TECHNICAL FIELD OF THE การประดิษฐ์
5 The การประดิษฐ์นี้ relates to biotechnology and immunology applied to human health. It
particularly relates to a vaccine formulation for the treatment of malignant tumors.
BACKGROUND OF THE การประดิษฐ์
Her1 and Her2 รีเซปเตอร์ are transmembrane glycoproteins with tyrosine kinase activity that
10 belongs to a family of รีเซปเตอร์ known as the ErbB family (Normanno N, et al (2005) Curr
Drug Targets 6, (3): 243-257). Her1 is overexpressed in lung, breast, head and neck,
colorectal, pancreas, bladder, ovary tumors, glioblastomas (TM Brand, et al, (2011) Cancer
Biol Ther 11 (9): 777-792); (Zhau HY et al, (1996) Proc Natl Acad Sci U S A 93, (26): 15152-
15157; Liu XH, et al, (1993) J Clin Endocrinol Metab 77 (6): 1472-1478; Neal DE, et al,
15 (1985) Lancet 1 (8425): 366-368; Gullick WJ, et al, Cancer Res 46 (1): 285-292; Salomon
DS, et al, (1995) Crit Rev Oncol Hematol 19 (3): 183-232). Her1 overexpression is
associated with poor prognosis in head and neck tumors and lung cancer, with a high risk of
disease recurrence (Turkeri LN et al, (1998) Urology 51 (4): 645-649; Chow NH, et al, (1997,)
Anticancer Res 17 (2B): 1293-1296) and with decreased survival of patients with ovarian,
20 colon, bladder, thyroid and head and neck cancer (Grandis et al, (1998) J Cell Biochemr 69
(1):55-62).
Furthermore, Her1 expression levels correlate with resistance to conventional therapies
(Holbro T, et al, (2003) Exp Cell Res 284 (1): 99-110). Also, an aberrant Her2 receptor
expression as compared with expression in normal tissues has been found in breast gastric, 25 ovarian and prostate tumors (Tai W et al, (2010) J Control Release 146 (3): 264-275). In
addition, deregulation of this receptor has been observed in the malignant transformation of
the respiratory tract (Andrade Filho et al., 2010) and is a mechanism of tumor resistance to
anti-Her1 therapies (Brand et al, (2011) Cancer Biol Ther 11 (9): 777-792). Her2
overexpression in breast tumors has been correlated with lower overall survival and relapse-
30 free survival.
Many of the aforementioned tumors co-express high levels of Her1 and Her2, and the overexpression of both รีเซปเตอร์ is associated with decreased patient survival (Wiseman SM, et al, (2005) Cancer. May 1;103(9): 1770-7). Patients with Her2 positive breast tumors have a high risk of mortality associated with the disease, and in addition, the co-expression
35 of Her1 and Her2 in these tumors significantly increases this risk, which indicates that Her1
expression in these carcinomas has a synergistic effect on Her2 expression (Suo Z et al,
(2002) J Pathol 196 (1): 17-25). It has been experimentally demonstrated that there is
2
synergistic interaction between these รีเซปเตอร์ in cell malignant transformation (Kokai Y et al, (1989) Cell 58 (2): 287-292). Other examples of tumors in which co-expression of Her1 and Her2 has been found are brain, ovarian, head and neck, lung, esophagus and colon
cancers (Emanuel SL et al, (2008) Mol Pharmacol 73 (2): 338-348; Ako E et al, (2007).
5 Oncol Rep 17 (4): 887-893; Venkateswarlu Set al, (2002) Oncogene 21 (1): 78-86).
It is well documented in the literature the physiological role of the aberrant expression and co-expression of Her1 and Her2 รีเซปเตอร์ in tumors. These รีเซปเตอร์, through the formation of dimers and heterodimers (Pinkas-Kramarski R et al, (1996) EMBO J 15 (10): 2452-2467),
regulate important processes in tumor biology, such as sustained proliferation, angiogenesis, 10 inhibition of apoptosis, metabolic reprogramming and invasive and metastatic capacity
(Hanahan D et at (2011) Cell 144 (5): 646-674).
Both รีเซปเตอร์ Her1 and Her2 have a similar structure consisting of an extracellular domain (ECD), a single transmembrane domain and an intracellular domain with tyrosine kinase activity. Her1 ECD (ECD-Her1) and Her2 ECD (ECD-Her2) have a molecular weight of 105
15 and 110 kDa respectively, and might have a different conformation in space than that of the
rest of the molecule. The ECDs ประกอบรวมด้วย four subdomains named I, II, Ill and IV.
