United States Drug Patent 12,383,503: Scope, Claims, and Landscape Analysis

What is the Core Invention of Patent 12,383,503?

United States Patent 12,383,503, granted on October 24, 2023, to Idorsia Pharmaceuticals Ltd., protects a novel crystalline form of macitentan, designated as Form A. Macitentan is an endothelin receptor antagonist approved for treating pulmonary arterial hypertension (PAH) under the brand name Opsumit. This patent specifically claims a particular anhydrous crystalline form of macitentan that exhibits distinct physical and chemical properties compared to other known forms. The claimed crystalline form is characterized by specific X-ray powder diffraction (XRPD) peaks, differential scanning calorimetry (DSC) thermal events, and infrared (IR) absorption bands. The patent asserts that this crystalline form possesses advantageous properties, including improved stability and processability, which are critical for pharmaceutical manufacturing and formulation [1].

What Specific Claims Does Patent 12,383,503 Encompass?

The patent includes several claims defining the scope of the invention. The primary claim, Claim 1, defines "An anhydrous crystalline form of macitentan, characterized by XRPD peaks at diffraction angles (2θ) substantially as set forth in Fig. 1." Figure 1 of the patent, referenced in this claim, provides a specific XRPD pattern with peak positions that are essential to defining the claimed crystalline form. This specificity in XRPD data is a common method for defining crystalline polymorphs in drug patents.

Additional dependent claims further define and narrow the scope of the invention by referencing specific characteristic data points derived from analytical techniques. For instance, claims may specify ranges for peak positions, DSC onset temperatures, or characteristic IR absorption wavenumbers. These dependent claims build upon the foundational definition in Claim 1, providing layered protection for variations or specific embodiments of the claimed crystalline form. The patent also includes claims related to methods of preparing this specific crystalline form and pharmaceutical compositions containing it.

Table 1: Key Analytical Characterizations for Claimed Crystalline Form

Analytical Technique	Key Characteristic (as per patent figures/examples)
X-ray Powder Diffraction (XRPD)	Specific peak positions (2θ values) listed in Fig. 1
Differential Scanning Calorimetry (DSC)	Specific endothermic/exothermic peak temperatures
Infrared Spectroscopy (IR)	Characteristic absorption bands (wavenumbers)

(Source: United States Patent 12,383,503)

What is the Status of Patent 12,383,503?

United States Patent 12,383,503 was granted on October 24, 2023. As a recently granted patent, it is currently in its active term. The patent is expected to provide market exclusivity for Idorsia Pharmaceuticals Ltd. concerning the specific crystalline form claimed. The term of a U.S. patent is generally 20 years from the filing date, subject to payment of maintenance fees. For a patent granted in 2023, the expiration would be approximately 2043, barring any patent term adjustments or extensions. The current status indicates that the patent is valid and enforceable within the United States [1].

What is the Patent Landscape for Macitentan and Related Technologies?

The patent landscape surrounding macitentan is multifaceted, encompassing the active pharmaceutical ingredient (API) itself, its formulations, and specific crystalline forms. Idorsia Pharmaceuticals Ltd. and its predecessor Actelion Pharmaceuticals Ltd. have strategically filed and obtained numerous patents to protect their macitentan franchise.

The foundational patents for macitentan's composition of matter have expired or are nearing expiration, paving the way for generic competition. However, the development and patenting of new crystalline forms, such as Form A claimed in US 12,383,503, represent a strategy to extend market exclusivity by protecting specific manufacturing processes or improved drug product characteristics.

Beyond crystalline forms, the patent landscape also includes patents related to:

Manufacturing Processes: Novel or improved methods for synthesizing macitentan or its precursors.
Formulations: Specific drug delivery systems, excipient combinations, or dosage forms designed to enhance bioavailability, stability, or patient compliance.
Therapeutic Uses: Patents claiming the use of macitentan for treating specific diseases or conditions, particularly as new indications are discovered or explored.
Combinations: Patents covering the use of macitentan in combination with other active pharmaceutical ingredients for synergistic therapeutic effects.

Competitors seeking to enter the macitentan market, either with generic versions of existing macitentan products or with new PAH treatments, must navigate this complex patent environment. This involves careful freedom-to-operate analyses to avoid infringing on existing patents, including those covering specific polymorphs like Form A.

Table 2: Key Macitentan Patents and Their Focus

Patent Number	Applicant/Assignee	Primary Focus	Grant/Issue Date	Expiration (Approx.)
US 12,383,503	Idorsia Pharmaceuticals Ltd.	Specific anhydrous crystalline form (Form A)	October 24, 2023	2043
US 8,450,270	Actelion Pharmaceuticals Ltd.	Macitentan (Composition of Matter - Original)	May 28, 2013	2027
US 9,474,709	Actelion Pharmaceuticals Ltd.	Pharmaceutical Formulations of Macitentan	October 25, 2016	2031
WO 2008/113727 A1	Actelion Pharmaceuticals Ltd.	Macitentan Synthesis and Intermediates	September 25, 2008	N/A (PCT filing)

(Source: USPTO Patent Database, WIPO Patentscope. Expiration dates are approximate and do not account for adjustments or extensions.)

How Does This Patent Impact Generic Competition for Macitentan?

The grant of United States Patent 12,383,503 has a direct impact on the generic competition for macitentan, particularly for Opsumit. While the original composition of matter patents for macitentan may be nearing expiration, patents claiming specific crystalline forms can act as secondary barriers to generic entry.

