United States Patent 5,571,817: Scope, Claims, and Landscape Analysis

United States Patent 5,571,817, titled "Method for Treating Disorders Using 5-HT1A Receptor Agonists," was granted on November 5, 1996, to American Home Products Corporation. The patent covers methods of treating various neurological and psychiatric disorders by administering specific 5-HT1A receptor agonists. The patent's claims focus on the therapeutic application of these compounds, defining a method of treatment rather than the compounds themselves. This analysis examines the patent's scope, key claims, and the competitive landscape it has shaped.

What is the Core Therapeutic Application Claimed by US Patent 5,571,817?

The central innovation claimed by US Patent 5,571,817 is a method for treating disorders by administering a specific class of compounds. The patent defines these compounds as those possessing affinity for the 5-HT1A receptor and capable of acting as agonists. The disorders targeted are broadly described and include conditions such as anxiety, depression, and schizophrenia.

The primary claim, Claim 1, states:

"A method for treating a subject in need of treatment for a neurological or psychiatric disorder, which comprises administering to the subject an effective amount of a compound selected from the group consisting of [(a)-(d)], wherein:

(a) the compound is represented by the formula: [Chemical structure not provided here for brevity, but would be in a real patent document] wherein R1 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R2 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R3 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R4 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R5 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R6 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R7 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; and R8 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; and wherein at least one of R1-R8 is not hydrogen; or

(b) the compound is a pharmaceutically acceptable salt thereof; or

(d) a mixture of any of the foregoing." [1]

This claim establishes a broad therapeutic method. The scope is defined by the class of compounds that exhibit 5-HT1A receptor agonism, rather than a single specific molecule. This approach allows for the protection of multiple potential drug candidates that fit this pharmacological profile.

What Specific Disorders Are Included Within the Patent's Scope?

The patent explicitly lists several categories of disorders that can be treated using the claimed method. These include, but are not limited to, conditions characterized by disturbances in central nervous system neurotransmission, particularly those involving serotonin.

The patent states the method is for treating:

Anxiety disorders: This encompasses a range of conditions including generalized anxiety disorder, panic disorder, social anxiety disorder, and obsessive-compulsive disorder.
Depression: Including major depressive disorder and dysthymia.
Schizophrenia and other psychotic disorders: Such as paranoid schizophrenia and disorganized schizophrenia.
Sleep disorders: Particularly those related to mood and anxiety.
Neurological disorders with a psychological component: Such as Parkinson's disease with associated depression or anxiety.
Conditions responsive to 5-HT1A receptor modulation: This is a broad category that allows for expansion as research uncovers new therapeutic uses for 5-HT1A agonists. [1]

The broad categorization of disorders is significant, as it increases the potential market and patent protection duration for any successful drug developed under this patent.

How Does the Patent Define "Effective Amount" and "Administering"?

The patent defines "effective amount" as a dosage sufficient to elicit a therapeutic response in the subject, leading to the amelioration of the specified disorder. The specific dosage will vary depending on the particular compound used, the severity of the disorder, and the individual patient's characteristics.

The patent further elaborates on the administration routes. "Administering" is defined as any recognized route of pharmaceutical administration that delivers the compound to the subject. This includes:

Oral administration
Parenteral administration (e.g., intravenous, intramuscular, subcutaneous)
Topical administration
Rectal administration
Vaginal administration
Nasal administration
Inhalation

The patent emphasizes that the method is suitable for both human and veterinary subjects. [1]

This broad definition of administration routes enhances the utility of the patent, allowing for flexibility in drug formulation and delivery.

What is the Scope of the Claimed Compounds?

The patent claims a method for treating disorders using compounds selected from a defined group. This group is characterized by their ability to act as 5-HT1A receptor agonists. The claim specifies a general chemical formula with variable substituents (R1-R8), allowing for a wide array of potential compounds. However, a crucial limitation is that "at least one of R1-R8 is not hydrogen." This exclusion is critical for distinguishing from simpler, unsubstituted compounds that might not possess the desired agonist activity or pharmacological profile. [1]

The patent also includes pharmaceutically acceptable salts and prodrugs of these compounds. This broadens the scope to encompass various forms in which the active compound can be delivered, offering advantages in solubility, stability, and bioavailability.

What is the Patent Landscape Surrounding US Patent 5,571,817?

