TheraRadar
Data updated: May 26, 2026

IDELALISIB

Kinase Inhibitors Genetic Support
Oncology Approved 2026-02-17

Idelalisib is a kinase inhibitor used for patients with relapsed chronic lymphocytic leukemia (CLL). It is prescribed in combination with rituximab for individuals who have other health issues that make rituximab alone a suitable option. This medication is specifically for those whose cancer has returned and is not used as an initial therapy.

Source: FDA Label • NATCO • Kinase Inhibitor

How IDELALISIB Works

This drug works by targeting PI3Kδ, a protein found in both healthy and cancerous B-cells. By blocking this kinase and other signaling pathways, it prevents cancer cells from moving to the lymph nodes and bone marrow while also triggering cell death. This process stops the tumor cells from growing, sticking together, and surviving.

Source: FDA Label
1
Indication
--
Phase 3 Trials
0
Years on Market

Details

Status
Prescription
First Approved
2026-02-17
Routes
ORAL
Dosage Forms
TABLET

Companies

Active Ingredient: IDELALISIB

IDELALISIB Approval History

Original
New Indication
New Form
Label Update
2 FDA actions from 2026 to 2026
Feb 2026 ORIGINAL
Update

What IDELALISIB Treats

3 indications

IDELALISIB is approved for 3 conditions since its original approval in 2026. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Chronic Lymphocytic Leukemia
  • Follicular Lymphoma
  • Non-Hodgkin Lymphoma
Source: FDA Label

IDELALISIB Boxed Warning

FATAL AND SERIOUS TOXICITIES: HEPATIC, SEVERE DIARRHEA, COLITIS, PNEUMONITIS, INFECTIONS, and INTESTINAL PERFORATION Fatal and/or serious hepatotoxicity occurred in 16% of Zydelig-treated patients. Monitor hepatic function prior to and during treatment. Interrupt and then reduce or discontinue Zydelig as recommended [see Dosage and Administration (2.2) , Warnings and Precautions (5.1) ] . Fatal and/or serious and severe diarrhea or colitis occurred in 20% of Zydelig-treated patients. Monitor for...

IDELALISIB Target & Pathway

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Target

PI3K (Phosphoinositide 3-Kinase) Intracellular Kinase

A family of enzymes involved in cell growth, proliferation, and survival signaling. PI3K pathway activation is common in cancer. Inhibiting specific PI3K isoforms is effective in certain blood cancers and solid tumors.

IDELALISIB Competitive Set

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Three rings of competition based on shared molecular targets and treated indications.

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Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

What's emerging in IDELALISIB's indications

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Phase 3 candidates targeting molecules with no FDA-approved drug, in indications IDELALISIB treats. First-in-class if their pivotal trials read out positive.

