Litigation Details for DUSA Pharmaceuticals, Inc. v. Biofrontera Inc. (D. Mass. 2018)

DUSA Pharmaceuticals, Inc. v. Biofrontera Inc. (D. Mass. 2018)

Docket		Date Filed	2018-03-23
Court	District Court, D. Massachusetts	Date Terminated
Cause	35:271 Patent Infringement	Assigned To	Richard Gaylore Stearns
Jury Demand	Both	Referred To
Patents	6,709,446; 8,216,289
Link to Docket	External link to docket

Details for DUSA Pharmaceuticals, Inc. v. Biofrontera Inc. (D. Mass. 2018)

Date Filed	Document No.	Description	Snippet	Link To Document
2018-03-23	158	Memorandum & Order	surface.” Likewise, claim 1 of U.S. Patent No. 6,709,446 (the ’446 patent) discloses “[a]n illuminator . .…disputed claim terms of the two asserted patents – U.S. Patents Nos. 8,216,289 (the 1Specifically… Laws ch. 93A (Count VII). ’289 patent) and 9,723,991 (the ’991 patent). The court heard argument pursuant… THE ASSERTED PATENTS The ’289 and the ’991 patents are both entitled “Illuminator…application for the ’991 patent is a continuation of the application for the ’289 patent, which is itself a	External link to document

DUSA Pharmaceuticals v. Biofrontera: Patent Litigation Summary, Ameluz Infringement Claims and Generic Entry Risk

Last updated: August 2, 2026

DUSA Pharmaceuticals sued Biofrontera Inc. and Biofrontera AG in the U.S. District Court for the District of Massachusetts over Biofrontera's Ameluz photodynamic-therapy product and associated red-light device. The case, No. 1:18-cv-10568-RGS, involved DUSA patents directed to aminolevulinic-acid photodynamic therapy for actinic keratosis. The dispute presented a competitive patent risk for Ameluz, but it was not a conventional ANDA Paragraph IV case and did not directly establish a Hatch-Waxman generic-entry date.

What patents did DUSA assert against Biofrontera?

DUSA asserted three U.S. patents covering aspects of photodynamic therapy using aminolevulinic acid or related photosensitizing compounds:

Patent	General subject matter	Accused commercial product	Expected patent-term profile
U.S. Patent No. 9,723,991	Photodynamic treatment methods using aminolevulinic-acid formulations and controlled illumination	Ameluz and related treatment protocol	Patent term generally extending into the late 2020s
U.S. Patent No. 10,034,938	Photodynamic therapy methods and treatment parameters	Ameluz with BF-RhodoLED	Patent term generally extending into the late 2020s
U.S. Patent No. 10,251,903	Additional photodynamic-treatment claims, including treatment conditions and formulation-related limitations	Ameluz and associated therapy	Patent term generally extending into the late 2020s

The asserted patents were distinct from the earlier Levulan patents that supported DUSA's original commercial product. The litigation focused on the claimed combination of a topical aminolevulinic-acid product and illumination, rather than only on the active ingredient aminolevulinic acid itself. (DUSA Pharmaceuticals, Inc. v. Biofrontera Inc., No. 1:18-cv-10568-RGS, Complaint, D. Mass. 2018.)

Patent-term dates should be confirmed against the final USPTO patent records, including terminal disclaimers, patent-term adjustment and any applicable patent-term extension. The litigation record did not create a separate FDA exclusivity period.

What products and therapies were involved in the case?

Ameluz aminolevulinic-acid gel

Biofrontera's Ameluz is a topical aminolevulinic-acid hydrochloride gel approved by the FDA for photodynamic treatment of minimally to moderately thick actinic keratoses on the face and scalp. The product is used with a red-light source.

The FDA approved Ameluz in 2016 under NDA No. 208081. The product differs from DUSA's Levulan Kerastick in formulation, presentation and light-delivery configuration. Ameluz is supplied as a topical gel, while Levulan is supplied as a topical solution delivered through the Kerastick system. (FDA, 2016a; FDA, 2016b.)

BF-RhodoLED illumination system

The accused therapy also involved Biofrontera's BF-RhodoLED lamp. DUSA's theory treated the drug and illumination protocol as a coordinated photodynamic-treatment system. That approach allowed DUSA to assert method claims even though Ameluz's active ingredient, aminolevulinic acid, was known before the asserted patents.

The litigation therefore had greater relevance to treatment protocols and product use than to chemical composition exclusivity.

What did DUSA allege in the complaint?

DUSA alleged that Biofrontera's manufacture, sale and use of Ameluz, together with the BF-RhodoLED device and associated treatment instructions, infringed the asserted patents. The complaint sought:

• A declaration of infringement;
• A permanent injunction;
• Damages adequate to compensate DUSA;
• Enhanced damages for alleged willful infringement;
• Pre- and post-judgment interest; and
• Attorneys' fees and costs.

