Details for Patent: 10,357,567

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Which drugs does patent 10,357,567 protect, and when does it expire?

Patent 10,357,567 protects LEVULAN and is included in one NDA.

This patent has thirteen patent family members in three countries.

Summary for Patent: 10,357,567

Title:	Methods for photodynamic therapy
Abstract:	A method of enhancing penetration of a topical composition of 5-aminolevulinic acid (ALA) into tissue for photodynamic therapy includes topically applying ALA to a treatment area to be treated with photodynamic therapy. The method further includes, after the ALA is applied to the treatment area, covering the treatment area with a low density polyethylene barrier. The treatment area is covered with the low density polyethylene barrier prior to light treatment to minimize transepidermal water loss from the treatment area.
Inventor(s):	Scott Lundahl, Michael Guttadauro
Assignee:	Sun Pharmaceutical Industries Inc
Application Number:	US15/869,164
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 10,357,567
Patent Claim Types: see list of patent claims	Use; Composition;

US Patent 10,357,567: Claim Scope, Expiration, Litigation Risk, and ALA Photodynamic-Therapy Patent Landscape

US Patent No. 10,357,567 protects a treatment protocol for topical 5-aminolevulinic acid, or ALA, that uses a low-density polyethylene occlusive barrier before photodynamic-therapy illumination. The patent does not primarily protect ALA itself, an ALA formulation, or an illuminator. Its commercial scope is concentrated in the combination of topical ALA, polyethylene occlusion, defined treatment sites, removal timing, and specified blue- or red-light dosing.

The strongest practical risk is for products or clinical protocols that reproduce the patented occlusion step for ALA photodynamic therapy on the hands, forearms, or other skin sites. The patent is less threatening to products that use ALA without a low-density polyethylene barrier, use a different barrier material, or illuminate without following the claimed sequence.

What does US Patent 10,357,567 protect?

US 10,357,567 contains three independent method claims:

Independent claim	Core protected method	Principal limitations
Claim 1	Enhancing ALA penetration for photodynamic therapy	Apply ALA, cover with low-density polyethylene, remove within three hours, then apply light
Claim 4	Treating a hand or forearm	Apply ALA, cover with low-density polyethylene before light treatment
Claim 8	ALA, barrier, and blue-light treatment	Wet treatment site with ALA composition, cover with low-density polyethylene, remove barrier, deliver 10 J/cm² blue light

The claims are method-of-treatment claims. They require performance of the recited steps, rather than ownership or sale of a particular ALA molecule.

The patent’s central technical concept is occlusion. The low-density polyethylene barrier is used to minimize transepidermal water loss after ALA application. The claimed theory is that retaining moisture at the treatment site improves ALA penetration into tissue before illumination.

What elements are required for infringement?

A method practice would generally need to satisfy the following elements:

1. A composition containing 5-aminolevulinic acid.
2. Topical application to a treatment area or treatment site.
3. Covering the area after ALA application.
4. A low-density polyethylene barrier.
5. Subsequent removal of the barrier before illumination in claims 1 and 8.
6. Light treatment after barrier removal where expressly required.
7. Additional limitations for particular claims, including:
   • removal within three hours;
   • blue light at 10 J/cm²;
   • red light at 10 to 75 J/cm²;
   • treatment of the hand, forearm, dorsal hand, or dorsal forearm;
   • plasma ALA concentration below approximately 110 ng/mL;
   • illuminator distance of two to four inches.

A protocol that omits the polyethylene barrier should not literally meet the independent claims. A protocol using an occlusive material made from a different polymer may create a claim-construction dispute over whether the material is a low-density polyethylene barrier, but it would not automatically satisfy the express material limitation.

How do claims 1, 4, and 8 differ?

Claim 1: timing-focused protection

Claim 1 is directed to a sequence:

• ALA is applied.
• The treatment area is covered with low-density polyethylene.
• The barrier is removed within three hours.
• Light is then applied.

The claim does not limit the treatment site to the hand or forearm. It also does not specify a particular light wavelength or dose. Claim 1 therefore has broader anatomical and illumination coverage than claims 4 and 8, but it has a mandatory three-hour removal limitation.