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Clinical Trial Registry

51 trials
Trial Sponsor ID Phase Status Title
NCT02970318 results posted ACE-CL-309 2015-004454-17 Ph 3 active not recruiting A Study of Acalabrutinib vs Investigator's Choice of Idelalisib Plus Rituximab or Bendamustine Plus Rituximab in R/R CLL
NCT06846671 CaDAnCe-302 BGB-16673-302 2024-518893-15-00 Ph 3 recruiting A Study of BGB-16673 Compared to Investigator's Choice in Participants With Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma Previously Exposed to Both Bruton Tyrosine Kinase (BTK) and B-cell Leukemia/Lymphoma 2 Protein (BCL2) Inhibitors
NCT04666038 BRUIN CLL-321 results posted 18073 J2N-OX-JZNN, LOXO-BTK-20020 Ph 3 active not recruiting Study of LOXO-305 (Pirtobrutinib) Versus Investigator's Choice (Idelalisib Plus Rituximab or Bendamustine Plus Rituximab) in Patients With Previously Treated Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL)
NCT07218341 27296 J2N-MC-JZ03, J2N-MC-JZNY Ph 4 recruiting A Study of Pirtobrutinib (LY3527727) in Participants With Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma
NCT07139873 DZ2024B0002 Ph 3 recruiting A Study of DZD8586 Versus Investigator's Choice in r/r CLL/SLL (TAI-SHAN6)
NCT02135133 results posted 13-309 Ph 2 completed A Study of Idelalisib (GS1101, CAL101) + Ofatumumab in Previously Untreated CLL/SLL
NCT02787369 15-558 Ph 1 active not recruiting ACY-1215 in Combination With BCR Pathway Inhibitors in Relapsed CLL
NCT02457598 results posted GS-US-401-1757 2015-000834-30 Ph 1 terminated Dose Escalation and Dose Expansion Study of Tirabrutinib in Combination With Other Targeted Anti-cancer Therapies in Adults With B-cell Malignancies
NCT03890289 GAUDEALIS results posted FIL_GAUDEALIS Ph 2 terminated Idelalisib+Obinutuzumab in Patients With Relapsed/Refractory Follicular Lymphoma
NCT06205290 CA082-1170 Ph 3 withdrawn A Study to Compare the Efficacy and Safety of Lisocabtagene Maraleucel vs Investigator's Choice Options in Adult Participants With Relapsed or Refractory Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma, Whose Disease Has Failed Treatment With Both BTKi and BCL2i Therapies
NCT03878524 STUDY00015588 NCI-2020-02743, STUDY00015588 Ph 1 terminated Serial Measurements of Molecular and Architectural Responses to Therapy (SMMART) PRIME Trial
NCT03257722 PIL results posted GCC-16053 Ph 1, Ph 2 terminated Pembrolizumab + Idelalisib for Lung Cancer Study
NCT02332980 results posted MC1485 NCI-2014-02561, MC1485 Ph 2 completed Pembrolizumab Alone or With Idelalisib or Ibrutinib in Treating Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia or Other Low-Grade B-Cell Non-Hodgkin Lymphomas
NCT04699461 LOTIS-6 results posted ADCT 402-202 2020-003695-40 Ph 2 terminated Study to Evaluate the Efficacy and Safety of Loncastuximab Tesirine Versus Idelalisib in Participants With Relapsed or Refractory Follicular Lymphoma
NCT02962401 RemodelWM3 RemodelWM3 Ph 2 completed Efficacity of Idelalisib and Obinutuzumab in Patient With Relapsed Refractory Waldenstrom's Macroglobulinemia
NCT02536300 results posted GS-US-313-1580 2015-000366-66 Ph 3 terminated Dose Optimization Study of Idelalisib in Follicular Lymphoma
NCT05725200 EVIDENT EVIDENT Ph 2 recruiting Study to Investigate Outcome of Individualized Treatment in Patients With Metastatic Colorectal Cancer
NCT02968563 results posted GS-US-401-1958 2015-003909-42, CLLRUmbrella1 Ph 2 completed Study to Evaluate the Safety and Efficacy of the Combination of Tirabrutinib and Idelalisib With and Without Obinutuzumab in Adults With Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL)
NCT02639910 COSMOS results posted MOR208C205 Ph 2 completed Study to Evaluate Safety and Preliminary Efficacy of Tafasitamab With Idelalisib or Venetoclax in R/R CLL/SLL Patients Pretreated With BTKi
NCT01620216 results posted IRB00007195 NCI-2012-01084, CA180-392 Ph 2 terminated Targeted Therapy in Treating Patients With Relapsed or Refractory Acute Lymphoblastic Leukemia or Acute Myelogenous Leukemia
NCT03576443 ILIAD NLG-LBC-07 Ph 2 completed Trial of Idelalisib in Patients With Relapsed Diffuse Large B-cell Lymphoma
NCT03742323 REALIB-LLA-2017 Ph 1, Ph 2 terminated REALIB-LLA-2017: Idelalisib in Patients With Acute Lymphoblastic Leukemia
NCT02468557 results posted GS-US-385-1577 Ph 1 terminated Study of Single Agent Idelalisib Followed by Idelalisib in Combination With Chemotherapy in Adults With Metastatic Pancreatic Ductal Adenocarcinoma
NCT02242045 results posted GS-US-313-1380 Ph 1 completed Study to Evaluate Safety, Tolerability, and Pharmacokinetics of Idelalisib in Japanese Participants With Relapsed or Refractory Indolent B-Cell Non-Hodgkin Lymphomas (iNHL) or Chronic Lymphocytic Leukemia (CLL)
NCT01088048 results posted 101-07 Ph 1 completed Study to Investigate Idelalisib in Combination With Chemotherapeutic Agents, Immunomodulatory Agents and Anti-CD20 Monoclonal Antibody (mAb) in Participants With Relapsed or Refractory Indolent B-cell Non-Hodgkin's Lymphoma, Mantle Cell Lymphoma or Chronic Lymphocytic Leukemia
NCT02538614 results posted GS-US-312-1579 Ph 1 terminated Study of Idelalisib in Combination With BI 836826 in Participants With Chronic Lymphocytic Leukemia
NCT02436135 Madison results posted GS-US-397-1245 Ph 1 terminated Study to Evaluate Safety, Tolerability, and Pharmacokinetics of Idelalisib in Adults Receiving Ruxolitinib as Therapy for Primary, Post-Polycythemia Vera, or Post-Essential Thrombocythemia Myelofibrosis With Progressive or Relapsed Disease
