What specific pediatric and rare‑cancer NIH‑funded trials were reported by academic medical centers to have been paused or closed in 2025?
Executive summary
Academic medical centers reported that multiple NIH‑funded pediatric and rare‑cancer trials were paused or closed in 2025, most visibly those run through pediatric brain‑tumor networks: the Pediatric Brain Tumor Consortium (PBTC) paused new enrollments in several trials and lost NCI support, and individual centers such as Toronto’s SickKids halted enrollment in at least three brain‑cancer studies, including vaccine and CAR‑T programs [1] [2]. Reporting also identifies a specific early‑phase trial — a phase 1 autologous HER2‑specific CAR T cell trial for children with ependymoma — among studies that were halted while broader counts of terminated grants range into the hundreds [3] [4].
1. What academic centers and consortia publicly reported pausing trials
Major academic reporting and consortium statements show the Pediatric Brain Tumor Consortium announced it would pause new enrollments across several studies after the NCI informed the group its approximately $4 million annual grant would expire, a move described in memos circulated to sites and reported by The Globe and Mail and advocacy outlets [1] [2]. PBS and other outlets corroborated that pediatric trial networks paused enrollment in ongoing clinical trials, citing clinicians and parent advocates at U.S. children’s hospitals [5] [6].
2. The specific trials named in reporting
Available reporting names a small set of concrete trials affected: Toronto’s SickKids halted enrollment in three trials for incurable pediatric brain tumours, specifically including a cancer‑fighting vaccine trial and a CAR‑T therapy trial, and SickKids and other sites were also preparing to open three additional brain‑cancer trials that were paused [1]. Separately, a phase 1 trial of autologous HER2‑specific CAR T cells in children with ependymoma was explicitly cited among eight studies that “came to a grinding halt” in coverage summarizing terminated grants [3].
3. How networks and international sites were impacted
Reporting documents that the Pediatric Early Phase‑Clinical Trial Network (PEP‑CTN), the network slated to inherit some trials, closed enrollment to international sites as of July 31 and placed non‑U.S. enrolment on hold — a change that directly blocked Canadian children from entering certain U.S.‑led pediatric trials and led centers like SickKids to pause or close access for Canadian patients [1] [7]. PBS and CBC interviews emphasized that families and clinicians experienced immediate loss of available trial slots because of these network and funding shifts [5] [7].
4. The bigger numerical picture reported by academic investigators
Academic analyses and media reporting broaden the picture: a Harvard Medical School analysis described termination of grants for 383 clinical trials affecting more than 74,000 participants, and other outlets summarized that hundreds of NIH grants and thousands of proposals were disrupted by 2025 policy and budget actions — placing pediatric and rare‑disease trials among many affected fields [3] [4] [8]. These counts are aggregate and include adult and non‑oncology studies as well, while pediatric brain‑tumor networks figure prominently in qualitative reporting [3] [8].
5. Limits of the public record and competing narratives
The reporting names some trials and networks but does not provide a comprehensive, line‑by‑line public list of every paused or closed NIH‑funded pediatric or rare‑cancer trial in 2025; sources make clear that many actions were communicated via internal memos to sites and that national networks shifted trials between consortia [1] [2]. Advocacy coverage frames the freezes as catastrophic for rare and pediatric cancers because industry less often funds these studies, while government and federal briefings emphasize reassignment of trials to other networks and procedural reviews — an implicit tension over whether pauses represent temporary transition or long‑term closure [9] [2].