US Patent 9,149,477: Duvelisib PI3K Inhibitor Claims, Expiration, and Generic Risk

US Patent No. 9,149,477 is part of the U.S. patent estate for duvelisib, marketed as COPIKTRA. The patent protects methods using the S-enantiomer of a PI3K inhibitor, including methods directed specifically to phosphatidylinositol 3-kinase delta, or PI3K-delta, activity. Its principal commercial relevance is the protection of duvelisib treatment methods for hematologic malignancies.

The patent is a method-of-use patent rather than a basic composition patent. It does not, by the supplied claims alone, independently claim every formulation, salt, crystal form, manufacturing process, or therapeutic indication for duvelisib.

What drug and technology does US Patent 9,149,477 cover?

US 9,149,477 covers PI3K inhibitor compounds associated with duvelisib, also known as IPI-145. Duvelisib is an oral dual PI3K-delta and PI3K-gamma inhibitor. COPIKTRA is approved for certain patients with chronic lymphocytic leukemia, small lymphocytic lymphoma, and follicular lymphoma after prior therapy.[1]

The compound-specific portions of claims 4, 7, and 11 are represented as missing structures in the supplied transcription. The patent’s operative claim scope therefore depends on the chemical structures and formula definitions appearing in the issued patent. The S-enantiomer limitations in claims 3, 5, 6, 8, 10, and 12 are commercially important because the approved drug is the S-enantiomer of the relevant chiral compound.

Patent identification

Item	Data
Patent	U.S. Patent No. 9,149,477
Title	Phosphoinositide 3-kinase inhibitors
Grant date	September 29, 2015
Original assignee	Infinity Pharmaceuticals, Inc.
Technology	PI3K inhibitor compounds and therapeutic use
Key product	Duvelisib, IPI-145, COPIKTRA
Principal target	PI3K-delta, with activity against PI3K-gamma
Patent type	Method-of-use and compound-specific method claims
Earliest relevant priority	March 4, 2010, based on the patent family record
Standard patent expiration	March 4, 2031, subject to any applicable term adjustment or extension

The patent should be analyzed together with earlier and later members of the duvelisib patent family. Patent-family chronology is important because a continuation can have a later grant date while retaining an earlier priority date.

What do the claims of US 9,149,477 cover?

The claims form two principal groups:

General PI3K-inhibition methods.
PI3K-delta inhibition methods using the claimed compound or its S-enantiomer.

Claim-by-claim scope

Claim	Scope
1	Method of inhibiting PI3K activity in a cell using the claimed compound or pharmaceutically acceptable salt
2	Claim 1 plus administration to an individual in need
3	Claim 2 limited to the S-enantiomer or a pharmaceutically acceptable salt
4	Claim 2 limited to a specified compound structure
5	Claim 4 limited to the S-enantiomer
6	Claim 1 limited to the S-enantiomer
7	Claim 1 limited to another specified compound structure
8	Claim 7 limited to the S-enantiomer
9	Method of inhibiting PI3K-delta in a cell by administering the compound to an individual
10	Claim 9 limited to the S-enantiomer
11	Claim 9 limited to a specified compound structure
12	Claim 11 limited to the S-enantiomer

What is the legal significance of the S-enantiomer claims?

The S-enantiomer claims are narrower than the broader compound or racemate claims but are more closely aligned with the approved active pharmaceutical ingredient. A generic applicant seeking to market the same active enantiomer would face greater exposure under claims 3, 5, 6, 8, 10, and 12 than under a claim limited to a racemate that the generic does not intend to sell.

The claims also cover pharmaceutically acceptable salts. A salt conversion generally does not avoid a claim that expressly includes the salt form, although infringement depends on the precise claim language, product identity, and proposed commercial use.

Does US 9,149,477 claim duvelisib itself?

Yes, in practical commercial terms. The compound-specific claims and S-enantiomer claims are directed to the active compound used in COPIKTRA. The patent’s method claims are framed around use in inhibiting PI3K or PI3K-delta rather than as a standalone composition claim.

That distinction matters:

A product claim can directly cover manufacture, sale, or possession of the claimed compound.
A method claim generally requires performance of the claimed therapeutic method.
A method claim directed to administration can be relevant to an ANDA applicant whose label instructs physicians to use the generic product for the patented indication.
A label carve-out may reduce risk only if the omitted indication is not necessary to practice the asserted claim.

Because claim 1 refers to inhibition of PI3K activity and claim 9 refers specifically to PI3K-delta activity, the patent has broad target-based language in addition to the compound-specific limitations.

When does US Patent 9,149,477 expire?

The expected standard expiration date is March 4, 2031, based on the patent family’s earliest priority date. The operative date should be confirmed against the USPTO patent-term calculation and the current FDA Orange Book listing.

The relevant exclusivity timeline is:

Event	Date
Earliest family priority	March 4, 2010
Patent grant	September 29, 2015
COPIKTRA U.S. approval	September 24, 2018
Five-year new chemical entity exclusivity	Approximately through September 24, 2023
Expected patent expiration	March 4, 2031

The patent and regulatory exclusivity are separate rights. FDA NCE exclusivity prevented submission of an ANDA for five years, subject to statutory exceptions. The patent can continue to block or complicate generic entry after NCE exclusivity ends.

