• #. Histologically or cytologically confirmed diagnosis of any type of solid tumor malignancy or lymphoma:

• Phase 1 Dose Escalation only: Subjects with

• (A) any advanced solid tumors of

⁃ Head and Neck Cancers (HNC) (of any types),

⁃ Esophageal cancer,

⁃ Lung cancers (of any types),

⁃ Mesothelioma,

⁃ Pancreatic cancers,

• Or,

• (B) any NTRK1 gene fusion positive (NTRK1+) solid tumors or lymphomas, that is relapsed, refractory or intolerant (R/R/I) to standard of care (SOC) and for which there is no approved or curative therapy. Additionally, patients must not be candidates for or have exhausted regimens known to provide clinical benefit, including hematopoietic stem cell transplantation in lymphoma patients if they are deemed transplant eligible.

• Phase 2 Monotherapy and Combination with Pembrolizumab only:

• Subjects must have

⁃ TrkA-driven HNC, Esophageal, Lung, Mesothelioma, Pancreatic cancers; or,

⁃ any NTRK1+ solid tumors or lymphoma\*, that is R/R/I to SOC.

• Eastern Cooperative Oncology Group (ECOG) Performance Status: 0 or 1.

• Able to swallow and retain oral medication.

• Subjects must either have available archival tumor tissue samples, or consent to tumor tissue sampling prior to the first dose.

• Adequate organ system function as defined as follows:

∙ Absolute neutrophil count ≥1.5x10\^9/L

‣ Hemoglobin ≥9g/dL

‣ Platelets ≥100x10\^9/L

‣ PT/INR, PTT ≤1.5xULN

‣ Total bilirubin ≤1.5x ULN

‣ AST, ALT ≤2.5xULN

‣ Creatinine ≤1.2xULN for age, weight

‣ Calculated creatinine clearance or 24h urine creatinine clearance ≥60mL/min