First-in-Human Clinical Trial of Oral ONC201 in Patients with Refractory Solid Tumors

Clin Cancer Res. 2017 Aug 1;23(15):4163-4169. doi: 10.1158/1078-0432.CCR-16-2658. Epub 2017 Mar 22.


Purpose: ONC201 is a small-molecule selective antagonist of the G protein-coupled receptor DRD2 that is the founding member of the imipridone class of compounds. A first-in-human phase I study of ONC201 was conducted to determine its recommended phase II dose (RP2D).Experimental Design: This open-label study treated 10 patients during dose escalation with histologically confirmed advanced solid tumors. Patients received ONC201 orally once every 3 weeks, defined as one cycle, at doses from 125 to 625 mg using an accelerated titration design. An additional 18 patients were treated at the RP2D in an expansion phase to collect additional safety, pharmacokinetic, and pharmacodynamic information.Results: No grade >1 drug-related adverse events occurred, and the RP2D was defined as 625 mg. Pharmacokinetic analysis revealed a Cmax of 1.5 to 7.5 μg/mL (∼3.9-19.4 μmol/L), mean half-life of 11.3 hours, and mean AUC of 37.7 h·μg/L. Pharmacodynamic assays demonstrated induction of caspase-cleaved keratin 18 and prolactin as serum biomarkers of apoptosis and DRD2 antagonism, respectively. No objective responses by RECIST were achieved; however, radiographic regression of several individual metastatic lesions was observed along with prolonged stable disease (>9 cycles) in prostate and endometrial cancer patients.Conclusions: ONC201 is a selective DRD2 antagonist that is well tolerated, achieves micromolar plasma concentrations, and is biologically active in advanced cancer patients when orally administered at 625 mg every 3 weeks. Clin Cancer Res; 23(15); 4163-9. ©2017 AACR.

Publication types

  • Clinical Trial, Phase I

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / blood
  • Dose-Response Relationship, Drug
  • Female
  • Heterocyclic Compounds, 4 or More Rings / administration & dosage*
  • Heterocyclic Compounds, 4 or More Rings / adverse effects
  • Heterocyclic Compounds, 4 or More Rings / blood
  • Humans
  • Imidazoles
  • Male
  • Middle Aged
  • Neoplasms / blood
  • Neoplasms / drug therapy*
  • Neoplasms / genetics
  • Neoplasms / pathology
  • Pyridines
  • Pyrimidines
  • Receptors, Dopamine D2 / genetics*
  • Treatment Outcome


  • Antineoplastic Agents
  • DRD2 protein, human
  • Heterocyclic Compounds, 4 or More Rings
  • Imidazoles
  • Pyridines
  • Pyrimidines
  • Receptors, Dopamine D2
  • TIC10 compound