What is the Orange Book status of COPIKTRA?

COPIKTRA’s U.S. regulatory protection is based on a combination of FDA exclusivity and listed patents. The FDA-approved product contains duvelisib capsules in 15-mg and 25-mg strengths.[1]

The Orange Book analysis should distinguish among:

Drug-substance or composition patents;
Method-of-use patents;
Formulation patents;
Polymorph or crystal-form patents;
Manufacturing patents;
Pediatric exclusivity;
Patent-term extension or patent-term adjustment.

US 9,149,477 is commercially significant because it is associated with the approved drug’s therapeutic use and PI3K-delta mechanism. It should not be treated as the entire COPIKTRA patent estate. The earlier US 8,563,572 patent and related family members must be reviewed separately for overlapping compound, use, and priority claims.[2]

What formulation patents protect COPIKTRA?

US 9,149,477, based on the supplied claims, does not primarily protect a capsule formulation, excipient system, dissolution profile, or solid-state form. Its claims focus on using a PI3K inhibitor, particularly the S-enantiomer, to inhibit PI3K or PI3K-delta.

A competitor could therefore face separate barriers from patents covering:

Duvelisib composition;
Specific salts;
Crystalline or amorphous forms;
Capsule formulations;
Particle size or dissolution properties;
Manufacturing and purification;
Treatment of particular cancers.

The absence of a formulation limitation in the asserted claims can increase flexibility for the patent holder. A generic formulation that uses a different excipient system may still implicate method claims if it contains the claimed active ingredient and carries instructions for the patented use.

What method-of-use protection does the patent provide?

The patent has two method-of-use layers.

General PI3K inhibition

Claims 1 through 8 cover inhibition of PI3K activity in a cell, with dependent claims adding administration to an individual and narrowing the active compound to specified structures or the S-enantiomer.

PI3K-delta inhibition

Claims 9 through 12 focus on inhibiting PI3K-delta activity by administering the compound. These claims are closer to the pharmacological profile of duvelisib and may be particularly relevant to treatment indications in B-cell malignancies.

The claims do not, in the supplied text, expressly recite chronic lymphocytic leukemia, small lymphocytic lymphoma, or follicular lymphoma. That can affect the analysis of label-based infringement and potential section viii carve-outs. The complete issued claims and specification must be read to determine whether the claimed compound definitions, therapeutic examples, or incorporated limitations narrow the apparent breadth.

How strong is the patent estate for duvelisib?

The estate is commercially meaningful but structurally mixed.

Strength factor	Assessment
Approved active covered	Strong, because the S-enantiomer is expressly claimed
Target relevance	Strong, because PI3K-delta inhibition is expressly claimed
Salt coverage	Present in the supplied claims
Composition protection	Must be analyzed through related patents, not only US 9,149,477
Formulation coverage	Not apparent from the supplied claims
Indication specificity	Limited in the quoted claims
Patent duration	Extends into 2031 on the family priority basis
Design-around potential	Higher for nonclaimed compounds, targets, or uses
Generic risk	High for an ANDA using duvelisib for the approved indications

The strongest infringement theory would generally involve a generic product containing the same S-enantiomer, accompanied by labeling that instructs use for PI3K or PI3K-delta-mediated indications. A product using a different active compound would face a lower direct infringement risk under these claims but could encounter separate family patents.

Which companies are challenging COPIKTRA exclusivity?

No approved generic duvelisib product is identified in the FDA approval history through the cited regulatory materials. Publicly meaningful Paragraph IV risk would normally appear through ANDA litigation, a district court complaint, a declaratory judgment action, or a settlement announcement.

A Paragraph IV certification against US 9,149,477 could trigger patent litigation under 35 U.S.C. §271(e)(2). The patent holder could seek the statutory 30-month stay of FDA approval, subject to the filing date and litigation outcome.[3]

The commercial risk is higher if an ANDA applicant challenges both the compound patent family and the method patents. A successful attack on one patent would not necessarily permit launch if another Orange Book-listed patent remains enforceable.

What litigation and settlement issues affect generic launch?

The key litigation questions are:

Whether US 9,149,477 is listed for the specific approved strengths and indications.
Whether an ANDA applicant files a Paragraph IV certification.
Whether the patent holder sues within the statutory 45-day period.
Whether the ANDA label includes or carves out the patented methods.
Whether the asserted claims survive written-description, enablement, anticipation, obviousness, and claim-construction challenges.
Whether any settlement includes a delayed-entry date, license, authorized generic arrangement, or supply agreement.

The supplied record does not establish a public settlement granting an early generic-entry date. A settlement cannot be inferred merely from the patent’s grant or Orange Book listing.

How does duvelisib compare with competing PI3K inhibitors?

