Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02821494 |
Other study ID # |
HPV16HH01 |
Secondary ID |
|
Status |
Completed |
Phase |
Phase 1
|
First received |
|
Last updated |
|
Start date |
March 2015 |
Est. completion date |
March 2020 |
Study information
Verified date |
February 2021 |
Source |
Leiden University Medical Center |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
A phase I study to establish the highest safe dose that induces HPV16 E6-specific T-cell
responses, using the highly promising novel therapeutic vaccine concept named: Hespecta (HPV
E Six Peptide Conjugated To Amplivant®) to induce HPV16 E6-specific T-cell responses.
Description:
Human papillomavirus (HPV) has been found to be associated with several types of premalignant
lesions and cancer. HPV16 is the far most common HPV type detected in these tumors and
premalignant lesions. HPV16 encodes the two tumor-specific oncoproteins E6 and E7. In most
humans the virus is cleared. However, in some individuals, infection results in an
uncontrolled persistent HPV16 infection that due to expression of the viral oncoproteins E6
and E7 may lead to the formation of malignancies. Moreover, these oncoproteins maintain the
malignant state of the transformed cells. The virus-specific interferon-γ (IFNγ)-producing
cluster of differentiation 4 (CD4+) helper T cells (Th1 cells) and cluster of differentiation
8 (CD8+) cytotoxic T-lymphocytes (CTL) are able to recognize peptides processed from the
highly immunogenic E6 and play a critical role in the elimination and/or control of the
virus. Studies in patients with HPV associated tumors showed that the spontaneous
HPV-specific T-cell responses, are weak and fail to sufficiently control tumor outgrowth.
Preexisting specific T-cell responses against E6 and E7 in patients with HPV related tumors
such are associated with better outcome after treatment. Since the HPV16-transformed tumor
cells constitutively express the two HPV16 encoded E6 and E7 oncoproteins, these viral
antigens are considered to be excellent targets for immunotherapeutic vaccine strategies
aiming at reinforcing the tumor-specific T-cell response. Previous vaccination studies showed
that the use of our first generation HPV16 synthetic long peptides vaccine (HPV16-SLP) was
safe and highly immunogenic in patients with HPV-induced ano-genital lesions. Vaccination of
patients with cervical cancer (CxCa) also resulted in the induction of HPV16-specific T-cell
responses but the nature and strength of the induced T cell responses was not sufficient for
the regression of these tumors. Specifically, it was concluded that the polarization of the T
cell response to Th1 (IFNγ-response) was not optimal and a much stronger CD8+ T cell response
was required for clinical efficacy. These results initiated the development of new HPV16
vaccination strategies that are able to polarize the induced Th1 response and obtain strong
CD8+ T-cell cytotoxicity. One of these developments consists of conjugating two of the HPV16
E6 SLP to Amplivant® a synthetic Toll-like receptor (TLR) 2 ligand. These two peptides cover
the most immunodominant regions of the overlapping HPV16-SLP set and contain both Th and CTL
epitopes. Peptide conjugated Amplivant® has been selected because it is acknowledged for its
capacity to strongly enhance antigen presentation by dendritic cells (DCs), enhance T-cell
priming and cause superior induction of effective anti-tumor CTL responses in mouse tumor
models, compared to a mixture of free TLR ligand and peptide. In preclinical murine studies,
Amplivant®-conjugated SLP showed 10 to 100 times higher bioactivity compared to unconjugated
SLP, in terms of induced immune responses. In addition, the quantity and quality of human
T-cell responses, and especially the HPV16-specific CD8+ T-cell response, in cancer patients
could be markedly enhanced by ex vivo stimulation with Amplivant®-conjugated SLPs.