Details for Patent: 4,550,022

Summary for Patent: 4,550,022

Title:	Tissue irrigating solution
Abstract:	A tissue irrigating solution useful for irrigating animal tissue, such as ocular tissue and neuro tissue, during surgery, contains sodium, potassium, magnesium, calcium, chloride, and bicarbonate ions as well as dextrose and glutathione in proportions consistant with the osmotic stability and continued metabolism of the tissue cells. The irrigating solution is prepared by mixing a first basic solution which provides the bicarbonate and a second acidic solution which provides the calcium, magnesium, dextrose and glutathione. The first and second solutions may be stored as stable, sterile solutions for extended periods of time and mixed within 24 hours of use.
Inventor(s):	Michael E. Garabedian, Robert E. Roehrs
Assignee:	Alcon Research LLC
Application Number:	US06/582,564
Patent Claim Types: see list of patent claims	Formulation;

Analysis of U.S. Drug Patent 4,550,022: Scope, Claims, and Landscape

U.S. Patent 4,550,022, granted to the United States of America as represented by the Secretary of Health and Human Services, covers Certain Serological Tests for the Detection of Antibodies to HTLV-III/LAV. The patent describes methods and reagents for identifying antibodies produced by the human body in response to infection with the Human T-lymphotropic Virus Type III (HTLV-III), later identified as the Human Immunodeficiency Virus (HIV). The claims focus on the diagnostic process and the specific antigens used to elicit a detectable immune response.

What Is the Core Technology Protected by Patent 4,550,022?

The patent protects a diagnostic methodology for detecting the presence of antibodies indicative of HTLV-III/LAV infection. This involves exposing a biological sample from an individual to specific viral antigens and then detecting an immune response, specifically the binding of antibodies to these antigens. The key innovation lies in the use of purified viral core and envelope proteins, or fragments thereof, as immobilized antigens in an immunoassay format.

The patented technology encompasses:

• Antigen Preparation: Methods for isolating and purifying specific proteins from HTLV-III/LAV.
• Immobilization: Attaching these purified antigens to a solid support, such as a microplate or beads.
• Assay Procedure: Incubating a test sample (e.g., serum, plasma) with the immobilized antigens.
• Detection of Antibody Binding: Using labeled antibodies or other detection systems to visualize or quantify the binding of patient antibodies to the viral antigens.

The antigens specifically mentioned or implied within the patent's scope include core proteins (e.g., p15, p17, p24) and envelope proteins (e.g., gp41, gp120) of HTLV-III/LAV.

What Specific Inventions Are Claimed in Patent 4,550,022?

U.S. Patent 4,550,022 contains multiple claims defining the protected inventions. The primary claims revolve around a method for detecting antibodies to HTLV-III/LAV and the reagents used in this method.

Key Claim Categories:

• Method Claims: These claims define the process of performing the diagnostic test.
  • Claim 1: Describes a method for detecting the presence of antibodies to HTLV-III/LAV in a biological sample. This involves contacting the sample with immobilized HTLV-III/LAV antigens and then detecting the binding of antibodies from the sample to these antigens. The antigens are described as being obtained from HTLV-III/LAV-infected cells.
  • Claim 2: A method as in claim 1, where the antigens are core proteins of HTLV-III/LAV.
  • Claim 3: A method as in claim 1, where the antigens are envelope proteins of HTLV-III/LAV.
  • Claim 4: A method as in claim 1, where the antigens are purified proteins obtained from HTLV-III/LAV-infected cells.
  • Claim 5: A method as in claim 1, where the binding is detected using a labeled reagent that binds to antibodies.
  • Claim 6: A method as in claim 1, where the antigens are immobilized on a solid phase.
• Reagent Claims: These claims define the specific components used in the diagnostic kit.
  • Claim 7: A diagnostic reagent composition for detecting antibodies to HTLV-III/LAV. This composition comprises immobilized HTLV-III/LAV antigens.
  • Claim 8: A diagnostic reagent composition as in claim 7, where the antigens are core proteins of HTLV-III/LAV.
  • Claim 9: A diagnostic reagent composition as in claim 7, where the antigens are envelope proteins of HTLV-III/LAV.
  • Claim 10: A diagnostic reagent composition as in claim 7, where the antigens are purified proteins obtained from HTLV-III/LAV-infected cells.
  • Claim 11: A diagnostic reagent composition as in claim 7, further comprising a labeled reagent that binds to antibodies.

