Researchers have published data from a randomized Phase I trial of the personalized vaccine TG4050 for head and neck cancer. The study assigned patients with operable HPV-negative head and neck squamous cell carcinoma to receive the vaccine either immediately after standard treatment or only upon later recurrence. After a median follow-up of 30 months, none of the 16 evaluable patients in the immediate treatment arm had experienced recurrence, while 3 of 16 patients in the observation arm had recurrences. An updated analysis at median 41 months confirmed this result, with no additional recurrences in either arm. The results appeared on August 17, 2026, in the journal Nature Communications.
A vaccine tailored to the tumor
TG4050 is a personalized neoantigen vaccine that encodes up to 30 patient-specific predicted tumor neoantigens and is delivered via a modified vaccinia Ankara virus vector. According to the authors, AI-driven algorithms predict neopitopes; up to 30 target structures are selected based on expression, presentation, and likelihood of recognition by the patient's T cells. In total, the individual vaccine was successfully manufactured for 53 patients; for 3 other otherwise eligible patients, manufacturing failed.
17 patients were assigned to the immediate arm, 16 to the observation arm, which planned TG4050 only upon recurrence. According to CancerNetwork, the study was open, not blinded. The primary endpoint was safety; disease-free survival was recorded as a secondary endpoint. Exclusion followed pre-specified criteria for minimum exposure; the patient had received two doses and remained in the intent-to-treat population. The study authors themselves consider the sample size and number of recurrences too small to conclude on TG4050's efficacy; they point to the ongoing Phase II portion of the study.
In comparison: the signal at median 16.2 months
Already in 2024, the study authors reported the same difference at a professional conference of the AACR, according to their statement, at median 16.2 months: no recurrences in evaluable patients in the immediate arm, three recurrences in the observation arm at 6.2, 8.8, and 18.5 months. The updated analysis at median 41 months follow-up confirmed the same pattern, with no additional recurrences added.
What happens to the T cells of patients
In 11 of 15 patients from the immediate arm with available samples, 73.3 percent, researchers identified T-cell responses specific to tumor characteristics, with a median of 3 responding neoantigens per patient. CD8-positive T cells triggered by the vaccine remained detectable up to 24 months, one year after the final dose.
In the safety evaluation of 19 patients who had received at least one dose, there were no dose-limiting toxicity and no severe, vaccine-attributed side effects. In 18 of 19 patients, 94.7 percent, mild to moderate reactions occurred, mostly at the injection site.
Who stands behind the study
According to a 2024 AACR statement, Transgene sponsored the study; Transgene and NEC, the developers of TG4050, funded it jointly; Bpifrance supported the immunological analyses. According to the ClinicalTrials.gov registry, Transgene is the responsible sponsor of the entry. According to the same statement, immunologist Olivier Lantz is a shareholder of Mnemo Therapeutics and Cereus; his laboratory works as a contractor for Transgene.
As the trade publication PharmaTimes reported in April 2026, Transgene had completed patient allocation in the Phase II portion of the study with 38 participants. Chief executive officer Alessandro Riva announced there that the primary endpoint should be available by the end of the first quarter of 2028. For the two patients from the observation arm who received TG4050 only after recurrence, lasting disease control was not achieved; the authors consider combination with checkpoint inhibitors scientifically plausible because of high PD-1 expression in neoantigen-specific CD8-positive T cells.