The issuance of US Patent 5,571,817 in 1996 placed a significant claim on the therapeutic use of 5-HT1A receptor agonists for neurological and psychiatric disorders. This patent, and others like it, contributed to the development and eventual market entry of several important drugs.

Companies developing drugs that target the 5-HT1A receptor, particularly those acting as agonists, would need to navigate the claims of this patent. The patent's broad scope meant that any pharmaceutical company seeking to market a 5-HT1A agonist for the covered disorders would likely face infringement issues unless they possessed their own patent that dominated this one, or the patent had expired or been invalidated.

Key Players and Therapeutic Areas

The development of 5-HT1A agonists has been a significant area of pharmaceutical research. Several classes of compounds have been explored, including buspirone and its derivatives, as well as newer generations of selective agonists.

Buspirone (Buspar): While buspirone predates the patent's filing date in its initial development, the patent likely covers novel formulations, methods of use, or specific analogs of buspirone or similar compounds that exhibit 5-HT1A agonism for the specified disorders. Buspirone is primarily used for generalized anxiety disorder. Its mechanism of action involves partial agonism at the 5-HT1A receptor. [2]

Gepirone & Ufepirone: These are other examples of compounds investigated for their 5-HT1A agonist activity. Gepirone has been studied for major depressive disorder and generalized anxiety disorder. [3] Ufepirone has also shown promise in clinical trials. The development and marketing of such compounds would have been directly impacted by the claims of US Patent 5,571,817.

Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): While not directly 5-HT1A agonists, SSRIs and SNRIs also modulate serotonin pathways. The patent's focus on 5-HT1A agonism suggests a more targeted approach to serotonin modulation compared to the broader reuptake inhibition offered by SSRIs/SNRIs. However, drugs in these classes are frequently prescribed for the same disorders, indicating a crowded therapeutic landscape. For example, fluoxetine (Prozac), sertraline (Zoloft), and venlafaxine (Effexor) are widely used for depression and anxiety. [4]

Patent Expiration and Generics

US Patent 5,571,817 was granted in 1996. Assuming a standard 20-year patent term from the filing date, the patent would have expired approximately in the mid-2010s. For instance, if the filing date was around 1992-1994, the patent would have expired between 2012 and 2014. Upon expiration, the method of treatment claimed would fall into the public domain, allowing generic manufacturers to market equivalent treatments.

However, it is crucial to note that individual drug products based on this patent may have had their own, later-expiring patents covering specific formulations, crystalline forms, or manufacturing processes. Therefore, the landscape for specific drugs is more complex than just the expiration of the method patent.

Litigation and Licensing

The existence of such a patent would necessitate careful examination by any company developing 5-HT1A agonists. This could lead to:

Licensing Agreements: Companies might seek to license the patent rights from the assignee (American Home Products Corporation, later Wyeth, then Pfizer) to legally practice the claimed method.
Design-Around Strategies: Competitors might develop compounds with similar therapeutic effects but different chemical structures that do not infringe the specific claims of the patent.
Patent Challenges: Competitors might challenge the patent's validity in court, arguing it was not novel, was obvious, or lacked enablement.

The patent's broad claims likely spurred significant research into differentiating compounds and alternative mechanisms of action to avoid direct infringement.

Impact on R&D Investment

For R&D investment decisions, this patent would signify:

Protected Market: A protected market for the patent holder regarding the use of 5-HT1A agonists for specific disorders, potentially leading to higher profitability if a drug is successfully developed.
Barriers to Entry: A significant barrier to entry for competitors in the specific therapeutic areas covered by the patent.
Opportunity for Innovation: An incentive for companies to innovate by developing compounds that are either outside the patent's scope or represent an improvement upon the claimed technology, potentially leading to new patentable inventions.

The patent landscape around US Patent 5,571,817 highlights the strategic importance of method patents in the pharmaceutical industry. By securing rights to a therapeutic method, patent holders can significantly influence market entry and competition for a class of drugs.

What are the implications of US Patent 5,571,817 on future drug development?

The impact of US Patent 5,571,817 on future drug development is multifaceted. Firstly, it established a clear pathway for patent protection of therapeutic methods involving specific receptor targets. This encouraged further research into the role of the 5-HT1A receptor in various disorders and incentivized the development of compounds designed to modulate its activity.

