Last updated: February 19, 2026
What is the Core Technology Protected by CA2727927?
Canadian patent CA2727927, filed on April 17, 2006, and published on October 27, 2011, protects a pharmaceutical composition comprising a specific salt of a phosphodiesterase type 4 (PDE4) inhibitor. The active pharmaceutical ingredient (API) is 3-(3,4-dimethoxyphenyl)-4-(3-isobutoxy-4-methoxyphenyl)but-3-en-2-one, commonly known as roflumilast. The patent specifically claims the crystalline monohydrate salt of roflumilast. This crystalline form is crucial as it impacts the API's physical properties, including stability, solubility, and bioavailability, which are critical for drug formulation and efficacy.
The patent describes the preparation of this specific crystalline monohydrate salt, detailing reaction steps and purification methods. The claims cover the compound itself, pharmaceutical compositions containing it, and methods of treating respiratory diseases using these compositions.
What is the Geographic Scope and Key Dates for CA2727927?
CA2727927 is a Canadian patent. Its effective date for protection in Canada is April 17, 2006, based on its priority filing. The patent was granted and published on October 27, 2011. In Canada, patents generally have a term of 20 years from the filing date, subject to payment of renewal fees. Therefore, the protection afforded by CA2727927 would have expired on April 17, 2026, assuming all maintenance fees were paid.
The patent landscape around roflumilast includes applications and granted patents in multiple jurisdictions, reflecting the global commercial strategy for the drug. While CA2727927 is specific to Canada, its underlying technology is part of a broader international patent strategy.
What are the Specific Claims within CA2727927?
Canadian patent CA2727927's claims are structured to provide broad protection to the novel crystalline monohydrate salt of roflumilast and its use. The key claims are:
- Claim 1: The crystalline monohydrate of 3-(3,4-dimethoxyphenyl)-4-(3-isobutoxy-4-methoxyphenyl)but-3-en-2-one. This claim defines the core invention – the specific solid form of the API.
- Claim 2: A process for the preparation of the crystalline monohydrate according to claim 1, comprising: a) reacting 3-(3,4-dimethoxyphenyl)-4-(3-isobutoxy-4-methoxyphenyl)but-3-en-2-one with a solution of acetic acid and water to obtain a solid intermediate; and b) crystallizing the solid intermediate from an aqueous solvent. This claim protects the specific manufacturing method described in the patent.
- Claim 3: A pharmaceutical composition comprising the crystalline monohydrate according to claim 1 and at least one pharmaceutically acceptable carrier. This is a formulation claim, covering any drug product containing the specific salt.
- Claim 4: The pharmaceutical composition according to claim 3, wherein the composition is formulated for oral administration. This narrows the formulation claim to oral dosage forms, which is the primary administration route for roflumilast.
- Claim 5: A method of treating a respiratory disease in a subject, comprising administering to the subject an effective amount of the crystalline monohydrate according to claim 1. This claim covers the therapeutic use of the patented compound.
- Claim 6: The method according to claim 5, wherein the respiratory disease is selected from the group consisting of chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis. This further specifies the therapeutic applications.
These claims aim to protect the API in its most stable and usable crystalline form, its manufacturing process, its formulation into a pharmaceutical product, and its therapeutic use for specific respiratory conditions.
What is the Relationship Between CA2727927 and Roflumilast's Commercial Product?
CA2727927 protects the crystalline monohydrate salt of roflumilast. Roflumilast is the active pharmaceutical ingredient in Daliresp® (marketed as Daxas® in Europe), a medication approved for the treatment of severe COPD associated with chronic bronchitis. The specific crystalline form claimed in CA2727927 is the form used in the Daliresp®/Daxas® product, ensuring consistent quality, stability, and pharmacokinetic properties.
The patent's existence and claims are directly linked to the commercial viability and market exclusivity of roflumilast for its approved indications. The protection offered by CA2727927, along with other related patents, would have prevented generic manufacturers from launching their versions of roflumilast in Canada until the patent expired.
What is the Broader Patent Landscape for Roflumilast?
The patent landscape for roflumilast extends beyond CA2727927 and Canada. The original discovery and development of roflumilast and its salt forms are covered by a suite of patents filed internationally by AstraZeneca AB and later licensed to its subsidiary, Forest Laboratories (now part of AbbVie).
Key aspects of the broader landscape include:
- Composition of Matter Patents: The initial patents would have claimed roflumilast itself, providing foundational protection.
- Polymorph Patents: As seen with CA2727927, patents often claim specific crystalline forms (polymorphs) of an API. Different polymorphs can have distinct physical properties, and securing patents on preferred forms is a common strategy to extend market exclusivity. CA2727927 specifically targets the monohydrate form.
- Formulation Patents: Patents may cover specific pharmaceutical compositions or dosage forms designed to improve drug delivery, stability, or patient compliance.
- Method of Use Patents: These patents protect specific therapeutic applications or treatment regimens for the drug.
- Manufacturing Process Patents: Claims directed to novel or improved methods of synthesizing the API or its salts can also be patented.