Claim 4: anatomical-site protection

Claim 4 covers ALA treatment of a hand or forearm with a low-density polyethylene barrier. Unlike claim 1, claim 4 does not expressly require barrier removal within three hours.

Claims 6 and 7 narrow claim 4 to:

• the dorsal surface of the hand; or
• the dorsal surface of the forearm.

Claim 4 may be commercially important for actinic keratoses and other photodynamic-therapy indications involving extremity skin, where conventional ALA protocols may produce less consistent penetration than treatment on the face or scalp.

Claim 8: protocol and dose protection

Claim 8 is directed to a more operational protocol. It requires:

• contacting the treatment site with an ALA composition so that the site is wetted;
• covering the wetted site with low-density polyethylene;
• removing the barrier;
• illuminating the exposed site with a 10 J/cm² blue-light dose.

Claim 8 does not itself state the three-hour removal period. Claim 9 adds that limitation, and claim 10 adds the two-to-four-inch illuminator distance.

The claim structure creates several infringement pathways. A protocol may avoid claim 1 but still fall within claim 8 if it uses the specified 10 J/cm² blue-light dose. Conversely, a protocol using red light on a hand or forearm may implicate claims 4 and 5 without satisfying claim 8.

What patent family and ownership information is relevant?

Item	Information
Patent	US 10,357,567
Type	US utility patent
Subject matter	ALA topical photodynamic therapy with low-density polyethylene occlusion
Claim category	Method-of-treatment claims
Primary commercial relevance	ALA penetration, occlusion, and light-treatment protocols
Named assignee	DUSA Pharmaceuticals, Inc., according to the US patent record
Therapeutic field	Dermatologic photodynamic therapy
Active ingredient	5-aminolevulinic acid
Delivery approach	Topical application followed by polymer-barrier occlusion
Light modalities	Blue light and red light, depending on claim
Geographic effect	United States only for the US patent

The patent should be analyzed together with its continuity data, including any parent, continuation, divisional, or international filings. Continuation practice can materially affect risk because a patent family may contain claims directed to different combinations of ALA concentration, barrier materials, anatomical sites, illumination parameters, and treatment indications.

When does US Patent 10,357,567 lose exclusivity?

The patent’s enforceable term is generally determined by the earliest effective US nonprovisional priority date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and any applicable statutory adjustments under 35 U.S.C. §§ 154 and 156.

The public patent record should be used to confirm the exact expiration date and any patent-term adjustment. Based on the filing chronology associated with the patent family, the practical exclusivity period is expected to extend into the mid-2030s rather than expire with the older ALA product patents.

Exclusivity issue	Assessment
Patent term	20 years from the applicable earliest nonprovisional filing date, subject to adjustments
Expected commercial window	Mid-2030s
Patent-term extension	Unlikely to be material for this method patent unless separately granted
Regulatory exclusivity	Separate from patent term
Orange Book effect	Depends on listing status and the approved product to which the method claims are tied
Post-expiration risk	Generic or competing protocols may practice the claimed steps without patent infringement, subject to other unexpired family rights

The patent does not extend ALA molecule exclusivity. ALA is an established active ingredient. Its value lies in the claimed clinical-use protocol and the possible ability to restrict a competing sponsor from using the same occlusion and illumination sequence.

What is the Orange Book status of US 10,357,567?

A patent’s inclusion in the FDA Orange Book depends on its relationship to an approved drug product and the statutory listing requirements. The Orange Book is product-specific. A method patent does not automatically appear merely because it claims use of an active ingredient used in an approved drug.

The relevant FDA products include:

• Levulan Kerastick, an aminolevulinic acid hydrochloride product used with blue light for actinic keratoses.
• Ameluz, an aminolevulinate hydrochloride topical product used with a red-light device for actinic keratoses.

The patent’s claims are not limited to the commercial name Levulan or Ameluz. They cover treatment methods involving ALA, polyethylene occlusion, and specified light protocols. Whether US 10,357,567 is listed for a particular approved product must be verified against the current FDA Approved Drug Products with Therapeutic Equivalence Evaluations database and the product’s patent certifications. FDA Orange Book listing and patent enforceability are separate issues. A nonlisted patent may still be enforceable against direct method practice, while an listed patent may be vulnerable to a Paragraph IV challenge.