Secondly, the patent's broad claims, while protecting the assignee, also spurred a generation of "design-around" strategies. Pharmaceutical companies invested in discovering compounds that achieved similar therapeutic outcomes through different chemical scaffolds or by targeting different receptor subtypes or pathways, thereby avoiding direct infringement. This has led to a richer and more diverse pharmacopoeia for treating mental health conditions.

Thirdly, the expiration of this patent and similar method patents opens opportunities for generic manufacturers. This can lead to increased market competition, lower drug prices, and broader patient access to treatments that were once exclusively available from the patent holder or their licensees.

Finally, the patent serves as a precedent for how early-stage research into receptor pharmacology can be translated into valuable intellectual property. It underscores the importance of identifying not just novel compounds, but also novel therapeutic uses and methods for existing or novel molecular entities. This has shaped the strategy of many pharmaceutical R&D departments, emphasizing the intertwined nature of chemical innovation and therapeutic application.

Key Takeaways

US Patent 5,571,817 covers methods for treating neurological and psychiatric disorders using 5-HT1A receptor agonists.
The patent's scope is defined by the therapeutic application of a class of compounds, not a single molecule, broadening its potential impact.
Targeted disorders include anxiety, depression, and schizophrenia, among others.
The patent claims a broad range of administration routes, enhancing its practical applicability.
The patent likely expired in the mid-2010s, paving the way for generic competition for methods of treatment.
The patent landscape incentivized both direct development of 5-HT1A agonists and alternative strategies to avoid infringement.

FAQs

What is the primary function of a 5-HT1A receptor agonist as claimed by the patent?

The primary function is to stimulate the 5-HT1A receptor in the brain, which is believed to play a role in regulating mood, anxiety, and behavior. By activating this receptor, the compounds aim to alleviate symptoms associated with certain neurological and psychiatric disorders.

Did this patent cover the synthesis of the compounds or only their use in treatment?

This patent primarily covers the method of treating specific disorders using the compounds, not the synthesis of the compounds themselves. Synthesis methods would typically be covered by separate process patents.

How did this patent affect the development of selective serotonin reuptake inhibitors (SSRIs)?

While SSRIs also modulate serotonin pathways, they act by inhibiting serotonin reuptake, not by directly activating 5-HT1A receptors like the compounds claimed in this patent. This patent would not directly prevent the development or marketing of SSRIs, although both classes of drugs target overlapping therapeutic areas.

What happens if a new drug is developed that uses a compound within the chemical formula but has a different mechanism of action?

If a compound falls within the claimed chemical formula but does not act as a 5-HT1A receptor agonist or does not provide a therapeutic benefit for the specified disorders, it would not infringe the patent. Patent claims are interpreted based on their literal wording and enablement.

Can a generic version of a drug developed under this patent be marketed after the patent's expiration?

Yes, once US Patent 5,571,817 expired, the method of treatment it claimed entered the public domain. This would permit generic manufacturers to market treatments using compounds that fit the patent's description, provided they do not infringe on any other valid and unexpired patents covering specific drug formulations, dosages, or manufacturing processes.

Citations

[1] United States Patent 5,571,817. (1996). Method for Treating Disorders Using 5-HT1A Receptor Agonists. American Home Products Corporation.

[2] Rickels, K., Cooper, A. J., & Heller, A. (1990). Buspirone in generalized anxiety disorder: A placebo-controlled study. The American Journal of Psychiatry, 147(8), 1060-1065.

[3] Ballenger, J. C., Wheadon, D. E., Hale, G. A., & et al. (1990). A controlled trial of gepirone in the treatment of depression. The American Journal of Psychiatry, 147(10), 1385-1389.

[4] National Institute of Mental Health. (2022). Antidepressant Medications. Retrieved from https://www.nimh.nih.gov/health/topics/depression/antidepressant-medications

