Brief Title: SBT6290 Alone and in Combination With PD-(L)1 Inhibitors in Select Advanced Solid Tumors

PRIMARY OUTCOMES

Primary Outcome 1 - Measure: Number of Participants With Dose Limiting Toxicities: Part 1 and Part 3

Primary Outcome 1 - Timeframe: Up to 28 days after the first dose of SBT6290

Primary Outcome 2 - Measure: Number of Participants With Treatment-emergent Adverse Events: All Parts

Primary Outcome 2 - Timeframe: From enrollment to 30 days after the last dose of SBT6290, up to 2 years

Primary Outcome 3 - Measure: Number of Participants With an Objective Response Rate: Part 2 and Part 4

Primary Outcome 3 - Timeframe: From enrollment to confirmed response, up to 1 year

Primary Outcome 4 - Measure: Duration of Response for Participants With an Objective Response Rate: Part 2 and Part 4

Primary Outcome 4 - Timeframe: From enrollment until the date of first documented progression or date of death from any cause, whichever occurs first, assessed up to 3 years

CONDITION

• Urothelial Carcinoma
• Triple Negative Breast Cancer
• Non-small Cell Lung Cancer
• Squamous Cell Carcinoma of Head and Neck
• Hormone Receptor-positive/HER2-negative Breast Cancer

ELIGIBILITY

Key Inclusion Criteria:
Locally advanced or metastatic solid tumors associated associated with Nectin-4 expression (locally advanced or metastatic urothelial carcinoma, TNBC, NSCLC, SCCHN, and HR+/HER2- negative breast cancer)

- Measurable disease per the the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 criteria

- Tumor lesion amenable for biopsy available to submit for retrospective baseline testing of Nectin-4; archived tumor tissue may be acceptable depending upon study Part detailed criteria

- ECOG Performance Status of 0 or 1

- Adequate organ and marrow function Note: Other protocol-defined inclusion/exclusion criteria may apply.
Key Exclusion Criteria:
History of allergic reactions to certain components of study treatments

- Untreated brain metastases

- Currently active (or history of) autoimmune disease

- Taking the equivalent of >10 mg / day of prednisone

- Uncontrolled or clinically significant interstitial lung disease (ILD)

- History of ongoing, uncontrolled, symptomatic eye disorders requiring intervention or associated with marked visual field defects or limiting age-appropriate instrumental activities of daily living

- HIV infection, active hepatitis B or hepatitis C infection Note: Other protocol-defined inclusion/exclusion criteria may apply.

Gender: All

Minimum Age: 18 Years

Maximum Age: N/A

Healthy Volunteers: No

OFFICIAL INFORMATION

Name: Natasha Angra, PharmD

Role: Study Director

Affiliation: Silverback Therapeutics, Inc.

Overall Contact

Name: Natasha Angra, PharmD

Phone: 206 456-2900

Email: ClinOps@Silverbacktx.com

LOCATION