Scope, Claims, and U.S. Patent Landscape for U.S. Patent 10,052,385
U.S. Patent 10,052,385 is directed to a specific administration method for bendamustine formulations used to treat chronic lymphocytic leukemia (CLL) and indolent B-cell non-Hodgkin’s lymphoma (iNHL). The claims require a parenteral dosing duration of 15 minutes or less and a defined liquid composition in which bendamustine concentration, PEG/propylene glycol content, and optional antioxidant are bounded.
What is the claim scope in U.S. Patent 10,052,385?
Core independent claim structure (Claim 1)
Claim 1 requires all of the following limitations:
A. Indication
- Treating chronic lymphocytic leukemia or indolent B-cell non-Hodgkin’s lymphoma.
B. Administration regime
- Parenteral administration (the claim does not limit route beyond “parenterally”).
- Administration over a period ≤ about 15 minutes.
- A total administered volume of about 100 mL or less.
- The claim recites administration as part of the method of treating; it is not framed as a composition claim alone.
C. Formulation composition (liquid composition)
The composition must include:
1) Bendamustine concentration
- 0.96 to 5.59 mg/mL of bendamustine (or a pharmaceutically acceptable salt).
2) Non-aqueous component with PEG and propylene glycol
- 3.8 to 22.4 vol % of a non-aqueous component comprising:
- polyethylene glycol
- propylene glycol
3) Parenterally acceptable diluent
- A diluent acceptable for parenteral use is required.
4) Optional antioxidant
- An antioxidant is optional (not required for Claim 1).
This claim is tightly anchored to both the formulation boundaries and the administration time/volume boundaries. A variant that meets the formulation boundaries but fails the infusion time and volume constraints does not satisfy Claim 1.
How do the dependent claims narrow the scope?
Dependent claims 2 to 9 add patient identity, timing, dosing volume, excipient identity, excipient ratio, antioxidant identity, and indication specificity.
| Claim |
Additional limitation |
Practical narrowing effect |
| 2 |
Subject is human |
Limits to human therapeutic use (excludes veterinary) |
| 3 |
Administration in about 10 minutes |
Adds a concrete timing sub-range within the ≤15 minute regime |
| 4 |
Administer about 50 mL |
Adds a concrete volume sub-range within ≤100 mL |
| 5 |
PEG is PEG 400 |
Narrows PEG identity from “polyethylene glycol” to PEG 400 |
| 6 |
PEG:propylene glycol weight ratio about 90:10 |
Narrows the internal proportion of the PEG/PG system |
| 7 |
Antioxidant is monothioglycerol |
Narrows antioxidant from “optional antioxidant” to a specific molecule |
| 8 |
Method for CLL |
Narrows indication within the Claim 1 indication pair |
| 9 |
Method for iNHL |
Narrows indication within the Claim 1 indication pair |
Key point: The dependent claims do not remove the original constraints. For example, Claim 6 still requires the bendamustine concentration band, the non-aqueous component vol% band, the parenteral acceptable diluent, and the infusion time ≤15 minutes and total volume ≤100 mL.
What exact “design space” does Claim 1 define?
Formulation and infusion parameters (Claim 1)
Infusion/time
- Infuse “over a period of ≤ about 15 minutes”
Total volume
- Administer “about 100 mL or less” total liquid composition
Bendamustine
- Concentration: 0.96 to 5.59 mg/mL
PEG/propylene glycol non-aqueous component
- Total non-aqueous component: 3.8 to 22.4 vol %
- Non-aqueous component comprises:
- PEG (unspecified molecular weight in Claim 1)
- propylene glycol
Other components
- Parenterally acceptable diluent (unspecified)
- Antioxidant optional (identity unspecified in Claim 1)
What is missing from Claim 1 (important for landscape carving)
Claim 1 does not specify:
- Route (IV vs other parenteral routes are not limited beyond “parenterally”).
- Total bendamustine dose in mg (it sets concentration and volume cap, which indirectly constrains total dose).
