Subjects with Head and neck cancer with Squamous cell carcinoma other than Buccal mucosa or Buccal mucosa with any distant metastatic disease

Non squamous cell carcinoma HPE or Salivary gland tumors or Nasopharyngeal tumors

History of hepatitis B surface antigen (HBsAg) or hepatitis C antibody (anti-HCV) positive, or other clinically active liver disease, or tests positive for HBsAg or anti- HCV at Screening

History of human immunodeficiency virus (HIV) antibody positive, or tests positive for HIV at Screening

Other active malignancy requiring concurrent intervention.

Subject with previous malignancies (except non-melanoma skin cancers, and the following in situ cancers: bladder, gastric, colon, cervical/dysplasia, endometrial, melanoma, or breast) are excluded unless a complete remission was achieved at least 2 years prior to screening AND no additional therapy is required or anticipated to be required during the study period.

Subject with a condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of randomization. Corticosteroids with minimal systemic absorption and adrenal replacement steroid doses > 10 mg daily prednisone equivalent, are permitted in the absence of active autoimmune disease.

Subject with active, known or suspected autoimmune disease. Subject with type I diabetes mellitus, hypothyroidism only requiring hormone replacement, skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment or conditions not expected to recur in the absence of an external trigger are permitted to enroll.

Prior therapy with anti-tumor vaccines or other immuno-stimulatory antitumor agents

Prior radiotherapy or radiosurgery received within 2 weeks prior to screening.

Prior treatment with Nivolumab or any other anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CD-137, or anti-CTLA-4 antibody (including ipilimumab or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways)

Subject with interstitial lung disease that is symptomatic or may interfere with the detection or management of suspected drug-related pulmonary toxicity

Recent cardiac illness myocardial infarction within 6 months

Subject not recovered from the effects of major surgery or significant traumatic injury at least 14 days before the first dose of study treatment.

History of severe hypersensitivity reactions to other monoclonal antibodies.

Allergy or intolerance (unacceptable adverse event) to study drug components, or Polysorbate-80-containing infusions

Ongoing or planned administration of anti-cancer therapies other than those specified in this study or use of strong CYP3A4 inhibitors.

Have received treatment with any other investigational drug in the last 30 days before study entry, or within less than five half-lives after receiving the previous investigational drug.

Receipt of IV antibiotics for infection within 14 days of randomization  

Major surgical procedure or significant traumatic injury within 28 days prior to study treatment start or anticipation of the need for major surgery during study treatment.

Current severe, uncontrolled systemic disease (e.g., clinically significant cardiovascular, pulmonary, or metabolic disease; wound healing disorders; ulcers; or bone fractures)

Have a history or suspicion of unreliability, poor cooperation, or non-compliance with medical treatment or any other medical or psychiatric condition that could compromise study participation.

History of drug or alcohol abuse according to Diagnostic and Statistical Manual of Mental Disorders (5th edition) (DSM-V) criteria within 1 year before Screening or positive test result(s) for alcohol or drugs of abuse (including barbiturates, opiates, cocaine, cannabinoids, amphetamines, and benzodiazepines) at Screening if required as per medical history.

Have any concurrent disease or condition that, in the opinion of the investigator, would make the subject unsuitable for participation in the study.