Patent: 10,029,015

Summary for Patent: 10,029,015

Title:	Hydrogel formulations
Abstract:	A polymeric prodrug composition including a hydrogel, a biologically active moiety and a reversible prodrug linker. The prodrug linker covalently links the hydrogel and the biologically active moiety at a position and the hydrogel has a plurality of pores with openings on its surface. The diameter of the pores is larger than that of the biologically active moiety at least at all points of the pore between at least one of the openings and the position of the biologically active moiety.
Inventor(s):	Hersel; Ulrich (Heidelberg/Hanschuhsheim, DE), Rau; Harald (Heidelberg, DE), Schnepf; Robert (Heidelberg/Dossenheim, DE), Vetter; Dirk (Heidelberg/Neuenheim, DE), Wegge; Thomas (Heidelberg/Ziegelhausen, DE)
Assignee:	ASCENDIS PHARMA A/S (Hellrup, DK)
Application Number:	14/707,464
Patent Claims:	see list of patent claims

US Patent 10,029,015 analysis: polymeric prodrug hydrogel with mesopores, reversible covalent linkers, and in-vivo release kinetics

Executive summary: US 10,029,015 claims a platform for depot-style intrahydrogel delivery in which a hydrogel with 1–100 nm mesopores contains prodrug linkers covalently attached to mesopore surfaces and reversibly covalently bonded to a biologically active moiety whose in vivo cleavage rate is at least 10× faster than hydrogel degradation rate. Claim scope is broad across biologics (proteins/peptides, antibodies, enzymes, vaccines), small molecules, and oligonucleotides, and broad across degradable hydrogel chemistries (natural polysaccharides, synthetic polymers, and degradable crosslinks/bonds). The enforceable “center of gravity” is the combination of (i) mesopore geometry sized to exceed the active moiety diameter, (ii) active moiety coupled only to mesopores, (iii) reversible covalent prodrug linker cleavage governing release, and (iv) kinetic tuning (release >> hydrogel degradation).

Because the user-provided content includes only the claim set text and not the patent’s specification, priority dates, prosecution history, dependent-claim numbering beyond those shown, or the assignee list and independent claim support, this analysis is limited to claim-structure, claim breadth, and the likely competitive freedom-to-operate (FTO) fault lines that arise from these claim limitations.

---

What does US 10,029,015 claim about polymeric prodrug hydrogel mesopores and reversible covalent release?

Short answer: It claims a degradable hydrogel depot with mesopores (1–100 nm) having surface openings that hold an active moiety inside the pores via a reversible covalent prodrug linker tethered to the pore wall; in vivo cleavage releases the active moiety so it can freely diffuse out, with release behavior determined by linker cleavage kinetics and explicitly constrained by cleavage rate ≥10× hydrogel degradation rate.

Independent claim 1: key limitations that define infringement and design-around risk

Claim 1 can be decomposed into four technical “modules,” each of which can be a design-around wedge:

1. Mesopore architecture

   • Hydrogel contains mesopores with pore size 1–100 nm
   • Mesopores have surface openings
   • Average pore size is larger than the diameter of the biologically active moiety
   • Active moiety is contained in the mesopores

2. Dual covalent tethering scheme

   • A prodrug linker is covalently bonded to the mesopore (fixed tether to matrix)
   • The linker is reversibly covalently bonded to the active moiety
   • The active moiety is coupled only to mesopores in the hydrogel

3. Reversible covalent cleavage in vivo enables diffusion

   • Reversible bond is cleavable in vivo
   • After cleavage, the active moiety can freely diffuse out of mesopores

4. Kinetic hierarchy constraint

   • Release properties are governed by prodrug linker cleavage kinetics
   • The prodrug linker is configured to provide cleavage rate ≥10× faster than hydrogel degradation rate

Practical infringement reality: Most disputes for such platform claims tend to turn on (i) whether a competitor uses mesopores sized within 1–100 nm and whether the active moiety is residing in those mesopores, (ii) whether the active moiety is tethered via a reversible covalent bond to a pore-tethered linker, and (iii) whether the kinetic relationship (release faster than scaffold breakdown) is met.

Claim 1’s “kinetic ratio” is unusually specific

The “at least an order of magnitude higher” requirement is a measurable parameter. In litigation, it increases the chance that:

• The patentee will seek in vivo cleavage half-life/cleavage rate evidence and hydrogel degradation kinetics evidence.
• The accused will argue altered materials produce cleavage and degradation with closer timescales, or that “cleavage rate” is undefined/ambiguous versus “observed release rate.”

