We're excited to see this long-awaited publication. The CeGat clinic, based in Tubingen, Germany, provides advanced genetic testing of tumor samples and uses it to make personalized peptide vaccines for glioblastoma (GBM) patients. These vaccines were not tested in a formal trial setting, but the real-world results look promising. From Oct 2015 to Aug 2023, 173 GBM patients were treated, with a median of 19 personalized peptides included per vaccine. Seventy patients were treated before tumor progression (newly diagnosed) and 103 were treated after progression (recurrent). The vaccines were well tolerated, and many patients developed durable immune responses. Median overall survival (OS) for the newly diagnosed cohort had not been reached at the time of data cutoff, and median OS was 23.8 months for the recurrent cohort. Median on-treatment survival from initiation of vaccine treatment was 28.9 months for the newly diagnosed versus only 9.8 months for recurrent patients. Importantly, significantly prolonged survival was observed for patients who had multiple vaccine-induced T-cell responses (53 months) compared to those with no/low induced responses (27 months).
As acknowledged by the study authors, there are factors that may have biased the data, such as the time required for vaccine production (median time from diagnosis to first vaccination was 10.3 months; range 3-54 months), patients' socio-economic status (the cost of treatment, as well as travel for treatment, was substantial), and the varied additional treatments patients may have received (additional therapeutic strategies were applied at the discretion of patients' primary treating physicians). Nevertheless, the connection between vaccine-induced T-cell response and prolonged survival is cause for hope, and we look forward to seeing more data on personalized peptide vaccines, especially in combination with other treatment strategies!