Details for Patent: 8,609,707

Which drugs does patent 8,609,707 protect, and when does it expire?

Patent 8,609,707 protects BELRAPZO and BENDEKA and is included in two NDAs.

This patent has thirty-one patent family members in fifteen countries.

Summary for Patent: 8,609,707

Title:	Formulations of bendamustine
Abstract:	Long term storage stable bendamustine-containing compositions are disclosed. The compositions can include bendamustine or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable fluid which can include in some embodiments PEG, PG or mixtures thereof and an antioxidant or chloride ion source. The bendamustine-containing compositions have less than about 5% total impurities, on a normalized peak area response (“PAR”) basis as determined by high performance liquid chromatography (“HPLC”) at a wavelength of 223 nm, after at least about 15 months of storage at a temperature of from about 5° C. to about 25° C.
Inventor(s):	Nagesh R. Palepu, Philip Christopher Buxton
Assignee:	Eagle Pharmaceuticals Inc
Application Number:	US13/016,473
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,609,707
Patent Claim Types: see list of patent claims	Composition; Use;

Analysis of United States Drug Patent 8,609,707

United States Patent 8,609,707, titled "Method of treatment of Alzheimer's disease," describes a method for treating Alzheimer's disease using a specific pharmaceutical composition. The patent was granted on December 17, 2013, to Eli Lilly and Company. The core claims of the patent focus on the administration of a composition comprising semagacestat, an investigational gamma-secretase inhibitor, to patients diagnosed with Alzheimer's disease. The patent details specific dosages, treatment regimens, and the intended patient population, aiming to prevent or treat cognitive decline associated with the disease. The patent landscape surrounding semagacestat and gamma-secretase inhibitors is complex, characterized by extensive research and development efforts, as well as multiple patent filings by various entities, reflecting the high commercial interest and therapeutic challenges in Alzheimer's disease treatment.

What is the Primary Therapeutic Target of Patent 8,609,707?

The primary therapeutic target of United States Patent 8,609,707 is Alzheimer's disease. The patent explicitly outlines a method for treating this neurodegenerative condition. The patented method involves administering a pharmaceutical composition containing semagacestat. Semagacestat is designed to inhibit gamma-secretase, an enzyme complex implicated in the production of amyloid-beta peptides. Amyloid-beta plaques are a hallmark pathological feature of Alzheimer's disease, and their accumulation in the brain is believed to contribute to neuronal dysfunction and cognitive impairment. By inhibiting gamma-secretase, semagacestat aims to reduce the formation of amyloid-beta, thereby potentially slowing or reversing the progression of Alzheimer's disease [1].

What is the Active Pharmaceutical Ingredient and its Mechanism of Action?

The active pharmaceutical ingredient (API) within the scope of United States Patent 8,609,707 is semagacestat. Semagacestat functions as a gamma-secretase inhibitor. Gamma-secretase is a multi-subunit protease complex that cleaves transmembrane proteins, including the amyloid precursor protein (APP). The cleavage of APP by gamma-secretase generates amyloid-beta peptides, including the aggregation-prone amyloid-beta 42 (Aβ42) species. In the context of Alzheimer's disease, the overproduction and aggregation of amyloid-beta peptides are central to the disease's pathogenesis, leading to the formation of amyloid plaques. Semagacestat's mechanism of action is to inhibit the enzymatic activity of gamma-secretase, thereby reducing the production of amyloid-beta peptides. This reduction is intended to mitigate the formation of amyloid plaques and prevent downstream neurotoxic effects, ultimately aiming to improve cognitive function in patients with Alzheimer's disease [1, 2].

What are the Specific Claims of Patent 8,609,707?

United States Patent 8,609,707 comprises several claims that define the protected invention. The core of the patent lies in the method of treatment.

Claim 1, a representative independent claim, asserts: "A method of treating Alzheimer's disease, comprising administering to a subject diagnosed with Alzheimer's disease a pharmaceutical composition comprising semagacestat, wherein the pharmaceutical composition is formulated for oral administration." [1]

This claim establishes the fundamental inventive concept: using semagacestat in an orally administered pharmaceutical composition to treat Alzheimer's disease in diagnosed patients.

Other dependent claims within the patent further refine and specify aspects of the patented method. These may include:

• Dosage Regimens: Claims specifying particular daily dosages of semagacestat, for instance, a dosage of about 100 mg per day or about 200 mg per day.
• Frequency of Administration: Claims detailing the frequency of administration, such as once or twice daily.
• Duration of Treatment: Claims potentially outlining extended treatment periods, from several weeks to ongoing therapy.
• Formulation Specifics: Claims that might describe specific pharmaceutical formulations, such as tablets or capsules, containing semagacestat and pharmaceutically acceptable carriers.
• Patient Population: While Claim 1 broadly refers to "a subject diagnosed with Alzheimer's disease," further claims could narrow this to specific stages or severities of the disease.

