US Patent 8,513,293: Selumetinib Combination-Therapy Claims, Scope and Patent Landscape

US Patent 8,513,293 covers oncology treatment methods using selumetinib, also known as AZD6244 or ARRY-142886, in combination with either an anti-tumor agent or radiation therapy. The patent does not claim selumetinib itself, a formulation, a manufacturing process, or a diagnostic method. Its commercial value depends on whether a competing product uses selumetinib for one of the listed cancers together with a covered anti-tumor therapy or radiation regimen.

The claims are method-of-treatment claims directed to a defined MEK-inhibitor compound and selected hyperproliferative disorders. Claims 3 and 4 are duplicative melanoma-dependent claims, which limits their incremental value.

What compound does US Patent 8,513,293 protect?

The claimed compound is selumetinib:

Generic name: selumetinib
Development codes: AZD6244 and ARRY-142886
Chemical class: orally active MEK1/2 inhibitor
Sponsor and commercial holder: AstraZeneca
Approved product: Koselugo
FDA dosage form: oral capsules
FDA-approved indication: pediatric patients aged 2 years and older with neurofibromatosis type 1-associated symptomatic, inoperable plexiform neurofibromas [1]

The patent claims the compound by its chemical name rather than by the term “selumetinib.” The claim language covers the free compound and “pharmaceutically acceptable salts.”

That chemical definition is important. A product that contains a different MEK inhibitor, a prodrug, or a structurally modified analog would not infringe merely because it produces a similar pharmacological effect. Infringement would require that the administered active ingredient fall within the claimed compound or salt limitation.

What are the principal claims of US 8,513,293?

Claim	Subject matter	Required therapy	Covered cancers
1	Selumetinib treatment method	An anti-tumor agent from a broad Markush group	Lung, squamous cell, pancreatic, breast, head, neck, prostate, colorectal cancer or melanoma
2	Selumetinib treatment method	Radiation therapy	Same listed cancers
3	Dependent method claim	Anti-tumor agent under claim 1	Melanoma
4	Dependent method claim	Anti-tumor agent under claim 1	Melanoma; text duplicates claim 3

The patent therefore has two primary therapeutic pathways:

Selumetinib plus a qualifying anti-tumor agent.
Selumetinib plus radiation therapy.

A selumetinib monotherapy regimen for one of the listed cancers does not fall within claim 1 or claim 2 because each independent claim requires combination treatment.

How broad is claim 1?

Claim 1 is broad in the identity of the combination partner but narrow in the identity of the MEK inhibitor and disease categories.

The anti-tumor agent Markush group includes:

Mitotic inhibitors
Alkylating agents
Antimetabolites
Intercalating antibiotics
Growth-factor inhibitors
Cell-cycle inhibitors
Enzyme inhibitors
Topoisomerase inhibitors
Biological-response modifiers
Anti-hormones
Angiogenesis inhibitors
Anti-androgens

The claim does not identify a particular partner such as paclitaxel, carboplatin, gemcitabine, doxorubicin, bevacizumab, or an immune checkpoint inhibitor. Instead, it uses functional and class-based categories. That creates potentially broad coverage, but it also creates construction and enablement issues.

A potentially infringing regimen generally would need to satisfy all of the following:

The administered drug is selumetinib or a pharmaceutically acceptable salt.
Selumetinib is administered to a mammal.
The treatment is intended to alleviate or inhibit progression of a hyperproliferative disorder.
The disorder is one of the cancers listed in the claim.
An effective amount of a qualifying anti-tumor agent is administered in combination with selumetinib.

The claim does not expressly require a fixed sequence, dose ratio, schedule, or simultaneous administration. “In combination with” can therefore create disputes over sequential administration, treatment cycles, and whether the therapies are part of the same therapeutic regimen.

What does claim 2 cover?

Claim 2 covers selumetinib administered in combination with radiation therapy for the same cancer categories.

