BACKGROUND WP1066 is an orally bioavailable, small-molecule inhibitor of activated phosphorylated STAT3 (p-STAT3) that has demonstrated preclinical efficacy in pediatric brain tumor models.METHODS In a first-in-child, single-center, single-arm 3+3 design phase I clinical trial, 10 patients were treated with WP1066 twice daily, Monday-Wednesday-Friday, for 14 days of each 28-day cycle to determine the maximum tolerated dose/maximum feasible dose of WP1066. Compassionate-use treatment with WP1066 in 3 pediatric patients with H3.3G34R/V-mutant high-grade glioma (HGG) is also described.RESULTS There was no significant toxicity, and the maximum feasible dose (MFD) was determined to be 8 mg/kg. Treatment-related adverse events were grade 1–2 (diarrhea and nausea most common); there were no dose-limiting toxicities. Median progression-free and overall survival was 1.8 months and 4.9 months, respectively. One partial response was observed in a patient with pontine glioma. Among the H3.3G34R/V-mutant HGG patients not on study, WP1066 was administered after upfront radiation to one patient for 17 months. At all dose levels tested, WP1066 suppressed p-STAT3 expression by peripheral blood mononuclear cells (PBMCs). Single-cell RNA sequencing analysis of PBMCs demonstrated increased CD4+ and CD8+ T cells, proinflammatory TNFA signaling, differentiation activity in myeloid cells, and downregulation of Tregs after WP1066 treatment, consistent with systemically inhibited STAT3 activity.CONCLUSION WP1066 is safe, has minimal toxicity, and induces antitumor immune responses in pediatric brain tumor patients. Phase II investigation of WP1066 at the MFD in this patient population is warranted.TRIAL REGISTRATION ClinicalTrials.gov NCT04334863.FUNDING CURE Childhood Cancer and Peach Bowl Inc.
Robert C. Castellino, Hope Mumme, Andrea Franson, Bing Yu, Hope Robinson, Kavita Dhodapkar, Dolly Aguilera, Matthew Schniederjan, Rohali Keesari, Zhulin He, Manoj Bhasin, Waldemar Priebe, Amy B. Heimberger, Tobey J. MacDonald
Usage data is cumulative from December 2025 through June 2026.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 3,090 | 171 |
| 518 | 41 | |
| Figure | 835 | 0 |
| Table | 305 | 0 |
| Supplemental data | 461 | 11 |
| Citation downloads | 321 | 0 |
| Totals | 5,530 | 223 |
| Total Views | 5,753 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.