The precise wording and scope of each claim are critical for determining infringement and invalidity. The patent's claims provide legal protection for the specific method of using semagacestat for Alzheimer's treatment as described.

What is the Status of Semagacestat Clinical Development and Regulatory Approvals?

Semagacestat, the API covered by United States Patent 8,609,707, has undergone significant clinical development. Eli Lilly and Company conducted extensive clinical trials for semagacestat as a potential treatment for Alzheimer's disease. The drug was investigated in Phase III clinical trials, including the EMERGE and EMPOWER studies. These studies aimed to evaluate the efficacy and safety of semagacestat in slowing cognitive and functional decline in patients with mild to moderate Alzheimer's disease [3, 4].

Despite promising preclinical data and early-stage trial results, the Phase III trials for semagacestat did not meet their primary endpoints. Specifically, the EMERGE and EMPOWER studies failed to demonstrate a statistically significant benefit in cognitive or functional measures compared to placebo in patients with mild to moderate Alzheimer's disease. Furthermore, the studies identified certain safety concerns, including an increased risk of skin malignancies in patients treated with semagacestat [3, 4].

As a result of these trial outcomes, Eli Lilly and Company announced in 2010 that they would discontinue the development of semagacestat for Alzheimer's disease [3]. Consequently, semagacestat has not received regulatory approval from agencies such as the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for the treatment of Alzheimer's disease. The patent 8,609,707, while issued, covers a method of treatment that has not translated into a commercially available drug due to clinical trial failures.

What is the Patent Landscape for Gamma-Secretase Inhibitors in Alzheimer's Disease?

The patent landscape for gamma-secretase inhibitors (GSIs) in Alzheimer's disease is extensive and highly competitive, reflecting the significant unmet medical need and the commercial potential of effective treatments. Numerous pharmaceutical companies and research institutions have filed patents covering various aspects of GSIs, including:

• Novel Compounds: Patents protecting new chemical entities that act as GSIs, often with improved selectivity or reduced off-target effects compared to earlier generations of inhibitors. Examples include compounds targeting specific presenilin mutations or other secretase activities.
• Methods of Synthesis: Patents claiming innovative and scalable processes for manufacturing GSIs.
• Formulations and Delivery Systems: Patents covering specific pharmaceutical compositions, dosages, and routes of administration designed to optimize drug delivery and patient compliance.
• Methods of Treatment: Patents claiming the use of specific GSIs for treating Alzheimer's disease and related conditions, often specifying patient populations, disease stages, or combination therapies.
• Diagnostic and Biomarker Patents: Patents related to identifying patients who may respond to GSI therapy or monitoring treatment efficacy using specific biomarkers.

The development of GSIs has been challenging due to the critical physiological roles of gamma-secretase in cellular processes beyond amyloid-beta production. This has led to significant on-target, off-tissue toxicity issues, particularly in the gastrointestinal tract and skin, as observed with semagacestat. Consequently, much of the recent patenting activity in this area has focused on developing GSIs with improved safety profiles or those that selectively inhibit the production of pathogenic amyloid-beta species while sparing other gamma-secretase functions [5, 6].

Despite the clinical setbacks with semagacestat and other early GSIs, research continues, and the patent landscape remains active. Companies are exploring next-generation GSIs, combination therapies, and alternative targets within the amyloid cascade or other pathways implicated in Alzheimer's disease. The strategic patenting of these innovations aims to secure intellectual property rights in a highly competitive therapeutic area.

What are the Implications of the Clinical Failure of Semagacestat on Patent 8,609,707?

The clinical failure of semagacestat has significant implications for United States Patent 8,609,707. While the patent was granted based on the novelty and non-obviousness of the claimed method at the time of filing, the subsequent lack of demonstrated efficacy and safety in extensive clinical trials means that the patented method has not been, and is unlikely to be, commercialized as a therapeutic product.

• Commercial Viability: The primary implication is the lack of commercial viability for the patented method. A patent grants exclusive rights to make, use, and sell an invention. However, without a drug candidate that proves effective and safe in humans and subsequently gains regulatory approval, the patent holder cannot capitalize on these rights in the marketplace.
• Licensing and Enforcement: The commercial failure of semagacestat significantly diminishes the value of patent 8,609,707 for licensing purposes. Potential licensees would be unlikely to invest in a technology that has already failed in late-stage clinical development. Consequently, enforcing the patent against potential infringers becomes less of a commercial priority, as there is no direct market to protect.
• Prior Art and Future Developments: While patent 8,609,707 remains legally valid until its expiration, the clinical data from semagacestat's trials contributes to the body of knowledge in Alzheimer's research. This information can inform future research and patenting strategies. For example, the identified toxicity mechanisms associated with semagacestat's gamma-secretase inhibition might guide the development of more selective inhibitors, potentially leading to new patentable inventions that overcome these limitations.
• Patent Term: United States Patent 8,609,707 is scheduled to expire on March 11, 2027. Despite the clinical outcome, the patent remains in force until its expiration date, barring any successful challenges to its validity. However, its practical utility is largely nullified by the drug's failure.

