# Idelalisib

Idelalisib (Zydelig, Gilead Sciences Ireland UC) has 3 EU-approved indications in 2 tumour types. 1 needs a biomarker result: TP53/del(17p) (1).

## Approved indications

### Chronic lymphocytic leukaemia

| Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|
| 17p deletion or TP53 mutation | + rituximab | 1st line | Not eligible for any other therapies |
| None | + rituximab | 2nd line | After at least one prior therapy |

### Follicular lymphoma

| Biomarker requirement | Regimen | Setting | Conditions |
|---|---|---|---|
| None | Monotherapy | 3rd line+ | Refractory to two prior lines of treatment |

## Products

### Zydelig

- Company: Gilead Sciences Ireland UC
- Target: PI3Kδ inhibitor
- Class: Other antineoplastic agents
- ATC: L01XX47
- EU approval: 18 Sep 2014
- Label revised: 21 Oct 2024
- SmPC (EN): https://www.ema.europa.eu/en/documents/product-information/zydelig-epar-product-information_en.pdf
- Fachinformation (DE): https://www.ema.europa.eu/de/documents/product-information/zydelig-epar-product-information_de.pdf
- EPAR: https://www.ema.europa.eu/en/medicines/human/EPAR/zydelig

Mechanism (SmPC section 5.1): Idelalisib selectively inhibits PI3Kδ by blocking ATP binding to its catalytic domain, preventing Akt phosphorylation and inducing apoptosis in malignant B-cells.

## Label wording

- **Idelalisib** (Zydelig), Chronic lymphocytic leukaemia, 2nd line: “Zydelig is indicated in combination with rituximab for the treatment of adult patients with chronic lymphocytic leukaemia (CLL):
• who have received at least one prior therapy (see section 4.4), or
• as first line treatment in the presence of 17p deletion or TP53 mutation in patients who are not eligible for any other therapies (see section 4.4).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/zydelig-epar-product-information_en.pdf)
- **Idelalisib** (Zydelig), Chronic lymphocytic leukaemia, 1st line: “Zydelig is indicated in combination with rituximab for the treatment of adult patients with chronic lymphocytic leukaemia (CLL):
• who have received at least one prior therapy (see section 4.4), or
• as first line treatment in the presence of 17p deletion or TP53 mutation in patients who are not eligible for any other therapies (see section 4.4).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/zydelig-epar-product-information_en.pdf)
- **Idelalisib** (Zydelig), Follicular lymphoma, 3rd line+: “Zydelig is indicated as monotherapy for the treatment of adult patients with follicular lymphoma (FL) that is refractory to two prior lines of treatment (see section 4.4).” [SmPC](https://www.ema.europa.eu/en/documents/product-information/zydelig-epar-product-information_en.pdf)

Source: section 4.1 of each summary of product characteristics (SmPC), EMA data as of 5 Nov 2026. AI models structured these entries and no person has checked them yet. oncolabels is a non-commercial reference for education and research and gives no medical advice; the current SmPC takes precedence.

Data under CC BY 4.0: credit oncolabels and the European Medicines Agency. Page: https://oncolabels.com/drugs/idelalisib