Inclusion Criteria:

        To be eligible for participation in the study, patients must meet all of the following
        inclusion criteria:

          1. Patients enrolled in the Phase 1a study must:

               1. Have a histologically confirmed diagnosis of advanced metastatic or progressive
                  solid tumor

               2. Be refractory to, or intolerant of, established therapy known to provide clinical
                  benefit for their condition

          2. Patients enrolled in the Phase 1b study must meet criteria for one of the following
             tumor types:

               1. Have tumors that have progressed after achieving a best documented response of at
                  least stable disease (ie, SD, PR, or CR documented per iRECIST following at least
                  2 cycles (8 weeks) of immunotherapy and are felt to be appropriate for this type
                  of treatment*

               2. Have EGFR+ NSCLC and have demonstrated recent progression following a best
                  documented response of at least stable disease (ie, SD, PR, or CR documented per
                  per RECIST v1.1 on ≤2 lines of oral TKIs and are felt to be appropriate for this
                  type of treatment* Prior chemotherapy ± immunotherapy is allowed as long as the
                  patient is clearly demonstrating current progression on an EGFR TKI.

               3. Have BRAF-, KRAS-, or NRAS-mutated CRC for whom there is no standard therapy
                  remaining

               4. Have persistent/recurrent ovarian cancer who would be platinum refractory/
                  resistant and have had any number of lines of prior therapy

               5. Have BRAF-mutated melanoma that has not responded to immunotherapy or a
                  combination BRAF/MEK inhibitor

          3. Have one or more tumors measurable or evaluable as outlined by modified RECIST v1.1 or
             iRECIST

          4. Have an Eastern Cooperative Oncology Group (ECOG) (World Health Organization [WHO])
             performance of ≤1

          5. Have a life expectancy ≥3 months

          6. Be ≥18 years of age

          7. Have a negative pregnancy test (if female of childbearing potential)

          8. Have acceptable liver function:

               1. Bilirubin ≤1.5x upper limit of normal (ULN)

                  *Patients receiving immunotherapy should have a bilirubin level <3.0x ULN.

               2. Aspartate aminotransferase (AST/SGOT), alanine aminotransferase (ALT/SGPT) and
                  alkaline phosphatase ≤2.5x upper limit of normal (ULN)

                    -  If liver metastases are present, then ≤5x ULN is allowed.

                    -  Patients receiving immunotherapy should have AST and ALT levels <5.0x ULN.

          9. Have acceptable renal function:

             a. Calculated creatinine clearance ≥30 mL/min

         10. Have acceptable hematologic status:

               1. Granulocyte ≥1500 cells/mm3

               2. Platelet count ≥100,000 (plt/mm3)

               3. Hemoglobin ≥9 g/dL

         11. Have no clinically significant abnormalities on urinalysis

         12. Have acceptable coagulation status:

               1. Prothrombin time (PT) within 1.5x normal limits

               2. Activated partial thromboplastin time (aPTT) within 1.5x normal limits

         13. Be nonfertile or agree to use an adequate method of contraception. Sexually active
             patients and their partners must use an effective method of contraception (hormonal or
             barrier method of birth control; or abstinence) prior to study entry and for the
             duration of study participation and for at least 30 days after the last study drug
             dose (see Section 4.6.3). Should a woman become pregnant or suspect she is pregnant
             while participating in this study, she should inform her treating physician
             immediately.

         14. Have read and signed the IRB-approved informed consent form prior to any study related
             procedure. (In the event that the patient is re-screened for study participation or a
             protocol amendment alters the care of an ongoing patient, a new informed consent form
             must be signed.)

         15. Patients enrolled in each of the five Expansion Cohorts must be willing to consider
             pre-study and on-study biopsies, if safe and medically feasible, as determined by
             local interventional radiology (3 to 5 core samples requested at each biopsy
             timepoint)

        Patients meeting any one of these exclusion criteria will be prohibited from participating
        in this study:

          1. Have New York Heart Association (NYHA) Class III or IV, cardiac disease, myocardial
             infarction within the past 6 months prior to Day 1, unstable arrhythmia, or evidence
             of ischemia on electrocardiogram (ECG) or during Cardiac Stress Testing within 14 days
             prior to Day 1 (Appendix C)

          2. Have a corrected QT interval (QTcF, Fridericia's method) of >450 msec in men and >470
             msec in women

          3. Have a seizure disorders requiring anticonvulsant therapy

          4. Presence of symptomatic central nervous system metastatic disease or disease that
             requires local therapy such as radiotherapy, surgery, or increasing dose of steroids
             within 2 weeks prior to Day 1

          5. Have severe chronic obstructive pulmonary disease with hypoxemia (defined as resting
             O2 saturation of ≤88% breathing room air)

          6. Have undergone major surgery, other than diagnostic surgery, within 2 weeks prior to
             Day 1

          7. Have active, uncontrolled bacterial, viral, or fungal infections, requiring systemic
             therapy

          8. Are pregnant or nursing

          9. Received treatment with radiation therapy, surgery, chemotherapy, or investigational
             therapy within 28 days or 5 half lives, whichever occurs first, prior to study entry
             (6 weeks for nitrosoureas or Mitomycin C)

             a. This exclusion criterion is not applicable for patients with EGFR+ NSCLC or
             immunotherapy-resistant tumors who are enrolled in expansion cohorts at the MTD.

         10. Are unwilling or unable to comply with procedures required in this protocol

         11. Have known infection with human immunodeficiency virus (HIV), hepatitis B, or
             hepatitis C. Patients with history of chronic hepatitis that is currently not active
             are eligible

         12. Have a serious nonmalignant disease (eg, hydronephrosis, liver failure, or other
             conditions) that could compromise protocol objectives in the opinion of the
             investigator and/or the sponsor

         13. Are currently receiving any other investigational agent

         14. Have exhibited allergic reactions to a similar structural compound, biological agent,
             or formulation

         15. Have undergone significant surgery to the gastrointestinal tract that could impair
             absorption or that could result in short bowel syndrome with diarrhea due to
             malabsorption

         16. Have a history of severe adverse reaction (eg, hypersensitivity reaction, anaphylaxis)
             to sulfonamides

         17. Patients scheduled to receive immunotherapy or TKI regimens plus TP-0903 must not be
             currently taking high-dose steroids (ie, physiologic dose approximately equivalent to
             15 mg/day of prednisone)