US Patent 8,906,373: Claim Scrutiny and US Landscape for Adalimumab Regimens in Psoriasis and Psoriatic Arthritis
US Patent 8,906,373 (granted Dec. 2014) is structured as a treatment-method patent tied to subcutaneous adalimumab 40 mg every other week with patient-eligibility filters and, in claim 1, a 24-week clinical-response requirement (PASI 90). The set of dependent claims tightens the cohort by baseline psoriasis extent and expands coverage to chronic plaque psoriasis plus delivery format (prefilled syringe) and formulation concentration (50 mg/mL).
This patent is best read as an attempt to carve out a definable US NME for a specific adalimumab schedule and outcome, rather than as a broad composition or mechanism claim. That framing drives both its enforceability profile and the risk of obviousness/anticipation in view of earlier adalimumab labeling and trials.
What do the claims actually cover in scope and in practice?
Claim 1 is the core enforcement hook: PsA patients with psoriasis responder constraint
Claim 1:
A method of treatment of psoriasis in a patient with moderate to severe active psoriatic arthritis (PsA), comprising:
- Subcutaneous adalimumab 40 mg every other week
- Patient has ≥3 swollen joints and ≥3 tender joints prior to treatment
- Patient failed NSAID therapy
- Patient achieves PASI 90 at week 24
So the claim is not just “adalimumab treats psoriasis.” It is:
1) PsA severity and joint-count thresholds
2) NSAID failure
3) Schedule and dose (40 mg SC q2w)
4) Outcome at week 24 (PASI 90)
From a patent-assertion standpoint, the PASI-90-at-week-24 limitation can be a litigation lever. It can be used both ways:
- Narrowing: it reduces the class of patients and situations to those that meet the PASI90 responder endpoint.
- Enforcement friction: proving a defendant’s direct method meets the week-24 PASI90 condition can require trial-like evidence or patient-record linkage to the claim endpoint.
Dependent claims 2 and 3 split psoriasis extent
- Claim 2: baseline psoriasis <3% BSA
- Claim 3: baseline psoriasis ≥3% BSA
This creates an “either-or” cohort partition for baseline body surface area categories. It is unusual to see a claim that explicitly splits BSA cutoffs as dependent limitations unless the specification defined stratification or subgroup outcomes.
Claims 4–5 cover chronic plaque psoriasis as a standalone indication
- Claim 4: method for treating chronic plaque psoriasis with adalimumab 40 mg SC every other week
- Claim 5: patient has moderate to severe chronic plaque psoriasis
These claims are broader than claim 1 because they do not recite PsA joint thresholds, NSAID failure, or a PASI 90 requirement as an express limitation. Their enforceability therefore depends more on whether those elements were already taught in the prior art or already implied by label-supported use.
Claims 6–9 tie to product form and concentration
- Claim 6 (claim 1 dependent): prefilled syringe for SC injection
- Claim 7 (claim 1 dependent): formulation concentration 50 mg/mL
- Claim 8 (claim 5 dependent): prefilled syringe
- Claim 9 (claim 5 dependent): formulation concentration 50 mg/mL
These are “hardware” limitations. They can narrow infringement to specific marketed formulations and packaging, but in practice adalimumab products and device presentations in the US have been well characterized for years.
How does this claim-set map to prior clinical evidence and US regulatory labeling?
The schedule (40 mg SC every other week) aligns with established adalimumab dosing for plaque psoriasis and other indications
By the time of the patent grant, adalimumab 40 mg SC every other week was already an established regimen for plaque psoriasis in US practice and labeling, following earlier pivotal trials. The key question is not whether the regimen was known. The key question is whether US Patent 8,906,373 adds something materially non-obvious beyond what was already taught.
The differentiator is the “PsA with specific joint thresholds + NSAID failure + PASI 90 at week 24”
Claim 1 tries to link psoriasis response to a specific PsA phenotype and treatment-experience status:
- joint counts: ≥3 swollen and ≥3 tender
- prior therapy failure: NSAIDs
- efficacy: PASI 90 at week 24
This triad can create an argued separation from standard psoriasis treatment claims. It also invites an obviousness attack if the same endpoints and criteria were already disclosed for adalimumab in related trials, even if not framed as a patentable claim.
What does the patent landscape look like in the US for these adalimumab regimen claims?
Likely technology neighborhood: biosimilar-era freedom-to-operate and method-claim enforcement
US Patent 8,906,373 is from the period before the full biosimilar wave, but the method claims have become part of the FTO conversation because:
- method claims can be asserted against providers, prescribers, and manufacturers only if direct infringement can be shown
- direct infringement in method-of-treatment cases often hinges on documented patient selection and endpoint achievement
- biosimilars that match the dosing and formulation may still face method-of-use restrictions depending on the surviving patent claim set
Structural risk pattern for this patent type
For patents that claim:
- a known biologic
- a standard dose/schedule
- a claim endpoint (PASI 90 at a timepoint)
- a patient-eligibility filter (joint counts, NSAID failure)
the US enforceability typically turns on whether the same combination appears in earlier teachings.
