• Willing and able to provide informed consent

• ≥18 years of age at the time of signing the informed consent form

• Pathologically documented histological or cytological evidence of NSCLC, HNSCC, or melanoma.

• Has at least 1 measurable target lesion per RECIST v1.1 that has not been resected/biopsied/or irradiated before enrollment in the study

• Diagnosis of locally advanced unresectable or metastatic NSCLC, HNSCC, or melanoma in subjects who are ICI treatment-naive or relapsed/refractory, including PD-1/PD-L1 inhibitors

• ICI treatment-naive subjects must meet the following criteria:

∙ NSCLC: Subjects with metastatic or with unresectable, recurrent NSCLC whose tumors must have no EGFR or ALK genomic aberrations and express PD-L1 \[TPS≥50%\]

‣ HNSCC: Subjects with metastatic or with unresectable, recurrent HNSCC whose tumors express PD-L1 \[CPS ≥20\]

‣ Melanoma: Irrespective of PD-L1 result and BRAF V600 mutation

‣ Subjects has not received prior systemic treatment for their metastatic tumor. Subjects who received adjuvant or neoadjuvant therapy are eligible if the adjuvant/neoadjuvant therapy was completed at least 6 months before the development of metastatic disease.

• ICI treatment-refractory subjects as defined by the following criteria:

∙ Has received at least 2 cycles of anti-PD-(L)1 therapy either as monotherapy or in combination

‣ Has demonstrated disease progression after ICI treatment by RECIST v1.1

‣ Has received less than three lines of systemic therapy for metastatic tumor

• ECOG performance status of 0 or 1

• Be willing to provide archival tissue or fresh biopsy

⁃ Have adequate organ function

⁃ All Grade 3 or greater AEs resolved earlier to Grade 2 or less