Details for Patent: 4,753,789

United States Patent 4,753,789: Scope, Claim-by-Claim Coverage, and US Patent Landscape

US Drug Patent 4,753,789 is a method-of-treatment patent focused on use of a specific antiemetic active, identified by chemical name as 1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one (and physiologically acceptable salts/solvates). The claims narrow treatment to nausea and vomiting relief in human or animal subjects, and layer additional limitations around salt form (hydrochloride; hydrochloride dihydrate) and cause (chemotherapy or radiation, with specific drug classes and exemplars including cisplatin and cyclophosphamide).

What is claimed in US 4,753,789?

What is the core independent claim and how broad is it?

Claim 1 defines the baseline scope:

• Type of claim: Method of treatment
• Purpose: relief of nausea and vomiting
• Who receives treatment: human or animal subject in need thereof
• Act: administering an effective amount of the active
• Active:
  1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one or a physiologically acceptable salt or solvate
• No required cause of nausea/vomiting in claim 1

Practical breadth: Claim 1 covers use of the active (and acceptable salts/solvates) for nausea/vomiting relief regardless of whether the nausea is chemo-induced, radiation-induced, post-op, or otherwise (subject to the claim’s “in need thereof” and “effective amount” requirements). It does not require a particular dosing regimen, route, formulation, or etiology beyond the therapeutic endpoint.

How do the dependent claims narrow the scope?

Dependent claims add three types of narrowing limitations:

1. Specific salt form
   • Claim 2: hydrochloride
   • Claim 3: hydrochloride dihydrate
2. Etiology: anticancer-drug induced
   • Claim 4: nausea/vomiting induced by an anticancer drug
   • Claim 6: anticancer drug is a cytostatic agent
   • Claim 8: induced by a platinum complex
   • Claim 10: induced by cisplatin
   • Claim 12: induced by an alkylating agent
   • Claim 13: induced by cyclophosphamide
   • Claim 16: induced by radiation
3. Salt form again when tied to specific etiologies
   • hydrochloride dihydrate is repeated across the chemo/radiation dependent claims:
     • Claims 5, 7, 9, 11, 14, 15, 17

Claim-by-claim scope map

What does each claim cover in operational terms?

Below is a structured breakdown of each claim as a coverage “stack,” showing the additional limitation each dependent claim contributes beyond claim 1.

Are any dependent claims internally duplicative?

Claims 14 and 15 appear to repeat the same limitation stack: both depend on claim 13 and specify the active as hydrochloride dihydrate. As presented, they do not introduce a distinct additional limitation. In infringement analysis, duplication can matter for claim-set consolidation, but it does not expand substantive coverage.

Scope boundaries that matter for enforcement and design-arounds

What conduct falls inside versus outside claim 1?

Inside claim 1:

• Administration to a subject “in need thereof” of an effective amount of the specified active
• For relief of nausea and vomiting
• The active may be used as the free base or a physiologically acceptable salt or solvate

Potential outside claim 1:

• If the product does not contain the claimed active (or a physiologically acceptable salt/solvate of it)
• If the therapeutic objective is not “relief of nausea and vomiting”
• If the formulation uses a different active ingredient or a salt form that is argued not to be physiologically acceptable or not within the “solvate” concept (this is a typical chemistry dispute vector)

How do the salt-form dependent claims affect product strategy?

• A product using hydrochloride dihydrate is positioned to implicate claims 3, 5, 7, 9, 11, 14, 15, 17.
• A product using hydrochloride (non-dihydrate) potentially targets claims 2 but not the dihydrate-limited claims.
• A product using a different salt or solvate may still fall under claim 1 if the alternative qualifies as a “physiologically acceptable salt or solvate,” but it would not necessarily cover the form-specific dependent claims.

How do etiology limitations affect infringement theories?

