• Metarrestin is a first-in-class investigational agent targeting the peri-nucleolar compartment (PNC), a marker of genome organization associated with metastasis.
• Preclinical studies have shown that metarrestin effectively suppresses metastasis and extends overall survival in different cancer models.
• Multi-species allometric scaling and good laboratory practice (GLP) toxicology and toxicokinetic studies indicate that metarrestin administered at a calculated safe maximum recommended starting dose (MRSD) to human subjects is predicted to afford intratumoral exposure levels within the therapeutic range observed preclinically. Objectives
• Phase IA: To determine the maximum tolerated dose (MTD) of metarrestin.
• Phase IB: To determine the Objective Response Rate (ORR) according to Evaluation Criteria (RECIST 1.1) in patients treated with metarrestin at the MTD. Eligibility

-Adult subjects with any advanced solid tumors (Cohort IA), or pancreatic or breast tumors (Cohort IB1).

OR

• Pediatric subjects age 12 and older with solid tumors other than rhabdomyosarcoma and related skeletal muscle tumors (Cohort IB2).
• Patients must have progressed on prior standard chemotherapeutic therapy. Design
• This is first-in-human Phase I trial to investigate the safety and clinical activity of metarrestin in subjects with metastatic solid tumors.
• During Phase IA MTD of metarrestin will be estimated in adult patients with solid tumors.
• During Phase IB adult patients with breast or pancreatic cancer and pediatric patients with solid organ cancer will be treated at dose level of estimated MTD.
• Patients will receive treatment in cycles consisting of 28 (+/- 3) days.
• Metarrestin will be administered PO until progression or unacceptable toxicity.