BioNTech’s BNT113 plus pembrolizumab misses the PFS endpoint in AHEAD-MERIT. The Phase 2/3 trial continues to assess overall survival in HPV16+ HNSCC.
Written By: Anamika Koshti, PharmD
Reviewed By: Pharmacally Editorial Team
BioNTech SE announced on October 13, 2026, that its investigational mRNA cancer immunotherapy BNT113 (tenumomeran/raplemomeran, or tenu-ra) did not demonstrate a statistically significant improvement in progression-free survival (PFS) in the Phase 2/3 AHEAD-MERIT trial (NCT04534205). The study is evaluating BNT113 plus pembrolizumab against pembrolizumab monotherapy as first-line treatment for patients with unresectable recurrent or metastatic human papillomavirus 16-positive (HPV16+) head and neck squamous cell carcinoma (HNSCC) expressing programmed death-ligand 1 (PD-L1).
The Independent Data Monitoring Committee (IDMC) recommended that the trial continue to evaluate overall survival (OS), the second primary endpoint. Under the prespecified statistical design, a statistically significant improvement in OS could establish a positive trial outcome despite the failure to meet the PFS endpoint.
PFS Result Leaves Clinical Benefit Unresolved
At the reported analysis, BNT113 plus pembrolizumab did not demonstrate a statistically significant PFS improvement compared with pembrolizumab alone. BioNTech did not disclose median PFS, a hazard ratio, confidence intervals, a P value or detailed safety findings in its October 13 announcement.
Without these data, the magnitude and direction of the treatment effect cannot be independently assessed. The result establishes that the combination did not meet the statistical criterion for PFS improvement at this analysis. It does not, however, establish that BNT113 lacks antitumour activity or that outcomes were worse than with pembrolizumab monotherapy.
The IDMC’s recommendation allows the study to continue assessing whether the combination improves OS. Trial continuation does not establish efficacy, and the survival outcome remains unknown. BioNTech stated that it remains blinded to ongoing trial data in accordance with the study’s governance procedures.
Why Overall Survival Remains Important
The Phase 3 portion of AHEAD-MERIT has two primary endpoints: PFS and OS. These provide complementary measures of clinical benefit by assessing disease progression and survival, respectively.
The prespecified statistical design allows a statistically significant OS improvement to establish a positive trial outcome even though the PFS endpoint was not met. The forthcoming OS analysis will therefore be central to determining whether the combination provides a meaningful clinical benefit.
BioNTech’s Chief Medical Officer and co-founder, Prof. Özlem Türeci, said the first PFS analysis supported continued evaluation of the combination. She also stated that immune-mediated antitumour effects may develop over time, making OS important to assessing the potential for durable benefit.
These statements reflect the company’s interpretation. Although BioNTech said BNT113 was engaging its intended therapeutic mechanism, the announcement did not provide quantitative mechanistic or immunogenicity results to independently assess that claim. Whether the proposed immune response translates into prolonged survival remains unresolved.
AHEAD-MERIT Trial Design
AHEAD-MERIT is an open-label, controlled, multicentre, two-arm Phase 2/3 trial in patients with unresectable recurrent or metastatic HPV16+ HNSCC whose tumours express PD-L1 with a combined positive score (CPS) of at least 1.
The study comprises two parts:
- Part A: A nonrandomised safety run-in designed to confirm the safety and tolerability of BNT113 combined with pembrolizumab at the selected dose range.
- Part B: The randomised portion comparing BNT113 plus pembrolizumab with pembrolizumab monotherapy to generate pivotal efficacy and safety data.
Patients receive their assigned treatment for up to approximately 24 months. Secondary endpoints include safety, objective response rate and duration of response.
HPV16-Directed Immunotherapy and Regulatory Context
Approximately one-third of HNSCC cases are associated with HPV infection, with most HPV-associated cases linked to HPV16. BioNTech states that no HPV-targeted treatments are currently approved for this disease context, highlighting the need for additional treatment approaches.
BNT113 is an investigational mRNA cancer immunotherapy encoding the HPV16-derived E6 and E7 proteins, which are frequently expressed in HPV16-positive tumours. The approach is designed to induce HPV16-specific antitumour immune responses and potentially enhance the effects of checkpoint inhibitor treatment such as pembrolizumab.
In January 2026, the US Food and Drug Administration granted BNT113 Fast Track designation for HPV16-positive HNSCC based on preliminary safety and efficacy data from AHEAD-MERIT. The designation is intended to facilitate development and expedite regulatory review for treatments addressing serious conditions and unmet medical needs. It does not constitute marketing approval or establish clinical efficacy.
Clinical Significance of the PFS Result
The AHEAD-MERIT readout marks a clinical setback for BNT113 because the combination failed to demonstrate a statistically significant PFS improvement over pembrolizumab alone. However, the trial’s prespecified statistical design allows a statistically significant OS improvement to establish a positive outcome despite the missed PFS endpoint.
With OS results still pending and numerical PFS and detailed safety findings undisclosed, the magnitude of the treatment effect and its potential to extend survival remain uncertain.
References
BioNTech Provides Update on Phase 2/3 Clinical Trial for mRNA Cancer Immunotherapy Candidate BNT113 in Metastatic HPV16-positive Head and Neck Cancer, BioNTech, 13 October 2026
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 (AHEAD-MERIT), ClinicalTrials.gov ID NCT04534205
About the Writer
Anamika Koshti (LinkedIn) is a PharmD professional and healthcare writer with interests in clinical research, pharmacovigilance, and evidence-based medicine. She has authored peer-reviewed publications on Alzheimer’s disease and PCOS, presented research at national conferences, and gained hands-on experience in medical content development and clinical data interpretation. She is committed to translating complex medical research into accurate, accessible content for healthcare professionals and patients.