A Study of SGN-B6A in Chinese Participants With Advanced Solid Tumors

Inclusion Criteria: * Subjects must have histologically or cytologically confirmed metastatic or unresectable locally advanced solid malignancy within one of the tumor types listed below. * NSCLC * HNSCC * ESCC * GAC * EAC * GEJ adenocarcinoma * Subjects must have disease that is relapsed or refractory, or be intolerant to systemic standard-of-care therapies, and in the judgement of the investigator, should have no appropriate standard-of-care therapeutic option. If a standard-of-care therapy is available that has not been administered, the reason that the therapy is not appropriate must be documented. * Adequate organ function as defined by the baseline laboratory criteria obtained within 7 days prior to SGN-B6A initiation (Cycle 1 Day 1) * Measurable or non-measurable disease per RECIST v1.1 at baseline. * An Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1. Exclusion Criteria: * History of another malignancy within 3 years before the first dose of study intervention, or any evidence of residual disease from a previously diagnosed malignancy. Exceptions are malignancies with a negligible risk of metastasis or death. * Participants with any of the following respiratory conditions: * Evidence of noninfectious interstitial lung disease (ILD) or pneumonitis that: * \* Was previous diagnosed and required systemic steroids, or * \* Is currently diagnosed and managed, or * \* Is suspected on radiologic imaging at screening * K…