Study of MT-302 in Adults With Advanced or Metastatic Epithelial Tumors

Inclusion Criteria:

1. Adults age ≥ 18 inclusive at the time the Informed Consent Form (ICF) is signed.
2. Histologically proven, metastatic or advanced epithelial cancer including thefollowing cancer types:
3. Urothelial
4. Cervical
5. Ovarian epithelial
6. Triple-negative breast
7. HR+/HER2- breast
8. Pancreatic ductal adenocarcinoma
9. Gastric adenocarcinoma
10. Esophageal carcinoma
11. Non-small cell lung
12. Colorectal
13. Progressive disease at baseline, refractory or relapsed to standard of care or whohave declined standard therapy.
14. Measurable disease based on Response Evaluation Criteria in Solid Tumors (RECIST)criteria v 1.1.
15. Eastern Cooperative Oncology Group (ECOG) performance status grade of 0 or 1.
16. Life expectancy of > 12 weeks.
17. Echocardiogram (ECHO) or multiple gated acquisition scan showing an ejection fractiongreater than or equal to 50%.
18. Electrocardiogram (ECG) showing no clinically significant abnormality at Screening orshowing an average QTc interval < 450 msec in males and < 470 msec in females (< 480msec for participants with bundle branch block). Either Fridericia's or Bazett'sformula may be used to correct the QT interval.
19. Oxygen saturation of greater than or equal to 90% on room air measured by pulseoximetry.
20. Adequate organ function as defined by laboratory values at Screening.
21. Willing and able to provide written informed consent.
22. Willing to perform and comply with all study procedures including undergoingstudy-related biopsies and attending clinic visits as scheduled.
23. Men must abstain from sperm donation during study treatment or for 4 months followinglast dose of study treatment.
24. Men and WOCBP must be willing to practice a highly effective method of contraception.

Exclusion Criteria:

1. Known active CNS metastasis and/or carcinomatous meningitis. Participants withpreviously treated brain metastases may participate provided they are radiologicallystable, (ie, without evidence of progression for at least 4 weeks by repeat imaging),clinically stable, and without requirement of steroid treatment for at least 14 daysprior to the first dose of study intervention.
2. Pregnant or nursing women.
3. Must be > 28 days beyond major surgery, including hepatectomy or joint replacement.
4. Prior allogeneic bone marrow transplantation or solid organ transplant.
5. Spinal cord compression not definitively treated with surgery and/or radiation.
6. Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrentdrainage procedures.
7. Any acute illness including fever (> 100.4° F or > 38° C) within 7 days prior to Day 1
8. Active systemic bacterial, fungal, or viral infection within 7 days prior to Day 1.Participant cannot have tested positive for COVID-19 within 7 days prior to Day 1.
9. Active infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV),hepatitis C virus (HCV).
10. Other primary malignancies, except:
11. Adequately treated basal cell or squamous cell carcinoma
12. In situ carcinoma of the cervix or bladder, treated curatively and withoutevidence of recurrence for at least 2 years prior to the study, or
13. A primary malignancy which has been completely resected and in complete remissionfor at least 2 years
14. History of (noninfectious) pneumonitis/interstitial lung disease that requiredsteroids or has current pneumonitis/interstitial lung disease.
15. Prior grade > 3 immune-related AEs such as pneumonitis, colitis, hepatitis, nephritis;prior dermatitis and endocrinopathies are allowed provided corticosteroids are nolonger required and endocrine-replacement therapy is stable and discontinued fromprior therapy.
16. Active autoimmune disease not related to prior therapy for primary malignancy that hasrequired systemic therapy in the last 1 year.
17. History of symptomatic congestive heart failure (New York Heart Association classesII-IV) or serious active arrhythmias or other clinically significant cardiac diseasewithin 12 months of enrollment.
18. Toxicity from previous anti-cancer therapy defined as toxicities (other than alopecia,or laboratory values listed above) not yet resolved to NCI CTCAE v5.0 Grade ≤ 1 orbaseline. Participants with chronic Grade 2 toxicities (eg, peripheral neuropathy,laboratory values) may be eligible per the discretion of the Investigator and MedicalMonitor.
19. Has received:
20. Radiotherapy within 2 weeks of first administration of MT-302
21. Cytotoxic chemotherapy for treatment of the primary malignancy within 28 days or 5 half-lives, whichever is shorter, of administration of MT-302
22. Immune therapy for primary malignancy (eg, monoclonal antibody therapy,checkpoint inhibitors) within 28 days or 5 half-lives, whichever is shorter offirst administration of MT-302
23. Targeted therapies for primary malignancy within 28 days or 5 half-lives,whichever is shorter, of first administration of MT-302
24. Anti-cancer vaccine within 12 weeks of first administration of MT-302
25. COVID-19 mRNA vaccine within 6 weeks of first administration of MT-302
26. Has received a live vaccine ≤ 6 weeks prior to first administration of MT-302
27. Has received packed red blood cells or platelet transfusion within 2 weeks prior tofirst administration of MT-302
28. History of an allergic reaction to any of the excipients
29. Enrollment in another interventional clinical trial within 28 days or 5 half-lives ofthe drug, whichever is shorter, of first administration of MT-302
30. Any other condition that, in the opinion of the Investigator, would make theparticipant unsuitable for the study or unable to comply with the study requirements.