A Phase 1/2 Study to Evaluate CHM-2101, an Autologous Cadherin 17 Chimeric Antigen Receptor (CAR) T Cell Therapy

Inclusion Criteria:

1. Documented informed consent of the participant and/or legally authorizedrepresentative.

2. Confirmed histologic diagnosis of one of the following solid tumors of GI origin:

3. Gastric adenocarcinoma Note: for gastric adenocarcinoma patients only, centrallaboratory confirmation of CDH17+ tumor expression is required.

4. Colon and/or rectal adenocarcinoma

5. G1, G2, and well-differentiated G3 neuroendocrine tumors of the midgut andhindgut (ileal, jejunal, cecal, distal colonic, or rectal; with ≤ 55% Ki67expression)

6. Availability of unstained tumor tissue slides from archived tumor tissue or a newtumor biopsy, if medically feasible. Note: for gastric adenocarcinoma patients only,confirmation of CDH17+ is required prior to study inclusion.

7. Have received at least 1 prior line of systemic anti-cancer treatment in the locallyadvanced or metastatic setting, as defined by National Comprehensive Cancer Network (NCCN) guidelines. Participants must have received or declined FDA-approved andavailable treatment options, including targeted therapies for disease mutation orantigen expression status.

8. Age ≥ 18 years and ≤ 85 years.

9. For Phase 1 Dose Expansion and Phase 2 only: Measurable disease as per RECIST v1.1criteria (Note: Measurable disease is NOT required for Phase 1 Dose Escalation).

10. Eastern Cooperative Oncology Group (ECOG) ≤ 1.

11. Life expectancy ≥ 12 weeks.

12. No known contraindications to leukapheresis, cyclophosphamide, fludarabine, orsteroids.

13. Baseline laboratory values as shown in the following table: Minimum Laboratory Values for Study Entry Laboratory Assessment Criteria White bloodcell count > 4,000/mm3 Absolute neutrophil count (ANC) ≥ 1,500/mm3 Platelets ≥ 100,000/mm3 Hemoglobin ≥ 10 g/dL Total bilirubin ≤ 1.5 x upper limit of normal (ULN)Aspartate amino transferase (AST) ≤ 3 x ULN Alanine transaminase (ALT) ≤ 3 x ULNCreatinine clearance by Cockroft-Gault equation 60 mL/min Oxygen saturation ≥ 92% onroom air Albumin ≥ 3 g/dL

14. Left ventricular ejection fraction ≥ 50%.

15. Seronegative for human immunodeficiency virus (HIV) by antigen/antibody (Ag/Ab)testing.

16. Seronegative for hepatitis B and/or hepatitis C virus.

17. Women of childbearing potential (WOCBP) must have a negative urine or serumpregnancy test. If the urine test is positive or cannot be confirmed as negative, aserum pregnancy test is required.

18. Agreement by women and men of childbearing potential to use an effective method ofbirth control or abstain from heterosexual activity through at least 3 months afterthe last dose of CHM-2101.

Exclusion Criteria:

1. Previous treatment with CDH17-targeted therapies.

2. Unresolved toxicities from prior therapy except for chronic toxicity no greater thanGrade 1 and stable > 30 days (Note: alopecia of any grade is not exclusionary).

3. Uncontrolled seizure activity and/or known central nervous system (CNS) metastases.

4. History of allergic reactions attributed to compounds of similar chemical orbiologic composition to study agent.

5. Uncontrolled Crohn's disease, ulcerative colitis, or other autoimmune orinflammatory disorders of the GI tract. "Uncontrolled" is defined as requiringhospitalization, corticosteroids, or chronic medication increase (dosage orfrequency) within the previous 6 months.

6. Liver involvement ≥ 50%.

7. Active infection requiring oral or IV antibiotics.

8. Current diagnosis of pleural effusions, interstitial lung disease, or heart failureof New York Heart Association Classification of Heart Failure Class III or IV.

9. Ongoing treatment with systemic corticosteroid therapy at doses of prednisone ≥ 20mg/day or equivalent (lower doses of corticosteroid therapy are allowed until 7 daysprior to leukapheresis).

10. No prior malignancy within 5 years except for non-melanomatous skin cancer orcervical cancer treated with curative intent

11. Currently breastfeeding or planning to become pregnant within 9 months of studyenrollment.

12. Any other clinically significant uncontrolled illness or other comorbid conditionthat would, in the investigator's judgment, contraindicate the participant'sparticipation in the clinical study.