- PEG molecular weight beyond dependent Claim 5 (PEG 400).
- Exact PEG:propylene glycol ratio beyond dependent Claim 6.
- Antioxidant identity beyond dependent Claim 7 (monothioglycerol).
- Specific diluent identity (required only to be parenterally acceptable).
How should the claims be mapped to potential infringement scenarios?
Below are the most direct “all-elements” infringement paths implied by the claim language.
Scenario 1: Generic “same formulation, same fast infusion”
A competing product or protocol that:
- uses bendamustine in 0.96 to 5.59 mg/mL
- has 3.8 to 22.4 vol % PEG/propylene glycol non-aqueous component
- is infused ≤15 minutes
- totals ≤100 mL
- treats CLL or iNHL
would be within Claim 1 scope.
Scenario 2: Same formulation but slower infusion
If infusion is performed over >15 minutes, it fails the administration duration limitation. The claim is method-based and time-limited.
Scenario 3: Same infusion time/volume but outside formulation bands
If bendamustine concentration is outside 0.96–5.59 mg/mL, the claim fails even if infusion time is within bounds.
Scenario 4: Antioxidant absent or different
Claim 1 permits antioxidant as optional. So:
- no antioxidant does not avoid Claim 1.
- different antioxidant does not avoid Claim 1 (since antioxidant is optional and identity not required in Claim 1).
However, dependent Claim 7 would be implicated only if monothioglycerol is used.
Scenario 5: PEG identity and ratio
General PEG is allowed in Claim 1, but:
- using PEG 400 triggers dependent Claim 5
- using 90:10 PEG:propylene glycol by weight triggers dependent Claim 6
What does the claim set imply about the commercial product and delivery approach?
Claim 1 is structured for a ready-to-administer or quickly administered bendamustine liquid formulation that allows treatment within a short infusion window. The combination of:
- a narrow bendamustine concentration band,
- a bounded PEG/propylene glycol non-aqueous system vol%,
- and a hard time cap (≤15 minutes),
indicates the patent targets a practical administration workflow rather than a slow, reconstitution-heavy approach.
Dependent claims add support for a particular execution:
- PEG 400 (Claim 5),
- a specific excipient ratio (Claim 6),
- monothioglycerol (Claim 7),
- and practical dosing volumes (Claim 4) and timing (Claim 3).
What is the likely patent landscape posture around this claim set?
1) Claim 1’s “method + formulation + timing” cocktail creates cross-axis barriers
In the U.S., infringement of method-of-treatment claims requires matching the full set of recited steps/conditions. The coupling of:
- formulation ranges (concentration and non-aqueous composition),
with
- administration constraints (≤15 minutes and ≤100 mL),
creates a high bar for “design-around” that changes only one axis.
2) Competitors can try to design around by altering either axis
The two most straightforward design-around levers are:
- Time/volume design-around: administer in >15 minutes or >100 mL total volume (if clinically acceptable).
- Formulation design-around: keep infusion parameters but shift bendamustine concentration outside 0.96–5.59 mg/mL and/or non-aqueous PEG/PG vol% outside 3.8–22.4 vol%.
3) The dependent claims identify specific “anchor embodiments”
Dependent claims provide additional claim coverage for:
- PEG 400 (Claim 5)
- 90:10 PEG:propylene glycol (Claim 6)
- monothioglycerol antioxidant (Claim 7)
- 10-minute administration (Claim 3)
- 50 mL administration (Claim 4)
This structure signals that the patent family likely disclosed one or more preferred formulations and administration protocols. In landscape terms, these dependent claims broaden the ability to assert against closer “commercially adopted” versions even if a party argues differences in the broader range limitations.
How would validity and enforceability be assessed by a challenger? (Landscape-relevant reading of scope)
A challenger’s strongest attack vectors typically map to overbreadth or lack of support, but the claim language itself suggests where arguments would focus:
- Range boundaries: The claim uses numeric ranges for bendamustine concentration and non-aqueous vol%. Challengers often scrutinize whether those ranges are supported by examples and whether the boundaries are arbitrary.