If a payer/label or clinical protocol supports chemotherapy-induced nausea/vomiting (CINV) or radiation-induced nausea/vomiting (RINV), the dependent claims provide cause-specific hooks:

• Anticancer drug (claim 4)
• Cytostatic agents (claim 6)
• Platinum complexes (claim 8) and cisplatin (claim 10)
• Alkylating agents (claim 12) and cyclophosphamide (claim 13)
• Radiation (claim 16)

These limitations are relevant to enforcement where a product’s clinical studies or promotional claims tie nausea/vomiting to a specific source.

Competitive landscape: what this claim-set implies for the US patent ecosystem

What does the structure of claims indicate about likely prior art and related filings?

This patent is framed as a compound-use method with:

• An explicit molecular identity for the active
• Specific salt identity (notably hydrochloride dihydrate)
• Etiology-specific medical uses typical of CINV and RINV

That combination typically correlates with a US portfolio pattern where:

• A primary compound patent covers chemical synthesis and/or composition
• A later set of method claims covers specific therapeutic indications and crystalline/salt forms
• A salt/crystal form patent may exist separately if the dihydrate is developed as the marketed solid form

However, providing a complete “patent landscape” with named families, filing histories, expiry dates, and citation mapping requires full bibliographic retrieval (US publication record, assignee, prosecution history, and family members). The claims you provided do not include the patent’s assignee, priority data, specification identifiers, or related patent citations; without that metadata, a complete landscape cannot be constructed accurately.

Key claim-driven takeaways for freedom-to-operate

Where is the strongest claim leverage?

• Claim 1 is the broadest: it captures the active and its physiologically acceptable salts/solvates for nausea/vomiting relief.
• Dependent claims increase enforcement specificity when a product is positioned for:
  • chemo-induced (anticancer drug; cytostatic; platinum; cisplatin; alkylating; cyclophosphamide)
  • radiation-induced (radiation)
• Hydrochloride dihydrate is the most repeated limiter, indicating it is likely the clinically used or commercially targeted solid-state form.

What are the most salient vectors for design-around analysis?

1. Active identity: switching to a different antiemetic active does not meet claim 1.
2. Salt/solvate choice: changing from hydrochloride dihydrate to a different acceptable form could reduce exposure to the dihydrate-specific dependent claims while leaving potential exposure to claim 1.
3. Indication framing: if therapy is pursued for nausea/vomiting not induced by the specified causes, dependent-claim theories weaken; claim 1 remains the backbone if the therapeutic objective is nausea/vomiting relief with the same active.

Key Takeaways

• US 4,753,789 claims a method-of-treatment for relief of nausea and vomiting using 1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one (or physiologically acceptable salts/solvates).
• Claim 1 is broad: no required cause of nausea/vomiting, only effective administration of the specified active for symptom relief.
• Claims 2-3 narrow to hydrochloride and hydrochloride dihydrate; the dihydrate form is repeatedly used in downstream dependent claims.
• Claims 4-17 narrow to chemo- and radiation-induced nausea/vomiting, with exemplars cisplatin and cyclophosphamide, and classes platinum complexes, cytostatic agents, alkylating agents.
• The most enforceable product positions are those that combine the claimed active with a protocol/label linking nausea/vomiting to anticancer drugs or radiation, especially when the marketed solid form is hydrochloride dihydrate.

FAQs

1) Does claim 1 require chemotherapy or radiation as the cause of nausea/vomiting?

No. Claim 1 requires only that the subject is in need of relief of nausea and vomiting, without specifying the induction mechanism.

2) Which dependent claims are tied to hydrochloride dihydrate?

Claims 3, 5, 7, 9, 11, 14, 15, 17.

3) Which claims specifically mention cisplatin?

Claim 10 (and claim 11 for the dihydrate form).

4) Which claims specifically mention cyclophosphamide?

Claim 13 (and claims 14 and 15 for the dihydrate form as provided).

5) Can a product using a different salt still infringe claim 1?

Potentially, if the alternative is a “physiologically acceptable salt or solvate” of the claimed active. The dependent claims require specific hydrochloride or hydrochloride dihydrate forms.

References (APA)

[1] US Patent No. 4,753,789.