A Phase 1 Study of SGN-STNV in Advanced Solid Tumors

This trial will look at a drug called SGN-STNV to find out whether it is safe for patients
with solid tumors. It will study SGN-STNV to find out what its side effects are. A side
effect is anything the drug does besides treating cancer. It will also study how well
SGN-STNV works to treat solid tumors.

The study will have two parts. Part A of the study will find out how much SGN-STNV should be
given to patients. Part B will use the dose found in Part A to find out how safe SGN-STNV is
and if it works to treat certain types of solid tumors.

Inclusion Criteria:

- Disease indication

- Must have disease that is relapsed or refractory or be intolerant to
standard-of-care therapies and should have no appropriate standard-of-care
therapeutic option.

- Non-small cell lung cancer (NSCLC)

- HER2 negative breast cancer

- Ovarian cancer

- Cervical cancer

- Endometrial cancer

- Esophageal cancer

- Gastric cancer and GEJ carcinoma

- Colorectal cancer

- Exocrine pancreatic adenocarcinoma

- Appendiceal adenocarcinoma and pseudomyxoma peritonei of unknown origin

- Participants enrolled in the following study parts should have an appropriate tumor
site that satisfies the following criteria:

- Site has tumor that is not a target lesion and has not been previously irradiated
(unless progression has occurred since end of radiotherapy)

- Site has tumor that is accessible for a minimally invasive biopsy that does not
present a significant risk, AND

- Participant must agree to a biopsy as follows

- Disease-specific expansion cohorts: pre-treatment biopsy, unless medically
infeasible following consultation with the medical monitor

- Biology expansion cohort: pretreatment biopsy (required) and additional
on-treatment biopsy during Cycle 1 (unless medically infeasible following
consultation with the medical monitor)

- Measurable disease per the Response Evaluation Criteria in Solid Tumors Version 1.1
(RECIST v1.1) at baseline

- An Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1

- Adequate renal, hepatic, and hematologic function

Exclusion Criteria

- History of another malignancy within 3 years before the first dose of study drug, or
any evidence of residual disease from a previously diagnosed malignancy.

- Known active central nervous system metastases

- Carcinomatous meningitis

- Previous receipt of monomethylauristatin E (MMAE)-containing drugs

- Pre-existing neuropathy ≥ Grade 2 per the National Cancer Institute's Common
Terminology Criteria for Adverse Events (NCI CTCAE) v5.0

- Any uncontrolled ≥ Grade 3 (per the NCI CTCAE, Version 5.0) viral, bacterial, or
fungal infection within 2 weeks prior to the first dose of SGN-STNV

There are additional inclusion and exclusion criteria. The study center will determine if
criteria for participation are met.