A Clinical Trial Investigating the Safety, Tolerability, and Therapeutic Effects of BNT113 in Combination With Pembrolizumab Versus Pembrolizumab Alone for Patients With a Form of Head and Neck Cancer Positive for Human Papilloma Virus 16 and Expressing the Protein PD-L1

Key Inclusion Criteria:

• Patients must sign the written pre-screening informed consent form (ICF) before anypre-screening procedures.

• Patients who present histologically confirmed recurrent or metastatic HPV16+ HNSCCthat is considered incurable by local therapies.

• Patients who have a tumor that expresses PD-L1 [CPS ≥1] as determined by theEuropean Conformity (CE)-marked/Food and Drug Administration-approved CDx PD-L1immunohistochemistry 22C3 pharmDx performed according to the manufacturer'sinstructions for use.

• Patients must not have had prior systemic anticancer therapy administered in theincurable recurrent or metastatic setting. Systemic therapy which was completed morethan 180 days prior to randomization, if given as part of multimodal treatment forlocally advanced disease, is allowed.

• Patients who have measurable disease based on RECIST 1.1 as determined by the siteand confirmed by BICR. Tumor lesions situated in a previously irradiated area may beconsidered measurable, if progression has been demonstrated in such lesions diseaseby RECIST 1.1.

• All patients must provide a tumor tissue sample (formalin fixed paraffin embedded [FFPE] blocks or both slides and curls) from archival tissue. Alternatively, a freshbiopsy sample could be provided if a biopsy sample is performed as part of thepatient's standard clinical practice before the first dose of trial treatment. Thesample should be preferably derived from a current site of metastatic or recurrentdisease. Otherwise, a sample from the primary tumor can be submitted.

Key Exclusion Criteria:

Medical conditions:

• Patients present primary tumor site of nasopharynx (any histology).

• Patients with another primary malignancy that has not been in complete remission forat least 2 years, with the exception of those with a negligible risk of metastasisor death (such as adequately treated carcinoma in situ of the cervix, non-invasivebasal or non-invasive squamous cell skin cancer, localized prostate cancer,non-invasive superficial bladder cancer or breast ductal carcinoma in situ).

Prior/concomitant therapy:

• Patients who have received or currently receive the following therapy/medication:

1. Chronic systemic immunosuppressive treatment including corticosteroid treatment (prednisone >10 mg daily orally [PO] or intravenously [IV], or equivalent) inthe 7 days prior to the first dose of trial treatment.

2. Prior treatment with other immune-modulating agents that was (a) within fewerthan 4 weeks (28 days) or five half-lives of the agent (whichever is longer)prior to the first dose of BNT113, or (b) associated with immune-mediated AEsthat have not resolved prior to the first dose of BNT113 or that pose anadditional risk of on-trial complications, per investigator's assessment, or c)associated with toxicity that resulted in discontinuation of theimmune-modulating agent and that poses an additional risk of on-trialcomplications, per investigator's assessment.

3. Prior treatment with live attenuated vaccines within 4 weeks before the firstdose of BNT113.

4. Prior treatment with an investigational drug (including investigationalvaccines) within 4 weeks or five half-lives of the agent (whichever is longer)before the planned first dose of BNT113.

5. Ongoing treatment with therapeutic PO or IV antibiotics. Note: Patientsreceiving prophylactic antibiotics (e.g., for prevention of a urinary tractinfection or chronic obstructive pulmonary disease) may be enrolled.

• Prior treatment with anti-cancer immunomodulating agents, such as blockers ofprogrammed death receptor-1 (PD-1), PD-L1, tumor necrosis factor receptorsuperfamily member 9 (TNRSF9, 4 1BB, CD137), OX 40, therapeutic vaccines, cytokinetreatments, or any investigational agent within 4 weeks or five half-lives of theagent (whichever is longer) before the first dose of BNT113.

• Treatment with non-systemic anti-cancer therapy (e.g., radiotherapy or surgery)within 2 weeks prior to randomization. Note: Prior treatment with bone resorptivetherapy, such as bisphosphonates (e.g., pamidronate, zoledronic acid) and denosumab,is allowed.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.