When do biologic drug patents expire and when will biosimilars launch?

Executive summary
U.S. Patent 10,124,040 claims a tightly defined crystallization workflow for insulin lispro that uses (i) an alkaline insulin lispro feed (pH about 8.0), (ii) zinc addition at ~25°C followed by cooling to ~5°C and incubation, (iii) meta-cresol as a crystal stabilizing agent, (iv) specific solvent/cake-handling conditions (including optional phenol cap in the feed and defined cake wash pH windows), and (v) a targeted zinc loading specification in the resulting dried crystals. The enforceable core is not “insulin lispro crystallization with zinc,” but a combination of process parameters (pH, temperature, sequence, stabilizer/phenol behavior, filtration/centrifugation + defined wash chemistry) tied to a product attribute (zinc content per hexamer) and a crystal morphology/size profile.

Below is a claim-by-claim dissection and a practical landscape map of what competitors typically need to practice to avoid infringement, what design-arounds are likely to fail, and where the estate is strongest for enforcement or licensing leverage.

What does U.S. Patent 10,124,040 claim for insulin lispro crystal manufacturing?

Claim 1 core method: alkaline feed + zinc add at ~25°C + ~5°C incubation

Claim 1 defines a method for preparing insulin lispro crystals with a sequence and parameter set:

Feed composition: insulin lispro + water-miscible organic solvent + crystal stabilizing agent
Feed pH: about 8.0
Sequence:
1. Add zinc salt at about 25°C to form a “crystalizing solution”
2. Cool to about 5°C
3. Incubate until crystals form

Critical claim construction pressure points

“About 8.0” pH: leaves room for tolerance, but not unlimited. A court will treat “about” as a range constrained by the specification and examples (not provided in your prompt).
Zinc addition temperature ~25°C: is a distinct step; adding zinc during cooling or at lower temperatures weakens alignment with Claim 1.
Water-miscible organic solvent and crystal stabilizing agent are generic placeholders. Dependent claims narrow them (isopropanol, meta-cresol).

Claims 2–5: stabilizer chemistry narrowing (organic acid/base)

Claim 2: organic acid or salt among acetic acid/acetate, citric acid/citrate, glycine
Claim 3: acetate specifically
Claim 4: base among KOH, NaOH, NH4OH
Claim 5: ammonium hydroxide specifically

These features are not required by Claim 1 alone, but they can become part of the asserted combination under dependent-claim theories (literal infringement requires meeting the dependent limitations too).

Claims 6–10: concentration/solvent/stabilizer/zinc specificity + phenol cap

Claim 6: insulin lispro concentration about 1.5–2.5 g/L
Claim 7: solvent isopropanol
Claim 8: crystal stabilizing agent meta-cresol
Claim 9: zinc salt zinc chloride
Claim 10: meta-cresol present and phenol ≤ 0.08 mM

Claim 11: meta-cresol and “does not include phenol”

Claim 11 creates an either/or landscape relative to Claim 10: one option is a phenol cap, the other is total absence. A process with measurable phenol above 0.08 mM risks not meeting Claim 10 and would likely not meet Claim 11 either.

Claims 12–15: post-crystallization solid-liquid handling (settle/decant vs centrifuge + cake wash pH and wash chemistry)

Claim 12: after crystallization, produce a crystal slurry via either
(i) settling + decant, or
(ii) centrifugation
Claim 13: filter apparatus to make cake bed + dry
Claim 14: cake bed washed with solution containing water-miscible organic solvent + meta-cresol + zinc salt at pH about 5.5, then dry
Claim 15: centrifuge route; wash solution includes water-miscible organic solvent + meta-cresol + zinc salt with pH about 4.5 to 8.5, then dry

This is where process innovators typically diverge: cake washing is a major lever affecting retained zinc and polymorph/size distribution. Claim language makes the wash solution chemistry and pH material.

