WhichTrial Monthly Report · Issue 5

The US Clinical Trial Recruiting Pipeline

August 2026 → September 2026. One month of movement, and a continuity check on the drugs we've been tracking.

Published September 17, 2026 · Data through 2026-09 · By WhichTrial

The numbers at a glance

12,227

drugs in active recruiting trials (September 2026)

10,767

of 30,649 recruiting trials have a US site

441

drugs exited recruiting since August

560

drugs entered recruiting since August

One month of change. The recruiting pipeline grew by 119 drugs on net. 315 drugs picked up additional recruiting trials, 235 lost ground but kept at least one open study, and 11,117 held flat. Nothing broke out on size: the largest single move was Dexamethasone at plus seven, and it is not a story about dexamethasone. Nine of its twelve newly observed trials are multiple myeloma studies, and five more of the top 15 gainers are myeloma regimen components (Pomalidomide, Lenalidomide, Daratumumab, Teclistamab, and daratumumab with hyaluronidase). A batch of new myeloma studies opened, and the backbone drugs they share all moved together. The month's real news is in the continuity check below, where three of Issue 4's calls held and four reversed.

A note on scope. We track every trial recruiting worldwide for these 17 conditions, but we only record trial sites located in the United States. Of the 30,649 trials recruiting for these conditions right now, 10,767 have at least one US site you could enroll at. The remaining 19,882 are running entirely outside the US. Drug-level counts throughout this report are worldwide unless stated otherwise; where a drug's US footprint differs sharply from its worldwide one, we say so.

Top gainers

Drugs that added the most recruiting trials between August and September. Over a single month the moves at the top of this list are small by nature, a few trials each. Pembrolizumab, highlighted below, is one of the drugs in this month's continuity check.

DrugAugSepΔ trialsSponsors
Dexamethasone156163+7102
Pembrolizumab413418+5231
Pomalidomide3135+426
Cytarabine8285+341
Lenalidomide8083+360
Irinotecan7376+365
Daratumumab4649+338
Teclistamab2326+319
Balstilimab1720+316
5-FU1518+316
Botensilimab1316+313
Elecoglipron58+31
Efimosfermin alfa36+31
Daratumumab and Recombinant Human Hyaluronidase14+33
Bevacizumab205207+2130

Top losers

Drugs that lost the most recruiting trials but still have at least one study open. A drop here means trials have moved out of the recruiting phase. They either completed enrollment, were terminated, or moved to active-not-recruiting status.

DrugAugSepΔ trialsSponsors
Venetoclax180175-598
Durvalumab114109-579
Capecitabine168164-4100
Rituximab129125-481
Fulvestrant6157-441
Ribociclib3632-423
Iberdomide1612-411
Enzalutamide5148-338
Letrozole4845-333
Palbociclib4037-330
Ruxolitinib3734-323
Empagliflozin1714-39
SI-B003107-31
OH2 injection52-31
Cyclophosphamide342340-2147

Spotlight · Continuity check

Three calls held, four went the other way

Issue 4 made seven calls that this month's snapshot can check. Three held and four moved against us, and the four broke the same way: drugs we described as shrinking or finished stopped shrinking.

Pumitamig held, and it was the specific call we staked out. Issue 4 said that if the sponsor count stayed at two while trials kept climbing, this was two companies pushing one asset rather than broad adoption. Sponsors are still exactly two. Recruiting trials went from 21 to 23 across 33 conditions, with Bristol-Myers Squibb running 13 and BioNTech 10. The additions are at the early end: phase 1/2 went from nine to ten and one new phase 1 appeared, leaving the registrational count (phase 3 plus phase 2/3) unchanged at seven. Twenty of the 23 have a US site, up from 18.

The narrowing we flagged for Pembrolizumab stopped. Its condition count had fallen in every snapshot we have taken, 851 to 833 to 820 to 790 to 784. This month it rose to 807, with trials up 413 to 418 and sponsors up 227 to 231. Nivolumab moved the same way on a smaller scale. Its trial count ticked up to 161 after five straight declines had taken it from 176 to 159, though its condition count kept falling, 519 to 512. One month of data is not a trend. It does mean Issue 4's read that both checkpoint-inhibitor backbones were contracting no longer stands without qualification.

Sacituzumab tirumotecan was the clean miss. Issue 4 called it a finished story until something changed, on the strength of three identical snapshots at 22 trials. It went to 24 trials, picked up a sixth sponsor, and widened from 31 conditions to 35.

In the GLP-1 class, Tirzepatide reversed the narrowing we noted, with conditions back from 67 to 71 while trials held at 36. Semaglutide sat still at 27 trials and lost a sponsor, 21 to 20, its lowest in six snapshots. The class is not where this month's movement is.

The other two holds were quiet. BL-B01D1 added one trial, 31 to 32, and still has exactly one with a US site, with Sichuan Baili Pharmaceutical running 30 of the 32. Ivonescimab did not move on any count: 36 trials, 23 sponsors, 73 conditions.

The call for Issue 6. Elecoglipron has gone from one trial in June to five, then five, then eight. All eight are phase 3, all eight are sponsored by AstraZeneca, seven have a US site, and three appeared in this run. If the trial count keeps climbing while the sponsor count stays at one, that is a single-company registrational program running well ahead of its visibility.