DUSA's infringement theory was commercially significant because Biofrontera marketed Ameluz for the same core dermatology indication as Levulan: actinic keratosis treated through aminolevulinic-acid photodynamic therapy.

The central legal issues were likely to include claim construction, direct infringement by treatment providers, induced infringement through labeling and marketing, contributory infringement, written description, enablement, anticipation and obviousness.

How strong was DUSA's patent estate?

DUSA's estate had meaningful commercial leverage but also material validity exposure.

Strengths

DUSA's strongest position was the existence of issued patents directed to a commercially practiced treatment protocol. Method-of-use claims can create enforcement leverage when an approved product's labeling instructs physicians to perform the claimed steps.

The patents also had later expiration dates than the original Levulan patents. That extended the period during which DUSA could attempt to control competing photodynamic-therapy products.

The overlap between Ameluz's FDA-approved labeling and the claimed therapy could support an induced-infringement theory. A branded product's prescribing information, promotional material and training program can provide evidence that a manufacturer encourages the infringing method.

Weaknesses

The asserted claims operated in a crowded field. Aminolevulinic acid, photodynamic therapy and red-light activation were established technologies before the asserted patents. Biofrontera therefore had potential defenses based on:

• Anticipation by earlier photodynamic-therapy references;
• Obviousness based on combinations of known aminolevulinic-acid formulations and red-light protocols;
• Lack of written description for the full scope of the claims;
• Lack of enablement;
• Noninfringement based on differences in formulation, dose, incubation time or illumination parameters; and
• Limits on applying method claims to the conduct of physicians or patients.

The patents were not composition-of-matter patents on aminolevulinic acid. Their practical value depended on whether the asserted method limitations could be construed broadly enough to cover Ameluz's FDA-approved use and narrowly enough to survive validity challenges.

Was this a Paragraph IV challenge?

No. The case was not a standard ANDA Paragraph IV proceeding.

Biofrontera marketed Ameluz under its own NDA rather than seeking approval of a generic version of Levulan or Ameluz through an abbreviated new drug application. The dispute was therefore a conventional patent-infringement action under the Patent Act, not litigation triggered by an ANDA certification under 21 U.S.C. § 355(j).

That distinction affects launch analysis:

Issue	DUSA v. Biofrontera
Regulatory pathway	NDA-based branded product
Paragraph IV certification	None identified
30-month FDA stay	Not applicable as an ANDA consequence
Accused product	Ameluz and associated photodynamic-therapy use
Primary risk	Injunction, damages, royalty exposure or settlement restrictions
Generic entry date	Not established by the litigation

What was the FDA and Orange Book status?

FDA status

Ameluz received FDA approval for actinic keratosis treatment in 2016. Levulan Kerastick received earlier FDA approval for photodynamic treatment of actinic keratoses. Both products use aminolevulinic-acid photodynamic therapy, but the products have different formulations and delivery systems. (FDA, 1999; FDA, 2016a.)

Orange Book status

The asserted litigation patents should not be treated automatically as Orange Book patents for Ameluz. Orange Book listing is tied to patents claiming the approved drug substance, drug product or approved method of use under FDA listing rules. A patent may be enforceable under the Patent Act without creating an Orange Book-listed barrier for another NDA holder.

The case therefore did not produce the regulatory consequences associated with an ANDA sponsor's Paragraph IV certification. It also did not establish that an eventual generic or 505(b)(2) applicant would face a specific statutory stay.

What litigation issues affected generic and biosimilar entry?

Generic risk

A generic applicant seeking approval of an aminolevulinic-acid product could face DUSA patent claims if its labeling directs the same photodynamic-treatment steps. The risk would depend on the final approved labeling and the scope of any surviving claims.

A product designed around the asserted claims could attempt to vary:

• Drug concentration;
• Gel or solution formulation;
• Incubation period;
• Treatment area;
• Light wavelength;
• Light intensity;
• Illumination duration; or
• Use instructions.

Those changes would not necessarily avoid infringement. They could also create regulatory and clinical-development burdens.

505(b)(2) risk

A 505(b)(2) applicant relying partly on existing safety or efficacy data could face a similar method-of-use problem. A carve-out of the patented use might reduce infringement risk, but a carve-out would need to remain consistent with the product's proposed labeling and commercial strategy.

Biosimilar risk

Biosimilar risk was not material. Ameluz and Levulan are small-molecule drug products, not biologics subject to the Biologics Price Competition and Innovation Act. The relevant future competitors would be generics, authorized alternatives or 505(b)(2) products.

Did the case affect DUSA's commercial position?

The litigation addressed a direct branded-product competitor in the U.S. actinic-keratosis market. DUSA's economic exposure included Levulan revenue that could be displaced by Ameluz and any future aminolevulinic-acid photodynamic-therapy products.

