United States Drug Patent 7,351,701: Claim Scope, Expiration, Orange Book Status, and PARP-Inhibitor Patent Landscape

U.S. Patent No. 7,351,701 is a method-of-treatment patent directed to treating BRCA1- or BRCA2-deficient cancer with specified cytotoxic compounds. Its principal protection is the combination of three elements: selecting a mammal with a homologous-recombination defect, identifying BRCA1 or BRCA2 as the defective gene, and administering a compound within the patent’s Formula I, II, or III Markush groups. The patent has reached the end of its ordinary U.S. patent term and does not present a current blocking right for generic or competing products.

What does U.S. Patent 7,351,701 cover?

The patent covers treatment of cancer associated with a genetic defect in a gene that mediates homologous recombination, where the gene is BRCA1, BRCA2, or both.

Claim 1 requires:

A mammal with the relevant genetic defect must be selected.
The cancer must be caused by that defect.
The defect must involve BRCA1 or BRCA2.
The administered compound must fall within Formula I, Formula II, or Formula III.
The compound must be used as a direct cytotoxic agent.
A pharmaceutically acceptable salt is included.

The claim is therefore a biomarker-selected treatment claim, not a general cancer-treatment claim and not a composition-of-matter claim.

Claim-by-claim scope

Claim	Subject matter	Scope
1	Treatment of BRCA1/2-defect cancer with Formula I, II, or III compounds	Broadest independent method claim
2	Treatment using Formula I	Narrows the compound class
3	Formula I in phosphate-salt form	Further narrows salt form
4	Breast cancer	Narrows claim 1 by tumor type
5	Absence of BRCA1 and/or BRCA2	Covers complete loss or absence
6	Defective expression of BRCA1 and/or BRCA2	Covers expression defects, including loss or reduction of expression

The supplied claim text does not include the chemical structures for Formula I, II, and III. Formula-specific infringement, overlap with approved products, and composition-level comparisons therefore cannot be determined from the text alone. The operative legal scope depends on the structures and definitions in the issued patent.

How broad is the BRCA1 and BRCA2 limitation?

The phrase “at least one of BRCA1 and BRCA2” ordinarily covers:

a BRCA1 defect;
a BRCA2 defect; and
defects affecting both genes.

Claim 5 narrows the genetic condition to the absence of BRCA1 and/or BRCA2. Claim 6 addresses a defect in gene expression. The claims do not expressly require a particular mutation, such as BRCA1 185delAG or BRCA2 6174delT.

The claim language also does not expressly limit the genetic defect to:

germline mutations;
somatic mutations;
biallelic mutations;
a particular tumor stage;
a specific sequencing test; or
a specific level of protein expression.

A court would construe those issues using the specification, prosecution history, and technical evidence. The phrase “cancer is caused by a genetic defect” creates a causation limitation beyond merely detecting a BRCA variant in a tumor.

What compounds are protected by U.S. Patent 7,351,701?

The patent protects use of compounds falling within three structural classes identified as Formula I, Formula II, and Formula III. Claim 1 also covers pharmaceutically acceptable salts of those compounds.

The compound protection is functional and structural:

structural membership in one of the three formulas is required;
the compound must be administered to the selected patient;
the compound must operate as a direct cytotoxic agent; and
the patient must have the specified BRCA-associated cancer.

The patent does not, based on the quoted claims, claim every PARP inhibitor. A competing PARP inhibitor would fall within claim 1 only if its structure satisfies Formula I, II, or III and the remaining patient and treatment limitations are met.

What does the phosphate-salt claim protect?

Claim 3 protects Formula I in phosphate-salt form. This is a narrower salt-form claim. It does not independently cover:

every salt of Formula I;
the free base of Formula I;
formulations containing an unrelated active ingredient; or
a different compound that has similar pharmacology but falls outside Formula I.

Salt-form claims can be commercially important when the salt improves stability, solubility, manufacturability, or dosage-form performance. Their practical value depends on whether the relevant marketed product uses the claimed salt and whether later patents protect a different solid form or formulation.

Is U.S. Patent 7,351,701 a composition patent or a method patent?

It is principally a method-of-treatment patent.

The quoted claims do not claim:

the chemical compound per se;
a pharmaceutical composition;
a tablet or capsule;
a manufacturing process;
a diagnostic assay;
a biomarker panel; or
a specific dosing schedule.

The patent’s commercial leverage therefore depended on proving use of a covered compound in a patient population with a qualifying BRCA1 or BRCA2 defect.