Unlike claim 1, claim 2 does not require an anti-tumor drug. The radiation limitation is independent of the Markush list in claim 1. The claim could therefore reach a regimen involving:

External-beam radiation
Fractionated radiotherapy
Stereotactic radiation
Other clinically recognized radiation-treatment protocols

The claim requires that the selumetinib and radiation therapy, in combination, provide an effective treatment for the listed hyperproliferative disorder. A radiation regimen with no therapeutic relationship to selumetinib would create a weaker infringement case.

The claim does not specify radiation dose, fractionation, timing, tumor site, or sequencing. Those omissions increase the apparent breadth of the claim but may create disputes concerning claim construction, written description, enablement, and proof of combination use.

What do claims 3 and 4 add?

Claims 3 and 4 both depend on claim 1 and specify melanoma. Based on the supplied claim text, claim 4 is identical to claim 3.

The duplicate language gives no additional technical limitation. It does not add:

A specific anti-tumor agent
A dose
A dosing interval
A route of administration
A melanoma subtype
A biomarker
A treatment line
A response criterion

Claims 3 and 4 may have resulted from prosecution drafting or claim-renumbering history, but the text supplied does not show a substantive distinction between them. Their practical value is narrower than claim 1 because both are limited to melanoma.

Which cancer types are covered?

The independent claims cover the following cancer categories:

Cancer category	Claim 1	Claim 2	Claim 3	Claim 4
Lung cancer	Yes	Yes	No	No
Squamous cell cancer	Yes	Yes	No	No
Pancreatic cancer	Yes	Yes	No	No
Breast cancer	Yes	Yes	No	No
Head cancer	Yes	Yes	No	No
Neck cancer	Yes	Yes	No	No
Prostate cancer	Yes	Yes	No	No
Colorectal cancer	Yes	Yes	No	No
Melanoma	Yes	Yes	Yes	Yes

The language “head cancer” and “neck cancer” is unusual because oncology claims commonly use “head and neck cancer.” Courts would assess the ordinary meaning of the issued claim language and the specification. The separate wording could affect claim construction, particularly for tumors arising in anatomically overlapping regions.

The patent does not cover every solid tumor. A use in renal cancer, ovarian cancer, gastric cancer, hepatocellular carcinoma, sarcoma, or neurofibromatosis-associated plexiform neurofibroma is outside the listed disease categories unless a broader claim or doctrine of equivalents applies.

What type of patent protection does US 8,513,293 provide?

US 8,513,293 is primarily a method-of-use patent.

Protection category	Covered by the supplied claims?
Selumetinib chemical composition	No
Pharmaceutically acceptable salt as part of treatment	Yes
Combination therapy	Yes
Radiation combination	Yes
Specific formulation	No
Capsule or tablet design	No
Manufacturing process	No
Polymorph or crystal form	No
Treatment of NF1-associated plexiform neurofibroma	No, based on supplied claims
Biomarker-selected treatment	No
Specific dose or schedule	No
Specific anti-tumor drug	No

This distinction matters for generic and follow-on products. A generic manufacturer may avoid the patent if its label omits the patented combination uses and the product is marketed under a permissible “skinny label.” That strategy depends on the scope of the FDA-approved labeling, physician prescribing behavior, promotional conduct, and the evidence linking the generic product to the patented method.

When does US Patent 8,513,293 expire?

US Patent 8,513,293 issued on August 20, 2013. Its precise expiration date depends on the earliest effective nonprovisional or international filing date and any applicable patent-term adjustment or patent-term extension.

A conventional term estimate for the selumetinib patent family places expiration in the mid-2020s, subject to the official USPTO term calculation. Patent term should be confirmed against the USPTO Patent Center record and the Orange Book listing before relying on a specific launch date [2,3].

The patent’s issuance date is not the relevant expiration-date measure. US utility patents generally expire 20 years from the earliest effective nonprovisional filing date, subject to statutory adjustments under 35 U.S.C. §§ 154 and 156 [4].

Patent-term considerations

The following factors can alter the effective end date:

Patent-term adjustment for USPTO examination delay
Patent-term extension for regulatory review
Terminal disclaimers
Continuation or divisional prosecution
PTA recalculation
Any disclaimer or correction recorded after issuance

A patent-term extension under 35 U.S.C. § 156, if granted, would apply only to the eligible patent and approved product relationship. It would not automatically extend every patent covering selumetinib.

