Safety and Tolerability Study of GIM-531 in Advanced Solid Tumors

Key Inclusion Criteria:

Written informed consent
Cytologically or histologically confirmed locally advanced or metastatic solid tumor that has progressed on standard therapy or for which no standard therapy exist; or be intolerant of standard therapy
Have not received an experimental drug within 4 weeks or 5 half-lives (whichever is shorter) of Screening or already be enrolled in a clinical study
ECOG performance status 0-1
Laboratory and ECG assessments within 28 days of enrollment including acceptable cardiac, renal, and hepatic functions
Agree to baseline core needle biopsy or archival (within 12 months of screening) tumor submission; Note: Participants whose only site(s) of disease are in areas considered moderate or high risk for biopsy complications may be enrolled without a fresh biopsy upon Sponsor approval.
Non pregnant participants; female participants of child bearing potential with non-sterile partners agree to use an effective form of contraception from the time of first dose of study drug (or 14 days prior to first dose for oral contraception) until 7 months after the last dose of study drug. Effective forms of contraception include hormonal (injection or oral), double barrier method, or intrauterine device. Non-sterile male participants with sexual partners of childbearing potential agree to use a barrier contraception method and agree to not donate sperm from the time of first dose of study drug until 4 months after the last dose of study drug.
Measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1

Phase 2 Specific Inclusion Criteria (in addition to above inclusion criteria):

Have confirmed unresectable Stage III or metastatic Stage IV cutaneous melanoma that has radiographically progressed (as confirmed by imaging assessed by the Investigator) on an approved first-line single-agent or combination anti-PD-1 therapy
Receiving anti-PD-1 therapy as their first line of treatment at the time of enrollment and amenable to continuing anti-PD-1 therapy during the study

Key Exclusion Criteria:

Ongoing >Grade 1 toxicity from prior therapy according to Common Terminology Criteria for Adverse Events v5.0 (Note: Grade 2 alopecia and Grade 2 sensory neuropathy are not exclusionary)
Has melanoma with documented BRAF mutation (Phase 2 only)

Has known brain metastases, except participants with the following:

Brain metastases that have been treated locally and are clinically stable for at least 4 weeks prior to the first administration of study drug; Note: Participants receiving steroids for brain metastases must be either off steroids or on a stable, or decreasing dose, of <10 mg daily of prednisone (or equivalent) in order to be eligible for enrollment; and
No ongoing neurological symptoms related to the anatomic location of the brain metastases.

Note: Neurological symptoms that are considered sequelae to treatment for brain metastases are allowed.

Has known structural cardiac disease
Has known serious arrythmia, serious dysrhythmia, history of long QT syndrome, or clinically relevant cardiac conduction abnormalities
Has an active autoimmune disease that has required systemic treatment in the past 2 years (ie, with use of disease modifying agents, corticosteroids, or immunosuppressive drugs). Replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment and is allowed.
At time of screening, is receiving systemic steroid therapy (greater than or equal to 10 mg/day of prednisone or equivalent) or is taking any immunosuppressive therapy; Note: Use of topical, inhaled, nasal, or ophthalmic steroids is allowed.
Has active and clinically significant bacterial, fungal, or viral infection, including known hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV)
Has a history of, or currently has, an acquired or primary (congenital) immunodeficiency;
Has had prior anti-cancer treatment with chemotherapeutic agents or immune modulating agents within <4 weeks or 5 half-lives, whichever is shorter, prior to the first dose of study drug.
Has received a live vaccine within 30 days of first dose of study drug;
Has had or has planned major surgery within 2 weeks of the first dose of study drug;
Inability to swallow an oral dose of a medication (eg, oral capsules)
Is taking medications that are considered strong inducers or inhibitors of CYP2C8 or CYP3A4/5, P-glycoprotein (P-gp), breast cancer resistant protein (BCRP), or sensitive substrates of P-gp and BCRP (Appendix C) that cannot be discontinued at least 1 week prior to first dose of study drug and for the duration of the study.
Is taking drugs that modify gastric pH, such as proton-pump inhibitors (PPIs) or H2 blockers. Antacids such as calcium carbonate or aluminum hydroxide-based products are permitted.