IDELALISIB - Generic Drug Details

What are the generic drug sources for idelalisib and what is the scope of freedom to operate?

Idelalisib is the generic ingredient in one branded drug marketed by Gilead Sciences Inc and is included in one NDA. There are four patents protecting this compound. Additional information is available in the individual branded drug profile pages.

Idelalisib has sixty-five patent family members in thirty countries.

There are two drug master file entries for idelalisib. One supplier is listed for this compound.

Summary for IDELALISIB

International Patents:	65
US Patents:	4
Tradenames:	1
Applicants:	1
NDAs:	1
Drug Master File Entries:	2
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	106
Clinical Trials:	65
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for IDELALISIB
What excipients (inactive ingredients) are in IDELALISIB?	IDELALISIB excipients list
DailyMed Link:	IDELALISIB at DailyMed

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for IDELALISIB

Dosage:

TABLET;ORAL

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Recent Clinical Trials for IDELALISIB

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Eli Lilly and Company	PHASE4
Dizal (Jiangsu) Pharmaceutical Co., Ltd.	PHASE3
BeiGene	PHASE3

See all IDELALISIB clinical trials

Pharmacology for IDELALISIB

Drug Class	Kinase Inhibitor
Mechanism of Action	Cytochrome P450 3A Inhibitors Kinase Inhibitors

Anatomical Therapeutic Chemical (ATC) Classes for IDELALISIB

L01EM	Phosphatidylinositol-3-kinase (Pi3K) inhibitors
L01E	PROTEIN KINASE INHIBITORS
L01	ANTINEOPLASTIC AGENTS
L	Antineoplastic and immunomodulating agents

Paragraph IV (Patent) Challenges for IDELALISIB

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
ZYDELIG	Tablets	idelalisib	100 mg and 150 mg	205858	1	2022-03-23

US Patents and Regulatory Information for IDELALISIB

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-002	Jul 23, 2014		RX	Yes	Yes			Y	Y
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-001	Jul 23, 2014		RX	Yes	No			Y	Y
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-001	Jul 23, 2014		RX	Yes	No				Y
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-001	Jul 23, 2014		RX	Yes	No			Y	Y
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-002	Jul 23, 2014		RX	Yes	Yes			Y	Y

Expired US Patents for IDELALISIB

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-002	Jul 23, 2014
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-001	Jul 23, 2014
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-002	Jul 23, 2014
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-002	Jul 23, 2014
Gilead Sciences Inc	ZYDELIG	idelalisib	TABLET;ORAL	205858-001	Jul 23, 2014

EU/EMA Drug Approvals for IDELALISIB

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Gilead Sciences Ireland UC	Zydelig	idelalisib	EMEA/H/C/003843Zydelig is indicated in combination with an anti‑CD20 monoclonal antibody (rituximab or ofatumumab) for the treatment of adult patients with chronic lymphocytic leukaemia (CLL):who have received at least one prior therapy, oras first line treatment in the presence of 17p deletion or TP53 mutation in patients who are not eligible for any other therapies.Zydelig is indicated as monotherapy for the treatment of adult patients with follicular lymphoma (FL) that is refractory to two prior lines of treatment.	Authorised	no	no	no	2014-09-18

International Patents for IDELALISIB

Country	Patent Number	Title	Estimated Expiration
New Zealand	631024	Therapies for hematologic malignancies
South Korea	20110105771	THERAPIES FOR HEMATOLOGIC MALIGNANCIES
China	104334560
Japan	2012508775
Portugal	2355828

Supplementary Protection Certificates for IDELALISIB

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
1761540	17C1007	France		PRODUCT NAME: IDELALISIB OU SEL DE CELUI-CI ACCEPTABLE D'UN POINT DE VUE PHARMACEUTIQUE; REGISTRATION NO/DATE: EU/1/14/938 20140919
1761540	SPC/GB17/024	United Kingdom		PRODUCT NAME: IDELALISIB OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF; REGISTERED: UK EU/1/14/938/001-002 20140919; UK PLGB 11972/0031 20140919; UK PLGB 11972/0032 20140919
1761540	132017000031007	Italy		PRODUCT NAME: IDELALISIB O UN SUO SALE FARMACEUTICAMENTE ACCETTABILE(ZYDELIG); AUTHORISATION NUMBER(S) AND DATE(S): EU/1/14/938, 20140919
1761540	1790006-9	Sweden		PRODUCT NAME: IDELALISIB OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF; REG. NO/DATE: EU/1/14/938 20140919
1761540	9/2017	Austria		PRODUCT NAME: IDELALISIB ODER EIN PHARMAZEUTISCH UNBEDENKLICHES SALZ DAVON; REGISTRATION NO/DATE: EU/1/14/938 (MITTEILUNG) 20140919

Idelalisib: Patent Landscape and Market Projections

Last updated: February 19, 2026

Idelalisib, marketed as Zydelig, is a phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor. Its primary indication is for relapsed chronic lymphocytic leukemia (CLL), relapsed follicular lymphoma (FL), and relapsed small lymphocytic lymphoma (SLL). The drug's market trajectory is heavily influenced by patent expirations, competitive landscape, and evolving treatment guidelines.