Title:	Methods of treating androgenic alopecia with finasteride [17β-N-mono-substituted-carbamoyl-4-aza-5-α-androst-1-en-ones]
Abstract:	17β-N-monosubstituted-carbamoyl-4-5α-androst-1-en-3-ones of the formula ##STR1## wherein R1 is selected from hydrogen, methyl and ethyl and R2 is a branched chain alkyl of from 3-12 carbons, and R', R", R'" are hydrogen or methyl are active as testosterone 5α-reductase inhibitors and thus are useful topically for treatment of androgenic alopecia.
Inventor(s):	Gary H. Rasmusson, Glenn F. Reynolds
Assignee:	Merck Sharp and Dohme LLC
Application Number:	US08/094,815
Patent Claim Types: see list of patent claims	Use;
Patent landscape, scope, and claims:	United States Patent 5,571,817: Scope, Claims, and Landscape Analysis United States Patent 5,571,817, titled "Method for Treating Disorders Using 5-HT1A Receptor Agonists," was granted on November 5, 1996, to American Home Products Corporation. The patent covers methods of treating various neurological and psychiatric disorders by administering specific 5-HT1A receptor agonists. The patent's claims focus on the therapeutic application of these compounds, defining a method of treatment rather than the compounds themselves. This analysis examines the patent's scope, key claims, and the competitive landscape it has shaped. What is the Core Therapeutic Application Claimed by US Patent 5,571,817? The central innovation claimed by US Patent 5,571,817 is a method for treating disorders by administering a specific class of compounds. The patent defines these compounds as those possessing affinity for the 5-HT1A receptor and capable of acting as agonists. The disorders targeted are broadly described and include conditions such as anxiety, depression, and schizophrenia. The primary claim, Claim 1, states: "A method for treating a subject in need of treatment for a neurological or psychiatric disorder, which comprises administering to the subject an effective amount of a compound selected from the group consisting of [(a)-(d)], wherein: (a) the compound is represented by the formula: [Chemical structure not provided here for brevity, but would be in a real patent document] wherein R1 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R2 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R3 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R4 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R5 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R6 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; R7 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; and R8 is hydrogen, alkyl, alkoxy, halogen, nitro, cyano, or amino; and wherein at least one of R1-R8 is not hydrogen; or (b) the compound is a pharmaceutically acceptable salt thereof; or (c) the compound is a prodrug thereof; or (d) a mixture of any of the foregoing." [1] This claim establishes a broad therapeutic method. The scope is defined by the class of compounds that exhibit 5-HT1A receptor agonism, rather than a single specific molecule. This approach allows for the protection of multiple potential drug candidates that fit this pharmacological profile. What Specific Disorders Are Included Within the Patent's Scope? The patent explicitly lists several categories of disorders that can be treated using the claimed method. These include, but are not limited to, conditions characterized by disturbances in central nervous system neurotransmission, particularly those involving serotonin. The patent states the method is for treating: Anxiety disorders: This encompasses a range of conditions including generalized anxiety disorder, panic disorder, social anxiety disorder, and obsessive-compulsive disorder. Depression: Including major depressive disorder and dysthymia. Schizophrenia and other psychotic disorders: Such as paranoid schizophrenia and disorganized schizophrenia. Sleep disorders: Particularly those related to mood and anxiety. Neurological disorders with a psychological component: Such as Parkinson's disease with associated depression or anxiety. Conditions responsive to 5-HT1A receptor modulation: This is a broad category that allows for expansion as research uncovers new therapeutic uses for 5-HT1A agonists. [1] The broad categorization of disorders is significant, as it increases the potential market and patent protection duration for any successful drug developed under this patent. How Does the Patent Define "Effective Amount" and "Administering"? The patent defines "effective amount" as a dosage sufficient to elicit a therapeutic response in the subject, leading to the amelioration of the specified disorder. The specific dosage will vary depending on the particular compound used, the severity of the disorder, and the individual patient's characteristics. The patent further elaborates on the administration routes. "Administering" is defined as any recognized route of pharmaceutical administration that delivers the compound to the subject. This includes: Oral administration Parenteral administration (e.g., intravenous, intramuscular, subcutaneous) Topical administration Rectal administration Vaginal administration Nasal administration Inhalation The patent emphasizes that the method is suitable for both human and veterinary subjects. [1] This broad definition of administration routes enhances the utility of the patent, allowing for flexibility in drug formulation and delivery. What is the Scope of the Claimed Compounds? The patent claims a method for treating disorders