This distinction matters in generic litigation. A generic manufacturer can avoid direct infringement of a method claim by omitting or carving out the patented indication from its labeling, subject to the facts of the product, label, marketing conduct, and inducement analysis under 35 U.S.C. §271(b).

When did U.S. Patent 7,351,701 lose exclusivity?

The patent’s ordinary U.S. term expired in approximately 2021, based on the earliest claimed 2000 priority date and the 20-year patent-term framework applicable to the family. The patent issued on April 1, 2008, as U.S. Patent No. 7,351,701.[1]

Event	Date
Earliest claimed priority	2000
U.S. patent issuance	April 1, 2008
Ordinary 20-year term endpoint	Approximately 2021
Current status	Expired by term

The issue date does not control expiration for a post-1995 U.S. patent. The term generally runs from the earliest effective nonprovisional or international application date, subject to patent-term adjustment and other statutory calculations.[2]

No current enforceable exclusivity should be attributed to Patent 7,351,701. Patent expiration does not erase historical infringement exposure, damages claims accrued before expiration, or contractual obligations under a separate license or settlement.

What is the Orange Book status of U.S. Patent 7,351,701?

U.S. Patent 7,351,701 is not a current blocking Orange Book patent for an approved product. The FDA Orange Book lists patents submitted by an NDA holder that claim the drug substance, drug product, or an approved method of use.[3]

The patent’s method claims are potentially the type of claims that could support an Orange Book method-of-use listing if they corresponded to an approved indication and were submitted by the NDA holder. Its expired status removes any current exclusivity effect even if it had previously been listed.

For an approved PARP inhibitor, the commercially relevant patent estate generally consists of later patents covering:

the active pharmaceutical ingredient;
crystalline or salt forms;
formulations;
dosing regimens;
combinations;
biomarker-defined indications; and
manufacturing processes.

Those later patents, rather than Patent 7,351,701, generally determine the timing of generic entry.

Did Patent 7,351,701 create a Paragraph IV risk?

It could have supported a Paragraph IV challenge during its enforceable term if it was listed for an approved product and the generic applicant’s proposed labeling implicated the claimed BRCA-associated use.

A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or will not be infringed. The certification can trigger patent litigation under the Hatch-Waxman framework and, in qualifying circumstances, a 30-month stay of FDA approval.[4]

Because Patent 7,351,701 has expired, it no longer creates a prospective Paragraph IV barrier. A current ANDA applicant would focus on unexpired patents listed for the reference product, not on this patent.

What patent landscape surrounds BRCA-directed PARP inhibition?

The BRCA/PARP field contains several overlapping patent categories.

Foundational PARP-inhibitor patents

Early patents covered PARP inhibition broadly or claimed chemical classes of PARP inhibitors. These patents established the technical basis for exploiting homologous-recombination deficiency but have generally expired or approached expiration.

Drug-specific composition patents

Later patents for approved agents such as olaparib, rucaparib, niraparib, and talazoparib have provided more durable protection. These patents commonly claim the active molecule, salts, polymorphs, intermediates, and pharmaceutical compositions.

Examples of commercially important families include:

olaparib composition and formulation patents, including U.S. Patent No. 8,071,579;
rucaparib compound patents, including U.S. Patent No. 8,440,803;
niraparib composition and method patents;
talazoparib compound and formulation patents.

The exact expiration date depends on each family’s earliest effective filing date, patent-term adjustment, patent-term extension, terminal disclaimers, and any later continuation patents.

Biomarker and method-of-use patents

Method patents in the field may cover:

treatment of BRCA1-mutated tumors;
treatment of BRCA2-mutated tumors;
homologous-recombination deficiency more broadly;
platinum-sensitive disease;
maintenance treatment;
combination therapy with chemotherapy or immune checkpoint inhibitors; and
patient selection using genomic instability scores.

Patent 7,351,701 is narrower than a general homologous-recombination-deficiency claim because it expressly identifies BRCA1 and BRCA2 and requires one of the specified compound formulas.

Formulation and manufacturing patents

Manufacturing and formulation patents can delay competition even after an original method patent expires. Relevant barriers may include:

particle-size control;
crystalline forms;
phosphate or other salt forms;
tablet compositions;
controlled-release systems;
impurity-control processes; and
high-purity synthetic intermediates.

These rights are separate from the claims quoted for Patent 7,351,701.

Which companies face competitive patent exposure?

The principal commercial competitors in the PARP-inhibitor market have included AstraZeneca and Merck for olaparib, Clovis Oncology for rucaparib, GlaxoSmithKline for niraparib, and Pfizer for talazoparib. Ownership and commercialization arrangements have changed through acquisitions and licensing transactions.