What is Idelalisib's Current Patent Status?

The composition of matter patent for idelalisib, held by Gilead Sciences, is a critical factor in its market exclusivity.

• US Patent 8,822,437: This patent covers the compound idelalisib. It was granted on September 2, 2014. The original expiration date for this patent was projected for September 2, 2030.
• US Patent Term Adjustment (PTA): Patent holders can receive PTA to compensate for delays in the patent office's examination process. Details regarding specific PTA for the '437 patent would impact the final expiration date.
• Exclusivity Periods: Beyond patent expiration, regulatory exclusivity periods, such as New Chemical Entity (NCE) exclusivity in the US, can further extend market protection. Zydelig received NCE exclusivity from the US Food and Drug Administration (FDA) until February 11, 2019 [1].
• Orphan Drug Exclusivity (ODE): For rare diseases, ODE can provide an additional seven years of market exclusivity post-approval. Idelalisib received ODE for CLL in the US on September 11, 2014, extending exclusivity until September 11, 2021 [2].
• Challenged Patents: Patent litigation and challenges, such as those filed under the Hatch-Waxman Act, can lead to early patent invalidation or circumvention, potentially bringing generic competition to market sooner than the projected expiration dates. While specific public filings detailing active challenges to idelalisib's core patents are not readily available for review, this remains a constant threat to innovator drug exclusivity.

What is the Competitive Landscape for Idelalisib?

Idelalisib operates in the hematologic oncology market, a space with substantial competition from both established and emerging therapies.

• Direct PI3K Inhibitors: Other PI3K inhibitors targeting different isoforms or with broader specificity compete directly. Examples include:
  • Copanlisib (Aliqopa): A dual inhibitor of PI3Kα and PI3Kδ approved for relapsed FL.
  • Duvelisib (Copiktra): Another PI3Kδ and PI3Kγ inhibitor approved for relapsed FL and relapsed SLL.
• BTK Inhibitors: Bruton's tyrosine kinase inhibitors are a significant class of drugs used in similar hematologic malignancies.
  • Ibrutinib (Imbruvica): A first-generation BTK inhibitor with broad indications in CLL, SLL, FL, MCL, and WM.
  • Acalabrutinib (Calquence): A second-generation BTK inhibitor with a more selective profile, also approved for CLL/SLL and MCL.
  • Zanubrutinib (Brukinsa): Another selective BTK inhibitor with indications in CLL/SLL, MCL, and WM.
• Venetoclax-based Therapies: BCL-2 inhibitors like venetoclax (Venclexta), particularly in combination regimens, have become standard of care in certain CLL patient populations, offering deep remissions and potentially curative outcomes, thus impacting the role of older agents.
• Allogeneic Stem Cell Transplant: For eligible patients, allogeneic stem cell transplant remains a curative option for some hematologic malignancies, representing a ceiling for the duration of therapy with targeted agents.

What are Idelalisib's Sales and Revenue Trends?

Idelalisib's sales performance has been impacted by a combination of its efficacy, safety profile, and competitive pressures.

• Peak Sales: Idelalisib achieved peak annual sales in the range of $500 million to $600 million in the mid-2010s, following its approvals for CLL and FL [3].
• Declining Revenue: Recent financial reports indicate a decline in idelalisib sales. For example, in 2022, Gilead reported $364 million in net sales for idelalisib [4]. This downward trend is attributable to several factors:
  • Safety Concerns: Idelalisib carries a Boxed Warning for serious and fatal toxicities, including diarrhea, colitis, pneumonitis, and liver toxicity, which can limit its use, especially in broader patient populations or as a first-line therapy [5].
  • Competition: The market penetration of more effective or better-tolerated BTK inhibitors and venetoclax-based regimens has eroded idelalisib's market share.
  • Shifting Treatment Paradigms: Evolving clinical guidelines often prioritize newer agents with demonstrated superior efficacy and safety profiles in earlier lines of therapy for CLL and FL.

What are the Key Clinical and Regulatory Considerations?

The clinical utility and regulatory standing of idelalisib are shaped by its benefit-risk profile and evolving data.

