Inclusion Criteria:

1. Signed written informed consent granted

2. Men or women 18 years of age

3. Histologically or cytologically confirmed, locally advanced, inoperable, or
metastatic solid tumors. Subjects eligible for enrollment in the Expanded Cohort must
have documented and/or confirmed FGFR genetic alterations, including iCCA with FGFR2
gene fusion.

4. Failure to respond to standard therapy, or for whom standard therapy does not exist.

5. Evaluable or measurable disease

6. Archival and/or fresh biopsy tissue samples must be available prior to the first dose
of the study drug

7. Life expectancy 12 weeks

8. Eastern Cooperative Oncology Group (ECOG) performance status 2

9. Hemoglobin (Hgb) 9.0 g/dL

10. Absolute neutrophil count (ANC) 1.5 x 10^9/L

11. Platelet count 100 x 10^9/L

12. Total bilirubin 1.5 upper limit of normal (ULN) ( 2 x ULN for subjects with
cholangiocarcinoma)

13. Aspartate transaminase (AST) and alanine transaminase (ALT) 3 ULN ( 5 x ULN for
subjects with liver metastases)

14. Serum creatinine 1.5 x ULN or creatinine clearance > 60 mL/min/1.73 m^2 for
subjects with creatinine levels above institutional normal

15. Albumin 2.8 g/dL

16. INR 0.8 to ULN or 3 for subjects receiving anticoagulant therapy

17. Men or women of child-producing potential must agree to use double-barrier
contraceptive measures, oral contraception, or avoid intercourse during the study and
for 90 days after the last dose of study drug

18. Women of childbearing potential must have a negative serum pregnancy test during
Screening Period and within 48 hours of the first dose of ARQ 087.

Exclusion Criteria:

1. Anti-cancer therapy, such as chemotherapy, immunotherapy, hormonal, targeted therapy,
or investigational agents within four weeks or five times of the drug half life,
whichever is longer, of the first dose of ARQ 087

2. Major surgery or radiation therapy within four weeks of the first dose of ARQ 087

3. Previous treatment with FGFR inhibitors

4. History of allergic reactions attributed to compounds of similar chemical or
biological composition as ARQ 087

5. Unable or unwilling to swallow the complete daily dose of ARQ 087

6. Clinically unstable central nervous system (CNS) metastasis

7. History of myocardial infarction (MI) or congestive heart failure defined as Class II
to IV per the New York Heart Association classification within 6 months of the first
dose of ARQ 087 (MI occurring >6 months of the first dose of ARQ 087 will be
permitted)

8. Significant GI disorder(s) that could interfere with the absorption, metabolism, or
excretion of ARQ 087 (e.g. Crohn's disease, ulcerative colitis, extensive gastric
resection)

9. History and/or current evidence of clinically relevant ectopic
mineralization/calcification

10. Previous malignancy within 2 years prior to the first dose of ARQ 087, except
curatively treated non-melanoma skin cancer, carcinoma in-situ of the breast or
cervix, or superficial bladder tumors

11. Known human immunodeficiency virus (HIV) infection

12. Concurrent uncontrolled illness not related to cancer, including but not limited to:

- Psychiatric illness/substance abuse/social situation that would limit compliance
with study requirements.

- Uncontrolled diabetes mellitus

13. Blood transfusion within 5 days of the blood draw being used to confirm eligibility

14. Pregnant or breastfeeding

Minimum Eligible Age: 18 Years

Maximum Eligible Age: N/A

Eligible Gender: Both