Inclusion Criteria:

          -  Female or male patients, aged at least 18 years (no upper limit of age)

          -  ECOG PS 0 or 1

          -  Life expectancy of at least 3 months

          -  Patients with histologically or cytologically documented metastatic or
             refractory/recurrent HPV-16 + cancer: cervical, vulvar, vaginal, penile and anal.

          -  Disease MUST not be amenable to curative surgery resection or curative radiotherapy
             with documented disease progression

          -  Prior therapy:

               -  No more than one prior systemic treatment for recurrent /metastatic disease

               -  Prior treatment for recurrent or metastatic disease is not required for:

                    -  Patients with recurrence/progression within 6 months after completion of
                       prior multimodal therapy for localized or locally advanced disease

                    -  Patients who are unsuitable for platinum-based therapy

                    -  Patients who refuse chemotherapy or other standard therapies for the
                       treatment of metastatic or recurrent disease

          -  Limited hepatic disease for patients with liver metastases at baseline

          -  Availability of tumor tissue from biopsy

          -  At least one measurable lesion by CT scan according to RECIST 1.1.

          -  Adequate hematological, hepatic and renal function

          -  Negative blood pregnancy test at screening for women of childbearing potential

          -  Highly effective contraception for both male and female patients if the risk of
             conception exists during the study period and for 3 months after the last study
             treatment administration

        Exclusion Criteria:

          -  Prior exposure to cancer immunotherapy including cancer vaccines, any antibody/drug
             targeting T cell co-regulatory proteins (immune checkpoints)

          -  Patients under chronic treatment with systemic corticosteroids or other
             immunosuppressive drugs for a period of at least 4 weeks and whose treatment was not
             stopped 2 weeks prior to the first study treatment, with the exception of patients
             with adrenal insufficiency who may continue corticosteroids at physiological
             replacement dose, equivalent to ≤ 10 mg prednisone daily. Steroids with no or minimal
             systemic effect (topical, inhalation) are allowed

          -  Patients with CNS metastases except those with brain metastases treated locally and
             clinically stable during 4 weeks prior to start of study treatment, and those without
             ongoing neurological symptoms that are related to the brain localization of the
             disease

          -  Other active malignancy requiring concurrent systemic intervention

          -  Patients with previous malignancies other than the target malignancy to be
             investigated in this trial (except non-melanoma skin cancers, and the following in
             situ cancers: bladder, gastric, colon, endometrial, cervical/dysplasia, melanoma, or
             breast) are excluded unless a complete remission was achieved at least 2 years prior
             to study entry AND no additional therapy is required during the study period

          -  Patient with any organ transplantation, including allogeneic stem cell transplantation

          -  Known severe hypersensitivity reactions to monoclonal antibodies (Grade ≥ 3 NCI-CTC),
             any history of anaphylaxis, or uncontrolled asthma

          -  Any known allergy or reaction to eggs, gentamycin or attributed to compounds of
             similar chemical or biological composition to therapeutic vaccines/immunotherapeutic
             products

          -  Any known allergy or reaction to any component of anti-PD-L1/PD-1 or its excipients

          -  Patients with known history or any evidence of active interstitial lung disease /
             pneumonitis

          -  Patients with active, known, or suspected auto-immune disease or immunodeficiency,
             except type I diabetes mellitus, hypothyroidism only requiring hormone replacement or
             skin disorders (such as vitiligo, psoriasis) not requiring systemic treatment

          -  Clinically significant (that is, active) cardiovascular disease: cerebral vascular
             accident/stroke or myocardial infarction (< 6 months prior to enrollment), unstable
             angina pectoris, congestive heart failure (New York Heart Association Classification
             Class ≥ II), or serious uncontrolled cardiac arrhythmia requiring medication/active
             intervention, history of myocarditis

          -  History of uncontrolled intercurrent illness including but not limited to:

               -  Hypertension uncontrolled by standard therapies (not stabilized to 150/90 mmHg or
                  lower)

               -  Uncontrolled diabetes (e.g., hemoglobin A1c ≥ 8%)

               -  Uncontrolled infection