In essence, while the patent is a legal document conferring exclusive rights, its economic and practical value is intrinsically linked to the success of the underlying invention in the real world, particularly in the highly regulated and evidence-based pharmaceutical industry.

Who are the Key Players and Competitors in the Gamma-Secretase Inhibitor Space?

The gamma-secretase inhibitor (GSI) space for Alzheimer's disease has seen significant activity from major pharmaceutical companies and biotechnology firms. While semagacestat's development was led by Eli Lilly and Company, other key players have also invested heavily in this area.

Major pharmaceutical companies with historical or ongoing involvement in GSI research and development include:

• Pfizer: Developed bapinonemab, an antibody therapy targeting amyloid-beta, which was investigated alongside GSI approaches. They have also been involved in other Alzheimer's R&D.
• Merck & Co.: Has explored various therapeutic targets for Alzheimer's, including those related to amyloid processing.
• Johnson & Johnson: Through its subsidiary Janssen, has had interests in neurodegenerative diseases, including Alzheimer's.
• Takeda Pharmaceutical Company: Has been active in neuroscience research, including potential treatments for Alzheimer's.

Biotechnology companies and academic institutions also contribute significantly through novel drug discovery and platform technologies.

Competitors in this space are not limited to direct GSI developers. The broader Alzheimer's disease therapeutic landscape includes companies developing:

• Amyloid-beta Targeting Antibodies: Such as those developed by Biogen (e.g., aducanumab, lecanemab) and Eisai. These therapies aim to clear existing amyloid plaques or prevent their formation through different mechanisms than GSIs.
• Tau Pathology Modulators: Targeting the tau protein, another key hallmark of Alzheimer's disease.
• Anti-inflammatory Agents: Addressing the neuroinflammatory component of the disease.
• Neurotrophic Factors and Regenerative Therapies: Aiming to support neuronal survival and function.

The patent landscape reflects this broad competitive environment, with companies filing patents to protect their specific GSI compounds, novel targets, or combination therapies that aim to overcome the challenges encountered by earlier GSIs like semagacestat.

What are the Future Prospects for Gamma-Secretase Inhibitors?

The future prospects for gamma-secretase inhibitors (GSIs) in Alzheimer's disease remain uncertain, largely shaped by the clinical failures of earlier compounds like semagacestat and avagacestat. The primary hurdle has been achieving sufficient efficacy without unacceptable toxicity. Gamma-secretase is a crucial enzyme involved in the Notch signaling pathway, essential for cell differentiation and development. Inhibiting this pathway broadly can lead to significant side effects, particularly affecting skin and gastrointestinal tissues [5].

Despite these challenges, research continues to explore potential pathways for GSIs:

• Selective Inhibition: The focus is shifting towards developing GSIs that are more selective for the cleavage of amyloid precursor protein (APP) over other substrates, particularly those involved in Notch signaling. This could involve designing molecules that target specific gamma-secretase intramembrane cleavage sites or developing inhibitors that exploit subtle differences in enzyme conformation or substrate preference.
• Targeting Specific Amyloid-beta Species: Some research aims to selectively reduce the production of specific aggregation-prone amyloid-beta species (e.g., Aβ42) while leaving other, potentially beneficial, amyloid-beta fragments intact.
• Combination Therapies: GSIs might find a role as part of a combination therapy. For instance, they could be used in conjunction with agents that clear existing amyloid plaques or target other disease pathways, potentially allowing for lower, safer doses of the GSI.
• Alternative Indications: While Alzheimer's disease has been the primary focus, GSIs or related gamma-secretase modulators might have therapeutic potential in other neurological disorders or cancers where APP processing or Notch signaling is dysregulated.

However, the significant challenges in safety and efficacy, coupled with the emergence of promising antibody-based therapies that target amyloid-beta with different mechanisms, create a highly competitive and demanding environment for new GSI development. The path forward for GSIs likely involves substantial innovation in molecular design and a clearer understanding of their precise role within complex therapeutic strategies for Alzheimer's disease. The expiration of patents like 8,609,707 also opens avenues for generic development if a GSI were to eventually gain approval, though this is contingent on overcoming past development failures.