Drug	Target profile	Product status	Commercial patent comparison
Duvelisib, COPIKTRA	PI3K-delta and PI3K-gamma	FDA-approved	US 9,149,477 and related family protection through approximately 2031
Idelalisib, Zydelig	PI3K-delta	FDA-approved	Separate Gilead patent estate; earlier commercial launch
Umbralisib, Ukoniq	PI3K-delta and CK1-epsilon	U.S. approval withdrawn	Commercial and regulatory status materially weaker after withdrawal
Parsaclisib	PI3K-delta	Development-stage or discontinued by program	No equivalent approved-product entry position
Nemiralisib	PI3K-delta	Investigational	Respiratory and inflammatory development focus

Duvelisib’s differentiation is its dual delta/gamma activity and its patent claims directed to the S-enantiomer. Idelalisib has a different chemical structure and separate patent landscape, so a generic challenge to duvelisib would not automatically create a substitution pathway based on idelalisib patents.

What generic launch scenarios exist?

Launch after patent expiration

The lowest-risk scenario is launch after expiration of all blocking patents and any applicable regulatory exclusivity. On the current family chronology, March 2031 is the key date for US 9,149,477.

Launch after a successful Paragraph IV challenge

An ANDA applicant could launch before patent expiration if it obtains a favorable judgment, the patent is not asserted, or the listed patent is otherwise removed as a barrier. This route carries litigation cost and possible damages exposure.

Label carve-out launch

A generic applicant may omit a patented method from its labeling under the section viii pathway if the remaining label does not encourage infringement. This strategy is less certain where the patent claims broadly cover the active ingredient’s central pharmacology rather than a narrow disease indication.

Authorized or licensed launch

A license or authorized-generic arrangement could permit earlier entry. No such arrangement is established by the supplied patent record.

What are the geographic and manufacturing barriers?

US 9,149,477 is a U.S. patent. It does not, by itself, block manufacture or sale outside the United States. Foreign family members must be reviewed individually because claim scope, prosecution history, validity standards, and expiration dates vary by jurisdiction.

Manufacturing risk can arise from separate patents covering:

Enantiomer resolution;
Chiral synthesis;
Intermediate compounds;
Salt formation;
Purification;
Crystallization;
Finished-dose manufacture.

A manufacturer could avoid the method claims by producing a nonclaimed compound, but that strategy would not avoid composition or process patents in related families.

Key Takeaways

US 9,149,477 is a duvelisib-related PI3K inhibitor patent.
Its principal claims cover methods of inhibiting PI3K and PI3K-delta using the claimed compound, its S-enantiomer, or pharmaceutically acceptable salts.
The patent is commercially aligned with COPIKTRA’s active ingredient and mechanism.
The expected standard expiration date is March 4, 2031.
The patent is a method-of-use patent and should be analyzed with US 8,563,572 and other related composition, formulation, and manufacturing patents.
A generic using the same S-enantiomer for approved COPIKTRA indications would face substantial Paragraph IV and label-based infringement risk.
The quoted claims do not by themselves establish formulation protection, a particular cancer indication, or an early-entry settlement.
Duvelisib’s patent position remains dependent on the validity and enforceability of the broader patent family, not US 9,149,477 alone.

FAQs

Does US 9,149,477 cover a racemic mixture of duvelisib?

The supplied claims include broader compound language, but multiple dependent claims expressly narrow coverage to the S-enantiomer. Whether a racemate is covered depends on the complete chemical definitions and claim construction.

Can a generic avoid US 9,149,477 by using a different salt?

Not necessarily. The quoted claims expressly include pharmaceutically acceptable salts. A different salt may avoid a claim only if it falls outside the patent’s chemical and salt definitions.

Does the patent cover PI3K-gamma inhibition?

The claims quoted expressly identify PI3K generally and PI3K-delta specifically. They do not separately recite PI3K-gamma. Duvelisib’s PI3K-gamma pharmacology may be relevant to the specification and other patent claims, but it cannot be assumed to be independently claimed here.

Is US 9,149,477 a formulation patent?

No. The quoted claims are directed to therapeutic inhibition of PI3K or PI3K-delta. Separate formulation, solid-form, or manufacturing patents would require independent analysis.

Could COPIKTRA face biosimilar competition?

No conventional biosimilar pathway applies because duvelisib is a small-molecule drug. Competition would proceed through the ANDA generic-drug pathway, not the biologics license application and biosimilar pathway.

References

U.S. Food and Drug Administration. (2018). COPIKTRA (duvelisib) prescribing information. FDA.
U.S. Patent and Trademark Office. (2015). U.S. Patent No. 9,149,477: Phosphoinositide 3-kinase inhibitors. U.S. Department of Commerce.
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. FDA.
U.S. Food and Drug Administration. (2024). Abbreviated new drug application regulations and patent certifications. FDA.
U.S. Food and Drug Administration. (2022). Withdrawal of approval of Ukoniq (umbralisib). FDA.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1761540	⤷ Start Trial	PA2017004	Lithuania	⤷ Start Trial
European Patent Office	1761540	⤷ Start Trial	300867	Netherlands	⤷ Start Trial
European Patent Office	1761540	⤷ Start Trial	122017000008	Germany	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,149,477

Summary for Patent: 9,149,477