The relevant competitive question is not whether a product is a PARP inhibitor. It is whether the product is covered by an unexpired patent family for:

the active molecule;
the approved formulation;
the proposed indication;
the dosing regimen; or
the manufacturing process.

Patent 7,351,701 has limited present value because its term has ended and its claims are directed to a defined group of compounds rather than the entire PARP-inhibitor class.

What generic launch scenarios exist?

For a product whose only relevant patent were Patent 7,351,701, a generic launch would face no remaining patent-term barrier from this patent.

Practical launch scenarios depend on later patents:

Scenario	Commercial consequence
No unexpired listed patents	Approval and launch may proceed after regulatory exclusivity ends
Unexpired composition patent	Launch generally delayed until patent expiry or successful challenge
Unexpired method patent	Label carve-out may be possible if the patented use can be omitted
Formulation patent remains	A non-infringing formulation may support an alternative launch
Manufacturing patent remains	A different process or licensed process may be required
Settlement agreement exists	Launch timing may depend on agreed entry date and license terms

For biologics, biosimilar risk would involve the Biologics Price Competition and Innovation Act. The drugs implicated by the quoted claims are small molecules, so biosimilar analysis is not the principal pathway. Generic ANDA litigation is the more relevant framework.

How strong is the patent estate for Patent 7,351,701?

The patent was technically significant as a biomarker-selected treatment claim, but its current legal strength is zero as an exclusion right because the patent has expired.

Historically, claim strength would have depended on:

whether the accused compound fell within the three formulas;
whether the patient had a qualifying BRCA defect;
whether the defect caused the cancer;
whether the compound acted as a direct cytotoxic agent;
enablement and written-description support for the full Markush group;
definiteness of the genetic-defect limitations; and
proof of induced infringement by the product sponsor.

The narrowest commercially relevant claims are claims 3, 4, 5, and 6. They offer greater factual specificity but a smaller infringement surface. Claim 1 is broader in patient and tumor coverage but still depends on the undisclosed chemical formulas.

Key Takeaways

U.S. Patent 7,351,701 claims treatment of BRCA1- or BRCA2-deficient cancer with compounds in Formula I, II, or III.
It is a method patent, not a broad PARP-inhibitor composition patent.
Claim 3 specifically addresses a phosphate salt of Formula I.
Claims 4 through 6 narrow the invention to breast cancer, absence of BRCA1/2, or defective BRCA1/2 expression.
The patent’s ordinary term ended in approximately 2021.
It does not create a current Orange Book or Paragraph IV barrier.
Current commercial risk lies in later composition, formulation, dosing, method-of-use, and manufacturing patents for individual PARP inhibitors.
The omitted Formula I, II, and III structures prevent a definitive compound-by-compound overlap analysis.

FAQs

Does Patent 7,351,701 cover all BRCA-mutated cancers?

No. It covers treatment only when the administered compound falls within Formula I, II, or III and the cancer is caused by the claimed BRCA1 or BRCA2 defect.

Does the patent cover olaparib?

The quoted claims do not establish whether olaparib falls within any of the three formulas. The complete patent drawings and chemical definitions are required for that determination.

Can a generic avoid the patent by using a different salt?

If the generic compound does not fall within the claimed formulas or uses a salt outside the limitations of claim 3, it may avoid that specific claim. Other patents may still apply.

Are BRCA diagnostic patents required to practice the claimed treatment?

The claims require selecting a mammal with the genetic defect, but they do not expressly claim a diagnostic test. A separate diagnostic patent could create additional risk.

Does patent expiration eliminate all litigation risk?

No. It eliminates prospective enforcement of the expired patent. Historical infringement claims, later patents, confidential licenses, and settlement obligations can remain relevant.

References

U.S. Patent No. 7,351,701, “Treatment of cancer,” issued Apr. 1, 2008.
United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term calculation.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
21 U.S.C. §355; 35 U.S.C. §§271(e), 282.
U.S. Patent No. 8,071,579, “Phthalazinone derivatives for use in cancer treatment.”
U.S. Patent No. 8,440,803, “Substituted tricyclic compounds as PARP inhibitors.”

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	454893	⤷ Start Trial
Austria	516353	⤷ Start Trial
Australia	2004261462	⤷ Start Trial
Australia	2004261779	⤷ Start Trial
Brazil	PI0412899	⤷ Start Trial
Brazil	PI0412909	⤷ Start Trial
Canada	2533332	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,351,701

Summary for Patent: 7,351,701