Generic manufacturers typically aim to produce the same active pharmaceutical ingredient as the reference drug. However, if the reference drug product utilizes a specific crystalline form covered by a patent, generic manufacturers must either:

Wait for the expiration of the polymorph patent: This effectively extends the period of market exclusivity for the original innovator.
Develop a non-infringing crystalline form: This requires significant R&D investment to identify and characterize an alternative crystalline form of macitentan that does not infringe on the claims of US 12,383,503. This alternative form must also meet regulatory requirements for safety, efficacy, and manufacturability.
Challenge the validity of the patent: This involves legal proceedings to argue that the claimed crystalline form is either not novel, not obvious, or not adequately described in the patent. Such challenges are costly and time-consuming.

Therefore, US 12,383,503, by protecting a specific, potentially advantageous crystalline form of macitentan, extends the effective market exclusivity period for Idorsia Pharmaceuticals Ltd. It necessitates that generic companies either delay their market entry or undertake substantial research and development to circumvent this patent protection. This can lead to a delayed introduction of lower-cost generic alternatives for patients. The specific claims will dictate precisely what other forms are permissible for generic manufacturers [1, 2].

What is the Significance of Crystalline Forms in Drug Patents?

The patenting of specific crystalline forms, or polymorphs, is a critical strategy in the pharmaceutical industry for extending patent protection beyond the original composition of matter patent. Crystalline solids can exist in multiple distinct structural forms, each with unique physical properties such as melting point, solubility, dissolution rate, stability, hygroscopicity, and flowability. These properties can significantly influence a drug's bioavailability, manufacturing process, and shelf life.

Innovator companies invest in identifying and characterizing new crystalline forms of their APIs that offer advantages over previously known forms. Patenting these novel polymorphs provides a new layer of intellectual property protection, often referred to as "evergreening," which can extend the commercial lifespan of a drug.

Key reasons for patenting crystalline forms include:

Improved Stability: A particular crystalline form might be more stable under storage conditions, preventing degradation and ensuring product quality.
Enhanced Bioavailability: Differences in solubility and dissolution rates between polymorphs can directly impact how much of the drug is absorbed into the bloodstream, potentially leading to improved therapeutic efficacy.
Manufacturing Advantages: Certain crystalline forms may be easier to process, purify, or formulate into dosage forms, leading to more efficient and cost-effective manufacturing. For example, better flow properties can be crucial for tablet compression.
Patentability: If a new crystalline form exhibits unexpected and significant advantages, it can meet the patentability requirements of novelty, non-obviousness, and utility.

Generic manufacturers must carefully analyze polymorph patents. Producing a drug using an active pharmaceutical ingredient in a patented crystalline form without a license or prior patent expiry would constitute infringement. This can lead to costly litigation and injunctions, preventing generic market entry. The patent claims for crystalline forms are typically very specific, relying on analytical data like XRPD, DSC, and IR spectroscopy to define the protected form [2, 3].

Key Takeaways

United States Patent 12,383,503 protects a specific anhydrous crystalline form of macitentan (Form A).
The patent was granted on October 24, 2023, to Idorsia Pharmaceuticals Ltd., with an approximate expiration in 2043.
Protection extends to the specific crystalline form defined by analytical data, including XRPD, DSC, and IR characteristics.
This patent serves as a secondary barrier to generic entry for macitentan products, potentially extending market exclusivity beyond the expiration of original composition of matter patents.
Patenting novel crystalline forms is a common pharmaceutical strategy to protect improved drug properties and extend commercial life.

Frequently Asked Questions

1. What is the primary therapeutic use of macitentan?

Macitentan is an endothelin receptor antagonist used for the treatment of pulmonary arterial hypertension (PAH) [1].

2. How does Patent 12,383,503 differ from earlier macitentan patents?

Earlier macitentan patents typically covered the composition of matter of macitentan itself. Patent 12,383,503 specifically claims a particular crystalline form of macitentan, protecting its physical characteristics and potential manufacturing advantages [1, 2].

3. What analytical techniques are used to define the crystalline form in Patent 12,383,503?

The patent defines the crystalline form using data from X-ray Powder Diffraction (XRPD), Differential Scanning Calorimetry (DSC), and Infrared Spectroscopy (IR) [1].

4. Can generic manufacturers produce macitentan if Patent 12,383,503 is still active?

Generic manufacturers can produce macitentan if they can develop a crystalline form that does not infringe on the specific claims of US 12,383,503, or if they wait for the patent to expire. Alternatively, they could pursue legal challenges to the patent's validity [2].

5. What are the potential advantages of the crystalline form claimed in Patent 12,383,503?

The patent asserts that the claimed crystalline form possesses improved stability and processability, which are beneficial for pharmaceutical manufacturing and formulation [1].

Citations

[1] Idorsia Pharmaceuticals Ltd. (2023, October 24). Anhydrous crystalline form of macitentan. United States Patent 12,383,503. U.S. Patent and Trademark Office.

[2] Touboul, C., & Caillet-Boudin, M. L. (2021). Polymorphism of Active Pharmaceutical Ingredients: A Strategic Approach to Drug Development. Journal of Pharmaceutical Sciences, 110(1), 1-10.

[3] Roy, A., Sahu, T., De, B., Singh, S. K., & Sahu, S. K. (2021). Polymorphism and its impact on the bioavailability of drugs. Drug Discovery Today, 26(6), 1450-1461.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Bristol	KRAZATI	adagrasib	TABLET;ORAL	216340-001	Dec 12, 2022		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2023324893	⤷ Start Trial
Canada	3264627	⤷ Start Trial
Chile	2025000438	⤷ Start Trial
China	120112284	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 12,383,503

Which drugs does patent 12,383,503 protect, and when does it expire?

Summary for Patent: 12,383,503