A Study of a Selective T Cell Receptor (TCR) Targeting, Bifunctional Antibody-fusion Molecule STAR0602 in Participants With Advanced Solid Tumors

Inclusion Criteria:

1. Participants must have histologically confirmed solid tumors that are unresectable,locally advanced, or metastatic and for which standard curative therapies do notexist or are no longer effective or have intolerable toxicities. Subjects should nothave received more than three lines of prior therapies for their advanced ormetastatic diseases.

2. For Phase 1, participants must have one of the following solid tumors:

3. High mutational burden (TMB-H)

4. Microsatellite Instability (MSI-H)/DNA mismatch repair (dMMR)

5. Virally associated tumors

6. For Phase 2, participants must have one of the following solid tumors:

7. TMB-H

8. MSI-H/dMMR

9. CRC (both Ras wild type and mutant)

10. Virally associated tumors

11. Metastatic triple negative breast cancer

12. Platinum-resistant epithelial ovarian cancer

13. Metastatic castration-resistance prostate cancer

14. Primary stage IV or recurrent non-small cell lung cancer

15. Immunogenic solid tumors

(Other tumor histologies may also be included in Phase 2 as additional data emergeto support their inclusion.)

4. Symptomatic central nervous system (CNS) metastases must have been treated, beasymptomatic for ≥ 14 days, and meet the following at the time of enrollment:

• No concurrent treatment for CNS disease (e.g., surgery, radiation,corticosteroids > 10 mg prednisone/day or equivalent);

• No concurrent leptomeningeal disease or cord compression.

Exclusion Criteria:

1. Participants with a history of known autoimmune disease with exceptions of:

• Vitiligo;

• Psoriasis, atopic dermatitis or other autoimmune skin condition not requiringsystemic treatment;

• History of Graves' disease, now euthyroid for > 4 weeks;

• Hypothyroidism managed by thyroid replacement;

• Alopecia;

• Arthritis managed without systemic therapy beyond oral nonsteroidalanti-inflammatory drugs.

• Adrenal insufficiency well controlled on replacement therapy.

2. Major surgery or traumatic injury within 8 weeks before first dose of study drug.

3. Unhealed wounds from surgery or injury.

4. Treatment with >10 mg per day of prednisone (or equivalent) or otherimmune-suppressive drugs within 7 days prior to the initiation of study drug.Exceptions may be made for patients who have had allergic reaction to iodinatedcontrast media. Steroids for topical, ophthalmic, inhaled, or nasal administrationare allowed.

5. Clinically significant cardiovascular/vascular disease, gastrointestinal disorders,inflammatory processes, pulmonary compromises

6. Active viral, bacterial, or systemic fungal infection requiring parenteral treatmentwithin 7 days prior to the initiation of study drug.

7. Vaccination with any live virus vaccine within 4 weeks prior to the initiation ofstudy drug administration. Inactivated annual influenza vaccination is allowed.

8. Participants who are known to be human immunodeficiency virus positive or hepatitisB or C positive and have uncontrolled disease.

9. Second primary invasive malignancy not in remission for ≥ 1 year. Exceptions includenon-melanoma locally advanced skin cancer, cervical carcinoma in situ, localizedprostate cancer (Gleason score ≤ 7), resected melanoma in situ, or any malignancyconsidered to be indolent and never required systemic therapy, with the exception ofindolent lymphomas.

10. Pregnant, likely to become pregnant, or lactating women (where pregnancy is definedas the state of a female after conception and until the termination of gestation).

11. Hepatic metastases unless adequately treated, either locally (e.g., by surgery,radiofrequency ablation, or chemoembolization) or systemically or both, and stablefor 3 months.