Claim 16: method tied to a target zinc loading specification

Claim 16 is the most infringement-relevant because it adds a product-spec boundary condition:

Target zinc content: 0.30% to 0.60% zinc (dried basis), or ~2–3 zinc atoms per hexamer
Process steps include:
- Feed at pH about 8.0
- Add zinc chloride at ~25°C
- Cool to ~5°C and incubate
- Remove crystalizing solution to make slurry
- Filter or centrifuge to make cake bed
- Add cake wash solution (water-miscible organic solvent + meta-cresol + zinc salt) and set wash pH about 5.0 (as written)
- Incubate wash mixture to remove unbound zinc
- Dry to reach the zinc-loaded specification

Enforcement geometry A competitor trying to match the general crystallization conditions but produce “low-zinc” product will not fit Claim 16, even if it fits Claim 1. The claim is both process and outcome constrained.

Claim 17: crystalline composition with morphology/size + zinc loading + meta-cresol

Claim 17 is a product-by-structure/attribute claim:

Composition: insulin lispro crystals with
- zinc content 0.30%–0.60% (dried basis) or ~2–3 zinc atoms per six molecules (as stated)
- meta-cresol
Morphology/size:
- cubic crystals with 20–30 µm average size
- or rhombohedral crystals with >40 µm average size

This provides a direct product claim pathway for injunction leverage if the competitor’s material meets zinc + meta-cresol + morphology/size thresholds.

How broad are the claims, and where is the claim “center of gravity”?

Breadth by claim hierarchy

Claim 1 is broad on solvent and stabilizer identities but narrow on sequence and pH/temperature.
Claims 7–11 narrow to typical formulation excipient roles (isopropanol, meta-cresol, zinc chloride) and handle phenol.
Claims 12–15 narrow to specific solid handling modalities and cake wash chemistry, with pH windows.
Claims 16–17 add a target zinc-loading/product attribute and morphology, making them less likely to be met accidentally but more useful for enforcement once met.

Most likely asserted combinations

In practice, patent plaintiffs tend to plead:

Claim 1 + dependent limitations (e.g., meta-cresol, zinc chloride, isopropanol, phenol cap/absence, and concentration range) to lock into a specific competitor process
Claim 16 for outcome-based zinc loading
Claim 17 for the crystalline drug substance end product

Where design-arounds usually work

Changing feed pH away from ~8.0 (or shifting from “zinc addition at ~25°C” to zinc addition during cooling) breaks Claim 1/16 alignment.
Using a different stabilizer (substituting cresol isomers not meeting “meta-cresol”) breaks Claims 8/10–15/16.
Targeting a different zinc retention outside 0.30–0.60% (dried basis) breaks Claims 16–17.
Changing wash pH outside the specified region in Claims 14–15 breaks those dependent claims.

Which specific process parameters must be replicated to infringe?

Parameter map tied to the claims

Parameter	Claim(s) that require it	Literal anchor from text
Feed includes insulin lispro	1, 16	“providing a solution comprising insulin lispro”
Water-miscible organic solvent present	1, 16	required; identity narrowed to isopropanol in 7
Crystal stabilizing agent present	1, 16	narrowed to meta-cresol in 8; used again in wash in 14–15
Feed pH	1, 16	about 8.0
Zinc salt addition	1, 16	zinc addition at about 25°C
Cooling temperature	1, 16	cooling to about 5°C
Incubation time	1, 16	“sufficient” to form crystals
Zinc salt identity	9, 16	zinc chloride
Insulin lispro concentration range	6	1.5–2.5 g/L
Stabilizer identity	8, 10–11	meta-cresol
Phenol inclusion threshold	10	phenol ≤ 0.08 mM
Phenol absence	11	no phenol
Solid handling	12–15	settle/decant or centrifuge; filter cake and cake wash; centrifuge wash option
Wash solution pH	14, 15	pH about 5.5 (14); pH about 4.5–8.5 (15)
Wash solution composition	14–15, 16	water miscible solvent + stabilizer + zinc salt (and pH)
Product zinc loading	16–17	0.30–0.60% zinc (dried basis) or ~2–3 zinc atoms per hexamer; plus meta-cresol
Crystal morphology/size	17	cubic 20–30 µm or rhombohedral >40 µm

What patents or prior art typically compete with U.S. 10,124,040 for insulin lispro crystallization?

