommendation and in consultation with the US Food and Drug Administration (FDA). All front-line studies of idelalisib, including this study, were also terminated.

Key Inclusion Criteria:

• Documented diagnosis of B-cell CLL, according to International Workshop on Chronic Lymphocytic Leukemia 2008
• Presence of 17p deletion in CLL cells as demonstrated by fluorescence in-situ hybridization (FISH) testing
• No prior therapy for CLL other than corticosteroids for disease complications
• CLL that warrants treatment
• Presence of measurable lymphadenopathy
• Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2

Key Exclusion Criteria:

• Known histological transformation from CLL to an aggressive lymphoma (ie, Richter transformation)

• Known presence of myelodysplastic syndrome

• History of a non-CLL malignancy except for the following:

  • the malignancy has been in remission without treatment for ≥ 5 years prior to enrollment, or
  • carcinoma in situ of the cervix, or
  • adequately treated basal or squamous cell skin cancer or other localized non-melanoma skin cancer, or
  • asymptomatic prostate cancer without known metastatic disease and with no current requirement for therapy or requiring only hormonal therapy and with normal prostate specific antigen for ≥ 1 year prior to enrollment, or
  • ductal carcinoma in situ (DCIS) of the breast treated with lumpectomy alone, or
  • other adequately treated Stage 1 or 2 cancer currently in complete remission

• Evidence of ongoing systemic bacterial, fungal, or viral infection at the time of enrollment

• Ongoing liver injury

• History of noninfectious pneumonitis

• Ongoing inflammatory bowel disease

• History of prior allogeneic bone marrow progenitor cell or solid organ transplantation

• Ongoing immunosuppressive therapy other than corticosteroids

• Received last dose of study drug on another therapeutic clinical trial within 30 days prior to enrollment

• Prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, electrocardiogram (ECG) finding, or laboratory abnormality

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Qualified external researchers may request IPD for this study after study completion. For more information, please visit our website at http://www.gilead.com/research/disclosure-and-transparency.

18 months after study completion

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After conclusion of the study and without prior written approval from Gilead, investigators in this study may communicate, orally present, or publish in scientific journals or other media only after the following conditions have been met:

• The results of the study in their entirety have been publicly disclosed by or with the consent of Gilead in an abstract, manuscript, or presentation form; or
• The study has been completed at all study sites for at least 2 years