Determine Safety & Recommended Phase 2 Dosing of Zeaxanthin Alone or in Combination w/Pembrolizumab in Patients With Metastatic Cancer

Must have received: all standard therapies known to provide clinical benefit

refractory to all standard therapies known to provide clinical benefit (unless the therapy is contraindicated or intolerable) in the opinion of the treating investigator for his/her tumor type

Cannot have received: chemotherapy or radiotherapy

Exception: allowed if completed >21 days prior and recovered to grade 1 or less from adverse events (excluding alopecia, grade 2 fatigue, grade 2 hearing loss from platinum agent, and endocrinopathies on stable replacement therapy)

Patients who have had chemotherapy or radiotherapy within 21 days prior to initiating study treatment or those who have not recovered to grade 1 or less from adverse events due to agents administered more than 21 days earlier excluding alopecia, gd 2 fatigue, gd 2 hearing loss from platinum agent, and endocrinopathies on stable replacement therapy

Cannot have received: other investigational agents or concomitant chemotherapy or radiation therapy

Exception: hormonal therapy is not exclusionary

Patients may not be receiving any other investigational agents or concomitant chemotherapy or radiation therapy. Hormonal therapy is not exclusionary.