Details for Patent: 8,791,270

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Which drugs does patent 8,791,270 protect, and when does it expire?

Patent 8,791,270 protects BELRAPZO, BENDEKA, and TREANDA, and is included in three NDAs.

Protection for TREANDA has been extended six months for pediatric studies, as indicated by the *PED designation in the table below.

This patent has thirty-four patent family members in twenty countries.

Summary for Patent: 8,791,270

Title:	Bendamustine pharmaceutical compositions
Abstract:	The present invention provides pharmaceutical formulations of lyophilized bendamustine suitable for pharmaceutical use. The present invention further provides methods of producing lyophilized bendamustine. The pharmaceutical formulations can be used for any disease that is sensitive to treatment with bendamustine, such as neoplastic diseases.
Inventor(s):	Jason Edward BRITTAIN, Joe Craig Franklin
Assignee:	Cephalon LLC
Application Number:	US13/969,724
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,791,270
Patent Claim Types: see list of patent claims	Use; Composition;

US Patent 8,791,270: Bendamustine Hydrochloride Composition Claims and Patent Landscape

US Patent 8,791,270 protects bendamustine hydrochloride compositions defined by impurity levels, particularly the degradation product identified as HP1. Its strongest commercial relevance is to lyophilized bendamustine products that are reconstituted before administration. The patent does not claim bendamustine as a molecule, a broad cancer-treatment method, or every bendamustine formulation.

The central infringement question is whether a competing product, after reconstitution or in its finished dosage form, contains HP1 and total bendamustine degradants within the claimed analytical limits.

What does US Patent 8,791,270 claim?

US 8,791,270 contains composition and method-of-treatment claims directed to bendamustine hydrochloride purity profiles. The claims fall into four groups.

Claim group	Claims	Principal limitation
Reconstituted lyophilized composition	1-6	HP1 at no more than about 0.9%, 0.5%, or 0.4% area percent of bendamustine
Total degradant composition	7-19	Total bendamustine degradants at no more than 4.0%, generally 2.0%-4.0%
Formula IV impurity	13, 19	Formula IV compound at no more than about 0.5%
Treatment method	20-23	Administration of a claim 7 composition to treat specified cancers

The claims use area-percent measurements rather than weight percent or molar concentration. That distinction is central. A product may satisfy a claim even if the absolute impurity mass is low, provided the impurity peak represents the claimed proportion of the bendamustine chromatographic area.

What is the scope of claim 1?

Claim 1 requires a pharmaceutical composition that:

1. Contains bendamustine or bendamustine hydrochloride;
2. Has been reconstituted from a lyophilized preparation; and
3. Contains no more than about 0.9 area percent HP1 relative to bendamustine.

The claim is product-focused. It does not require a particular vial size, excipient, dose, reconstitution solvent, administration route, or cancer indication.

The claim also does not expressly require the composition to be immediately administered. A finished composition prepared from a lyophilized product may fall within the claim before administration if the impurity and reconstitution limitations are met.

Claims 2, 4 and 6 specify that the HP1 measurement is taken at "time zero" after reconstitution. Claims 3-6 narrow the HP1 limit to 0.5% or 0.4%.

What does "time zero" mean?

"Time zero" is a claim-construction and testing issue. The claim language links the measurement to the composition shortly after reconstitution, rather than to the lyophilized cake before reconstitution or to a later stability time point.

A dispute may focus on:

• The precise interval constituting time zero;
• Whether the sample must be tested immediately after reconstitution;
• The reconstitution solvent and volume;
• Agitation and sampling conditions;
• HPLC or other chromatographic method;
• Treatment of co-eluting peaks;
• Whether HP1 is quantified against total bendamustine area or another reference.

The patent's numerical limitations are vulnerable to testing variability if the patent and accused-product methods produce materially different results.

How broad are claims 7 through 19?

Claim 7 is the broadest independent composition claim in the issued set. It covers a pharmaceutical composition of bendamustine hydrochloride containing no more than 4.0 area percent of bendamustine degradants.

Unlike claim 1, claim 7 does not require the composition to have been reconstituted from a lyophilized preparation. Claims 14 and 15 expressly cover lyophilized compositions, while claims 9-12 add reconstitution and HP1 restrictions.

