US Patent 12,558,349: Scope of Claims, Likely Interpretation, and US Landscape for IV Delafloxacin in Obese ABSSSI Patients
What does US 12,558,349 claim in practice?
US patent 12,558,349 claims IV delafloxacin regimens for acute bacterial skin and skin structure infections (ABSSSI) in overweight or obese patients, using a specific dose conversion and (in dependent claims) specific excipients and concentration ranges.
Core claim scope (independent claim)
Claim 1 recites a treatment method with these key limitations:
- Indication: “Acute Bacterial Skin and Skin Structure Infection (ABSSSI)”
- Patient population: “overweight or obese patient”
- Administration route: “intravenously (IV)”
- Regimen: twice a day
- Drug product amount: 433 mg delafloxacin meglumine salt, which “corresponds to 300 mg delafloxacin”
This structure is typical of method-of-treatment patents where infringement is tied to the clinician’s choice of patient category + indication + dosing schedule + exact drug amount (as a salt-to-free-acid conversion).
BMI gating (dependent claim ladder)
Claims narrow the “overweight or obese” population using BMI thresholds:
- Claim 2: BMI > 25
- Claim 3: BMI ≥ 30
- Claim 4: BMI ≥ 35
- Claim 5: BMI ≥ 40
This creates a hierarchy of narrower sub-sets. From an enforceability perspective, the broadest BMI threshold (Claim 2, >25) is most useful for coverage breadth; the tighter cutoffs (≥30/35/40) can align with subpopulations present in trials, post-hoc analyses, or dosing rationale used by the patent.
Formulation/excipient-dependent limits
Claims also add product composition limitations:
- Claim 6: composition further comprises beta-cyclodextrin sulfobutyl ether (SBEβCD)
- Claim 7: SBEβCD amount is 2400 mg
- Claim 8: composition further comprises disodium EDTA
- Claim 9: disodium EDTA amount is 1.32 mg
- Claim 10: composition further comprises meglumine
- Claim 11: meglumine amount is 58.56 mg
These features convert Claim 1 from a dosing concept into a highly specific IV product once SBEβCD/EDTA/meglumine limitations are invoked.
How does claim 12 expand the scope?
Claim 12 is a second independent method claim (it is drafted as a method with composition parameters). It ties together:
- Indication: ABSSSI
- Patient population: overweight or obese
- Route and schedule: IV twice a day
- Drug amount conversion: composition includes 433 mg delafloxacin meglumine corresponding to 300 mg delafloxacin
- Composition specification (quantitative):
- 25 mg/mL delafloxacin meglumine (calculated as free acid)
- 4.88 mg/mL meglumine
- 200 mg/mL beta-cyclodextrin sulfobutyl ether
Practical interpretation
Claim 12 provides two ways to capture product practice:
- The salt amount and free-acid conversion (433 mg delafloxacin meglumine = 300 mg delafloxacin)
- The concentration profile for the delafloxacin meglumine formulation ingredients (25 mg/mL delafloxacin meglumine as free acid; 4.88 mg/mL meglumine; 200 mg/mL SBEβCD)
This is the claim most likely to survive design-around attempts that preserve the same active dose but change excipient forms or concentrations, because it nails specific concentration targets rather than generic “contains SBEβCD” language.
What is the enforceable “center of gravity” of the patent?
Most enforceable combination
The enforceable “hook” is the combination of:
- ABSSSI
- overweight/obese patient
- IV twice daily
- 433 mg delafloxacin meglumine per dose (300 mg delafloxacin equivalent)
- plus, for narrower coverage: excipient presence/amounts or concentrations (SBEβCD, EDTA, meglumine)
In litigation terms, the strongest factual points for infringement are typically:
- Patient BMI
- Medical decision to treat ABSSSI
- The dosing regimen used (twice daily)
- The exact delafloxacin salt amount (and salt-to-free-acid equivalence)
- If asserted via dependent claims: whether the infused solution meets the specific excipient composition and concentration.
Claim-by-claim scope matrix
Independent claim coverage
| Claim |
Core limitations |
Patient population threshold |
Composition constraints |
| 1 |
ABSSSI; overweight/obese; IV; twice daily; 433 mg delafloxacin meglumine (=300 mg delafloxacin) |
“overweight or obese” (no numeric) |
No explicit excipient requirement unless via dependent claims |
| 12 |
ABSSSI; overweight/obese; IV; twice daily; same 433 mg conversion |
“overweight or obese” (no numeric) |
Includes explicit concentration profile: 25 mg/mL delafloxacin meglumine (as free acid); 4.88 mg/mL meglumine; 200 mg/mL SBEβCD |
BMI narrowing ladder (claims 2-5)
| Claim |
BMI threshold |
| 2 |
> 25 |
| 3 |
≥ 30 |
| 4 |
≥ 35 |
| 5 |
≥ 40 |
Dependent formulation limits (claims 6-11)
| Claim |
Excipient |
Numeric limit |
| 6 |
SBEβCD (beta-cyclodextrin sulfobutyl ether) |
present |
| 7 |
SBEβCD |
2400 mg |
| 8 |
Disodium EDTA |
present |
| 9 |
Disodium EDTA |
1.32 mg |
| 10 |
Meglumine |
present |
| 11 |
Meglumine |
58.56 mg |
What is the likely patent landscape around this claim set?