Does the patent create Paragraph IV risk for generic ALA products?

Yes, but the risk depends on the proposed product and labeling.

A generic applicant seeking approval for an ALA product may face several categories of patent certification:

Generic product scenario	Likely patent issue
ALA product labeled for use with standard blue-light PDT without polyethylene occlusion	Lower direct risk under these claims
ALA product labeled for use with low-density polyethylene occlusion	High method-claim risk
Product label instructing removal within three hours	Directly implicates claims 1 and 9
Product labeled for 10 J/cm² blue light	Raises claims 2, 8, and 9
Product for hand or forearm lesions using occlusion	Raises claims 4 through 7
Product used with red light at 10 to 75 J/cm² on extremities	Raises claims 4 and 5
Physician-directed off-label use	Creates different inducement and divided-infringement questions

A generic applicant may attempt a section viii carve-out that excludes the patented occlusive protocol from the proposed labeling. The effectiveness of that strategy depends on whether the patented use is separable from the approved indication and whether the remaining label still encourages the claimed steps.

The key litigation question would be induced infringement under 35 U.S.C. § 271(b). A manufacturer may face risk if its label, training materials, device instructions, or sales activities specifically encourage use of ALA with a low-density polyethylene barrier.

What formulation patents are relevant to ALA photodynamic therapy?

US 10,357,567 is not principally a formulation-composition patent. It does not claim a proprietary ALA chemical entity, a defined excipient system, or a specific cream or gel composition as such. Its protection attaches to the use of the composition with a barrier and light-treatment sequence.

The broader ALA patent landscape generally includes four categories:

ALA composition patents

These may cover:

• ALA concentration;
• ALA hydrochloride or other salt forms;
• aqueous, gel, cream, or solution vehicles;
• stabilizers and pH control;
• packaging and reconstitution systems;
• penetration enhancers.

Device patents

These may cover:

• blue-light illuminators;
• red-light illuminators;
• LED arrays;
• dose-control systems;
• treatment-distance controls;
• energy-delivery profiles.

Method-of-use patents

These may cover:

• actinic keratoses;
• superficial skin cancers;
• acne;
• photorejuvenation;
• treatment of hands, forearms, face, scalp, or other sites;
• incubation time and illumination sequence.

Barrier and penetration patents

US 10,357,567 falls primarily into this category. The important limitation is not simply occlusion. It is the use of a low-density polyethylene barrier after ALA application to reduce transepidermal water loss before light treatment.

How strong is the patent estate?

The patent is strongest against direct, standardized clinical protocols that reproduce all material limitations. Its commercial strength is lower against flexible physician practice because several limitations are operational and may not appear in the drug label.

Strength factor	Effect on enforceability
Independent claims cover the core ALA-plus-barrier concept	Broadens exposure
Low-density polyethylene is expressly required	Narrows material scope
Three-hour limitation appears in selected claims	Creates design-around options
Anatomical limits apply to claims 4 through 7	Limits those claims to extremities
Specific blue-light dose is required by claim 8	Narrows claim 8
No ALA concentration in the principal independent claims	Reduces formulation-specific limitations
Plasma concentration limitation is dependent	Difficult to establish without pharmacokinetic evidence
Method claims require proof of performance	Can complicate enforcement against supply-chain participants
Patent does not claim ALA itself	Does not block all generic ALA products

Claim 1 is likely the principal broad claim because it combines the barrier with a three-hour timing limitation without restricting the body site or light type. Claim 4 is commercially significant for hand and forearm use. Claim 8 is narrower but may be easier to map where a commercial blue-light protocol specifies a 10 J/cm² dose.

What validity challenges are available?

A Paragraph IV or district-court validity challenge would likely focus on:

Anticipation

The challenger would search for prior art disclosing all elements in one reference:

• topical ALA;
• polyethylene occlusion;
• reduction of transepidermal water loss;
• subsequent illumination;
• three-hour removal where required;
• specified blue-light or red-light dose.