In that context, US Patent 8,906,373 sits in a crowded ecosystem:
- multiple adalimumab patents around formulations, dosing, and methods were filed by the original sponsor and others over time
- unrelated companies in the same biologic class often learned the same clinical space
- litigation across biologics has repeatedly emphasized the boundaries between “known regimen” and “patentable method definition”
Practical inference: claim 4–5 are the most vulnerable portion
Claims 4 and 5 read like a straightforward recitation of:
- adalimumab 40 mg SC q2w
- for chronic plaque psoriasis
- in moderate-to-severe patients
Those elements are strongly likely to have been in prior art and in label-supported use by 2014. Without the PsA and PASI-90-at-week-24 constraints, claims 4–5 provide less definitional separation.
Practical inference: claim 1 is the most defensible portion
Claim 1’s combination is narrower and more specific:
- PsA patient selection (joint thresholds)
- NSAID failure requirement
- psoriasis treatment endpoint at week 24 (PASI 90)
Even so, defensibility depends on whether the prior art already disclosed the same eligibility criteria and the same endpoint relationship for adalimumab.
What are the strongest and weakest aspects of enforceability?
Strongest aspects (litigation-adjacent)
1) Patient selection specificity in claim 1
Joint-count thresholds and NSAID failure are concrete selection gates.
2) Timebound efficacy limitation (PASI 90 at week 24) in claim 1
The claim requires a responder outcome at a defined timepoint.
Weakest aspects (likely invalidity/avoidance vectors)
1) Baseline BSA splits (claims 2 and 3)
If the prior art used BSA thresholds or subgroup analyses, these dependent limitations can be attacked as obvious refinements or as non-inventive stratification.
2) Plaque psoriasis claims without PsA constraint (claims 4–5)
A known dosing regimen for plaque psoriasis in moderate-to-severe patients is the hardest class of claims to keep patentably distinct at the method level.
3) Device/formulation limitations (claims 6–9)
Packaging and concentration are often easier to find in prior art or product information. They can narrow infringement but do less to improve validity.
How would a defendant avoid these claims in practice?
Avoidance routes by claim-structure design
- For claim 1: use a different dose schedule, a different route, or treat a cohort that does not meet the explicit joint threshold or NSAID failure condition, or argue that the PASI 90 requirement is not met at week 24.
- For claims 4–5: prescribe for chronic plaque psoriasis under a regimen that differs from 40 mg SC q2w, or argue non-infringement by patient severity/definition issues if the clinical charting does not satisfy the “moderate to severe” framing in a claim-congruent way.
- For claims 6–9: deliver using formulations and concentrations not matching the 50 mg/mL and not in a “prefilled syringe” presentation (if alternative presentations exist). This depends on actual product offerings.
Where does “direct infringement” get contested for method-of-treatment patents like this?
Method-of-treatment claims often trigger disputes over:
- who performs the method (physician vs. manufacturer vs. patient)
- what constitutes proof that the patient achieved PASI 90 at week 24
- whether “failed NSAID therapy” is documented in a way that can be matched to the claim
The endpoint limitation in claim 1 can increase the evidence burden for enforcement. Defendants may press for an interpretation that requires strong proof of achievement, not just the prescribing decision.
What is the likely litigation posture across the claim set?
Claim-by-claim priority for defense and challenges
- Claims 4–5 likely face the most aggressive prior-art-based invalidity pressure (known regimen for plaque psoriasis).
- Claims 6–9 likely face an obviousness challenge framed around known formulation concentration and device type.
- Claim 1 likely becomes the last surviving core if the court accepts that the PsA selection plus outcome requirement is non-trivial over the art.
Likely remedy strategy
In infringement suits, plaintiffs typically focus on the most specific claim(s). Here, that likely means claim 1, with dependent claims 2 and 3 as cohort-specific add-ons.
Key Takeaways
- US 8,906,373 claim 1 is the most distinctive piece, tying PsA joint-count thresholds + NSAID failure + adalimumab 40 mg SC q2w + PASI 90 at week 24.
- Claims 4–5 read like standard plaque psoriasis method dosing and are likely the most vulnerable to prior-art and obviousness challenges.
- Claims 2–3 split baseline psoriasis extent and can be attacked as subgroup stratification unless the specification supports non-obvious discovery.
- Claims 6–9 limit to prefilled syringe and 50 mg/mL, narrowing infringement but often not improving validity if product information and formulations were already known.
- For an FTO or competitive strategy, the patent’s enforceability will hinge on whether earlier teachings disclose the same patient-eligibility criteria and week-24 PASI 90 linkage for adalimumab.
FAQs
1) Is the patent primarily about psoriasis, psoriatic arthritis, or adalimumab itself?
It is primarily about adalimumab treatment methods in psoriasis, with claim 1 specifically requiring psoriatic arthritis patient criteria and a psoriasis responder outcome.
2) What makes claim 1 harder to infringe than claim 4?
Claim 1 includes multiple patient eligibility limitations and an explicit PASI 90 at week 24 outcome requirement. Claim 4 does not.
3) Do the claims require pretreatment joint counts and NSAID failure?
Yes, in claim 1: the patient must have ≥3 swollen and ≥3 tender joints prior to treatment and must have failed NSAID therapy.
4) What are the “non-dosing” limitations in claims 6–9?
They cover delivery format (prefilled syringe) and formulation concentration (50 mg/mL) for the adalimumab product used in the method.
5) Which part of the claim set is most likely to be attacked first in invalidity proceedings?
Claims 4–5 are the first candidates for invalidity pressure because they recite a dosing schedule and a plaque psoriasis treatment class with fewer differentiating patient-response constraints.
References (APA)
[1] United States Patent. US 8,906,373. (Publication/issuance details available via USPTO).