The structure is important:

• Claim 7 covers the composition based on total degradants.
• Claim 8 narrows the degradant range to approximately 2.0%-4.0%.
• Claim 9 requires a reconstituted lyophilized composition.
• Claims 10-12 add HP1 thresholds.
• Claim 13 adds a Formula IV threshold.
• Claims 16-19 add HP1 or Formula IV limitations directly to claim 7.

The 2.0%-4.0% range in claim 8 is unusual from an invalidity and infringement perspective. A product with less than 2.0% total degradants may avoid claim 8 while still potentially satisfying claim 7. A product above 4.0% may avoid both claims 7 and 8, subject to measurement accuracy.

What products are most exposed to US 8,791,270?

The highest-risk products are lyophilized bendamustine hydrochloride injections that generate low HP1 and low total degradant levels after reconstitution.

Product characteristic	Exposure under US 8,791,270
Lyophilized bendamustine HCl vial	High
Reconstituted lyophilized vial with HP1 below 0.9%	High under claims 1-6
Reconstituted vial with HP1 below 0.4%	Potentially high under claims 5, 6 and 12
Product with total degradants below 4.0%	Potentially high under claim 7
Product with total degradants between 2.0% and 4.0%	Potentially high under claim 8
Ready-to-dilute liquid formulation	Depends on whether it satisfies claim 7; claims 1-6 may not apply
Product with HP1 above 0.9%	Lower exposure under claims 1-6, but claim 7 may remain relevant
Product with total degradants above 4.0%	Lower exposure under claim 7, subject to testing
Bendamustine free-base product	Claim 7 expressly refers to bendamustine hydrochloride; product composition must be analyzed separately

The patent does not require a particular impurity-control process. A competitor could infringe with a different manufacturing process if the finished product meets the claimed composition limits.

What are the key claim-construction issues?

"Pharmaceutical composition"

The phrase likely requires a composition intended for pharmaceutical use, not merely an analytical sample or intermediate. The claims do not appear limited to a particular excipient system.

"Bendamustine degradants"

Claim 7 raises an identification issue. The claim refers to total bendamustine degradants, while claims 1-6 identify HP1 specifically. A party asserting the patent would need to establish which chromatographic peaks qualify as bendamustine degradants and how the total is calculated.

"About"

The word "about" gives some tolerance around the numerical limits but does not eliminate the need for a defined analytical result. The practical dispute will be whether a measured result near 0.9%, 0.5%, 0.4%, or 4.0% falls within the permitted range.

"Area percent of bendamustine"

This is not a conventional percentage of total product weight. It is an analytical purity measurement, generally based on chromatographic peak areas. A specification that reports impurity levels by weight percent may not directly establish infringement or noninfringement.

Formula IV

Claims 13 and 19 depend on a specific compound of Formula IV. The exact chemical identity and analytical method must be matched to the patent disclosure. A generic impurity result cannot establish Formula IV infringement unless the compound has been correctly identified.

What is the legal status and expected expiration of US 8,791,270?

US 8,791,270 is an issued U.S. utility patent relating to bendamustine hydrochloride compositions. Patent term generally runs 20 years from the earliest effective nonprovisional U.S. filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable statutory adjustments under 35 U.S.C. §§ 154 and 156.[1]

The patent was issued on July 29, 2014. Public patent-family records associate the application with the bendamustine hydrochloride composition disclosure and a priority history preceding issuance.[2] A precise enforceability and expiration analysis requires the issued patent's continuity data, terminal-disclaimer status, and USPTO patent-term-adjustment calculation. The expected commercial planning window is the late 2020s or approximately 2030, rather than the earlier expiration period associated with the original bendamustine compound patent.

The patent term should not be confused with FDA regulatory exclusivity. A patent can remain in force after FDA exclusivity expires, and FDA exclusivity can expire before relevant patents.

What is the Orange Book status of US 8,791,270?

The Orange Book question is product-specific. A patent is relevant to an ANDA only if it is listed for the particular reference product and dosage form. FDA Orange Book listings identify patents submitted by the NDA holder and do not determine patent validity or infringement.[3]

For bendamustine, the relevant reference-product categories have included:

• Treanda, an injectable bendamustine hydrochloride product;
• Bendeka, a ready-to-dilute bendamustine hydrochloride injection;
• Generic bendamustine hydrochloride products approved through the ANDA pathway.