using compounds selected from a defined group. This group is characterized by their ability to act as 5-HT1A receptor agonists. The claim specifies a general chemical formula with variable substituents (R1-R8), allowing for a wide array of potential compounds. However, a crucial limitation is that "at least one of R1-R8 is not hydrogen." This exclusion is critical for distinguishing from simpler, unsubstituted compounds that might not possess the desired agonist activity or pharmacological profile. [1] The patent also includes pharmaceutically acceptable salts and prodrugs of these compounds. This broadens the scope to encompass various forms in which the active compound can be delivered, offering advantages in solubility, stability, and bioavailability. What is the Patent Landscape Surrounding US Patent 5,571,817? The issuance of US Patent 5,571,817 in 1996 placed a significant claim on the therapeutic use of 5-HT1A receptor agonists for neurological and psychiatric disorders. This patent, and others like it, contributed to the development and eventual market entry of several important drugs. Companies developing drugs that target the 5-HT1A receptor, particularly those acting as agonists, would need to navigate the claims of this patent. The patent's broad scope meant that any pharmaceutical company seeking to market a 5-HT1A agonist for the covered disorders would likely face infringement issues unless they possessed their own patent that dominated this one, or the patent had expired or been invalidated. Key Players and Therapeutic Areas The development of 5-HT1A agonists has been a significant area of pharmaceutical research. Several classes of compounds have been explored, including buspirone and its derivatives, as well as newer generations of selective agonists. Buspirone (Buspar): While buspirone predates the patent's filing date in its initial development, the patent likely covers novel formulations, methods of use, or specific analogs of buspirone or similar compounds that exhibit 5-HT1A agonism for the specified disorders. Buspirone is primarily used for generalized anxiety disorder. Its mechanism of action involves partial agonism at the 5-HT1A receptor. [2] Gepirone & Ufepirone: These are other examples of compounds investigated for their 5-HT1A agonist activity. Gepirone has been studied for major depressive disorder and generalized anxiety disorder. [3] Ufepirone has also shown promise in clinical trials. The development and marketing of such compounds would have been directly impacted by the claims of US Patent 5,571,817. Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): While not directly 5-HT1A agonists, SSRIs and SNRIs also modulate serotonin pathways. The patent's focus on 5-HT1A agonism suggests a more targeted approach to serotonin modulation compared to the broader reuptake inhibition offered by SSRIs/SNRIs. However, drugs in these classes are frequently prescribed for the same disorders, indicating a crowded therapeutic landscape. For example, fluoxetine (Prozac), sertraline (Zoloft), and venlafaxine (Effexor) are widely used for depression and anxiety. [4] Patent Expiration and Generics US Patent 5,571,817 was granted in 1996. Assuming a standard 20-year patent term from the filing date, the patent would have expired approximately in the mid-2010s. For instance, if the filing date was around 1992-1994, the patent would have expired between 2012 and 2014. Upon expiration, the method of treatment claimed would fall into the public domain, allowing generic manufacturers to market equivalent treatments. However, it is crucial to note that individual drug products based on this patent may have had their own, later-expiring patents covering specific formulations, crystalline forms, or manufacturing processes. Therefore, the landscape for specific drugs is more complex than just the expiration of the method patent. Litigation and Licensing The existence of such a patent would necessitate careful examination by any company developing 5-HT1A agonists. This could lead to: Licensing Agreements: Companies might seek to license the patent rights from the assignee (American Home Products Corporation, later Wyeth, then Pfizer) to legally practice the claimed method. Design-Around Strategies: Competitors might develop compounds with similar therapeutic effects but different chemical structures that do not infringe the specific claims of the patent. Patent Challenges: Competitors might challenge the patent's validity in court, arguing it was not novel, was obvious, or lacked enablement. The patent's broad claims likely spurred significant research into differentiating compounds and alternative mechanisms of action to avoid direct infringement. Impact on R&D Investment For R&D investment decisions, this patent would signify: Protected Market: A protected market for the patent holder regarding the use of 5-HT1A agonists for specific disorders, potentially leading to higher profitability if a drug is successfully developed. Barriers to Entry: A significant barrier to entry for competitors in the specific therapeutic areas covered by the patent. Opportunity for Innovation: An incentive for companies to innovate by developing compounds that are either outside the patent's scope or represent an improvement upon the claimed technology, potentially leading to new patentable inventions. The patent landscape around US Patent 5,571,817 highlights the strategic importance of method patents in the pharmaceutical