Tryggestad AMA, Axcrona K, Axcrona U, et al. - A personalized dendritic cell (DC) vaccine to reduce the risk of biochemical relapse (BCR) was tested in patients with high-risk prostate cancer (PC) after radical prostatectomy, and findings of this adjuvant first-in-man phase I/II DC vaccine study demonstrated promising outcomes. Safety of the vaccine was evident, with no side effects.

• BCR can occur despite surgery in high-risk PC cases, and noncurative disease can develop in these patients.

• This study involved 20 patients with high-risk PC and undetectable PSA who underwent robot-assisted laparoscopic prostatectomy (RALP) and 12 weeks after this procedure they received DC vaccinations for 3 years or until BCR.

• Of 20 patients, 11 remained BCR-free during a median of 96 months (range: 84–99), and BCR occurred in 9 patients, either during (n = 4) or after (n = 5) the vaccination period.

• Early BCR during the vaccination period occurred in three of five patients diagnosed with intraductal carcinoma.

• Remission after 84 months was achieved by five of the 12 patients with the International Society of Urological Pathology (ISUP) grade 5 PC, and all mounted immune responses.

• A particularly high risk of developing postsurgical BCR was observed in patients diagnosed with extraprostatic extension and ISUP grade 5 PC.

• In this subgroup, the vaccine response was associated with a decreased BCR incidence.