United States Patent 8,268,847: A Detailed Analysis of Scope and Claims
Overview of the Patent
United States Patent 8,268,847, titled "Therapeutic compositions comprising a specific endothelin receptor antagonist and a PDE5 inhibitor," is a crucial patent protecting the drug OPSUMIT (macitentan), which is used in the treatment of pulmonary arterial hypertension (PAH)[1][2][4].
Patented Use
This patent specifically covers the method of treating pulmonary hypertension by administering macitentan in combination with a compound having phosphodiesterase-5 (PDE5) inhibitory properties. This combination therapy is designed to enhance the efficacy of treating PAH by targeting both endothelin receptors and the PDE5 pathway[1][2].
Claims and Scope
The patent claims are focused on the therapeutic compositions and the method of use for these compositions. Here are some key aspects of the claims:
Therapeutic Compositions
- The patent claims cover compositions that include macitentan, a dual endothelin receptor antagonist, and a PDE5 inhibitor. This combination is intended to provide a synergistic effect in lowering blood pressure in the pulmonary arteries[1][2].
Method of Use
- The method-of-use claims specify the administration of macitentan in conjunction with a PDE5 inhibitor for the treatment of PAH. This method is designed to improve the therapeutic outcomes for patients with PAH by addressing multiple pathways involved in the disease[1][2].
Patent Expiration
The patent 8,268,847 is scheduled to expire on April 18, 2029. This expiration date is significant as it marks the period after which generic versions of the drug could potentially enter the market, assuming no additional patent extensions or new patent filings that could delay generic entry[2].
Patent Litigation and Challenges
The patent has been subject to various legal challenges and certifications. For instance, ANDA (Abbreviated New Drug Application) submissions have included paragraph IV certifications, which assert that the patent is invalid, unenforceable, or will not be infringed by the manufacture, use, or sale of generic macitentan tablets. Litigation has been initiated and subsequently dismissed in some cases, highlighting the ongoing legal battles surrounding this patent[2][5].
Impact on Generic Entry
The presence of this patent, along with other related patents (e.g., 7,094,781, 8,367,685, 9,265,762, and 10,946,015), creates a complex patent landscape that affects the timing of generic entry. Generic manufacturers must navigate these patents and their respective expiration dates to ensure that their products do not infringe on the protected methods and compositions[1][2][5].
Patent Scope and Quality
The scope of this patent, like many others, is a subject of debate in the context of patent quality. The patent's claims are specific to the combination therapy of macitentan and a PDE5 inhibitor, which narrows the scope compared to broader claims. This specificity can influence the patent's validity and enforceability. Research suggests that narrower claims, such as those in this patent, are associated with a higher probability of grant and a shorter examination process[3].
Clinical and Therapeutic Significance
The therapeutic significance of this patent lies in its protection of a treatment method that combines two potent mechanisms for managing PAH. Macitentan's role as an endothelin receptor antagonist, combined with the vasodilatory effects of a PDE5 inhibitor, provides a comprehensive approach to reducing pulmonary arterial pressure and improving patient outcomes[4].
Conclusion
United States Patent 8,268,847 is a critical component of the patent landscape surrounding OPSUMIT, protecting a specific and clinically significant method of treating PAH. The patent's expiration in 2029 will be a pivotal moment for the pharmaceutical industry, as it could open the door for generic versions of macitentan. Understanding the scope, claims, and legal challenges associated with this patent is essential for both pharmaceutical companies and regulatory bodies.
Key Takeaways
- Patent Protection: The patent protects the method of treating PAH using macitentan in combination with a PDE5 inhibitor.
- Expiration Date: The patent is set to expire on April 18, 2029.
- Legal Challenges: The patent has faced paragraph IV certifications and litigation related to generic entry.
- Therapeutic Significance: The combination therapy protected by this patent is clinically significant for managing PAH.
- Patent Scope: The patent's claims are specific, which can influence its validity and enforceability.
FAQs
What is the primary use of the drug protected by United States Patent 8,268,847?
The primary use is the treatment of pulmonary arterial hypertension (PAH) through the administration of macitentan in combination with a PDE5 inhibitor.
When is the patent 8,268,847 scheduled to expire?
The patent is scheduled to expire on April 18, 2029.
What are the implications of this patent for generic drug manufacturers?
Generic manufacturers must navigate the patent landscape and ensure their products do not infringe on the protected methods and compositions until the patent expires.
How does the combination therapy protected by this patent work?
The combination therapy works by targeting both endothelin receptors with macitentan and the PDE5 pathway with a PDE5 inhibitor, providing a synergistic effect in lowering pulmonary arterial pressure.
What are the legal challenges associated with this patent?
The patent has faced paragraph IV certifications and litigation related to generic entry, with some cases being initiated and subsequently dismissed.
How does the specificity of the patent claims affect its validity and enforceability?
The specificity of the claims narrows the scope of the patent, which can increase its validity and enforceability compared to broader claims.
