ACKR4 Biologics Sequence Review Report 2026: Atypical chemokine receptor 4 Similarity and Patent-Risk Signals

This ACKR4 Biologics Sequence Review Report was produced with PatSnap Biology Modality MCP workflows. It turns patent-scale sequence search, sequence retrieval, pairwise alignment and target evidence into a reproducible diligence narrative. Explore the PatSnap MCP servers used in this report.

Review date: 7 August 2026. This report supports R&D, competitive-intelligence and IP triage. It is not a legal opinion, freedom-to-operate conclusion or validity analysis. A sequence hit does not establish infringement, and a no-hit or low-hit result does not establish clearance.

Executive sequence-risk thesis

ACKR4 is a reviewed human protein asset represented by UniProt entry Q9NPB9. The reference sequence contains 350 amino acids and is annotated as Atypical chemokine receptor 4. PatSnap’s patent-scale screen returned 21 matching records in the configured result universe. The leading reviewed hit showed 100.00% query identity across 350/350, with the database claim annotation recorded as Yes.

The resulting screen is classified as elevated diligence priority. That label prioritizes diligence; it does not classify the asset as blocked, available or unique. Whole-protein identity can be driven by conserved domains, common signal peptides, transmembrane regions or endogenous human sequence. Patent relevance depends on whether live claims cover the complete sequence, a fragment, an engineered variant, an antibody recognizing the target, a use, or a functional genus.

Why this protein is a biologics-relevant review subject

Atypical chemokine receptor 4 is a traceable human protein sequence suitable for systematic similarity screening. For biologics teams, the sequence can matter in several distinct ways: it may be the administered protein, an extracellular target, an antigen used to raise antibodies, a receptor domain incorporated into a fusion, or a reference against which engineered variants are defined. Those possibilities produce different patent questions even when they share the same gene symbol.

This report therefore separates sequence proximity from legal scope. A close patent-sequence match can identify families worth reading, yet naturally occurring human protein sequence is not itself a conclusion about enforceable rights. Conversely, engineered substitutions, truncations, Fc fusions, linkers, glycosylation-site changes or epitope-defined claims may be commercially important even when the full-length reference is not reproduced verbatim.

Biology Modality MCP evidence workflow

The workflow began with ls_sequence_search_submit against ALLPATENT protein records and used ls_sequence_search_get_results to retrieve the leading evidence. ls_sequence_fetch resolved the selected patent-sequence record, and ls_sequence_alignment performed a PSA comparison to the reviewed UniProt query. Finally, ls_antibody_antigen_search tested target-linked antibody evidence and ls_patent_sequence_fetch retrieved sequences from a resolved patent record where available.

Similarity-search readout

The leading result was evaluated under the primary screen using 70–100% identity and 80–100% query coverage. It reported 350/350 identical positions, query coverage 350/350, subject coverage 350/363, E-value 0 and 0/350 gaps. The database marked the record as Yes for the claim annotation field.

The primary result was obtained inside the predefined strict screening window. That improves reproducibility, but the window still excludes lower-identity functional analogues, short motifs and nucleotide-level variants.

The raw count of 21 records should not be read as the number of independent inventions. One sequence can appear in applications, grants, continuations, divisionals and multiple jurisdictions. It can also recur as a reference, antigen, control or prior-art comparator. Family consolidation by earliest priority, applicant, simple family and legal status is therefore essential before ranking competitive risk.

Sequence fetch and pairwise alignment

ls_sequence_fetch resolved sequence number 18555221 with a length of 363 aa. The fetched record was then supplied to ls_sequence_alignment for pairwise comparison with the reviewed ACKR4 sequence.

The PSA returned 1 alignment block(s). Reviewers should map mismatches to functional domains, extracellular segments, transmembrane regions, cleavage sites and engineered junctions. A concentrated change at a binding interface can matter more than a similar number of substitutions distributed across a nonfunctional region.

Antibody–antigen and patent-sequence evidence

The target-name query returned 59 antibody–antigen records. The leading record was WO2025054328A1, “Bispecific binding construct capable of binding to ACKR4, compositions comprising a bispecific binding construct capable of binding to ACKR4, and methods of using bispecific binding construct capable of binding to ACKR4”. These records support target-context review, but they can describe research antibodies, comparators, parental molecules or constructs that do not correspond to the reviewed therapeutic asset.

Using the patent identifier resolved from the leading target record, ls_patent_sequence_fetch returned 475 associated patent sequences. The listing may include antigens, antibodies, fragments, controls, primers and manufacturing elements; each sequence number must be interpreted against the specification and claims.

Target-level evidence complements sequence similarity because biologics patents often define inventions through binding, epitope, function, disease use or combinations rather than an exact full-length target sequence. The strongest review links the returned sequence to a patent family, verifies the role of the sequence in the specification, and then reads live claims in the jurisdictions relevant to development or commercialization.

Patent-risk interpretation

Diligence actions

1. Confirm the exact therapeutic or experimental construct, including isoform, truncation, signal peptide, tags, linkers and fusion partners.
2. Cluster high-ranking sequence records by patent family and earliest priority date rather than counting publications.
3. Retrieve the underlying sequence listings and confirm the biological role of each selected sequence number.
4. Map alignment differences to extracellular domains, binding interfaces, catalytic motifs and engineered junctions.
5. Search ACKR4, Atypical chemokine receptor 4 and known aliases in target, antibody, claim and assignee contexts.
6. Build jurisdiction-specific claim charts for live families and document licenses or collaboration rights.
7. Rerun the Biology Modality MCP workflow at the transaction or development decision date because database and legal-status coverage changes.

Bottom line

ACKR4 produced a traceable sequence-search result with 100.00% leading identity, 350/350 query coverage, 1 PSA block(s), 59 target-linked antibody records and 475 directly fetched patent sequences. Together, these signals support elevated diligence priority and a prioritized family-and-claim review. They do not support a binary clearance or infringement statement.

Explore PatSnap Open Platform MCP Servers to produce sequence similarity and patent-risk reports for antibodies, proteins, peptides and nucleic-acid assets.

Sources and methodology notes

Reference sequence metadata: reviewed human UniProt entry Q9NPB9. Patent-scale similarity, sequence detail, PSA, patent-sequence and antibody–antigen evidence was retrieved through PatSnap Biology Modality MCP on 7 August 2026. Results are bounded by the configured query, thresholds, aliases, task limits and database coverage; rerun at the decision date.