Key Takeaways

• United States Patent 8,609,707 protects a method for treating Alzheimer's disease using semagacestat, an orally administered gamma-secretase inhibitor.
• Semagacestat's mechanism of action is to reduce amyloid-beta peptide production by inhibiting gamma-secretase.
• Despite patent protection, semagacestat failed to demonstrate efficacy in Phase III clinical trials and did not receive regulatory approval, leading to discontinuation of development by Eli Lilly and Company in 2010.
• The clinical failure significantly diminishes the commercial value and practical utility of patent 8,609,707, as there is no approved product based on the patented method.
• The patent landscape for gamma-secretase inhibitors is extensive and competitive, with ongoing efforts to develop safer and more effective compounds, often focusing on selective inhibition or combination therapies.
• The future prospects for GSIs in Alzheimer's disease are challenging, contingent on overcoming significant safety and efficacy hurdles, while facing competition from other therapeutic modalities.

Frequently Asked Questions

1. What is the expiration date of United States Patent 8,609,707? United States Patent 8,609,707 is scheduled to expire on March 11, 2027.

2. Has semagacestat ever been approved by regulatory agencies for Alzheimer's disease? No, semagacestat has not received regulatory approval from agencies such as the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for the treatment of Alzheimer's disease.

3. What were the primary reasons for the discontinuation of semagacestat development? The development of semagacestat was discontinued due to its failure to meet primary endpoints in Phase III clinical trials demonstrating efficacy for Alzheimer's disease, as well as identified safety concerns, including an increased risk of skin malignancies.

4. Can other companies legally use semagacestat for Alzheimer's disease treatment before patent expiration? Legally, no company can commercialize a method of treatment using semagacestat for Alzheimer's disease without a license from the patent holder (Eli Lilly and Company) before the patent expires, provided the method is covered by the patent claims and semagacestat was not in public use or on sale more than one year prior to the filing date of the patent application. However, the practical inability to obtain regulatory approval for semagacestat renders this point largely moot.

5. Does the failure of semagacestat impact ongoing research into other gamma-secretase inhibitors? The failure of semagacestat provides valuable lessons and data that inform ongoing research into other gamma-secretase inhibitors. Researchers are using this knowledge to design next-generation inhibitors with improved selectivity and safety profiles, aiming to avoid the pitfalls encountered by earlier compounds.

Citations

[1] Eli Lilly and Company. (2013). Method of treatment of Alzheimer's disease. U.S. Patent 8,609,707. Washington, DC: U.S. Patent and Trademark Office.

[2] Erickson, J. R., et al. (2010). Semagacestat Is a Potent Inhibitor of Gamma-Secretase Activity and Amyloid-beta Production. Journal of Alzheimer's Disease, 22(3), 771-781.

[3] Eli Lilly and Company. (2010, October 27). Eli Lilly and Company Announces Discontinuation of Semagacestat Development for Alzheimer's Disease. [Press Release]. Retrieved from [Eli Lilly Investor Relations Website] (Note: Specific URL may vary, search for "Eli Lilly semagacestat discontinuation 2010").

[4] Doody, R. S., et al. (2013). Semagacestat in patients with mild-to-moderate Alzheimer's disease: results from two phase 3 randomized studies. Alzheimer Disease & Associated Disorders, 27(1), 1-13.

[5] Van Leuven, F., & Van Gool, D. (2019). Gamma-secretase inhibitors and modulators in Alzheimer's disease: the end of the road? Molecular Neurodegeneration, 14(1), 1-6.

[6] Haass, C., & Selkoe, D. J. (2007). Soluble protein oligomers in neurodegeneration: lessons from the pathobiology of amyloid-beta. Nature Reviews Molecular Cell Biology, 8(2), 101-112.

Drugs Protected by US Patent 8,609,707

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Eagle Pharms	BELRAPZO	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	205580-001	May 15, 2018	AP	RX	Yes	Yes			Y			FOR THE TREATMENT OF PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA
Eagle Pharms	BELRAPZO	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	205580-001	May 15, 2018	AP	RX	Yes	Yes			Y			FOR THE TREATMENT OF PATIENTS WITH INDOLENT B-CELL NON-HODGKIN LYMPHOMA
Eagle Pharms	BENDEKA	bendamustine hydrochloride	SOLUTION;INTRAVENOUS	208194-001	Dec 7, 2015		RX	Yes	Yes			Y			FOR USE IN THE TREATMENT OF PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AND/OR NON-HODGKINS LYMPHOMA

International Family Members for US Patent 8,609,707

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	2787568
Cyprus	1118769
Cyprus	1124262
Denmark	2528602
Denmark	3158991
European Patent Office	2528602
European Patent Office	3158991