TP53 Y220C

Findings from a phase I study show that the p53 reactivator rezatapopt is safe and can elicit responses in patients with a range of solid tumors containing the Y220C mutation. Although the drug was ineffective in tumors with KRAS mutations, and whether the strategy can be applied to more common missense mutations remains unclear, the findings offer proof of concept for p53 reactivation.

The Y220N mutant, despite exhibiting high-nanomolar affinity for rezatapopt and substantial stabilization, did not show noticeable effects in cells at the concentrations tested, as rezatapopt binding resulted in only partial compensation for the mutation-induced loss of stability, for which we provide a structural explanation. Our data suggest that the development of clinical pan-Y220C/N/S reactivators, which could benefit an additional 10,000 patients per year, is challenging but not impossible.

In this phase 1 study involving heavily pretreated patients, the most common adverse events associated with rezatapopt were nausea and vomiting. Antitumor activity occurred across multiple tumor types, providing proof of concept for p53 reactivation. (Funded by PMV Pharmaceuticals; PYNNACLE ClinicalTrials.gov number, NCT04585750.).

P1, N=14, Not yet recruiting, PMV Pharmaceuticals, Inc

In conclusion, p53 expression is heterogeneous in EC with TP53 missense mutations; gene-protein discordance correlates with distinct clinicopathological features. Integrating genetic and protein detection results is recommended for risk stratification and individualized treatment.

Targeted therapy with avapritinib and ruxolitinib was initiated but yielded limited response. Given the consistent co-occurrence of KIT mutations in previously reported similar cases, we propose the recognition of a distinct disease entity: ovarian germ cell tumor/mastocytosis with KIT mutations. This report emphasizes the importance of early genetic profiling and multidisciplinary collaboration in diagnosing and managing rare, genetically unified malignancies in pediatric oncology.

This triple allosteric framework underscores the regulatory regions' critical role in restoring p53 functionality. By providing a first-order exploration into the behavior of full-length p53, this study advances our understanding of its regulatory mechanisms and sets the stage for developing targeted therapies aimed at reactivating mutant p53 in cancer.

Functional modeling confirmed these double mutants eliminate p53 reactivation and target gene induction by rezatapopt. These findings establish a molecular framework for resistance to p53 Y220C reactivators and inform strategies to overcome resistance with next-generation agents.

Clinical proteomic analysis of platinum-resistant ovarian cancer tissues reveals tumor-specific factors and acquired resistance pathways linked to p53 mutations. Our findings elucidate the multilayered regulatory landscape of p53 mutations and identify potential risk factors for platinum resistance associated with these mutations.

This work establishes a mechanistic foundation for rational stabilizer design, proposing a new strategy centered on allosteric network restoration and mutation-adaptable anchoring. It offers broader implications for targeting conformationally unstable transcription factors previously considered "undruggable".

Our results demonstrated the viability of the DUBTAC strategy for p53 Y220C, successfully re-establishing conformation and promoting deubiquitination. More importantly, this study provides the first proof-of-concept for DUBTAC application in vivo, establishing targeted deubiquitination as a therapeutic approach.

Our findings position JC16 and JC36 as early-stage chemical leads with potential to restore mutant p53 function in a context-dependent manner. While their exact mechanism of action remains to be fully elucidated, these results provide a foundation for further development of indazole-based scaffolds as reactivators of the p53-Y220C mutant in cancer therapy.