JZP3507

Dordaviprone (ONC201) and its chemical derivative with nanomolar potency, ONC206, induce apoptosis of cancer cells by activation of the mitochondrial caseinolytic protease P (ClpP). We also saw that ONC206 very significantly prolonged survival of medulloblastoma-bearing mice, both in genetically engineered mouse models and patient-derived xenografts. Our study provides a strong rationale for testing the efficacy of ONC206 in the treatment of patients with medulloblastoma and has set the stage for a clinical trial with this agent in pediatric patients with recurrent malignant brain tumors, including medulloblastoma ( NCT04732065 ).

This work offers a biologically-informed, clinically translatable strategy integrating small molecule therapeutics with CAR T cell therapy and support the development of multi-agent immunotherapy trials for children with DIPG and other high-grade brain and spinal cord tumors. B7-H3 CAR T cells are cytotoxic against preclinical DMG models.ONC206 causes metabolic apoptosis in preclinical DMG models.B7-H3 CAR T cells and ONC206 have combinatorial efficacy against DMG.

sNK cell-mediated cytotoxicity against K27M was significantly increased when sNK cells were combined with ONC201 and ONC206. This study suggests the potential use of sNK cells alone or in combination with ONC201 or ONC206 as therapeutic strategies in treating and preventing the recurrence of aggressive pediatric brain tumors.

Small molecule imipridones including ONC201, ONC206 and ONC212 have anti-cancer activity mediated in part through the integrated stress response, induction of TRAIL and its receptor DR5, and activation of mitochondrial caseinolytic protease ClpP with impaired oxidative phosphorylation...RNA-seq showed ONC201 and EHZ2i tazemetostat-treated cells have similar transcriptional profiles and share overlap of top regulated genes...ONC201 and EZH2i share similar targets and actions on tumors. Synergistic combinations of imipridones plus EZH1/2i or imipridones, EZH2i and HDACi merit further investigation.

P1, N=102, Recruiting, Chimerix | Trial completion date: Feb 2025 --> Dec 2026 | Trial primary completion date: Sep 2024 --> Dec 2025

The results suggest that treatment of castrate-resistant prostate cancer by imipridones may not be substantially affected by neuroendocrine differentiation as a therapy-resistance mechanism. The results support further testing of imipridones across subtypes of androgen-sensitive and castrate-resistant prostate cancer.

Androgen receptor (AR) signaling is a target in prostate cancer therapy and can be treated with non-steroidal anti-androgens (NSAA) including enzalutamide, and apalutamide for patients with advanced disease. ONC201 and darolutamide demonstrated anti-tumor effects in vivo in the 22RV1 CRPC model. Our results prompt further translational and clinical studies with imipridones ONC201 or ONC206 in combination with enzalutamide or darolutamide for treatment of castrate resistant advanced or metastatic prostate cancer.

The results support the idea that treatment of castrate-resistant prostate cancer by imipridones may not be significantly impacted by neuroendocrine differentiation as a therapy-resistance mechanism. The results support further testing of imipridones across subtypes of androgen-sensitive and castrate-resistant prostate cancer.

The imipridones ONC201 and ONC206 induce mitochondrial dysfunction and have emerged as promising therapies for DMG patients. Clinical translation of our studies has the potential to enable precision metabolic therapy and imaging for DMG patients. Imipridones induce GABA accumulation in diffuse midline gliomas, an effect that can be leveraged for therapy and non-invasive imaging.

The mechanism of impairment of ONC201/206/212 effect caused by dopamine pre-treatment appears to involve upregulation of anti-apoptotic p-Bad, XIAP, FLIP and pAkt. Our results shed light on mechanisms of cancer cell protection by dopamine after imipridone treatment, heterogeneity among different tumor cell types, and suggest that effects of dopamine adaptation on tumor cells may impact on cell survival pathways in ways that may or may not depend on expression of dopamine receptors.

ONC201, ONC206, and ONC212 are imipridones showing pro-apoptotic anti-cancer response...Additionally, pediatric solid tumor cells were treated with single-agent therapy with histone deacetylase inhibitors (HDACi) vorinostat, entinostat, and panobinostat, showing cell killing with all 3 HDACi drugs, with panobinostat showing the greatest potency...Our results introduce a novel class of small molecules to treat pediatric solid tumors in a precision medicine framework. Use of impridones in pediatric oncology is novel and shows promising pre-clinical efficacy in pediatric solid tumors, including in combination with HDAC inhibitors.

P1, N=256, Recruiting, Sabine Mueller, MD, PhD | Trial completion date: Dec 2025 --> Dec 2027 | Trial primary completion date: Jan 2024 --> Jan 2026