A complete competitor mapping requires the full patent text, priority data, prosecution history, and the patent family’s cited references, none of which are contained in your prompt. Because that dataset is not available here, the only defensible statement is the scope mechanics: U.S. 10,124,040 likely targets a “zinc-bearing insulin lispro crystal” manufacturing window with meta-cresol and controlled phenol, plus defined cake wash chemistry to tune zinc retention and morphology.

The practical competitive risk is that if a rival crystallization method does not hit the specific pH/temperature/wash sequence or does not hit the zinc loading/morphology window, it can avoid literal infringement while still producing insulin lispro crystals suitable for formulation. Conversely, if a rival’s cGMP solids process is tuned to the same zinc retention target, it becomes vulnerable to both process claims (16) and product claims (17).

Is U.S. 10,124,040 a product claim or a process claim, and which is stronger?

Product claim strength: Claim 17

Claim 17 is a crystalline composition with defined attributes:

zinc content range
meta-cresol presence
morphology and size profile

Product claims are often stronger for leverage because:

infringement can be proven by analyzing the finished drug substance crystals
there is no need to fully reconstruct the manufacturing process, only to show the product meets the defined parameters

Process claim strength: Claim 16

Claim 16 ties the process to a measured zinc loading and specific process chemistry and conditions. It is enforceable against manufacturing routes that produce the specified zinc loading in the dried product.

Claim 1 alone

Claim 1 is broad in solvent/stabilizer identities, but narrow in sequence and pH/temperature. Without dependent limitations, it is easier for competitors to attempt to escape by changing solvent, stabilizer, or zinc salt identity, or by adjusting pH and temperature schedules.

How does the phenol limitation affect infringement risk?

Claim 10 vs Claim 11

If phenol is present at low levels (≤0.08 mM), Claim 10 becomes relevant.
If phenol is absent, Claim 11 becomes relevant.
If phenol is present above the cap, Claim 10 does not read on that scenario, and Claim 11 also does not read on it.

From an infringement-risk standpoint, phenol control is a high-sensitivity variable. A rival using phenol as an antimicrobial at concentrations that translate to >0.08 mM in the relevant crystallization feed risks avoiding the dependent claim sets but could still be hit under less-specific claims that do not require phenol absence/cap (e.g., Claim 1 and the zinc/morphology claims if they are asserted without Claim 10/11 dependencies).

What does the zinc loading definition imply for proof and defenses?

“0.30% to 0.60% zinc (dried basis)” is outcome constrained

This is a measurable product specification. In litigation, zinc loading can be tested (commonly by ICP-based methods) on:

dried insulin lispro crystals
possibly intermediary solids depending on evidence

Hexamer framing

Claim 16 also expresses zinc atoms per hexamer. That can be used to tie measured zinc content back to expected coordination states. It increases the technical burden for a defendant to dispute both chemical analysis and structural interpretation.

Most common defense strategy

A defendant typically shifts product specification:

run crystallization to reduce retained zinc below 0.30% or above 0.60%
adjust wash conditions and wash incubation time to strip unbound zinc differently

But that must be consistent with cGMP feasibility and must not fall back into Claim 16 or Claim 17.

When does exclusivity end for a patent like U.S. 10,124,040?

A precise exclusivity timeline requires:

filing date, priority date, patent issue date, and any PTA
whether term adjustments or terminal disclaimers apply
whether any related patents are in the same family

These elements are not in the provided prompt, so an accurate “expires on X date” timeline cannot be produced from the information given.

What does this patent suggest about likely generic or biosimilar launch barriers?

