One assignee leads the ranked list with 75 of the 111 records tracked in this dataset, well ahead of the other four ranked companies, the smallest of which holds a single record. This is a five-company ranking returned by the data endpoint, not a top-50 or top-100 view, so it should not be read as covering every filer in the field. The concentration at the top suggests a freedom-to-operate review should start with that leading assignee's portfolio before looking elsewhere.

The tracked data shows filings falling from 3 in 2021 to 0 in 2024, a -100% change over that span, and the peak year so far was 2017 at 43. However, patent publication typically lags filing by around 18 months, so the 2025-26 figures in this dataset are still incomplete and should not be read as evidence of a continued decline. A fairer read is that the field had its most active filing period around 2017 and current activity cannot yet be confirmed either way.

EP3309168B1, filed by F. Hoffmann-La Roche AG and published 2026-07-08, addresses methods for improved virus removal during protein purification — the same technical thread as the field's most-cited record, WO2011031397A1, cited 35 times for a related virus-removal method. Anyone designing a purification process with a membrane-based virus-clearance step should review this claim family specifically, since Roche's related filings account for a meaningful share of the ranked assignee activity. A full claim-by-claim comparison against your process design is the only reliable way to confirm whether a specific implementation falls inside its scope.

The clearest gap in this dataset is between claims on protein and peptide chemistry (C07K, covering all 111 records) and claims on the separation-process mechanics of the membrane itself (B01D, covering only 11.7% of records). That gap points to under-claimed territory in module geometry, ligand density engineering, and multi-modal chemistries that pair cation-exchange with other separation mechanisms. A first filing targeting the membrane-mechanics side of the process, rather than the biochemistry around it, would sit in comparatively less-crowded claim space based on this evidence.

In this dataset, Israel leads with 16 filings, followed by the European Patent Office and the United States at 13 each, then Australia at 6, and Canada and Germany at 5 each. That spread suggests filers are pursuing a mix of major biopharmaceutical markets rather than concentrating on a single jurisdiction, which is typical for a purification technology tied to global drug manufacturing supply chains.