How delafloxacin patents typically cluster in the US
Delafloxacin (fluoroquinolone-class) historically appears in US patent families across several categories that can be relevant to this patent’s enforcement:
- Active composition and salt formation (delafloxacin free acid vs salts; meglumine salt is one)
- Formulation and solubilization (cyclodextrin derivatives like SBEβCD; chelators like EDTA; pH buffering; tonicity)
- Dosing regimens (IV dosing frequency and amount; weight/BMI adjustments)
- Indications and treatment methods (ABSSSI and related skin infections)
- Patient subgroups (obesity/BMI-specific treatment method claims)
US 12,558,349, based strictly on the claim text you provided, sits most clearly in category (3)+(4)+(5), with strong penetration into category (2) via quantitative excipient requirements in dependent claims and explicit concentration targets in Claim 12.
Enforcement implications for generics and biosimilars-adjacent entrants
For parties seeking to compete with an IV delafloxacin product:
- If they keep the same dose and schedule but use a different solubilizer or concentration profile, Claim 1 might still be asserted unless the patentee limits itself to excipient-dependent claims; Claim 12 is the more formulation-sensitive hook.
- If they change the BMI gating (for example, treat all patients uniformly without focusing on an “overweight or obese” method), the method claim still can read on actual treated populations. Method-of-treatment claims do not require that the prescriber labels the patient “obese” in paperwork; the objective BMI is the key.
- If they adjust dose based on weight/BMI, any protocol that lands in the patented combination (overweight/obese + ABSSSI + IV BID + 300 mg equivalent as delafloxacin) can remain at risk.
Design-around routes that are suggested by the claim language
This section does not predict outcomes; it maps risk based on what the claim requires.
Route A: change the excipient system
- SBEβCD swap: If a substitute IV formulation uses a different cyclodextrin system or solubilizer, dependent claims 6 and 7 and independent 12 (which fixes SBEβCD at 200 mg/mL) are harder to infringe.
- EDTA and meglumine swap: Dependent claims 8-11 add specific presence/amounts; changing or omitting disodium EDTA and/or reducing meglumine amounts could avoid those narrower claims.
Route B: change the concentration targets
Claim 12 uses specific concentrations (mg/mL). Even if the delivered total amount matches the same free-acid equivalent, a formulation that deviates from:
- 25 mg/mL delafloxacin meglumine (as free acid),
- 4.88 mg/mL meglumine,
- 200 mg/mL SBEβCD,
may avoid Claim 12 while still potentially implicating Claim 1 depending on whether excipient-dependent narrowing is asserted.
Route C: change the dosing frequency
The independent method claims require “twice a day.” Switching to once-daily or a different BID schedule that does not align with the patented regimen could be a direct avoidance route, assuming it is implemented for the patented patient population and indication.
Route D: change the dose amount/converted equivalent
Both independent method claims hinge on 433 mg delafloxacin meglumine salt corresponding to 300 mg delafloxacin. Any reduction in delafloxacin equivalent or a different salt amount that does not map to the same equivalent could avoid the independent hooks.
Where the BMI threshold matters to scope
The BMI ladder (claims 2-5) provides structured fallback positions:
- Claim 1 covers “overweight or obese” as a class.
- Claims 2-5 provide numeric footholds that align with how clinical studies report obesity.
- If an accused clinician treats a patient with BMI 26-29, claims 2 can be asserted but claims 3-5 are not.
- If BMI is 32, claims 2 and 3 are viable; claims 4 and 5 depend on whether BMI reaches ≥35 or ≥40.
What parts of the claim set are most vulnerable to “paper vs practice” disputes
Method patents frequently hinge on factual recordkeeping:
- BMI: often derived from height/weight records; variability in measurement date can matter.
- Indication: ABSSSI diagnosis codes and clinical criteria; the record matters.
- Formulation: the pharmacy record and product label/IFU; the infusion composition must match the claim.
- Dose conversion: 433 mg salt to 300 mg free acid must match how the formulation is characterized and administered.
The presence of both:
- an amount-based anchor (433 mg salt = 300 mg delafloxacin), and
- a concentration-based anchor (Claim 12),
creates multiple technical points for infringement proof.
Key Takeaways
- US 12,558,349 is a BMI-restricted, ABSSSI, IV twice-daily delafloxacin method patent anchored to 433 mg delafloxacin meglumine (=300 mg delafloxacin).
- Claim 12 is formulation-precise: it specifies mg/mL targets for delafloxacin meglumine (as free acid), meglumine, and SBEβCD.
- Dependent claims add additional excipient specificity (SBEβCD amount, disodium EDTA amount, meglumine amount) and create narrower enforcement lanes even if the broader dosing concept is harder to prove.
- Design-around risk concentrates on three levers: (1) dose amount/equivalent mapping, (2) dosing frequency (BID), (3) excipient system and concentration profile.
FAQs
1) Is the patent limited to a specific BMI number in the independent claims?
No. Independent claims require “overweight or obese” generally; numeric thresholds are set in dependent claims (BMI >25; ≥30; ≥35; ≥40).
2) Does the patent require a particular IV infusion excipient system?
Claim 1 does not require excipients by itself, but dependent claims 6-11 do. Claim 12 requires a specific formulation concentration profile including SBEβCD at 200 mg/mL.
3) What is the dosing equivalence the claims enforce?
They enforce 433 mg delafloxacin meglumine salt corresponding to 300 mg delafloxacin, administered IV twice daily.
4) If a competitor uses the same dose but different SBEβCD concentration, what happens?
Claim 12 is designed to catch concentration-specific formulations. If the concentration profile deviates from the stated mg/mL targets, Claim 12 is less likely to read; Claim 1 could still remain relevant depending on how the patentee asserts.
5) Which BMI group is easiest to capture for enforcement?
The broadest dependent numeric foothold is BMI >25 (Claim 2). Higher BMI thresholds (≥30/35/40) require those exact patient categories.
References
[1] United States Patent No. 12,558,349. Claimed subject matter as provided in user prompt.
