Key clinical point: The DNA vaccine (pTVG-HP) did not show an increase in 2-year metastasis-free survival (MFS) in patients with castration-sensitive prostate cancer (PCa), apart from a subgroup with rapidly progressive disease.

Major finding: Changes in total standardized uptake value on 18F-NaF PET/CT from months 3 to 6 increased 50% in patients treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) alone and decreased 23% in patients treated with pTVG-HP.

Study details: 99 patients with castration-sensitive PCa and prostate-specific antigen (PSA) doubling time (DT) of > 12 months were randomly assigned to treatment with either pTVG-HP co-administered intradermally with 200 μg GM-CSF adjuvant or 200 μg GM-CSF alone 6 times at 14-day intervals and then quarterly for 2 years.