From a defense perspective, this is a meaningful constraint for a generic/platform competitor.

Dependent claims expand active class breadth but keep the same core structure

The dependent claims change what can be inside the mesopores without changing the core mechanism. That means non-infringement requires attacking at least one core limitation, not merely swapping payload class.

---

How broad is US 10,029,015 across biologics, small molecules, and oligonucleotides?

Short answer: It is intentionally payload-flexible: proteins/polypeptides are enumerated broadly, insulin is singled out, organic small molecules are covered by functional categories, and antisense/interfering oligonucleotides are covered.

What payloads are explicitly enumerated (claim 3)

Claim 3 lists proteins/polypeptides including, among many:

• Hormones and growth factors (e.g., insulin, erythropoietins, growth hormone/somatropins, leuprolide, thyroid hormones)
• Enzymes and enzyme replacement (e.g., agalsidase, galactosidase, glucocerebrosidase, DNase)
• Antibody and fragments/fusions
• Thrombolytics and hemostasis factors (e.g., alteplase, anistreplase, factor VIIa/VIII/FIX)
• Cytokines and immune modulators (e.g., interleukins, interferons, TNF, IL-1ra)
• Vaccines (e.g., hepatitis B vaccines, influenza vaccines, lyme vaccine)
• Antisense is not in claim 3 but is separately covered in claim 7

Legal impact: Enumerating a long list does not guarantee unlimited scope, but it signals that the patentee intended to claim across a wide payload genus under the same hydrogel + linker + pore geometry.

Claim 4: insulin

Insulin is called out in claim 4. That suggests either (i) commercial value in diabetes depot contexts, (ii) perceived prior art separation, or (iii) that specification support ties insulin to specific prodrug-linker chemistry or hydrogel behavior.

Claim 5–6: organic small molecules

Small molecules are covered via categories:

• CNS-active, anti-infective, anti-neoplastic, antibacterial, antifungal
• analgesic, contraceptive, anti-inflammatory, steroidal
• vasodilating/vasoconstricting, cardiovascular

Design-around pressure point: The “biologically active moiety diameter” limitation from claim 1 can still apply. Many small molecules fit physically into a wide pore size window, but the “average pore size larger than diameter” can be argued depending on how “diameter” is defined for flexible or solvated molecules.

Claim 7: antisense/interfering oligonucleotide

Oligonucleotides are often delivered with electrostatic complexes or conjugates. Here, the claim requires reversible covalent bonding via the prodrug linker to the pore-tethered system. A competitor using non-covalent adsorption, ion pairing, or encapsulation without reversible covalent cleavage would fall outside the core mechanism.

---

What claims protect the prodrug linker chemistry in US 10,029,015?

Short answer: Claims cover broad “reversible covalent bond” concepts via masking/activating group linkers and specific bond types like carbamate, plus broad functional group lists.

Claim 8: masking group + activating group

This maps to standard prodrug architectures: a group that keeps activity masked until cleavage, followed by unmasking/activation. It strengthens infringement for competitors who use two-stage linker behavior.

Claim 9: carbamate bond

Carbamate is a specific reversible covalent motif. Even if a competitor uses a different cleavable reversible bond, the platform claim 1 still requires a reversible covalent bond cleavable in vivo, so the carbamate dependent claim is an additional arrow.

Claim 10–11: “functional group” and functional group exemplars

Claim 10 introduces a “functional group.” Claim 11 gives a list that includes:

• carboxylic acids/derivatives, carbonate/derivatives
• hydroxyl, hydrazine, hydroxylamine
• maleamic acid derivatives
• ketone, amino, aldehyde
• thiol/disulfide

Interpretive risk: “Functional group” language can be broad, but depends heavily on whether the specification defines how those groups participate in masking/activation and the actual cleavage pathway. Still, claim text aims to capture many cleavable/catalytically processed linkers.

Design-around wedge

To avoid literal coverage, a competitor would look for:

• non-covalent tethering,
• irreversible cleavage only (no reversibility as claimed),
• covalent tether cleavage that is slower than scaffold degradation such that cleavage is not ≥10× degradation,
• active moiety not coupled only to mesopores (e.g., some linkage to polymer outside pores, or a different internal architecture).

---

What hydrogels and biodegradable bonds are covered by US 10,029,015?