A reference that discloses ALA photodynamic therapy but does not disclose low-density polyethylene occlusion would not anticipate the full combination claim.

Obviousness

The stronger challenge may be obviousness under 35 U.S.C. § 103. The expected argument would combine:

• known ALA topical photodynamic therapy;
• known occlusive dressings;
• known polyethylene films;
• known moisture-retention techniques;
• known blue- or red-light PDT dosing.

The patent owner would likely argue that the specific barrier material, treatment timing, extremity application, and pharmacokinetic results produced an unexpected penetration or safety profile.

Written description and enablement

The patent’s broadest claims could be tested against whether the specification supports:

• different ALA compositions;
• different treatment sites;
• different light sources;
• the low plasma concentration limitation;
• the full range of red-light doses;
• the claimed barrier material across commercial implementations.

Indefiniteness and claim construction

Potential disputes include:

• the meaning of “low density polyethylene barrier”;
• whether a multilayer film containing low-density polyethylene qualifies;
• the meaning of “within 3 hours”;
• whether “10 J/cm² light dose” requires a precise delivered dose or a nominal device setting;
• whether “minimize transepidermal water loss” is a limiting functional phrase or merely describes intended use.

Which companies are most exposed?

The principal commercial entities are those selling or developing ALA products, PDT illuminators, or combined ALA-light systems:

Company or product category	Exposure
DUSA Pharmaceuticals	Patent owner and commercial ALA/PDT participant
Sun Pharmaceutical Industries	Parent-company commercial interest through DUSA
Levulan-based competitors	Exposure depends on use of claimed occlusion steps
Ameluz-related competitors	Exposure depends on red-light use and polyethylene occlusion
Generic ALA developers	Paragraph IV and labeling risk
Dermatology-device companies	Risk if device instructions encourage the claimed protocol
Compounding pharmacies	Potential direct-use or inducement exposure depending on instructions
Clinics and physician practices	Direct practice risk, although commercial enforcement usually focuses on suppliers

Biosimilar risk is not a central issue. ALA is a small-molecule active ingredient, not a biologic. The relevant competitive pathway is generic-drug approval and competing branded or compounded topical products, not the FDA biosimilar pathway under the Public Health Service Act.

What litigation and settlement issues matter?

A patent-litigation review should examine:

• district-court complaints involving US 10,357,567;
• inter partes review petitions;
• post-grant review activity;
• Paragraph IV notices;
• ANDA litigation involving Levulan or related ALA products;
• settlement agreements with generic applicants;
• consent judgments and covenants not to sue;
• licensing or co-promotion agreements involving DUSA, Sun Pharma, and PDT-device manufacturers.

The supplied claims alone do not establish a current litigation or settlement disposition. Patent status, ownership, and enforceability should be evaluated against the latest USPTO assignment record, Patent Center prosecution history, PTAB docket, PACER filings, and FDA Orange Book data.

How does this patent compare with older ALA patents?

Patent category	Main protected asset	Relationship to US 10,357,567
Early ALA PDT patents	Use of ALA with light for dermatologic disease	Earlier and broader therapeutic foundation
Levulan-related patents	ALA formulations, kits, and blue-light treatment	May cover the product or device independently
Ameluz-related patents	ALA hydrochloride formulation and red-light treatment	May create separate formulation and product barriers
Device patents	Illuminator architecture and dosing	Can restrict the light source independently
US 10,357,567	Polyethylene occlusion and treatment sequence	Adds a protocol-level barrier to selected uses

The patent is therefore best understood as a secondary-use or protocol patent layered onto the established ALA photodynamic-therapy platform. It may not block a competitor from selling ALA, but it can restrict a commercially attractive administration method.

What generic launch scenarios exist?

Scenario 1: Standard ALA use without occlusion

A generic product labeled for ALA application followed by conventional illumination, without low-density polyethylene, presents the lowest risk under this patent.

Scenario 2: Occlusion omitted from the label but used in practice

The product may obtain approval with reduced patent exposure, but promotional materials, device instructions, or clinical training could create inducement risk.

