Degraders, particularly bifunctional molecules, routinely exceed classical rule-of-five limits on molecular weight and polar surface area, which caps oral bioavailability regardless of how potent the binding is. That has pushed a large share of recent claim activity toward molecular weight penalty, metabolic stability and formulation-enabling technology rather than target engagement alone. In this dataset, 79.9% of the 3,016 records in scope touch A61K medicinal-preparation claims, which is where much of this formulation and exposure work is captured.

The ranked assignee list returns 100 companies, with the leader holding 299 of the 3,016 records in scope and a fifth-place holder at 121. The top five assignees combined account for 981 records, or 32.5% of all records, showing real concentration at the top even though the ranking itself covers a broad set of academic, mid-cap and large-pharma filers. Individual identities and their exact standings are best read directly from the ranking table rather than summarised here, since positions shift as new records publish.

Filings fell from 153 in 2021 to 129 in 2024, a 16% decline over the most recent three-year span that can be treated as complete. That is a real pullback but not a collapse, and it should not be read from 2025 or 2026 figures, since publication typically lags filing by about 18 months and those years are still filling in. The more informative signal is that several previously dominant assignees show zero filings in the latest tracked year, which is consistent with portfolio consolidation around established chemotypes.

The composition data shows A61K and C07D carrying the bulk of claim density, at 79.9% and 61.2% of the 3,016 records respectively, while C07F organo-metallic chemistry sits at 10.1% and C07K peptide-based claims at just 5.7%. Those lower-density subclasses are where structurally distinct approaches to PK mitigation, such as organo-metallic warhead linkers or peptide-based scaffolds, are less likely to run into dense prior art. A first claim there would need to tie the structural novelty directly to a specific PK outcome, such as reduced efflux liability, to differentiate from the dominant small-molecule chemotypes.

Citation counts in this corpus favour older filings simply because they have had more time to accumulate citations, so the most-cited records skew toward filings from the earlier part of the 2015-2026 window. They are a reasonable signal of which claims shaped later drafting in the field, but a poor proxy for which technology is most commercially relevant today. For current relevance, filing recency, assignee momentum and IPC composition are more useful than citation rank alone.