CD55 Biologics Sequence Review Report 2026: Complement decay-accelerating factor Similarity and Patent-Risk Signals

This CD55 Biologics Sequence Review Report was produced with PatSnap Biology Modality MCP. The workflow connects patent-scale sequence searching, result retrieval, full-sequence inspection, pairwise alignment and target-linked patent evidence in one reproducible screen. Explore the PatSnap MCP servers used in this report.

Review date: 4 August 2026. The query is the reviewed human Complement decay-accelerating factor reference sequence, UniProt accession P08174, with a length of 381 amino acids. This report is an R&D and IP-triage resource, not a legal opinion, freedom-to-operate conclusion, infringement analysis or validity assessment.

Executive sequence-risk thesis

CD55 is a immune or complement protein topic centered on Complement decay-accelerating factor. The ALLPATENT protein search returned 20 records within the configured task window. The selected review hit reached 100.00% query identity, 381/381 query coverage and 381/975 subject coverage; its database-level claimed flag was Yes.

The resulting screening position is elevated diligence priority, not “blocked” or “clear.” A high-identity record may reproduce a natural reference protein, an antigen construct, a diagnostic reagent, a control, an expression cassette or a therapeutic component. Conversely, relevant claims may cover variants, fragments, binding regions or percentage-identity genera without reproducing the complete reference sequence. Sequence similarity is therefore a prioritization signal that directs family and claim review.

How the Biology Modality MCP workflow was run

The reference protein was submitted with ls_sequence_search_submit as a PROTEIN-to-PROTEIN query against ALLPATENT, with gaps enabled, E-value at or below 0.001, identity from 30% to 100%, query coverage from 30% to 100% and a 20-record task limit. After status completion, ls_sequence_search_get_results retrieved the ranked evidence. The selected sequence number was resolved with ls_sequence_fetch, and ls_sequence_alignment ran a PSA comparison against the query.

Target context was tested with ls_antibody_antigen_search using both the gene symbol and recommended protein name when needed. When that step returned a target-linked patent number, ls_patent_sequence_fetch retrieved the corresponding patent sequence bundle. The six-tool design separates raw sequence proximity from target annotation and patent-document context, while preserving gaps when a direct target-linked record is unavailable.

Similarity search readout

The selected subject sequence was 29722881, with a reported length of 975 amino acids, score 785 and E-value 0. The comparison contained 0/381 gaps and mapped query positions 1–381 to subject positions 368–748. The returned organism annotation was synthetic construct.

Search totals are records, not unique inventions, families or enforceable claims. The same sequence can be repeated across jurisdictions, continuations, examples and reference sections. A useful next step is to consolidate results by earliest priority, simple family, applicant and legal status, then distinguish sequences appearing in claims from those disclosed only in descriptions or sequence listings.

Sequence fetch and pairwise alignment

ls_sequence_fetch resolved the selected record as sequence 29722881, with a stored length of 975 amino acids. Associated gene annotation was not specified, and the record was not marked as an antibody.

The PSA output aligned query positions 1–381 with target positions 368–748. This coordinate-level view is more useful than a percentage alone because it shows whether similarity spans the full reference, a domain, a signal peptide, a transmembrane region or another localized segment.

For diligence, mismatches and gaps should be mapped to functional domains, extracellular versus intracellular regions, cleavage sites, ligand-binding surfaces and construct boundaries. A complete natural-protein match can be highly relevant to antigen and replacement-protein patents, but its meaning differs from a partial intracellular-domain match or a short conserved motif. Domain context should therefore be reviewed before ranking families.

Antibody–antigen and patent-sequence evidence

Neither the gene symbol nor the recommended protein name produced a direct antibody–antigen record in the configured exact-name pass. This is a bounded no-hit result. Synonyms, legacy target names, therapeutic codes and antigen-domain names can be indexed differently, so the absence of a direct record should be treated as an evidence gap rather than a negative biological conclusion.

The antibody–antigen step did not return a target-linked patent number that could support a defensible ls_patent_sequence_fetch request. The report therefore records a patent-bundle coverage gap instead of filling the section with an unrelated document. That gap does not indicate freedom to operate; it means alias, family, applicant and claim searches remain necessary.

What the claimed flag does—and does not—show

A “Yes” claimed flag raises review priority, but it is not a claim chart. The annotation must be checked against the filed document, the exact SEQ ID, the relevant independent and dependent claims, prosecution history and current legal status. Claims may be abandoned, narrowed, expired, territorially limited or directed to uses and combinations that do not read on a proposed asset.

A “No” or unspecified flag is equally not a clearance result. A family can claim a broader genus, a fragment, a functional binding property, a nucleic acid, a vector, a host cell, a method of treatment or a combination without labeling the exact protein sequence as claimed. The safest interpretation is to use the flag to order document review, never as a substitute for legal analysis.

Patent-risk interpretation

Recommended diligence actions

1. Confirm the exact protein, isoform, mature chain, engineered variant and construct boundaries intended for development.
2. Repeat searches for functional domains, extracellular regions, cleavage products and nucleic-acid sequences where relevant.
3. Cluster high-similarity records by simple family, earliest priority, applicant, inventor and jurisdiction.
4. Retrieve the source documents and verify every important sequence ID against the claims and sequence listing.
5. Review live independent and dependent claims for sequence, identity-threshold, functional, use, combination and manufacturing scope.
6. Record licenses, collaborations, platform rights and prosecution events that can change practical exposure.
7. Rerun the Biology Modality workflow at each transaction or development decision date because database and legal-status coverage changes.

Bottom line

CD55 produced a traceable patent-scale similarity signal: 100.00% closest reviewed query identity, 381/381 query coverage, a Yes claimed annotation, 0 antibody–antigen records and 0 directly fetched target-linked patent sequences. Together these support elevated diligence priority. The defensible output is a prioritized, domain-aware patent-family and claim review—not a binary clearance 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 P08174. Patent-scale similarity, sequence-detail, PSA, patent-sequence and antibody–antigen evidence was retrieved through PatSnap Biology Modality MCP on 4 August 2026. Results are bounded by the configured query, thresholds, aliases, task limits and database coverage; rerun at the decision date.