Cellular and humoral immune responses
| Cohort 1 | Cohort 2 | Cohort 3 | Cohort 4 | |||
|---|---|---|---|---|---|---|
| Open-label | Open-label | Randomized, double-blinded | Open-label | |||
| GTL001 100 μg solution + imiquimod | GTL001 solution 600 μg + imiquimod | GTL001 solution 600 μg + imiquimod | GTL001 solution 600 μg + placebo | Placebo injection + imiquimod | GTL001 600 μg powder + imiquimod | |
| Measure | N = 5 | N = 5 | N = 14 | N = 7 | N = 7 | N = 9 |
| T-cell response, n/N (%)a | 2/5 (40.0) | 4/5 (80.0) | 7/13 (53.8) | 1/6 (16.7) | 1/6 (16.7) | 5/8 (62.5) |
| Seroconversion, n (%)b | ||||||
| Anti-HPV16 E7 antibody | 1/5 (20.0) | 1/5 (20.0) | 1/14 (7.1) | 0/7 (0.0) | 1/7 (14.3) | 0/9 (0.0) |
| Anti-HPV18 E7 antibody | 0/5 (0.0) | 1/5 (20.0) | 0/14 (0.0) | 1/7 (14.3) | 1/7 (14.3) | 0/9 (0.0) |
| Anti-CyaA antibody | 5/5 (100.0) | 5/5 (100.0) | 14/14 (100.0) | 7/7 (100.0) | 0/7 (0.0) | 9/9 (100.0) |
NOTE: Values are for the intent-to-treat population.
↵aThe T-cell response to overlapping 15-mer peptides covering HPV16 or HPV18 E7 was assessed by IFNγ ELISpot in PBMC collected at weeks 2, 6, 10, and 26. For each subject, peptide pool, and time point, the specific ELISpot response was calculated as [(mean antigen-stimulated spot-forming cells [SFC] − SD of antigen-stimulated SFC) − (mean SFC for medium + 2 × SD of SFC for medium)]. A specific response was considered to be positive if it was >20 SFC per 4 × 105 PBMC and the mean antigen-specific SFC was >3 × mean SFC for medium alone. For each peptide pool, a subject was considered a responder if (i) they had a positive specific response to any peptide pool at any post-vaccination time point before week 26 and did not have a specific response at baseline; or (ii) they had a specific positive response to any peptide pool at any post-vaccination time point before week 26 ≥ 2 × specific response at baseline (if they had a specific positive response at baseline).
↵bSerum antibodies to CyaA, HPV16 E7, and HPV18 E7 were assessed by ELISA at weeks 2, 6, 10, and 26. Seroconversion was defined as (i) no detectable antibody at baseline and detectable antibody at any post-baseline time point; or (ii) if detectable antibody was present at baseline, a four-fold increase in antibody titer at any post-baseline time point.