US 8,791,270 is most commercially relevant to lyophilized bendamustine products. Its relevance to a ready-to-dilute liquid product depends on whether the product satisfies the independent composition limitations, particularly claim 7.

An Orange Book listing would create a potential Paragraph IV notice issue for an ANDA applicant. The listing itself would not prove that the product infringes. The applicant could assert that the patent is invalid, unenforceable, not infringed, or inapplicable to the proposed formulation.

When does generic entry occur under a Paragraph IV challenge?

For an ANDA referencing a listed bendamustine product, a Paragraph IV certification can trigger patent litigation under the Hatch-Waxman Act. A timely infringement action by the patent owner may impose a 30-month stay of FDA approval, subject to statutory exceptions and court rulings.[4]

A generic applicant targeting a lyophilized bendamustine product would likely need to address:

1. Whether its reconstituted product contains HP1 below the claimed threshold;
2. Whether total bendamustine degradants are no more than 4.0%;
3. Whether Formula IV is below 0.5%;
4. Whether the proposed labeling practices induce use of a patented treatment method;
5. Whether the patent is listed against the relevant reference product;
6. Whether other bendamustine patents create separate approval or launch barriers.

A noninfringement strategy could use a formulation or process that produces impurity levels outside the claim ranges. That strategy carries regulatory and commercial tradeoffs because higher degradation may affect product quality, stability, or approval prospects.

Does the patent create biosimilar risk?

No. Bendamustine is a small-molecule drug. Competitors generally use the ANDA pathway, not the Biologics Price Competition and Innovation Act biosimilar pathway.[5]

The relevant risks are generic competition, patent litigation, formulation differentiation, and possible authorized-generic entry. Biosimilar concepts such as interchangeability, reference biologic exclusivity, and Purple Book listings do not apply.

What manufacturing and formulation barriers does the patent create?

The patent may increase the value of formulation and analytical-control capabilities. A competitor must control:

• Bendamustine hydrochloride degradation during manufacture;
• Moisture and thermal exposure;
• Lyophilization-cycle conditions;
• Reconstitution stability;
• HP1 generation;
• Formula IV formation;
• Container-closure performance;
• Assay reproducibility.

The patent does not claim a particular lyophilization cycle in the provided claims. A competitor therefore cannot avoid infringement solely by using a different cycle if the resulting composition meets the claim limits.

The most defensible design-around is a product outside the claimed impurity profile, not simply a different excipient or manufacturing sequence. That approach must still satisfy FDA chemistry, manufacturing, and controls requirements.

How does US 8,791,270 compare with the core bendamustine patent?

The original bendamustine patent estate protected the active pharmaceutical ingredient and related chemical subject matter. US 8,791,270 is different because it focuses on product quality after manufacture and, in several claims, after reconstitution.

Issue	Core bendamustine patent	US 8,791,270
Primary subject matter	Bendamustine compound and related chemistry	Bendamustine hydrochloride impurity profile
Product-stage focus	Active ingredient	Finished or reconstituted composition
Main limitation	Chemical structure or use	HP1 and total degradant thresholds
Generic risk	Compound-patent expiration	Formulation and purity-based infringement
Design-around	Alternative active ingredient or route	Different impurity profile or formulation
Biosimilar relevance	None	None

The later patent can remain commercially important after earlier compound protection ends because it may constrain a specific finished-product profile.

What patent litigation and settlement issues matter?

The supplied claim text does not establish a current litigation docket, Paragraph IV notice, or settlement agreement involving US 8,791,270. Those matters must be evaluated from PACER, FDA Orange Book records, ANDA litigation notices, and company disclosures rather than inferred from the claims.

For diligence, the critical litigation questions are:

• Whether the patent was asserted against an ANDA applicant;
• Whether the case was dismissed, settled, or adjudicated;
• Whether a settlement permits an agreed generic launch date;
• Whether the patent was delisted or disclaimed;
• Whether a terminal disclaimer limits its enforceable term;
• Whether claim construction addressed HP1, Formula IV, or area-percent testing.

