This phase I trial studies the long-term side effects of the continuation of oral ONC201 in treating patients with solid tumors that have spread to other places in the body who have previously benefited from receiving this drug. Oral ONC201 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.

PRIMARY OBJECTIVES:

I. To evaluate the long-term safety and tolerability of ONC201 (oral ONC201) administered orally in patients with advanced cancers.

SECONDARY OBJECTIVES:

I. To characterize pharmacokinetics of ONC201. II. To assess serum biomarkers of therapeutic response to ONC201. III. To assess preliminary antitumor activity of ONC201 as a single agent in advanced solid tumors.

OUTLINE:

Patients receive oral ONC201 orally (PO) on day 1. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up for 4 weeks.

Inclusion Criteria:

• Patient has completed participation in one of the ONC201 protocols, has not shown tumor progression while on study treatment, and has tolerated the study drug without unacceptable toxicities
• Patient has not met criteria for withdrawal from the base protocol
• Patient is willing to comply with protocol requirements and procedures, and keep scheduled study visits
• Patient agrees to practice effective contraception during the entire study period unless documentation of infertility exists
• Patient is able to understand and is willing to sign the informed consent form

Exclusion Criteria:

• Patient is receiving concomitant standard and/or investigational anticancer therapy; local palliative radiotherapy is permissible upon discussion with the principal investigator
• Patient has alcohol or substance abuse which, in the opinion of the investigator, would interfere with compliance or safety
• Patient has any condition or laboratory abnormality which, in the opinion of the investigator, would pose additional risk in administering the study drug to the patient