Two Trials, Both Listed as Recruiting
NCT04951622 (registry record) is a Janssen Phase 3 study in myasthenia gravis. Its deadline for finishing primary data collection passed almost three years ago, but the record is well maintained: 63 versions, posted results, the latest change in July 2026.
NCT01185132 (registry record) is a Phase 3 breast cancer study from Rocky Mountain Cancer Centers. Its deadline passed in July 2018. The record was last edited in June 2014.
It has said "Recruiting" for twelve years without a single edit.
On ClinicalTrials.gov the two records carry the same status line, and nothing in the status itself says which trial is alive and which is abandoned.
They have plenty of company. Nearly three in ten trials currently listed as recruiting are past their own deadline: 13,517 of 47,419, or 28.5 percent (interventional trials, ClinicalTrials.gov, August 16, 2026).
The deadline in question is the primary completion date: the day the sponsor said they would finish collecting data for the trial's main question. These trials are still enrolling patients after that day came and went.
One Word Tells Them Apart
Every completion date on ClinicalTrials.gov carries a one-word tag: Estimated or Actual.
- Actual means someone came back after the milestone and recorded what happened. The Janssen trial's past date is marked Actual.
- Estimated means it is still a forecast. The Rocky Mountain trial's 2018 date is still marked Estimated. Nobody ever came back.
That tag separates the maintained records from the abandoned ones:
The Actual group is a control, not a second discovery: a past date becomes Actual only when someone edits the record after the date, so it must count zero untouched records if the tag means what it says, and it does (0 of 728). The finding is the Estimated bar.
Researchers have documented stale registry records for a decade: 24% of open-recruitment trials already listed a past completion date in 2014 (Pfiffner et al., PLOS ONE), and a 2017 audit found 31% of trials with a wrong or badly outdated status (Jones et al., BMJ Open). What those studies did not offer is a way to tell, from the record alone, which stale trials are dead. The date tag closes most of that gap, and it is on every study page already.
When a Deadline Moves, It Usually Moves Later
Deadlines still in the future deserve the same skepticism. We watched every completion-date change our pipeline caught between March 27 and August 7, 2026: about 79,000 monitored trials for most of that window, until a one-time backfill in late July extended coverage to every active trial on the registry, 150,000+ records in all. Every rate below also holds inside the constant cohort of 79,288 trials monitored for the entire window (details in the methodology note). When a date moved, it moved later three times out of four, by a typical five months:
Pushed later
Pulled earlier
The largest pushes we caught were on big Phase 3 industry programs, each still recruiting:
| Sponsor | Trial | Completion date moved | Delay |
|---|---|---|---|
| Loxo Oncology (Lilly) | NCT05254743 Pirtobrutinib vs ibrutinib, CLL |
Jun 2025 → Oct 2027 | +843 d |
| AbbVie | NCT06012240 Upadacitinib, pediatric |
Jan 2028 → Apr 2030 | +821 d |
| AstraZeneca | NCT06129864 Volrustomig (MEDI5752) |
Apr 2028 → Apr 2030 | +729 d |
| Seagen (Pfizer) | NCT05253651 Tucatinib combo, colorectal |
Apr 2026 → Dec 2027 | +637 d |
| Anthos Therapeutics | NCT05712200 Abelacimab, atrial fibrillation |
Aug 2026 → Dec 2027 | +486 d |
Each verified against the live registry record. A date change is a documented sponsor action, not evidence of a problem with the drug.
We expected Phase 3 industry trials to slip more often than everything else. They do not. Once we controlled for how long each trial had been under observation, they slip at about the same rate as the rest of the registry; the methodology note has the details.
Enrollment Targets Get Cut in Half
The second signal is quieter than a moved date. When a sponsor cuts an enrollment target, the median cut removes roughly half the planned patients.
The three warning signs (a pushed date, a cut target, a changed endpoint) rarely appear together. Our Trials at Risk scan currently counts 4,706 active trials showing at least one signal in the past 90 days, 310 showing two, and 22 showing all three; how the signals are computed and ranked is in the launch post.
It Is All in the Version History
All of this is public. The registry keeps every version of every record, but the history sits behind a tab, one trial at a time, and the study page always shows the latest version. A date that has moved three times looks identical to a date that has never moved. In July we published a correction to our launch post for wrongly claiming the registry discards old versions; this analysis is built on that same version history, and every figure in it can be re-derived from the registry's own records.
Meanwhile, the records go quiet. Among trials that say they are recruiting today, the median record has not been edited in 192 days, and three in ten have gone more than a year. "Recruiting" means the sponsor said so once, on a date you have to dig for.
How to Use This
- On a past-due record, read the date's tag first. Estimated and in the past means the record is almost certainly untouched since the date passed. Actual means someone went back and updated it.
- Check the last-update date before you trust a status. More than half of recruiting records have gone six months without one.
- Treat future dates as optimistic. When they move, three out of four times it is later, and a cut enrollment target usually loses half its patients.