How strong is the patent estate?

The patent has meaningful claim breadth at the composition level but substantial proof burdens.

Strengths include:

• Claim 7 does not require lyophilization;
• The claims cover measurable finished-product attributes;
• Claims 1-6 target reconstituted lyophilized products;
• Method claims extend protection to specified cancer treatments;
• A different manufacturing process does not avoid product claims.

Weaknesses include:

• Dependence on analytical testing;
• Potential ambiguity around total degradants;
• Potential disputes over "time zero";
• Numerical thresholds close to ordinary assay variability;
• Limited cancer-indication coverage in claims 20-23;
• Lack of a claim to the active molecule itself;
• Potential design-around through a materially different impurity profile.

The patent is stronger against a product whose batch-release and stability data clearly fall inside the claimed ranges. It is weaker where results are near the thresholds, the testing method differs, or the accused product is a non-lyophilized liquid with impurity levels outside claims 1-6.

Key Takeaways

• US 8,791,270 is a bendamustine hydrochloride formulation and impurity patent.
• Claims 1-6 focus on reconstituted lyophilized products with HP1 at or below 0.9%, 0.5%, or 0.4%.
• Claim 7 is the broadest independent claim and covers bendamustine hydrochloride compositions with total degradants at or below 4.0%.
• Claims 13 and 19 separately limit Formula IV to about 0.5%.
• The principal infringement evidence will be chromatographic impurity data, not the manufacturing process alone.
• Generic applicants face ANDA and possible Paragraph IV issues, subject to Orange Book listing status.
• Bendamustine is a small molecule, so biosimilar rules do not apply.
• The practical patent term is likely in the late 2020s or around 2030, subject to the official USPTO term calculation.
• The principal design-around is a finished product outside the claimed impurity ranges while remaining compliant with FDA quality requirements.

FAQs

Can a liquid bendamustine product infringe US 8,791,270?

Yes, potentially under claim 7 if it is a bendamustine hydrochloride pharmaceutical composition with total degradants at or below 4.0%. Claims requiring reconstitution from a lyophilized preparation would be less directly applicable.

Does exceeding 0.9% HP1 avoid the entire patent?

No. It may avoid claims 1-6, but claim 7 and related claims may still apply if total degradants remain at or below 4.0% and other limitations are met.

Does a different reconstitution solvent avoid infringement?

Not necessarily. A different solvent may avoid a claim only if the resulting product fails a required limitation, such as the lyophilized-reconstitution requirement or the HP1 threshold.

Can a generic applicant challenge the patent without changing its formulation?

Yes. An ANDA applicant may pursue Paragraph IV invalidity, unenforceability, or noninfringement positions. The applicant would still need to address the patent's relevance to the reference product and proposed product.

Is claim 20 limited to chronic lymphocytic leukemia?

Claim 20 is not limited to one cancer indication. Claims 21-23 narrow the treatment method to listed cancers, including chronic lymphocytic leukemia and non-Hodgkin's lymphoma.

References

1. United States Code. (2024). 35 U.S.C. §§ 154, 156.
2. United States Patent and Trademark Office. (2014). Bendamustine hydrochloride compositions, U.S. Patent No. 8,791,270.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations (Orange Book).
4. United States Code. (2024). 21 U.S.C. § 355(j).
5. U.S. Food and Drug Administration. (2024). Biosimilar and interchangeable biologic products.

Drugs Protected by US Patent 8,791,270

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Eagle Pharms	BELRAPZO	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	205580-001	May 15, 2018	AP	RX	Yes	Yes	8,791,270		Y			FOR THE TREATMENT OF PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA
Eagle Pharms	BELRAPZO	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	205580-001	May 15, 2018	AP	RX	Yes	Yes	8,791,270		Y			FOR THE TREATMENT OF PATIENTS WITH INDOLENT B-CELL NON-HODGKIN LYMPHOMA
Eagle Pharms	BENDEKA	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	208194-001	Dec 7, 2015		RX	Yes	Yes	8,791,270		Y			FOR USE IN TREATMENT OF PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND/OR NON-HODGKIN'S LYMPHOMA

International Family Members for US Patent 8,791,270

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	052877
Australia	2006204817
Brazil	PI0606332