Because insulin lispro is an established recombinant protein product (and generic pathways depend on regulatory status), the practical barrier from this patent is manufacturing of the drug substance in the specific crystal form and zinc loading window. Even if a competitor has:

correct amino acid sequence
correct formulation potency

it can still be exposed if it manufactures or sells crystalline insulin lispro that matches the claimed crystal attributes (Claim 17) or performs the claimed workflow that yields the target zinc loading (Claim 16).

A competitor that can show its crystals are outside:

zinc content
meta-cresol content
morphology/size bands
would reduce infringement risk materially.

Key takeaways

U.S. 10,124,040 is anchored on insulin lispro crystallization using a zinc addition at ~25°C into an ~pH 8 solution, followed by cooling to ~5°C and incubation, with meta-cresol as the crystal stabilizer.
The enforcement “center of gravity” is the combination of process sequence + wash chemistry and a measurable zinc-loading target (0.30%–0.60% zinc dried basis) tied to hexamer-level zinc atoms.
Claim 17 creates a direct product infringement pathway via zinc content + meta-cresol presence + crystal morphology/size.
The phenol cap/absence in Claims 10–11 is a high-sensitivity variable that can help or hurt alignment with dependent claim sets.
Design-arounds with the best chance of avoiding infringement are those that shift feed pH from ~8, shift zinc addition temperature/timing, substitute non-meta-cresol stabilizers, or target zinc retention outside 0.30%–0.60% and/or different morphology/size distributions.

FAQs

What makes Claim 16 harder to design around than Claim 1?

Claim 16 is outcome constrained by zinc content (0.30%–0.60% dried basis / ~2–3 zinc atoms per hexamer), so a process change must alter zinc retention without compromising crystallization.

Can a competitor avoid infringement by changing only the organic solvent?

It depends on claim set asserted. Claim 1 requires a water-miscible organic solvent, and Claim 7 narrows it to isopropanol. Avoiding Claim 7 by using a different solvent can help only if plaintiffs assert not the broader claim elements tied to other dependencies.

Does adding zinc during cooling avoid Claim 1?

Claim 1 specifies zinc addition at about 25°C before cooling to about 5°C. Timing changes can move the process outside the literal reading, depending on actual thermal history and evidence.

How do washing steps influence zinc retention and morphology?

Wash solution composition and wash pH (Claims 14–15) directly affect unbound zinc removal and retained zinc, which in turn can affect whether the dried crystals meet the zinc-loading specification and morphology bands in Claim 17.

If a competitor’s crystals are outside the zinc range, is Claim 17 still at risk?

Claim 17 requires 0.30%–0.60% zinc and meta-cresol with specified morphology/size thresholds. Falling outside the zinc range avoids that product claim, even if the manufacturing process otherwise resembles Claim 1.

References

(No sources were provided in the prompt to cite for the full patent text, prosecution history, or any referenced prior art.)

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Eli Lilly And Company	HUMALOG	insulin lispro	Injection	020563	June 14, 1996	10,124,040	2035-08-21
Eli Lilly And Company	HUMALOG	insulin lispro	Injection	020563	August 06, 1998	10,124,040	2035-08-21
Eli Lilly And Company	HUMALOG	insulin lispro	Injection	020563	September 06, 2007	10,124,040	2035-08-21
Eli Lilly And Company	HUMALOG	insulin lispro	Injection	020563	June 06, 2017	10,124,040	2035-08-21
Eli Lilly And Company	HUMALOG	insulin lispro	Injection	020563	November 15, 2019	10,124,040	2035-08-21
Merck Sharp & Dohme Llc	VAXNEUVANCE	pneumococcal 15-valent conjugate vaccine	Injection	125741	July 16, 2021	10,124,040	2035-08-21
>Applicant	>Tradename	>Biologic Ingredient	>Dosage Form	>BLA	>Approval Date	>Patent No.	>Expiredate

Country	Patent Number	Estimated Expiration
European Patent Office	3185887	⤷ Start Trial
United States of America	2017209545	⤷ Start Trial
World Intellectual Property Organization (WIPO)	2016032869	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration

Patent: 10,124,040

Summary for Patent: 10,124,040