Scenario 3: Polyethylene occlusion with a different timing protocol

Removing the barrier after more than three hours may avoid claims with the express three-hour limitation, but claim 4 may remain relevant for hand or forearm treatment because it does not include that timing limitation.

Scenario 4: Alternative barrier material

A foil, silicone sheet, polyurethane film, or other material may avoid literal infringement if it is not low-density polyethylene. Equivalence arguments remain possible, particularly if the substitute performs the same moisture-retention function in substantially the same way.

Scenario 5: Red-light treatment on extremities

A protocol using red light at 10 to 75 J/cm² on the dorsal hand or forearm presents material risk under claims 4 and 5.

Key Takeaways

• US 10,357,567 is a method patent centered on topical ALA plus low-density polyethylene occlusion.
• It does not broadly monopolize ALA, ALA formulations, or photodynamic therapy.
• Claims 1, 4, and 8 are the principal independent claims.
• Claim 1 requires barrier removal within three hours before light treatment.
• Claims 4 through 7 focus on the hand, forearm, dorsal hand, and dorsal forearm.
• Claim 8 targets a 10 J/cm² blue-light protocol; claims 9 and 10 add timing and illuminator-distance limitations.
• The expected patent term extends into the mid-2030s, subject to USPTO term calculations.
• Generic exposure is highest when the label or promotional materials instruct low-density polyethylene occlusion.
• Biosimilar competition is not relevant because ALA is a small molecule.
• The principal design-around options are removing polyethylene occlusion, changing the barrier material, altering timing, changing the light dose, or limiting the treated site.
• Orange Book listing, Paragraph IV activity, litigation, settlements, and terminal expiration must be checked against current FDA, USPTO, PTAB, and court records.

FAQs

Does US 10,357,567 cover Levulan itself?

No. The claims do not cover ALA as a chemical compound. They cover particular methods of using topical ALA with a low-density polyethylene barrier and light treatment.

Can a competing ALA product use blue light without infringing?

Potentially yes, if the protocol does not use the claimed low-density polyethylene barrier or does not satisfy the relevant timing and dose limitations. Other patents may still apply.

Does a polyethylene dressing automatically infringe?

No. The material, sequence, timing, treatment site, and illumination parameters must be assessed against the asserted claim. A multilayer product may also raise a separate construction issue regarding whether it is a low-density polyethylene barrier.

Is claim 3 commercially important?

Claim 3 adds a maximum plasma ALA concentration below approximately 110 ng/mL. It may be difficult to apply without pharmacokinetic testing, but it can strengthen infringement allegations where the accused protocol produces the claimed exposure profile.

Can a generic applicant avoid the patent through a skinny label?

A carve-out may reduce induced-infringement risk if the patented occlusive use is separable from the approved indication. The outcome depends on the approved labeling, FDA use code, patent listing, and the applicant’s promotional conduct.

References

1. United States Patent and Trademark Office. (2019). US Patent No. 10,357,567, methods of enhancing penetration of 5-aminolevulinic acid for photodynamic therapy. U.S. Department of Commerce.

2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA.

3. U.S. Food and Drug Administration. (n.d.). Levulan Kerastick prescribing information. FDA.

4. U.S. Food and Drug Administration. (n.d.). Ameluz prescribing information. FDA.

5. 35 U.S.C. §§ 154, 156, 271, 282.

6. U.S. Patent and Trademark Office. (n.d.). Patent Center and Patent Examination Data System. U.S. Department of Commerce.

7. U.S. Food and Drug Administration. (n.d.). Approved drug product and patent listing requirements. FDA.

Drugs Protected by US Patent 10,357,567

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sun Pharm Inds Inc	LEVULAN	aminolevulinic acid hydrochloride	SOLUTION;TOPICAL	020965-001	Dec 3, 1999		RX	Yes	Yes						TREATMENT OF ACTINIC KERATOSIS OF UPPER EXTREMITIES BY PHOTODYNAMIC THERAPY

International Family Members for US Patent 10,357,567

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2019200152
Australia	2020103365
Australia	2020267186
Australia	2021102111
Australia	2021107564
Australia	2022209242