DrugTrials (Jul → Aug → Sep)With US site (Sep)Sponsors (Aug → Sep)
PumitamigIssue 4 spotlight; still 2 sponsors17 2123 (+2)20 of 2322
BL-B01D1Issue 4 contrast; 1 US-sited trial26 3132 (+1)1 of 3233
IvonescimabIssue 4: June → July riser that had stopped35 3636 (0)18 of 362323
Tirzepatiderecurring GLP-1 class leader37 3636 (0)22 of 363233
Semaglutiderecurring GLP-1 class leader29 2727 (0)14 of 272120
Retatrutiderecurring GLP-1 / triple-agonist class leader2 11 (0)1 of 111
Pembrolizumabrecurring PD-1 leader; in this month's top gainers412 413418 (+5)323 of 418227231
Nivolumabrecurring PD-1 leader163 159161 (+2)117 of 1619696
Sacituzumab tirumotecanTROP2 ADC watch22 2224 (+2)19 of 2456

Drugs that left recruiting

441 drugs that had at least one recruiting trial in August no longer do in September. Over a one-month window these are typically long-tail compounds with one or two trials that wrapped enrollment.

New entrants

560 drugs began recruiting between August and September that hadn't previously appeared in our snapshot. As usual, most are early-phase, single-sponsor studies, the first signals of new programs.

Who is actually running the trials

Since Issue 4 we have tracked which organization leads each trial. The ranking below is the current picture.

2,472 organizations are running the 10,767 trials recruiting at US sites. The 10 largest run 19% of everything open, while 1,664 organizations, 67% of all sponsors, are running exactly one trial each.

The percentage below is how much of an organization's work sits in its single biggest condition, which separates the specialists from the generalists. Conditions overlap, so a trial can count toward more than one and the percentages do not sum to 100 across a row.

These are lead sponsors only. ClinicalTrials.gov records one lead sponsor per trial and does not let us count collaborators, so every figure here understates how involved an organization really is. The full rankings cover the top 25 and how the whole field is distributed.

What changed since August

Issue 4 said this issue would carry month-over-month sponsor figures, so here they are, counted in US-sited recruiting trials. 2,472 organizations have at least one, up from 2,468. 245 ran more US trials than in August and 237 ran fewer, while 105 appear for the first time and 101 dropped to none. Both lists below are dominated by academic medical centers, which is what you would expect when they run most of the trials. The exception is on the rising side: GlaxoSmithKline added six US trials and AstraZeneca four, and no pharma company is among the ten biggest fallers.

Biggest risers

OrganizationUS trials (Aug → Sep)
Dana-Farber Cancer Institute9299 (+7)
GlaxoSmithKline3339 (+6)
University of Texas Southwestern Medical Center6974 (+5)
AstraZeneca113117 (+4)
Medical College of Wisconsin4347 (+4)
Ohio State University2630 (+4)
Cerenome04 (+4)
Johns Hopkins University7780 (+3)
University of Washington6164 (+3)
Northwestern University5760 (+3)

Biggest fallers

OrganizationUS trials (Aug → Sep)
Mayo Clinic297290 (-7)
University of Pennsylvania5447 (-7)
Virginia Commonwealth University3124 (-7)
University of Colorado, Denver108102 (-6)
Cedars-Sinai Medical Center4034 (-6)
Wake Forest University Health Sciences7469 (-5)
University of Florida6964 (-5)
Abramson Cancer Center at Penn Medicine6459 (-5)
University of North Carolina, Chapel Hill2823 (-5)
Brigham and Women's Hospital6258 (-4)

A fall here does not mean an organization stopped work. A trial leaves this count when it finishes enrolling, which is the normal end of a successful study, and large centers cycle studies in and out every month.

About this report

Data source. All figures are derived from the public ClinicalTrials.gov registry, queried monthly across 17 condition categories.

Worldwide trials, US sites. Our query is not restricted by country, so the trial counts here cover everything recruiting for these conditions anywhere in the world. We only store site locations that are in the United States, across ~50 metro areas. A trial therefore counts toward our totals whether or not you could enroll in it domestically, and 10,767 of 30,649 currently have a US site. Issues 1 through 3 reported the worldwide figure under a US heading without drawing this distinction; the numbers in those issues were correct as worldwide counts, but the label was not. The condition and city pages elsewhere on this site have always filtered to trials with a US site.

A note on the window. This issue compares consecutive months (August → September), the same one-month cadence as Issues 2 through 4. Deltas over a single month are naturally smaller than the two-month window Issue 1 covered, so read the magnitudes here against that shorter window.

What “recruiting” means. A trial is recruiting when ClinicalTrials.gov flags its overall status as RECRUITING. When a trial no longer appears in our monthly fetch, we mark it as “not recruiting”. It may have completed enrollment, been suspended, terminated, or moved to active-not-recruiting status. We don't distinguish between those states in the aggregates above.

What “exited” means. A drug exited recruiting if it had at least one trial flagged RECRUITING in August 2026 and has zero such trials in September 2026. The drug itself isn't gone. Its open trial pipeline is.

Limitations. Our extraction filters out generic terms (placebo, chemotherapy, radiation, saline) and intervention names longer than 60 characters, so very long trial-arm descriptions aren't counted as drugs. Some drugs appear under multiple aliases; we deduplicate where we can.