PEG in the Clinic: Registered Trials of PEGylated Drugs, LNPs and ADCs

Registered studies by start year, 2005 to 2026

Phase, sponsor and status

Phase counts cover studies with a start year from 2021 to 2025. A study listed as Phase 1/Phase 2 is counted under Phase 1 or 1/2; Phase 2/Phase 3 under Phase 2/3 or 3.

Method

We downloaded every study record matching three fixed search terms from the ClinicalTrials.gov API v2 (https://clinicaltrials.gov/api/v2/studies, parameter query.term; data timestamp 2026-11-12T10:00:05), then counted studies by start year, phase, overall status and lead sponsor class. Queries, exactly as sent:

• PEGylated: PEGylated (1,506 studies)
• LNP: "lipid nanoparticle" OR "lipid nanoparticles" OR LNP OR LNPs (191 studies)
• ADC: "antibody-drug conjugate" OR "antibody-drug conjugates" (1,004 studies)

The term search matches the whole study record, including titles, descriptions, interventions and eligibility text. 21 studies match both the PEGylated and ADC terms; the LNP set does not overlap the other two.

How accurate are keyword counts?

We checked a random sample of 20 studies from each set by hand (random seed 20261112; the sampled study IDs and verdicts are at the end of the CSV). A PEGylated product, an LNP or an ADC was the studied intervention in 16 of 20 PEGylated studies, 18 of 20 LNP studies and 18 of 20 ADC studies. The misses mention the term elsewhere, for example in eligibility criteria or as an earlier drug, or use a different technology (solid lipid nanoparticles, a lipid nanoemulsion). As a second test we counted only studies whose intervention names match a strict list of terms. The trend direction is the same: PEGylated 50 in 2015 to 25 in 2025, ADC 14 to 59, LNP 0 to 11. The strict counts are lower because many investigational drugs are listed only by code name.

Counted by the names of approved PEGylated drugs listed as interventions, studies starting in 2015 and 2025 fell from 198 to 156. This count uses the registry's intervention search (query.intr) with these names joined by OR: peginterferon OR pegfilgrastim OR pegaspargase OR "certolizumab pegol" OR pegloticase OR pegvisomant OR pegvaliase OR pegcetacoplan OR "avacincaptad pegol" OR ropeginterferon OR eflapegrastim OR "calaspargase pegol" OR lonapegsomatropin OR palopegteriparatide OR navepegritide OR pegunigalsidase OR elapegademase OR "methoxy polyethylene glycol-epoetin beta" OR naloxegol OR pegaptanib OR peginesatide OR "liposomal doxorubicin" OR "pegylated liposomal doxorubicin" OR zilucoplan OR pegzilarginase OR "rurioctocog alfa pegol" OR "damoctocog alfa pegol" OR "turoctocog alfa pegol" OR "nonacog beta pegol" (server-side counts, data timestamp 2026-11-13T10:00:06).

Limits

• Start dates for studies that have not begun are anticipated dates and can change; the 2026 figures will rise as studies register.
• 15 records have no start date and are left out of the year counts; studies starting before 2005 or after 2026 are in the totals but not in the chart.
• ClinicalTrials.gov is a US registry with worldwide coverage, but not every study worldwide is registered there.
• The registry search engine expands terms with its own synonyms, so counts can change slightly if the registry updates its search.

Sources

• U.S. National Library of Medicine, ClinicalTrials.gov API v2, clinicaltrials.gov/data-api/api, retrieved 12 Nov 2026 (data timestamp 2026-11-12T10:00:05).

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