Table 1. Summary of recently completed and ongoing clinical trials.

Vaccine	Description	Is it safe?	Latest completed clinical trials: (main findings)	Clinical trials active (a) or recruiting (r)
ProstVac VF (PSA-TRICOM)	Heterologous prime/multiple boosts vaccinia virus (PSA-CD54-CD58-CD80) – fowlpox virus (PSA-CD54-CD58-CD80)	Yes19,20	●Phase II: Enhanced OS over control group by a median 8.5 mo21 ●Phase II: Enhanced OS compared with Halabi nomogram prediction22	●Phase III (r): Comparison of OS with or without GM-CSF (NCT01322490) ●Phase II (r): Comparison of disease progressions with flutamide and flutamide alone (NCT00450463)
ProstVac VF + ipilimumab (nivolumab)	ProstVac VF + dose-escalation trial of anti-CTLA4 antibody	Yes*,23	Phase I: Safe and tolerable*,23
ProstVac VF/ProstVac VF-like + docetaxel	ProstVac VF-like (rV-PSA + rV-CD80) prime/rF-PSA boost)	Yes24	Phase II: Safe. Docetaxel does not inhibit vaccine specific T-lymphocyte responses24
Ad5-PSA	PSA-encoding adenovirus 5– one administration with/without Gelfoam® (Phase I) and three administrations with Gelfoam® (Phase II)	Yes25	Phase I: Safe. In Ad5-PSA/Gelfoam® group 77% of PCa patients had detectable anti-PSA T cells25	Phase II (r): Assessment of effect of Ad5-PSA on PSADT (NCT00583024 and NCT00583752)
Sipuleucel-T	Leukopheresed patients PBMCs transduced ex vivo with PAP-GM-CSF construct (PAP2024) an then reintroduced into patients	Yes9,10	Phase III:IMPACT trial: Enhanced OS over placebo group by a median of 4.1 mo12	Phase II (a):NCT00715078a Phase II (a):NCT00715104b Phase II (a):NCT00901342c Phase IIIB (a):NCT00779402d Phase II (r):NCT01306890e Phase II (a):NCT01487863f Phase II (a):NCT01431391g
GVAX-PCa	Irradiated PCa cell lines, LNCaP and PC-3, that constitutively express GM-CSF – Prime/Boosts	Yes26,27	Phase I/II (×2): Safe. Enhanced median survival (for high dose boosts) over radiotherapy and low dose boosts by 8.7 mo26 and 11.9 mo27 respectively
GVAX-PCa + docetaxel	GVAX-PCa + docetaxel compared with docetaxel alone in PCa patients with symptomatic metastatic CRPC	No - imbalance in deaths in the combined treatment group28	Phase III: VITAL-2:† terminated due to safety concerns.
GVAX-PCa + ipilimumab	GVAX-PCa (described above) + dose-escalation trial anti-CTLA4 antibody	Yes††,29	Phase I: Safe†† (up to 3 mg/kg ipilimumab safe and well tolerated)
DNA-PAP	Multiple intradermal vaccinations of rhGM-CSF with a plasmid (pTVG-HP) encoding PAP	Yes30	Phase I/II: Safe. 7/22 patients had ≥2-fold increase in PSADT	●Phase II (r): Comparison of GM-CSF ± DNA-PAP (NCT01341652) ●Phase II (a): Determine safety and immunogenicity (NCT00849121)
DNA-PSA	Multiple intradermal vaccinations of GM-CSF + IL-2 with a plasmid (pVAX) encoding PSA	Yes31	Phase I: Safe. 2/3 patients (given high dose pVax/PSA) had significantly elevated levels of PSA-specific IFNγ+ T cells
GMCI	AdV-tk/anti-herpetic prodrug (GCV) prior to prostatectomy	Yes32,33	Phase I–II: Significant influx of CD8+ T cells No improvement in patient prognoses34
GMCI + RT	AdV-tk/anti-herpetic prodrug (GCV) prior to prostatectomy + RT	Yes74	Phase I/II: Safe. Good locoregional control but inadequate systemic control72	Phase III (r): Comparing disease-free survival: GMCI + RT vs. placebo (NCT01436968)

^*Grade 3–4 side effects observed with 3–10 mg/kg ipilimumab (colitis and neutropenia); ^†Phase III trials (×2) with GVAX-PCa were terminated, as discussed in the main text; ^††Hypophysitis and/or sarcoid alveolitis diagnosed in patients receiving 5 mg/kg ipilimumab; ^aAims to assess CD54 upregulation with varying fusion protein (PAP2024) concentrations; ^bAims to assess the immune response within prostate tissue following the neo-adjuvant administration of sipuleucel-T (prostatectomy specimens taken after sipuleucel-T vaccinations will be compared with tissue from the core biopsy specimen obtained prior to treatment); ^cAims to evaluate the magnitude of immune responses to sipuleucel-T in patients with metastatic prostate cancer; ^dAims to determine if sipuleucel-T is effective in early stage, non-metastatic prostate cancer patients (end-point: biochemical failure); ^eAims to quantify the risk of cerebrovascular events following sipuleucel-T therapy for all subjects with CRPC; ^fAims to evaluate the impact of concurrent or sequential administration of abiraterone acetate plus prednisone on product parameters of sipuleucel-T; ^gAims to evaluate immune responses in patients with non-metastatic prostate cancer when androgen deprivation therapy is started before or after sipuleucel-T. CRPC, castration-resistant prostate cancer; GCV, ganciclovir; GMCI, gene-mediated cytotoxic immunotherapy; GM-CSF, granulocyte macrophage colony-stimulating factor; IFNγ, interferon γ; IL-2, interleukin-2; OS, overall survival; PAP, prostate acid phosphatase; PBMC, peripheral blood mononuclear cell: PSA, prostate-specific antigen; PSADT, PDA doubling time; RT, radiotherapy.