- Indication breadth: Claim 1 covers both CLL and iNHL. If the underlying data support one more than the other, that can affect validity arguments.
- Administration-time limitation: The infusion time constraint is a distinctive feature. Challengers often examine whether the claim properly ties the time limitation to the formulation effect or whether it reads as an arbitrary procedural limitation.
This is not a legal opinion; it is a scope-based indicator of where the claim is most vulnerable in practice.
What are the likely “design-around” targets indicated by the claim text?
The claim text points to discrete parameter targets that a competitor can adjust:
Formulation parameters to adjust
- Bendamustine concentration away from 0.96–5.59 mg/mL
- Non-aqueous PEG/propylene glycol vol% away from 3.8–22.4 vol%
- PEG identity away from PEG 400 (if trying to avoid Claim 5)
- PEG:propylene glycol weight ratio away from 90:10 (to avoid Claim 6)
- Antioxidant away from monothioglycerol (to avoid Claim 7, though Claim 1 does not require an antioxidant)
Administration parameters to adjust
- Infusion duration: away from ≤15 minutes (to avoid Claim 1)
- Total administered volume: away from ≤100 mL (to avoid Claim 1)
- If close to the boundary, avoid matching about 10 minutes (Claim 3) and about 50 mL (Claim 4)
What is the actionable “scope snapshot” for business decisions?
Claim 1 coverage checklist
A product/protocol must satisfy all bullets:
- Indication: CLL or iNHL
- Route: parenteral
- Infusion duration: ≤15 minutes
- Total volume: ≤100 mL
- Liquid composition:
- bendamustine 0.96–5.59 mg/mL
- PEG + propylene glycol as a non-aqueous component at 3.8–22.4 vol%
- parenterally acceptable diluent
- antioxidant optional
Dependent claim triggers
- Human subject: Claim 2
- About 10 minutes: Claim 3
- About 50 mL: Claim 4
- PEG 400: Claim 5
- PEG:PG weight ratio about 90:10: Claim 6
- Monothioglycerol antioxidant: Claim 7
- CLL only: Claim 8
- iNHL only: Claim 9
Key Takeaways
- U.S. Patent 10,052,385 claims a method of treating CLL and/or iNHL using a specific bendamustine liquid composition administered parenterally in ≤15 minutes and ≤100 mL total volume.
- Claim 1 is broad on excipient identity (PEG molecular weight unspecified) and antioxidant identity (optional), but it is tight on numeric formulation ranges and administration-time and volume limits.
- Dependent claims lock in commercially meaningful embodiments: PEG 400, 90:10 PEG:propylene glycol, monothioglycerol antioxidant, 10-minute administration, and 50 mL dosing.
- For a design-around, the most direct approach is to change either:
- the administration window (time and/or volume), or
- the formulation numeric ranges (bendamustine concentration and/or PEG/propylene glycol non-aqueous vol%).
FAQs
1) Does Claim 1 require an antioxidant?
No. Claim 1 states antioxidant is optional, so Claim 1 can be met even if no antioxidant is present.
2) Is PEG molecular weight limited in Claim 1?
No. Claim 1 requires polyethylene glycol but does not specify molecular weight. PEG identity is narrowed only in Claim 5 to PEG 400.
3) Is the method restricted to IV infusion?
The claim uses the term parenterally administering without specifying IV. Route is therefore not limited beyond “parenteral.”
4) If a competitor matches the formulation ranges but infuses over 20 minutes, is it within Claim 1?
No. Claim 1 requires administration over a period ≤ about 15 minutes.
5) What single most important “design-around” lever is suggested by the claim text?
The strongest lever is to shift at least one of the two anchor constraints in Claim 1: infusion time (≤15 minutes) or total volume (≤100 mL), or to move formulation parameters outside the specified numeric ranges.
References
[1] U.S. Patent 10,052,385 (claims as provided).