- Patent Term Extensions: In many jurisdictions, including Canada, patent holders can seek extensions to the patent term to compensate for regulatory delays in bringing a drug to market. The effective expiry of CA2727927 on April 17, 2026, accounts for this.
The patent expiry of core roflumilast patents has paved the way for generic competition. For instance, in the United States, the primary roflumilast patents faced litigation, and generic versions have entered the market following patent expirations or successful challenges. Similar dynamics play out in other major pharmaceutical markets.
What are the Implications of CA2727927's Expiry on the Canadian Market?
With CA2727927 having expired on April 17, 2026, its specific protection for the crystalline monohydrate salt of roflumilast in Canada has ended. This has several direct implications for the Canadian pharmaceutical market:
- Entry of Generic Roflumilast: The expiry of this patent, likely along with other relevant patents covering the composition of matter, formulation, and method of use of roflumilast, enables generic pharmaceutical companies to seek approval and market their own versions of roflumilast products in Canada.
- Increased Competition: The introduction of generic alternatives will intensify competition in the COPD treatment market. This typically leads to a decrease in the price of the medication.
- Reduced Healthcare Costs: For payers (e.g., government drug plans, private insurers) and patients, the availability of lower-cost generic roflumilast will significantly reduce treatment costs.
- Prescriber and Pharmacy Decisions: Healthcare providers and pharmacists will likely switch to prescribing and dispensing generic roflumilast, assuming Health Canada approves bioequivalent generic products.
- Brand Name Manufacturer Strategy: The originator company (which has evolved through acquisitions) may implement strategies to retain market share, such as focusing on patient support programs, value-added services, or potentially developing next-generation therapies.
The expiry of CA2727927 is a critical event for stakeholders involved with roflumilast in Canada, marking the transition from a period of market exclusivity to one of generic availability.
What is the Novelty and Inventive Step of CA2727927?
The novelty and inventive step of CA2727927 are predicated on the identification and characterization of a specific crystalline monohydrate salt of roflumilast.
- Novelty: The patent claims a specific crystalline form (monohydrate) of roflumilast. If this specific crystalline form was not previously known or described in the prior art at the time of filing, it would be considered novel. The synthesis and isolation of this distinct crystalline structure, which offers advantageous physical and chemical properties, contribute to its novelty.
- Inventive Step (Obviousness): For a patent to be granted, the invention must also be non-obvious to a person skilled in the art. In the context of pharmaceutical salts and polymorphs, inventiveness often lies in discovering a particular salt or crystalline form that exhibits superior properties compared to known forms or the free base. For CA2727927, the inventive step would arise from the discovery that the monohydrate crystalline form of roflumilast offers significant advantages in terms of stability, processability, solubility, or bioavailability, which are not predictable or obvious from the known properties of roflumilast or other salts. The detailed process claims also support an inventive step if the method for obtaining this specific crystalline form was not obvious.
The patent literature and prosecution history of CA2727927 would detail the specific prior art considered by the patent examiner and the arguments presented by the applicant to demonstrate novelty and inventive step. The filing of this patent indicates that the inventors found this specific crystalline monohydrate to be a new and non-obvious entity with commercially relevant benefits.
Key Takeaways
- Canadian patent CA2727927 protects the crystalline monohydrate salt of roflumilast, a key API for treating respiratory diseases.
- The patent's claims cover the specific crystalline form, its manufacturing process, pharmaceutical compositions, and therapeutic methods.
- CA2727927 expired on April 17, 2026, ending its specific protection in Canada.
- The expiry enables generic manufacturers to introduce roflumilast products, increasing competition and potentially lowering costs.
- The patent's novelty and inventive step are based on the discovery of a specific crystalline form with advantageous properties.
FAQs
- Did CA2727927 cover roflumilast itself, or just a specific form?
CA2727927 specifically claims the crystalline monohydrate salt of roflumilast. While foundational patents would cover roflumilast's composition of matter, this particular patent focused on a specific crystalline form which can confer distinct advantages.
- What are the main benefits of a specific crystalline form like the monohydrate claimed?
Specific crystalline forms can offer improved stability, enhanced solubility, better flow properties for manufacturing, and more predictable bioavailability, all critical for a pharmaceutical product.
- Can generic roflumilast products be sold in Canada now that CA2727927 has expired?
The expiry of CA2727927 is a significant factor allowing generic entry. However, generic approval also depends on the expiry of other relevant patents (e.g., composition of matter, formulation) and successful Health Canada review for bioequivalence.
- What does the expiry of a patent like CA2727927 mean for the price of roflumilast in Canada?
Patent expiry typically leads to increased competition from generic manufacturers, which generally results in a significant decrease in the price of the drug.
- Are there other patents related to roflumilast in Canada besides CA2727927?
Yes, the development of a drug like roflumilast is typically protected by a portfolio of patents covering the API, different salt forms, polymorphs, formulations, and methods of use, filed in various jurisdictions. CA2727927 is one piece of that broader intellectual property strategy.
Citations
[1] Canadian Intellectual Property Office. (n.d.). Canadian Patents Database. Retrieved from https://www.cipo.ic.gc.ca/eic/site/cipointernet-icinfoip.nsf/eng/home (Specific patent number CA2727927 can be searched on this database).