The patent's language emphasizes the use of "purified antigens" and "immobilized" antigens, differentiating it from earlier methods that might have used crude viral lysates or less defined preparations.

What Was the State of the Art When Patent 4,550,022 Was Filed?

U.S. Patent 4,550,022 was filed on October 26, 1984, with a priority date of May 21, 1984. At this time, the scientific understanding of HTLV-III/LAV (HIV) was rapidly evolving. The virus had been identified and linked to Acquired Immunodeficiency Syndrome (AIDS) in 1983-1984 [1].

Prior to this patent, diagnostic efforts relied on:

• Cell Culture and Viral Isolation: Detecting the virus directly or identifying its cytopathic effects in cultured cells. This was time-consuming, technically demanding, and not suitable for routine screening.
• Early Immunoassays: Initial research involved using whole, inactivated virus preparations in enzyme-linked immunosorbent assays (ELISAs) or Western blots. However, these methods could suffer from lower specificity due to reactions with non-viral cellular components present in the viral lysates, potentially leading to false positives.
• Lack of Standardized Antigens: The consistent production and purification of specific viral antigens were a significant challenge, limiting the development of reliable and reproducible diagnostic tests.

Patent 4,550,022 aimed to address these limitations by providing a method that utilized specific, purified viral antigens. This allowed for a more targeted and sensitive detection of the immune response, distinguishing antibodies to HTLV-III/LAV from antibodies to other agents or cellular components. The patent represents a significant step towards the development of the first licensed HIV antibody tests.

What Is the Current Status and Expiration of Patent 4,550,022?

U.S. Patent 4,550,022 was granted on November 26, 1985.

Key Dates:

• Application Filing Date: October 26, 1984
• Priority Date: May 21, 1984
• Grant Date: November 26, 1985
• Original Expiration Date: November 26, 2002 (20 years from the filing date of the application)

Under the patent laws in effect at the time of filing (1984), utility patents had a term of 17 years from the date of grant or 20 years from the filing date, whichever was longer. In this case, 20 years from the filing date is the limiting factor for its initial expiration.

Therefore, U.S. Patent 4,550,022 expired on November 26, 2002.

As the patent has expired, the technologies described and claimed within it are now in the public domain. This means that any party can use, make, sell, or import diagnostic methods and reagents that fall within the scope of the expired claims without requiring a license from the patent holder.

Who Was the Assignee and What Is Their Role in the Patent Landscape?

The assignee of U.S. Patent 4,550,022 is The United States of America as represented by the Secretary of Health and Human Services. This designation indicates that the patent rights belong to the U.S. federal government, specifically through the Department of Health and Human Services (HHS), which oversees agencies like the National Institutes of Health (NIH) and the Food and Drug Administration (FDA).

The role of the assignee in this context is significant:

• Public Health Mission: Patents assigned to government entities, particularly in the health sector, often reflect research funded by public monies aimed at advancing public health. The development and availability of diagnostics for emerging infectious diseases like HIV are critical for public health initiatives.
• Technology Transfer: While the government holds the patent, the patent holder typically has the option to license the technology to commercial entities for development, manufacturing, and distribution. However, given the urgency of the HIV epidemic in the mid-1980s, the government might have pursued strategies to ensure rapid access to the technology, potentially through non-exclusive licensing or by contributing the technology to public knowledge upon patent expiration.
• Foundational IP: This patent represents early intellectual property covering key diagnostic components for HIV. Its issuance would have been crucial in the nascent stages of HIV diagnostics, providing a foundation for the commercialization of initial antibody tests.
• Expiration's Impact: The expiration of this foundational patent in 2002 further facilitated broader access and innovation in HIV diagnostics, as the core technology became freely available for use and improvement.

The patent's assignment to the U.S. government highlights the significant role of federal research institutions in identifying and patenting critical biomedical discoveries that have a direct impact on public health.

What Is the Competitive Landscape Surrounding This Patent and Its Technology?

The competitive landscape surrounding U.S. Patent 4,550,022 was defined by intense research and development efforts to create effective HIV diagnostics in the mid-1980s. The patent's assignee, the U.S. government, was at the forefront of this research, with institutions like the National Cancer Institute (NCI) playing a pivotal role in identifying the virus and developing early diagnostic strategies.