What is the Orange Book status of US 8,513,293?

Orange Book listing cannot be inferred solely from the patent claims. FDA listing is tied to an approved drug application, the approved labeling, and the patent owner’s certification to FDA.

Koselugo was approved under NDA 213756 for NF1-associated symptomatic, inoperable plexiform neurofibromas, not for the solid-tumor indications recited in US 8,513,293 [1]. The supplied claims do not cover the approved NF1 indication.

The practical Orange Book questions are:

Whether US 8,513,293 is listed against NDA 213756.
Whether FDA assigned a use code corresponding to an approved use.
Whether the listed claim reads on the approved labeling.
Whether the patent has expired or been delisted.
Whether any patent-term extension applies.

A method patent directed only to unapproved cancer indications has limited Orange Book leverage against an ANDA seeking approval for the approved NF1 indication. A listed patent with a use code matching approved labeling can create a Paragraph IV certification issue, but an unapproved-use claim does not automatically block approval of an ANDA.

What generic-entry risks exist?

Selumetinib is a small molecule, so the principal abbreviated-approval risk is generic substitution rather than biosimilar competition.

Label-based generic entry

A generic applicant could seek approval using:

A Paragraph III certification if relevant patents remain in force and the applicant accepts a later launch date.
A Paragraph IV certification asserting that listed patents are invalid, unenforceable, or not infringed.
A section viii statement omitting patented methods from the proposed labeling, where permitted.

For US 8,513,293, the strongest non-infringement position would generally involve a label limited to the approved NF1 indication and omitting the patented solid-tumor combination uses. The risk increases if the generic label includes or encourages:

Selumetinib plus radiation
Selumetinib plus chemotherapy
Selumetinib in melanoma
Selumetinib in lung, breast, pancreatic, colorectal, or prostate cancer

A method patent can also create induced-infringement exposure if the manufacturer actively promotes the patented combination, even where the product has substantial non-infringing uses.

Biosimilar risk

Biosimilar risk is not applicable to selumetinib. Selumetinib is a chemically synthesized small molecule regulated through the ANDA pathway, not a biologic regulated under the Public Health Service Act biosimilar pathway [5].

Which patents are likely to matter alongside US 8,513,293?

The commercially relevant selumetinib landscape is broader than this single combination patent.

Patent category	Business significance
Core compound patents	Can block sale of selumetinib regardless of indication
Salt, polymorph or solid-form patents	May restrict alternative active-ingredient forms
Formulation patents	Can affect capsules, release profile, stability and excipient selection
Method-of-use patents	Can cover specific diseases, combinations, biomarkers or treatment schedules
Manufacturing patents	Can increase switching costs and constrain API suppliers
Regulatory exclusivity	Can delay approval independently of patent validity
Pediatric or orphan exclusivity	Can restrict approval for the protected indication and population

The supplied claims do not establish the existence, validity, expiration, or Orange Book status of these adjacent rights. They also do not establish whether any continuation, divisional, reissue, or foreign counterpart contains materially broader or narrower claims.

How strong is the patent estate for this specific patent?

The patent has moderate theoretical breadth but a narrower practical enforcement profile.

Strengths

It identifies a single, commercially relevant MEK inhibitor.
It covers combination treatment with broad classes of anti-tumor agents.
It separately covers radiation combinations.
It lists multiple commercially important cancer categories.
It does not require a particular dose, schedule, or combination partner.

Vulnerabilities

It is limited to selumetinib.
It does not cover monotherapy.
It does not cover the FDA-approved NF1 indication based on the supplied claims.
The anti-tumor-agent categories may invite claim-construction and enablement challenges.
“In combination with” may create factual disputes concerning timing and treatment purpose.
Claims 3 and 4 are duplicative.
The patent’s commercial value declines sharply after expiration of core selumetinib composition claims.
A generic may be able to use a label that omits the claimed solid-tumor indications.

The strongest infringement scenario would involve an originator or competitor actively promoting selumetinib together with radiation or a recognized anti-tumor therapy for melanoma or another expressly listed cancer.

What litigation or settlement issues affect this patent?

