Inclusion Criteria:

          -  Able to comprehend and willing to sign a written ICF for the study.

               -  Are 18 years of age or older (or as applicable per local country requirements).

               -  Histologically or cytologically verified, inoperable locally recurrent or
                  metastatic SCAC.

               -  No prior systemic therapy other than the following: a. Chemotherapy administered
                  concomitantly with radiotherapy as a radiosensitizing agent is permitted.

                  b. Prior neoadjuvant or adjuvant therapy if completed ≥ 6 months before study
                  entry.

               -  Has measurable disease per RECIST v1.1 as determined by local site
                  investigator/radiology assessment. Tumor lesions situated in a previously
                  irradiated area, or in an area subjected to other loco-regional therapy, are
                  usually not considered measurable unless there has been demonstrated progression
                  in the lesion.

               -  Able and willing to provide adequate tissue sample and whole blood sample with
                  central testing result prior to randomization. Biopsy for archival samples should
                  have occurred within 6 months prior to randomization.

               -  ECOG performance status 0 to 1.

               -  If HIV-positive, then must be stable as defined by: a. CD4+ count ≥ 300/μL, b.
                  Undetectable viral load per standard of care assay, c. Receiving antiretroviral
                  therapy (ART/HAART) for at least 4 weeks prior to study enrollment, and have not
                  experienced any HIV-related opportunistic infection for at least 4 weeks prior to
                  study enrollment.

               -  Willingness to avoid pregnancy or fathering children

        Exclusion Criteria:

          -  Has received prior PD-(L)1 directed therapy

          -  Has received prior radiotherapy with or without radiosensitizing chemotherapy within
             28 days of Cycle 1 Day 1 (note: all toxicities associated should have resolved to
             Grade ≤ 1).

          -  Participants with laboratory outside of the protocol defined ranges.

          -  History of second malignancy within 3 years (with exceptions).

          -  Clinically significant pulmonary, cardiac, gastrointestinal or autoimmune disorders.

          -  Active bacterial, fungal, or viral infections, including hepatitis A, B, and C.

          -  Receipt of a live vaccine within 28 days of planned start of study therapy.

          -  History of organ transplant, including allogeneic stem cell transplantation.

          -  Known active CNS metastases and/or carcinomatous meningitis.

          -  Known hypersensitivity to platinum, paclitaxel, another monoclonal antibody, or any of
             the excipients that cannot be controlled with standard measures (eg, antihistamines,
             corticosteroids).

          -  Participant is pregnant or breastfeeding.

          -  Current use of protocol defined prohibited medication.

          -  Has pre-existing peripheral neuropathy that is ≥ Grade 2 by CTCAE v5.

          -  Inability or unlikely, in the opinion of the investigator, to comply with the Protocol
             requirements