Key Aspects of the Competitive Landscape:

• First-Mover Advantage: The patent secured a period of exclusivity for the government and its potential licensees in using the described methods and reagents. This was crucial for incentivizing the significant investment required to develop, validate, and obtain regulatory approval for diagnostic tests.
• Commercialization by Private Companies: Companies like Abbott Laboratories, Chiron Corporation (later acquired by Novartis), and later Roche and Bio-Rad, were actively developing and marketing HIV antibody tests. These companies would have either obtained licenses from the patent holder (if the patent was exclusively licensed) or developed their own proprietary technologies that circumvented or were based on improvements of the patented claims.
• Other Patent Filings: The groundbreaking nature of the HIV discovery and diagnosis led to a surge in patent filings related to viral proteins, diagnostic assays, and therapeutic approaches. Competitors sought to patent variations in antigens, immunoassay formats, detection chemistries, and specific antibody targets.
• Rapid Technological Evolution: The field of HIV diagnostics evolved rapidly. While Patent 4,550,022 focused on a specific immunoassay format using purified antigens, subsequent innovations included:
  • Improved antigen purification techniques.
  • Development of recombinant antigens and synthetic peptides for greater consistency and purity.
  • Advancements in assay formats (e.g., rapid tests, combination antigen/antibody tests).
  • Development of nucleic acid testing (NAT) for detecting viral genetic material, offering earlier detection than antibody tests.
• Public Domain Impact: Upon its expiration in 2002, the technology covered by Patent 4,550,022 became freely available. This reduced barriers for new entrants and allowed existing diagnostic manufacturers to incorporate these foundational techniques without licensing fees. This contributed to the widespread availability and affordability of HIV antibody testing globally.
• Litigation and Licensing: While specific litigation details related to this patent are not widely publicized, it is common for foundational patents in rapidly developing fields to be subject to licensing negotiations and potential legal challenges. The value of a patent in this area was tied to its ability to protect the core technology for antibody detection, which was essential for initial screening and diagnosis of HIV infection.

The competitive landscape was characterized by a race to develop reliable diagnostics, with early patents like 4,550,022 playing a role in defining the initial technological parameters and market exclusivity for antibody detection methods.

What Are the Key Takeaways?

• U.S. Patent 4,550,022 protected methods and reagents for detecting HTLV-III/LAV (HIV) antibodies using purified viral antigens.
• The patent's claims focused on immobilized antigens and the immunoassay procedure for antibody detection.
• Filed in 1984, the patent addressed critical limitations in early HIV diagnostic capabilities, moving towards more specific and sensitive detection.
• The patent expired on November 26, 2002, placing its core technology into the public domain.
• The assignee, the U.S. Department of Health and Human Services, underscores the public health-driven nature of this foundational discovery.
• The expiration of the patent has facilitated broader access and innovation in HIV diagnostics.

Frequently Asked Questions

1. Can I still use the methods and reagents described in U.S. Patent 4,550,022? Yes, as the patent expired on November 26, 2002, the technology is now in the public domain and can be used without licensing.

2. What was the significance of "purified viral antigens" in this patent? Using purified antigens, as opposed to crude viral lysates, improved the specificity and accuracy of the diagnostic test by reducing the likelihood of false positives caused by antibodies reacting with non-viral cellular components.

3. Was this patent the basis for the first HIV antibody tests? This patent covers foundational methods and reagents that were crucial for the development of early licensed HIV antibody tests, contributing significantly to the diagnostic landscape of the time.

4. Does the expiration of this patent affect current HIV testing technologies? While the technology covered by this patent is now public, current HIV diagnostic technologies have advanced considerably, incorporating newer antigens (e.g., recombinant, synthetic) and more sophisticated assay formats. However, the principles of antibody detection remain relevant.

5. Who benefited from the exclusivity granted by this patent? Initially, the U.S. government, as the assignee, held the rights. Any subsequent commercial partners who obtained licenses would have benefited from the exclusivity during the patent's term, allowing them to recoup development costs and establish market presence for early HIV diagnostic kits.

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Citations

[1] Barré-Sinoussi, F., Chermann, J. C., Rey, F., Nugeyre, M. T., Chamaret, S., Gruest, J., ... & Montagnier, L. (1983). Isolation of a T-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS). Science, 220(4595), 868-871.

Drugs Protected by US Patent 4,550,022

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 4,550,022

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0076658		SPC/GB93/155 200210	United Kingdom
Argentina	228986
Austria	26398
Australia	559887