Safety, efficacy and immunogenicity of HPV 16 E7 DNA vaccination in HPV related squamous cell cancer.

Human papilloma virus (HPV) infection (genotypes 16 and 18) is strongly
associated with the development of squamous cell cancer, such as cancers of the
anogenital region and head and neck cancer. Because the persistence of
oncogenic HPV proteins E6 and E7 is required for carcinogenesis, these viral
antigens are exquisite targets for immunotherapeutic interventions.
Here we propose to initiate a phase I/II study in patients with HPV positive
squamous cell cancer of the cervix, penis, vagina, vulva or head and neck
region using a novel and potent intradermal HPV DNA vaccination strategy. In
preclinical studies this strategy was shown to be much more potent in the
induction of (E6 and) E7-specific CD8+ cytotoxic T cell immunity than existing
DNA vaccination strategies, providing a strong rationale for its clinical
evaluation. In this phase I/II study we will define the safety, efficacy and
immunogenicity of this highly promising DNA vaccination strategy in patients
with advanced HPV related squamous cell cancers and the value of a boost with
the HPV-DNA vaccine in order to optimally activate both the helper and
cytotoxic T-cell arm of the immune system. This will allow us to define the
value of this novel DNA vaccination strategy for the treatment of HPV
associated malignancies.

To study the toxicity, efficacy and immunogenicity of naked DNA vaccines
encoding the shuffled HPV 16 E7 gene products (TTFC-E7SH) in advanced-stage
patients with squamous cell carcinoma of the anogenital or the head and reck
region.

Phase I/II toxicity-evaluation design with an evaluation of the prime-boost
model in 35 patients.

TTFC-E7SH will be injected intradermally on days 0, 3 and 6 using a permanent
make up device, and boost vaccinations after 4 weeks (days 28, 31 and 34).

From eligible patients HPV will be analyzed in the primary tumor cells. If HPV
is present patients will receive intradermal DNA vaccination with TTFC-E7SH on
days 0, 3, and 6, and boost vaccinations after 4 weeks (days 28, 31, and 34).
At time points 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 16 and 20 weeks patients will be
seen at the outpatient clinic including physical examination and evaluation of
toxicity. Blood and urine samples will be taken and frozen for analyses. Prior
to the first vaccination (t=0), at t=14 days and t=42 days blood will be drawn
for immunomonitoring. In addition, skin biopsies will be taken from the
vaccination site at days 0, 14 and 42.
For the patients in phase I no standard treatment exists. Their median life
expectancy is less than 6 months. In phase II patients will undergo
chemoradiation prior to the vaccination. DNA vaccination is considered a safe
mode of vaccination. The vaccine that is being used in this clinical trial does
not contain factors favoring integration, nor does it contain sequences that
can lead to replication, or that can become part of viruses or bacteria.
Preclinical data show that intradermal DNA vaccination using a permanent
make-up device is much more potent than classic intramuscular DNA vaccination.
Tattooing of skin is a commonly used method for treatment of scars or as part
of reconstructive surgery (nipple tattooing after breast reconstructive surgery
for breast cancer patients). It may induce a burning sensation during
tattooing, which will stop the moment the tattooing is ended. Using this method
DNA will be applied intra-epidermally (in the epidermis), therewith limiting
spread to other tissues (in contrast to intramuscular of intravenous delivery).
Furthermore, flulike symptoms with fever during 48 hours after the vaccination
can occur.
We therefore consider the physical discomfort associated with participation in
this study as mild. As for participation in any phase I/II clinical study the
intensity of site visits, physical exams, blood tests and other tests, is not
different in this study.