See which of the trials you track are slipping
DataLookout monitors ClinicalTrials.gov every morning and flags the three signals in this post on the sponsors and diseases you follow. Every trial page shows the record's last-update date, its amendment history, and a Record status note when a record is untouched since its own past completion date. Free forever for one sponsor and one disease, no credit card.
Start monitoring freeTrials at Risk, the ranked per-trial slippage view behind this analysis, is included with Starter at $49/mo for 3 sponsors and 3 diseases. Pro $149/mo adds unlimited watchlists and CSV export.
(1) Registry-wide counts. One rule governs every past-due figure in this post: a completion date counts as past only when its entire stated period is over, so a day-precision date is past after that day and a month-precision date only after the month's last day. Under that rule, of the 47,419 recruiting interventional trials queried from the ClinicalTrials.gov v2 API on August 16, 2026, 13,517 (28.5%) are past their primary completion date; among active-not-recruiting trials the share is 58.3% (9,944 of 17,050). The partition is clean: exactly one recruiting record lacks a primary completion date, so the denominator is not inflated by records missing dates. The Actual/Estimated split (728 + 12,789, summing exactly to 13,517) uses the registry's own date-type field. The 97.0% figure (12,403 of 12,789) compares each record's last-update-posted date against its own primary completion date; a record counts as untouched only if its last update is on or before the earliest day its completion date could mean, so month-precision ambiguity counts against the finding and the figure is a floor. We verified the split two ways on August 9: 30 random draws from the estimated past-due population, each re-fetched individually (30 of 30 confirmed untouched since the date passed), and an inverse check drawing 30 recently-updated past-due recruiting trials (29 carried Actual dates, one had moved its estimated date into the future, none carried a past estimated date). The zero on the Actual side is a control, not a finding: a past date becomes Actual only through an edit made after the date, so that column tests whether the tag behaves as documented, and it does (0 of 728). Of the 386 estimated-date exceptions, 262 (68%) have dates that passed within the last twelve months and 384 (99%) within the last twenty-four. Record-staleness figures (median 192 days since update; 51.6% over six months, 30.4% over one year, 7.1% over two) cover the 47,419 trials listed as recruiting on August 16, fetched with ages measured as of August 16.
(2) Change counts. The date-change direction (74% later, 4,787 of 6,444 changes; median push 153 days; 17.0% of pushes longer than a year) and the enrollment finding (1,247 downward revisions, median cut 47% of target) come from DataLookout's own daily comparison of every tracked record (interventional and observational), March 27 to August 7, 2026. These measure movement we observed in that window, not lifetime slippage. The signal-stack figures (4,706 / 310 / 22) reflect the rolling 90-day Trials at Risk scan as of August 16, 2026.
The corpus grew mid-window, and we checked what that does to the numbers. In late July a one-time backfill roughly doubled our monitored universe, from about 79,000 trials to full coverage of every active trial on the registry (150,000+ records, including trials that finished while we watched). The added half was, by construction, the half with no recent record activity, and it entered with a suppressed baseline that produced no spurious events. The counts above therefore understate registry-wide movement. Rates are the bigger risk, so we recomputed every percentage inside the constant cohort of 79,288 trials monitored since at least June 18: the 74% pushed-later share holds exactly, the 47% median enrollment cut holds, and the median push is 140 days there against 153 overall. One claim did not survive that check. At first glance, recruiting Phase 3 industry trials had dates pushed at a higher rate than the full monitored set (5.6% of 1,707 versus 3.6% of 65,780 in the window), but industry trials were overrepresented in the half of the registry we watched longest; inside the constant cohort the rates are 7.4% versus 6.9%, computed over recruiting trials only, so we do not claim late-stage trials slip more. These figures are also not comparable to our June 7 launch post (2,443 flagged, 254 enrollment cuts): smaller corpus, shorter window, and several change-detection fixes since.
On sponsor obligations. Under 42 CFR 11.64, registration information generally must be updated once every 12 months; recruitment-status changes require updates within 30 days, but a primary completion date requires a 30-day correction only once the trial has actually completed. A past-due estimate is therefore consistent with the rules, which is part of why so many exist.
Known limitation. The extreme tail of completion-date pushes contains sponsor data-entry errors; the single largest push we recorded moved a date to the year 2050. All push statistics in this post are medians and percentiles for that reason. The named examples were individually verified against the live registry record (the delay table and the two opening trials, including their version counts of 63 and 6, on August 16, 2026). The timeline diagram shows each record's first-posted date, last-edit date, and stated primary completion date, all from the live registry. Registry-wide counts are current as of August 16, 2026 and will drift.
External sources cited: Jones CW, Safferman MR, Adams AC, Platts-Mills TF. Discrepancies between ClinicalTrials.gov recruitment status and actual trial status: a cross-sectional analysis. BMJ Open 2017;7(10):e017719 (BMJ Open); Pfiffner PB, Oh J, Miller TA, Mandl KD. ClinicalTrials.gov as a Data Source for Semi-Automated Point-Of-Care Trial Eligibility Screening. PLOS ONE 2014;9(10):e111055 (PLOS ONE).
Prior work: our Trials at Risk launch post describes how the three slippage signals are computed and ranked.