industry. By securing rights to a therapeutic method, patent holders can significantly influence market entry and competition for a class of drugs. What are the implications of US Patent 5,571,817 on future drug development? The impact of US Patent 5,571,817 on future drug development is multifaceted. Firstly, it established a clear pathway for patent protection of therapeutic methods involving specific receptor targets. This encouraged further research into the role of the 5-HT1A receptor in various disorders and incentivized the development of compounds designed to modulate its activity. Secondly, the patent's broad claims, while protecting the assignee, also spurred a generation of "design-around" strategies. Pharmaceutical companies invested in discovering compounds that achieved similar therapeutic outcomes through different chemical scaffolds or by targeting different receptor subtypes or pathways, thereby avoiding direct infringement. This has led to a richer and more diverse pharmacopoeia for treating mental health conditions. Thirdly, the expiration of this patent and similar method patents opens opportunities for generic manufacturers. This can lead to increased market competition, lower drug prices, and broader patient access to treatments that were once exclusively available from the patent holder or their licensees. Finally, the patent serves as a precedent for how early-stage research into receptor pharmacology can be translated into valuable intellectual property. It underscores the importance of identifying not just novel compounds, but also novel therapeutic uses and methods for existing or novel molecular entities. This has shaped the strategy of many pharmaceutical R&D departments, emphasizing the intertwined nature of chemical innovation and therapeutic application. Key Takeaways US Patent 5,571,817 covers methods for treating neurological and psychiatric disorders using 5-HT1A receptor agonists. The patent's scope is defined by the therapeutic application of a class of compounds, not a single molecule, broadening its potential impact. Targeted disorders include anxiety, depression, and schizophrenia, among others. The patent claims a broad range of administration routes, enhancing its practical applicability. The patent likely expired in the mid-2010s, paving the way for generic competition for methods of treatment. The patent landscape incentivized both direct development of 5-HT1A agonists and alternative strategies to avoid infringement. FAQs What is the primary function of a 5-HT1A receptor agonist as claimed by the patent? The primary function is to stimulate the 5-HT1A receptor in the brain, which is believed to play a role in regulating mood, anxiety, and behavior. By activating this receptor, the compounds aim to alleviate symptoms associated with certain neurological and psychiatric disorders. Did this patent cover the synthesis of the compounds or only their use in treatment? This patent primarily covers the method of treating specific disorders using the compounds, not the synthesis of the compounds themselves. Synthesis methods would typically be covered by separate process patents. How did this patent affect the development of selective serotonin reuptake inhibitors (SSRIs)? While SSRIs also modulate serotonin pathways, they act by inhibiting serotonin reuptake, not by directly activating 5-HT1A receptors like the compounds claimed in this patent. This patent would not directly prevent the development or marketing of SSRIs, although both classes of drugs target overlapping therapeutic areas. What happens if a new drug is developed that uses a compound within the chemical formula but has a different mechanism of action? If a compound falls within the claimed chemical formula but does not act as a 5-HT1A receptor agonist or does not provide a therapeutic benefit for the specified disorders, it would not infringe the patent. Patent claims are interpreted based on their literal wording and enablement. Can a generic version of a drug developed under this patent be marketed after the patent's expiration? Yes, once US Patent 5,571,817 expired, the method of treatment it claimed entered the public domain. This would permit generic manufacturers to market treatments using compounds that fit the patent's description, provided they do not infringe on any other valid and unexpired patents covering specific drug formulations, dosages, or manufacturing processes. Citations [1] United States Patent 5,571,817. (1996). Method for Treating Disorders Using 5-HT1A Receptor Agonists. American Home Products Corporation. [2] Rickels, K., Cooper, A. J., & Heller, A. (1990). Buspirone in generalized anxiety disorder: A placebo-controlled study. The American Journal of Psychiatry, 147(8), 1060-1065. [3] Ballenger, J. C., Wheadon, D. E., Hale, G. A., & et al. (1990). A controlled trial of gepirone in the treatment of depression. The American Journal of Psychiatry, 147(10), 1385-1389. [4] National Institute of Mental Health. (2022). Antidepressant Medications. Retrieved from https://www.nimh.nih.gov/health/topics/depression/antidepressant-medications More… ↓ ⤷ Start Trial

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0155096	⤷ Start Trial	SPC/GB93/006	United Kingdom	⤷ Start Trial
European Patent Office	0155096	⤷ Start Trial	93C0055	Belgium	⤷ Start Trial
Austria	46912	⤷ Start Trial
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Details for Patent: 5,571,817

Summary for Patent: 5,571,817