A Paragraph IV dispute would likely focus on four issues:

Whether the generic label induces the claimed combination use.
Whether the patent is valid under written-description and enablement standards.
Whether prior art discloses selumetinib combinations or radiation combinations.
Whether the patent remains enforceable and unexpired when the generic launches.

No litigation or settlement terms can be established from the claim text alone. A settlement could include a license, a delayed-entry date, a covenant not to sue, a permitted-label arrangement, or restrictions on promotion. None of those commercial terms changes the issued claim scope unless reflected in a court judgment, consent order, or recorded license.

What is the competitive landscape for selumetinib?

Selumetinib competes within the MEK-inhibitor class, including:

Trametinib
Cobimetinib
Binimetinib
Mirdametinib and other investigational MEK inhibitors

Competitors may avoid US 8,513,293 by using a different MEK inhibitor. The patent does not claim the therapeutic concept of MEK inhibition in combination with cancer therapy generally. It claims the specified selumetinib compound.

The patent therefore has greater value against a selumetinib-based competitor than against competing MEK inhibitors. Its relevance to Koselugo revenue is strongest where a competitor seeks to commercialize selumetinib for the claimed solid-tumor uses rather than the approved NF1 indication.

Key Takeaways

US 8,513,293 is a selumetinib combination-treatment patent.
Claim 1 covers selumetinib plus a broadly defined anti-tumor agent for nine listed cancer categories.
Claim 2 covers selumetinib plus radiation therapy for the same categories.
Claims 3 and 4 both narrow claim 1 to melanoma and are textually duplicative.
The patent does not claim selumetinib itself, a formulation, a manufacturing process, or the approved NF1 indication.
Generic risk depends heavily on labeling, promotion, Orange Book listing and the status of core compound patents.
Biosimilar competition is not relevant because selumetinib is a small molecule.
The patent’s effective expiration requires confirmation from the official USPTO term record.
The strongest practical enforcement case would involve active promotion of selumetinib with chemotherapy or radiation for one of the expressly listed cancers.

FAQs

Does US 8,513,293 cover Koselugo monotherapy?

No. The supplied independent claims require selumetinib to be administered with an anti-tumor agent or radiation therapy. They do not cover selumetinib monotherapy.

Does the patent cover selumetinib for neurofibromatosis type 1?

Not based on the supplied claims. The claims identify lung, squamous cell, pancreatic, breast, head, neck, prostate, colorectal cancer and melanoma. NF1-associated plexiform neurofibroma is not listed.

Can a generic sell selumetinib for an unpatented indication?

Potentially, if its approved labeling and commercial conduct avoid the patented uses and no separate patent or regulatory exclusivity blocks approval. The analysis depends on the complete Orange Book record, labeling and patent family.

Does a different MEK inhibitor infringe US 8,513,293?

Not literally under the supplied claims. The claims identify selumetinib by a specific chemical structure. A different MEK inhibitor would require a separate infringement theory.

Are claims 3 and 4 legally different?

Based on the supplied text, no substantive difference appears. Both depend on claim 1 and specify melanoma. Their prosecution history would determine whether an issued-document error or another distinction exists.

References

U.S. Food and Drug Administration. (2020). FDA approves selumetinib for pediatric patients 2 years of age and older with neurofibromatosis type 1 and symptomatic, inoperable plexiform neurofibromas. https://www.fda.gov
U.S. Patent and Trademark Office. (2013). U.S. Patent No. 8,513,293.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
35 U.S.C. §§ 154, 156.
U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application (ANDA) process. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/generic-drug-facts.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1482932	⤷ Start Trial	PA2019007	Lithuania	⤷ Start Trial
European Patent Office	1482932	⤷ Start Trial	LUC00100	Luxembourg	⤷ Start Trial
European Patent Office	1482932	⤷ Start Trial	300974	Netherlands	⤷ Start Trial
European Patent Office	1482932	⤷ Start Trial	2019C/510	Belgium	⤷ Start Trial
European Patent Office	1482932	⤷ Start Trial	CA 2019 00011	Denmark	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,513,293

Summary for Patent: 8,513,293