Short answer: The claim set covers a wide range of hydrogel polymer chemistries and both chemically cleavable and enzymatically cleavable biodegradable bonds, with explicit examples including polyacrylamide derivatives, PEG-based acrylamides, carbohydrate polymers, and degradable crosslink chemistries.

Claim 12: hydrogel polymer universe

The claim lists polymers including:

• polyalkyloxy-based polymers
• dextran, chitosan, hyaluronic acid derivatives, alginate, xylan, mannan
• carrageenan, agarose
• cellulose, starch, hydroxyethyl starch (HES)
• poly(vinyl alcohol), poly(oxazolines), poly(anhydrides), poly(ortho esters)
• poly(carbonates), poly(urethanes)
• poly(acrylic acids), poly(acrylamides), poly(acrylates), poly(methacrylates)
• poly(organophosphazenes), poly(siloxanes)
• poly(vinylpyrrolidone), poly(cyanoacrylates)
• poly(esters), poly(iminocarbonates), poly(amino acids)

This breadth suggests the patentee is claiming the system behavior more than a single hydrogel family.

Claims 13–19: specific polymer embodiments

Key examples include:

• poly(propylene glycol) or poly(ethylene glycol) (claim 13)
• HMPA (poly(hydroxypropylmethacrylamide)) for polyacrylamide (claim 14)
• poly(hydroxyethylmethacrylate) (claim 15)
• poly(lactic acid) or poly(glycolic acid) (claim 16)
• poly(glutamic acid), collagen, gelatin (claim 17)
• polyacrylamide or derivative (claim 18)
• poly(ethylene glycol acrylamide) or derivative (claim 19)

Claims 20–22: biodegradable bonds for degradation

Claim 20 enumerates chemically cleavable bonds in crosslinkers:

• phosphate, phosphonate, carbonate, carbamate, disulfide, ester

Claim 21 expands to “further comprising” biodegradable bonds beyond just crosslinkers.

Claim 22 adds enzymatically cleavable biodegradable bonds.

Litigation/validity relevance: Such breadth can be vulnerable if the specification does not support each class with mesopore formation and the kinetic ratio. But claim text itself signals platform-level intent.

---

What patent landscape risks does US 10,029,015 create for competitors?

Short answer: The claim set targets a multi-dimensional combination. Competitors are most exposed when they have (i) a mesoporous degradable hydrogel depot, (ii) covalent pore-wall tethering of a linker, (iii) reversible in vivo covalent cleavage to release cargo, and (iv) cleavage kinetics engineered to dominate over hydrogel degradation.

Where competitors most commonly stray (and potential non-infringement hooks)

1. Using non-covalent sequestration
   • Encapsulation by diffusion, adsorption, or ionic pairing without reversible covalent linkage.
2. Using covalent tether but no kinetic hierarchy
   • If hydrogel degrades quickly and the cargo release is dominated by scaffold erosion rather than linker cleavage, the ≥10× kinetic requirement becomes a major defense lever.
3. Not using mesopores within 1–100 nm
   • Larger pores, different pore distributions, or micro/nanogels without distinct mesopore architecture.
4. Linker tethered to the carrier but not specifically to pore mesopore walls
   • If the linker is tethered to bulk polymer rather than to the mesopore surface, the “prodrug linker covalently bonded to the mesopore” limitation is not met.
5. Active moiety not restricted to mesopores
   • If the active moiety is partially bound elsewhere in the matrix, “coupled only to mesopores” is contested.

Where competitors are likely to need licensing

If an accused product is a genuine mesoporous degradable hydrogel prodrug depot with reversible covalent linker release, the only easy clearance routes are:

• avoid the mesopore definition,
• avoid reversible covalent cleavage mechanics,
• or adjust material kinetics so cleavage is not ≥10× hydrogel degradation.

---

How strong is the patent estate for US 10,029,015 based on claim structure?

Short answer: Strength is high at the “combination claim” level due to the explicit mesopore geometry, reversible covalent linker mechanics, and kinetic hierarchy requirement. Strength is lower against prior art that already discloses mesoporous hydrogels with prodrug linkers, unless those references also disclose the same kinetic tuning and pore-contained coupling constraint.

Critical claim features that can support novelty in enforcement

• mesopores with openings
• pore size 1–100 nm
• active moiety diameter smaller than average pore size
• active coupled only to mesopores
• reversible covalent prodrug bond cleavable in vivo
• release governed by cleavage kinetics
• cleavage rate at least 10× hydrogel degradation

This reads like an attempt to differentiate from:

• drug-in-hydrogel systems where release is diffusion/erosion governed,
• non-mesoporous hydrogels,
• linkers where degradation dominates,
• covalent immobilization systems that do not meet the reversible release mechanism.

