onc201 and Pheochromocytoma

Tumor dopamine-like DRD2 receptor expression is higher in pheochromocytoma-paraganglioma (PC-PG) compared with other cancers. ONC201 is a bitopic DRD2 antagonist with preclinical ONC201 activity in desmoplastic small round cell tumor (DSRCT).. Patients (N = 30) with neuroendocrine tumors were treated on this investigator-initiated trial (NCT03034200). ONC201 dose and schedule were 625 mg orally weekly in cohorts A (PC-PG) + B (other neuroendocrine tumors) and 625 mg orally on 2 consecutive days each week in cohort C, which included 5 responding patients. The primary endpoint was radiographic response measured using RECIST. Secondary endpoints included progression-free survival, overall survival, and safety.. In arm A (n = 10; all PC-PG), 50% (5/10) exhibited a partial response (PR) and 2 additional patients had stable disease (SD) >3 months. Median duration of therapy for arm A patients was 9 months (range: 1.5-33 months) with 5 patients treated >1 year. In arm B (n = 12), there were 1 PR (DSRCT) and 2 SD (DSRCT; neuroblastoma) >3 months. Median duration of therapy in arm A was 18 months (range: 1-33 months) and arm B was 3 months (range: 1.5-33 months). Arm C PC-PG (N = 8) showed 1 PR and 7 SD at 3 months, with median duration of therapy >10 months. There was no decline in Karnofsky performance status at week 12 for 28 of 30 patients and no dose modification due to treatment-related adverse events.. Oral ONC201 was well tolerated in patients with metastatic neuroendocrine tumors and associated with clinical benefit, including tumor responses, particularly in some patients with DSRCT and the majority of patients with PC-PG. See related commentary by Owen and Trikalinos, p. 1748.

Topics: Adrenal Gland Neoplasms; Desmoplastic Small Round Cell Tumor; Humans; Imidazoles; Neuroendocrine Tumors; Paraganglioma; Pheochromocytoma; Pyridines; Pyrimidines

ONC201 is an oral selective antagonist of the dopamine D2 receptor and direct activator of caseinolytic protease P. In a phase II study, ONC021 was shown to be well tolerated with notable efficacy in patients with the rare neuroendocrine neoplasms pheochromocytomas-paragangliomas, although biomarkers for activity remain to be elucidated. See related article by Anderson et al., p. 1773.

Topics: Adrenal Gland Neoplasms; Desmoplastic Small Round Cell Tumor; Humans; Imidazoles; Neuroendocrine Tumors; Paraganglioma; Pheochromocytoma; Pyridines; Pyrimidines