Personalized RNA neoantigen vaccines stimulate T cells in pancreatic cancer.
Level 4 - case-series / case-control
Single-arm phase I trial without a randomized comparator group
PubMed 37165196 · doi:10.1038/s41586-023-06063-y
What was done
In a phase I trial evaluating oncologic feasibility, safety, and immunogenicity, 16 patients with surgically resected pancreatic ductal adenocarcinoma (PDAC) were treated sequentially with atezolizumab (anti-PD-L1), a personalized mRNA neoantigen vaccine (autogene cevumeran, up to 20 neoantigens per patient synthesized in real time), and subsequent mFOLFIRINOX chemotherapy (completed in 15 patients). Neoantigen-specific T-cell responses were evaluated via functional assays and a clone-tracking strategy (CloneTrack), alongside an 18-month recurrence-free survival endpoint.
What was found
Autogene cevumeran was administered within 3 days of benchmarked times and was tolerable. De novo high-magnitude neoantigen-specific T cells were induced in 8 of 16 patients (50%), with half targeting more than one vaccine neoantigen. Vaccine-expanded T cells comprised up to 10% of all blood T cells, re-expanded with a vaccine booster, and included long-lived polyfunctional neoantigen-specific effector CD8+ T cells. At 18-month median follow-up, responders had a longer median recurrence-free survival (not reached) compared with non-responders (13.4 months, P = 0.003). Responders and non-responders mounted equivalent immunity to a concurrent unrelated SARS-CoV-2 mRNA vaccine.
Why it matters
This trial shows that real-time personalized mRNA vaccines are feasible in resected pancreatic cancer and can induce durable neoantigen-specific T cells that correlate with reduced disease recurrence.
Limits
The study is an uncontrolled, single-arm phase I trial with a very small sample size (n = 16). Survival comparisons were made internally between immune responders and non-responders rather than against a randomized control group, and the multi-agent sequential regimen makes it difficult to isolate the vaccine's specific therapeutic effect.
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- partial Personalized neoantigen vaccines have achieved cures in patients with treatment-refractory pancreatic cancer and renal cell carcinoma.