---

What generic entry risks exist for US 10,029,015 (and why this is not a classic “formulation patent” risk)?

Short answer: This is not a “small-molecule generics” style Orange Book risk. It is a platform IP risk for any therapeutic that uses this specific hydrogel mesopore prodrug mechanism. “Generic entry” is better understood as entry by biosimilar analogs, follow-on biologics, or alternative depots that try to replicate therapeutic effect with different payloads but similar device-like release architecture.

Payload substitution does not necessarily clear infringement

Switching insulin to another protein or small molecule does not automatically avoid claim coverage because:

• claim 1 covers the mechanism for any “biologically active moiety,” and
• dependent claims enumerate subclasses rather than limit the platform.

Technology substitution is the real clearance lever

Design-arounds have to change the system mechanics, not just the payload.

---

What would a claim construction battle likely focus on for US 10,029,015?

Short answer: The disputes likely center on operational definitions: what counts as “mesopores,” what is “average pore size,” what defines “diameter” for biologics, what “reversibly covalently bonded” means mechanistically, and how to measure “cleavage rate” versus “hydrogel degradation rate” in vivo.

Terms likely to drive expert testimony

• “mesopores of pore size between 1 and 100 nm with surface openings”
• “average pore size larger than the diameter of the biologically active moiety”
• “prodrug linker covalently bonded to the mesopore”
• “reversibly covalently bonded”
• “cleavable in vivo”
• “release properties … governed by … cleavage kinetics”
• “cleavage rate … at least an order of magnitude higher than … degradation … in vivo”

---

Key Takeaways

• US 10,029,015 claims a mesoporous degradable hydrogel prodrug depot in which an active moiety is held inside 1–100 nm mesopores via a pore-tethered reversible covalent linker that cleaves in vivo.
• The kinetic hierarchy (cleavage rate ≥10× hydrogel degradation rate) is the most operationally constraining limitation and the most likely focal point in infringement and validity disputes.
• Dependent claims broaden the payload universe (proteins, antibodies, insulin, small molecules, oligonucleotides) and hydrogel chemistries (natural and synthetic polymers), so non-mechanism changes are unlikely to clear risk.
• Clearance is most feasible by changing one of the core modules: mesopore architecture, pore-wall tethering, reversible covalent release mechanism, or the release-degradation kinetics relationship.

---

FAQs

1. Does US 10,029,015 cover mesoporous particles embedded in a hydrogel, or only pore networks within the hydrogel matrix?
The claim text specifies a hydrogel having mesopores, with the prodrug linker covalently bonded to the mesopore, implying the mesopores are part of the hydrogel structure.

2. If an active moiety is released mainly by hydrogel erosion, does that avoid infringement?
It depends on whether the product meets the claim’s requirement that release properties are governed by prodrug linker cleavage kinetics with cleavage rate at least 10× hydrogel degradation rate.

3. Are non-covalent prodrug linkers covered?
No. Claim 1 requires a linker that is reversibly covalently bonded to the active moiety and cleavable in vivo.

4. Can the hydrogel polymer be natural (dextran/chitosan) or must it be synthetic (PEG/acrylamide)?
Claim 12 covers multiple natural and synthetic polymer families, including dextran, chitosan, hyaluronic acid derivatives, alginate, and PEG-based polymers, subject to the same mesopore and reversible linker requirements.

5. Does changing the drug payload (e.g., from insulin to another protein) change the scope?
Payload substitution typically does not avoid claim 1 because the platform mechanism remains the same; dependent claims add coverage for specific payloads rather than replace the core mechanism.

---

References

1. US Patent 10,029,015 claim set provided in prompt.

Details for Patent 10,029,015

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Ferring Pharmaceuticals Inc.	NOVAREL	chorionic gonadotropin	For Injection	017016	January 15, 1974		2035-05-08
Ferring Pharmaceuticals Inc.	NOVAREL	chorionic gonadotropin	For Injection	017016	December 27, 1984		2035-05-08
Ferring Pharmaceuticals Inc.	NOVAREL	chorionic gonadotropin	For Injection	017016	February 15, 1985		2035-05-08
Ferring Pharmaceuticals Inc.	NOVAREL	chorionic gonadotropin	For Injection	017016	February 16, 1990		2035-05-08