NCT01796470 results posted GS-US-339-0103 Ph 2 terminated Entospletinib in Combination With Idelalisib in Adults With Relapsed or Refractory Hematologic Malignancies
NCT02779283 IRB00011766 NCI-2016-00083, IRB00011766 Ph 1 completed Personalized Kinase Inhibitor Therapy Combined With Chemotherapy in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia and Acute Lymphoblastic Leukemia
NCT01569295 Tugela results posted GS-US-312-0115 2011-006292-20 Ph 3 completed Study Evaluating the Efficacy and Safety of Idelalisib in Combination With Bendamustine and Rituximab for Previously Treated Chronic Lymphocytic Leukemia (CLL) (Tugela )
NCT02739360 results posted GS-US-313-2120 2015-005766-39 Ph 4 terminated Roll Over Study to Provide Idelalisib to Participants Previously Treated With the Investigational PI3Kδ Inhibitor, GS-9820
NCT02603445 CBCL201X2102C Ph 1 completed Study of Safety and Efficacy of BCL201 and Idelalisib in Patients With FL and MCL
NCT01090414 results posted 101-99 Ph 1, Ph 2 terminated An Extension Study for Subjects Who Are Deriving Benefit With Idelalisib (GS-1101; CAL-101) Following Completion of a Prior Idelalisib Study
NCT01539291 results posted GS-US-312-0117 2011-006293-72 Ph 3 terminated Extension Study of Idelalisib in Participants With Chronic Lymphocytic Leukemia (CLL) Who Participated in GS-US-312-0116 (NCT01539512)
NCT01659021 results posted GS-US-312-0119 2012-001236-65 Ph 3 terminated Efficacy and Safety of Idelalisib in Combination With Ofatumumab for Previously Treated Chronic Lymphocytic Leukemia
NCT01282424 DELTA results posted 101-09 2010-022155-33 Ph 2 completed Efficacy and Safety Study of Idelalisib in Participants With Indolent B-Cell Non-Hodgkin Lymphomas
NCT01539512 results posted GS-US-312-0116 2011-005180-24 Ph 3 completed A Randomized, Double-Blind, Placebo-Controlled Study of Idelalisib in Combination With Rituximab for Previously Treated Chronic Lymphocytic Leukemia (CLL)
NCT02258529 results posted GS-US-313-1414 Ph 2 terminated Idelalisib in Combination With Rituximab for Previously Untreated Follicular Lymphoma and Small Lymphocytic Lymphoma
NCT03349346 GS-US-313-1090 2017-001468-39 Ph 1 withdrawn Idelalisib With Rituximab, Ifosfamide, Carboplatin, Etoposide (RICE) in Children and Adolescents
NCT01306643 results posted 101-10 Ph 1, Ph 2 completed Safety and Efficacy Study of Idelalisib (GS-1101, CAL-101) in Patients With Previously Treated Low-grade Lymphoma
NCT02044822 results posted GS-US-312-0133 2013-003314-41 Ph 2 terminated Efficacy and Safety of Idelalisib in Combination With Rituximab in Patients With Previously Untreated Chronic Lymphocytic Leukemia With 17p Deletion
NCT01980888 results posted GS-US-312-0123 2013-003313-17 Ph 3 terminated Efficacy and Safety of Idelalisib in Combination With Bendamustine and Rituximab in Adults With Previously Untreated Chronic Lymphocytic Leukemia
NCT01980875 results posted GS-US-312-0118 2013-004551-20 Ph 3 terminated Efficacy and Safety of Idelalisib in Combination With Obinutuzumab Compared to Chlorambucil in Combination With Obinutuzumab for Previously Untreated Chronic Lymphocytic Leukemia
NCT01393106 results posted 101-11 Ph 2 completed Safety and Efficacy of Idelalisib in Relapsed or Refractory Hodgkin Lymphoma
NCT01203930 results posted 101-08 Ph 2 terminated A Study of Idelalisib and Rituximab in Elderly Patients With Untreated CLL or SLL
NCT01732926 Bridalveil results posted GS-US-313-0125 2012-004034-42 Ph 3 terminated Efficacy and Safety of Idelalisib (GS-1101) in Combination With Bendamustine and Rituximab for Previously Treated Indolent Non-Hodgkin Lymphomas
NCT01732913 Yosemite results posted GS-US-313-0124 Ph 3 terminated Efficacy and Safety of Idelalisib (GS-1101) in Combination With Rituximab for Previously Treated Indolent Non-Hodgkin Lymphomas
NCT01838434 A051201 NCI-2012-01734, U10CA031946 Ph 1 completed Lenalidomide With or Without Idelalisib in Treating Patients With Relapsed or Refractory Mantle Cell Lymphoma
NCT01644799 A051202 CDR0000736814, NCI-2012-01988 Ph 1 completed Lenalidomide and Idelalisib in Treating Patients With Recurrent Follicular Lymphoma
NCT02662296 2561.00 NCI-2015-02201, 2561.00 Ph 2 withdrawn Ibrutinib or Idelalisib in Treating Patients With Persistent or Relapsed Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, or Non-Hodgkin Lymphoma After Donor Stem Cell Transplant

Showing 50 of 51 trials

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Active Pipeline

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

IDELALISIB FDA Label Details

Indications & Usage

IDELALISIB is indicated for the treatment of Chronic Lymphocytic Leukemia; Follicular Lymphoma; Non-Hodgkin Lymphoma.

⚠️ BOXED WARNING

WARNING: FATAL AND SERIOUS TOXICITIES: HEPATIC, SEVERE DIARRHEA, COLITIS, PNEUMONITIS, INFECTIONS, and INTESTINAL PERFORATION Fatal and/or serious hepatotoxicity occurred in 16% of Zydelig-treated patients. Monitor hepatic function prior to and during treatment. Interrupt and then reduce or disconti...

Looking for the branded version?

ZYDELIG

Full clinical data, patents, trials, and competitive landscape for idelalisib.

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Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.