Inclusion Criteria:

   - Participants who had advanced unresectable and/or metastatic cervical cancer (squamous
   cell carcinoma, adenocarcinoma, adenosquamous cell carcinoma) with disease progression
   during or after the prior platinum-containing chemotherapy:

      1. The prior platinum-containing chemotherapy may be a systemic treatment for
      advanced unresectable, recurrent, persistent or metastatic disease or treatment
      in the adjuvant or neo-adjuvant setting with disease progression or recurrence
      within 6 months of completion of platinum-containing chemotherapy

      2. Participants who previously only received platinum as a radiosensitizer are not
      eligible

      3. Participants must be naïve to checkpoint inhibitors

   - Participants who had measurable disease

   - Participants who provide a tumor tissue sample, either from archival tissue or newly
   obtained core or excisional biopsy. If the participant received local therapy (For
   example: radiation therapy or chemoradiotherapy) after the archival tissue was taken,
   a new biopsy was required

   - Participants who had Eastern Cooperative Oncology Group (ECOG) PS of 0 to 1

   - Life expectancy greater than or equals to (>=) 12 weeks as judged by the Investigator

   - Adequate hematological, hepatic and renal function as defined in the protocol

   - Participants with known Human Immunodeficiency Virus (HIV) infections were in general
   eligible if the following criteria are met:

      1. Clinically indicated participants must be stable on antiretroviral therapy (ART)
      for at least 4 weeks and agree to adhere to ART

      2. had no evidence of documented multi-drug resistance that would prevent effective
      ART

      3. had an HIV viral load of < 400 copies per milliliter (/mL) at Screening

      4. had CD4+ T-cell (CD4+) counts >= 350 cells/microliter

      5. For participants with a history of an Acquired immunodeficiency syndrome
      (AIDS)-defining opportunistic infection within the last 12 months, participants
      may be eligible only after consultation and agreement with the study Medical
      Monitor

      6. If prophylactic antimicrobial drugs were indicated, participants would still be
      considered eligible upon agreement with the study Medical Monitor

   - Participants with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections
   were in general eligible if the following criteria are met:

      1. HBV viral load below the limit of quantification. If medically indicated,
      participants infected with HBV must be treated and on a stable dose of antivirals
      at study entry and with planned monitoring and management according to
      appropriate labeling guidance

      2. Participants with a history of HCV infection should have completed curative
      antiviral treatment and require HCV viral load below the limit of quantification

      3. Participants on concurrent HCV treatment should have HCV below the limit of
      quantification

   - Other protocol defined inclusion criteria could apply

Exclusion Criteria:

   - Participants with active central nervous system (CNS) metastases causing clinical
   symptoms or require therapeutic intervention are excluded. Participants with a history
   of treated CNS metastases (by surgery or radiation therapy) are not eligible unless
   they have fully recovered from treatment, demonstrated no progression for at least 4
   weeks, and are not using steroids for at least 7 days prior to the start of study
   treatment

   - Participants with interstitial lung disease or has had a history of pneumonitis that
   has required oral or intravenous (IV) steroids

   - Participants with significant acute or chronic infections

   - Participants with active autoimmune disease that might deteriorate when receiving an
   immunostimulatory agent

   - Participants with clinically significant cardiovascular/cerebrovascular disease
   including: cerebral vascular accident/stroke, myocardial infarction, unstable angina,
   congestive heart failure, or serious cardiac arrhythmia

   - Other protocol defined exclusion criteria could apply