Before starting the trial, a tumor tissue sample will be required. This can be from previously collected tissue stored in blocks or slides, or from a fresh biopsy if one is performed as part of standard care.

Blood tests will be performed to check bone marrow function, liver function, kidney function, and blood clotting ability.

A pregnancy test will be required if applicable.

Tumor measurements will be taken using imaging scans to establish baseline measurements according to RECIST 1.1 criteria, which is a standard method for measuring tumors.

The tumor will be tested to confirm it is positive for human papilloma virus 16 and expresses the PD-L1 protein with a score of at least 1.

The trial has two parts. Part A is a safety phase with a small number of patients. Part B is the main randomized phase.

In Part B, assignment to one of two treatment groups will occur randomly. One group receives BNT113 combined with pembrolizumab. The other group receives pembrolizumab alone.

The treatment received will depend on which group is assigned.

Both BNT113 and pembrolizumab are administered through intravenous infusion, which means the medication is given directly into a vein.

Pembrolizumab will be given as an infusion into a vein. The specific dosage and frequency will be determined according to the trial protocol.

If assigned to the combination group, BNT113 will also be given as an injection or infusion into a vein, in addition to pembrolizumab.

Treatment will continue for as long as the tumor does not grow and side effects remain manageable.

Regular visits to the trial site will be required according to the treatment schedule.

At each visit, a physical examination will be performed and questions about any side effects or health changes will be asked.

Blood tests will be performed regularly to monitor organ function and overall health.

Imaging scans will be performed at scheduled intervals to measure the tumor and assess whether it is responding to treatment, staying stable, or growing.

All side effects will be recorded and assessed according to CTCAE version 5.0, which is a standard system for grading the severity of side effects.

Particular attention will be paid to serious side effects, those requiring hospitalization, and any side effects that are severe (Grade 3 or higher).

If significant side effects occur, the treatment dose may be reduced, delayed, or stopped depending on the severity.

Tumor response will be evaluated using imaging scans according to RECIST 1.1 criteria.

The scans will be reviewed both by the treating physician and by independent experts who do not know which treatment was received.

The response categories include complete response (tumor disappears completely), partial response (tumor shrinks significantly), stable disease (tumor neither shrinks nor grows significantly), or progressive disease (tumor grows).

Response assessments will occur at 6 months and 12 months after starting treatment, and at additional time points as specified in the trial protocol.

If applicable, a highly effective method of contraception must be used during treatment and for at least 6 months after receiving the last dose of trial medication.

Egg or sperm donation should not occur during this period.

Treatment will continue as long as the tumor is not progressing and side effects are tolerable.

Treatment may be stopped if the tumor grows, unacceptable side effects occur, or if withdrawal from the trial is requested.

If treatment is stopped due to side effects, continued monitoring may still be required as part of the trial.

After treatment ends, follow-up visits will continue to monitor overall survival and long-term outcomes.

Information about health status and any disease progression will be collected during these follow-up visits.

The trial is expected to continue collecting information until approximately April 2029.