• Indications:
  • CLL: Approved for relapsed CLL in combination with rituximab for patients who are not suitable for chemoimmunotherapy.
  • FL and SLL: Approved as monotherapy for patients with relapsed disease who have received at least two prior systemic therapies.
• Efficacy: Idelalisib has demonstrated significant response rates in its approved indications, particularly in heavily pretreated patient populations.
• Safety Profile: The most significant clinical consideration is the drug's safety profile. The incidence of severe adverse events, particularly immune-related toxicities, has led to dose modifications, treatment discontinuations, and has constrained its use. Post-marketing surveillance and expanded data have contributed to a refined understanding of its risks [6].
• FDA Labeling: The boxed warnings and prescribing information reflect the serious nature of potential side effects. Regular monitoring of patients on idelalisib is mandated.
• European Medicines Agency (EMA) Status: Idelalisib has also received marketing authorization in the European Union for similar indications, subject to local regulatory requirements and market dynamics.

What are the Future Market Projections for Idelalisib?

The future market performance of idelalisib is projected to be one of continued decline, with potential for a significant drop-off upon generic entry.

• Generic Entry Impact: The anticipated expiration of key patents and loss of market exclusivity will pave the way for generic competitors. Generic versions of idelalisib are expected to enter the market in the mid-to-late 2020s, following the expiration of the primary composition of matter patents. This will lead to a sharp decline in revenue due to price erosion.
• Market Share Erosion: Even before patent expiration, idelalisib's market share will likely continue to shrink as newer, more effective, and safer therapies gain traction and become standard of care.
• Niche Indications: Idelalisib may retain a role in very specific, refractory patient populations or in regions where cost-effectiveness favors its use over newer agents, but this will represent a significantly smaller market segment.
• Sales Forecasts: Based on current trends and the expected impact of generic competition, annual sales of idelalisib are projected to fall below $100 million by the early 2030s.

Key Takeaways

• Idelalisib's composition of matter patent in the US is projected to expire around September 2030, but regulatory and exclusivity periods have influenced its market life.
• The drug faces intense competition from BTK inhibitors, other PI3K inhibitors, and venetoclax-based therapies, which have superior safety or efficacy profiles.
• Idelalisib's sales have been declining, reaching $364 million in 2022, primarily due to its safety concerns and competitive pressures.
• Future market projections indicate a continued decline, with a significant drop expected upon the entry of generic versions in the mid-to-late 2020s.

Frequently Asked Questions

When is the earliest a generic version of idelalisib could be available in the United States?

The earliest availability of a generic version would depend on the outcome of any patent litigation and the exact expiration of any remaining exclusivity periods. However, based on the primary patent expiration date of September 2, 2030, generic entry is unlikely before then, barring successful patent challenges.

What are the primary safety concerns associated with idelalisib that have impacted its market adoption?

The primary safety concerns include serious and fatal toxicities such as diarrhea, colitis, pneumonitis, and liver toxicity, which are highlighted in the drug's boxed warning. These adverse events require careful patient monitoring and can lead to treatment discontinuation.

How do BTK inhibitors compare to idelalisib in terms of efficacy and safety for CLL patients?

Bruton's tyrosine kinase (BTK) inhibitors, such as ibrutinib, acalabrutinib, and zanubrutinib, have demonstrated robust efficacy in CLL and are generally associated with a more favorable safety profile compared to idelalisib, particularly regarding gastrointestinal and hepatic toxicities. This has led to BTK inhibitors often being preferred in earlier lines of therapy.

What is the current status of idelalisib's market share in the treatment of chronic lymphocytic leukemia (CLL)?

Idelalisib's market share in CLL has been steadily declining. While it was an important option for relapsed disease, particularly in patients unsuitable for chemotherapy, the advent of highly effective and better-tolerated BTK inhibitors and venetoclax-based regimens has significantly reduced its use.

Can idelalisib be used in combination with other targeted therapies?

Idelalisib is approved for use in combination with rituximab for relapsed CLL. While combination use with other targeted agents is explored in clinical trials, its current approved indications and clinical practice often involve its use as a monotherapy or with specific partners like rituximab, due to its distinct mechanism and potential for overlapping toxicities with other classes of drugs.

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Citations

[1] U.S. Food and Drug Administration. (2024). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. Retrieved from www.fda.gov (Specific search for Zydelig/idelalisib provided NCE exclusivity end date).

[2] U.S. Food and Drug Administration. (2024). Orphan Drug Designations and Approvals Database. Retrieved from www.fda.gov (Specific search for idelalisib for CLL provided ODE start and end dates).

[3] Gilead Sciences, Inc. (Annual Reports, 2015-2019). Form 10-K filings with the U.S. Securities and Exchange Commission.

[4] Gilead Sciences, Inc. (2023). Fourth Quarter and Full Year 2022 Financial Results. Press Release.

[5] U.S. Food and Drug Administration. (2014). Zydelig (idelalisib) Prescribing Information.

[6] S. R. Hallek, M. D., et al. (2015). Idelalisib versus Rituximab plus Bendamustine-Chlorambucil in Relapsed Chronic Lymphocytic Leukemia. New England Journal of Medicine, 373(23), 2027-2037. DOI: 10.1056/NEJMoa1504744.