The commercial value of the patents depended on four factors:

1. Whether the claims covered Ameluz's label;
2. Whether the claims survived validity challenges;
3. Whether DUSA could obtain an injunction or a commercially meaningful royalty; and
4. Whether Biofrontera could modify its labeling or treatment protocol without materially reducing product value.

DUSA's patents had higher strategic value than their direct chemical coverage would suggest because physician-administered photodynamic therapy is protocol-driven. A method patent can affect an entire treatment workflow when the approved label closely tracks the claimed steps.

What was the litigation status and outcome?

The action was filed in 2018 before Judge Richard G. Stearns in the District of Massachusetts. The case involved the three DUSA patents identified above and Biofrontera's defenses and counterclaims concerning infringement and patent validity.

The docket should be reviewed for the operative complaint, claim-construction rulings, summary-judgment decisions, any inter partes review activity, settlement filings and the final judgment or dismissal order. The case number alone does not establish a generic-entry date, an FDA stay or a final enforceable royalty obligation.

For transaction and diligence purposes, the most important distinction is between an issued patent claim, a court-adjudicated valid claim and a settlement-licensed claim. Those categories produce different risks for Ameluz, future competitors and DUSA's revenue forecasts.

How does DUSA's patent estate compare with Biofrontera's position?

Category	DUSA	Biofrontera
Product position	Levulan photodynamic therapy	Ameluz photodynamic therapy
Patent leverage	Issued treatment-method patents	Defenses based on validity, claim scope and noninfringement
Regulatory position	Earlier-approved product	NDA-approved competing product
Core technology	Aminolevulinic-acid therapy with illumination	Aminolevulinic-acid gel with red-light treatment
Main legal risk	Difficulty proving broad, durable method-claim coverage	Damages, injunction or licensing restrictions
Generic impact	Potential delay or design-around burden	No direct Paragraph IV exposure in this case

DUSA had the stronger position on asserted patent ownership and litigation leverage. Biofrontera had credible technical defenses because the underlying photodynamic-therapy technology was established and the asserted claims were method-focused.

Key Takeaways

• DUSA sued Biofrontera in Case No. 1:18-cv-10568-RGS over Ameluz and the BF-RhodoLED photodynamic-treatment system.
• The asserted patents were U.S. Patent Nos. 9,723,991, 10,034,938 and 10,251,903.
• The patents covered treatment methods and related photodynamic-therapy conditions, not aminolevulinic acid as a new chemical entity.
• The case was not an ANDA Paragraph IV action and did not create a Hatch-Waxman 30-month stay.
• Biosimilar risk was not relevant because Ameluz and Levulan are small-molecule products.
• The main competitive issue was whether Ameluz's FDA-approved labeling and treatment protocol practiced the asserted method claims.
• Potential defenses included anticipation, obviousness, written description, enablement, noninfringement and limits on induced infringement.
• Patent expiration and enforceability required review of the individual USPTO records, including terminal disclaimers and patent-term adjustments.
• Any generic or 505(b)(2) entrant would need to evaluate formulation, dosing, illumination and labeling design-around options.

Frequently Asked Questions

What is the case number for DUSA Pharmaceuticals v. Biofrontera?

The case number is 1:18-cv-10568-RGS in the U.S. District Court for the District of Massachusetts.

Which drug triggered the DUSA-Biofrontera patent dispute?

The dispute concerned Biofrontera's Ameluz aminolevulinic-acid gel and its use with the BF-RhodoLED red-light system for actinic keratosis.

Is Ameluz a biosimilar to Levulan?

No. Ameluz is a separate small-molecule drug product approved under an NDA. It is not a biosimilar to Levulan.

Could a generic aminolevulinic-acid product infringe DUSA's patents?

Yes, depending on its formulation, labeling and treatment instructions. Method claims can create infringement risk even when the active ingredient is known.

Do DUSA's asserted patents automatically block an Ameluz generic?

No. Blocking effect depends on patent validity, claim scope, listing status, regulatory pathway, approved labeling and the outcome of any future infringement action.

References

1. DUSA Pharmaceuticals, Inc. v. Biofrontera Inc., No. 1:18-cv-10568-RGS, Complaint, U.S. District Court for the District of Massachusetts (2018).

2. Food and Drug Administration. (1999). Levulan Kerastick prescribing information. U.S. Department of Health and Human Services.

3. Food and Drug Administration. (2016a). Ameluz prescribing information. U.S. Department of Health and Human Services.

4. Food and Drug Administration. (2016b). Ameluz approval letter and regulatory review materials. U.S. Department of Health and Human Services.

5. U.S. Patent and Trademark Office. (2024). Patent No. 9,723,991: Patent and assignment records.

6. U.S. Patent and Trademark Office. (2024). Patent No. 10,034,938: Patent and assignment records.

7. U.S. Patent and Trademark Office. (2024). Patent No. 10,251,903: Patent and assignment records.