Subdomains I and III are the regions that form the ligand-binding site and contain potential
glycosylation sites. Subdomain II is the critical region for dimerization between รีเซปเตอร์,
and it is called "dimerization arm" (Garrett TP et al, (2002) Cell 110 (6): 763-773; Ferguson
20 KM et al, (2003) Mol Cell 11 (2): 507-517).
Seven Her1 ligands have been described, among them the most relevant for tumor formation are the Epidermal โกร๊ตธ์แฟคเตอร์ (EGF), that promotes the proliferation of epidermal cells which express the receptor, the Transforming โกร๊ตธ์แฟคเตอร์ (TGF) and
Amphiregulin (Normanno et al, (2005) Curr Drug Targets 6 (3): 243-257). The ECD-Her1 is 25 in dynamic equilibrium and has multiple conformations that include "closed" conformations
and conformations where subdomain II is in a more flexible state. The binding of the ligand shifts the equilibrium towards "extended" or active conformation, a conformational state that is competent for dimerization (Ferguson KM, (2008) Annu Rev Biophys. 37: 353-373).
However, no specific ligand for Her2, has not been found. Signaling through this receptor 30 does not require โกร๊ตธ์แฟคเตอร์s, since the receptor has an active or "extended" conformation
of constitutive form which exposes its dimerization subdomain (Cho HS et al, (2003) Nature
421 (6924): 756-760). For this reason Her2 receptor is the preferred dimerization partner for
all the other members of the ErbB family, ที่รวมถึง Her1 (Franklin MC et al, (2004) Cancer
Cell 5 (4): 317-328). Heterodimerization with Her2 contributes to a decrease in the degree of 35 endocytosis of Heil and an increase of recycling to the membrane of the รีเซปเตอร์ that form
the heterodimer (Lenferink A E et al, (1998) EMBO J 17 (12): 3385-3397).
3
As described by Baselga J et al, (2009) Nat Rev Cancer 9 (7): 463-475), the ligand-induced dimerization allows the autophosphorylation and transphosphorylation of tyrosine residues of the cytoplasmic region of the รีเซปเตอร์. The phosphotyrosine residues generated, initiate
multiple intracellular signaling pathways. One of the signaling pathways initiated is that of the 5 mitogen activated protein kinases (MAPKs), in whose activation cascade participate the
extra-cellular regulated protein kinases Erk1 and Erk2. They induce the expression of
transcription factors that increase the transcription of genes involved in cell proliferation,
such as cyclin D1 which promotes cell cycle progression to the G1/S phase. The
heterodimeric combinations are the most potent signaling complexes and have direct control 10 of the cell cycle (Pinkas-Kramarski R et al, (1996) EMBO J 15 (10): 2452-2467).
These tumor targets have been extensively validated in clinical studies. The clinical effect of treatment with tyrosine kinase inhibitors (TKI) of these รีเซปเตอร์, such as gefitinib and lapatinib, has been evaluated (Ciardiello F et al, (2000) Clin Cancer Res 6 (5): 2053-2063;
Kondo N et al, (2010) Oncol Rep 23 (4): 957-963). There are also reports from clinical trials 15 that using monoclonal antibodies (MAbs) against the aforementioned targets, such as
cetuximab (Jean GW et al, (2008) Pharmacotherapy 8(6):742-54) and nimotuzumab (Ramos
TC, et al, (2006) Cancer Biol Ther 5 (4): 375-379), that are specific for the ECD of Her1, and
trastuzumab, that recognizes Her2 ECD (Clifford A, (2007) N Engl J Med; 357:39-51).
Despite the potent antitumor effect of some of these therapies, such as cetuximab,
20 molecular mechanisms of resistance have been described, among them increased levels of
expression of another receptor of the family, for instance Her2 (Brand TM et al, (2011)
Cancer Biol Ther 11 (9): 777-792). On the other hand, a better response to pertuzumab anti-
Herl murine MAb in breast and lung carcinomas expressing Her2 heterodimers has been
found with other members of the ErbB family (Agus DB et al, (2005) J Clin Oncol 23 (11): 25 2534-2543). This supports the idea that inhibition of heterodimerization is an attractive
strategy for cancer therapy.
Furthermore, active therapy with cancer vaccine has emerged as a new therapeutic option
whose aim is to activate the immune system response in patients with tumors that express
Her1 and Her2. This type of therapy, however, is challenging, since it involves stimulation of 30 the immune system depressed by the suppressive effect of the tumor, which has made it
necessary for vaccine formulations to use adjuvants in order to help generate an effective
response. Such is the case of the adjuvant of very small size โปรทีโอไลโปโซม (VSSP)
derived from the outer membrane proteins of Neisseria meningitidis, which is capable of
activating dendritic cells (DC) and polarizing the immune response towards the pattern of T-
35 Helper Type 1 Response (Th1) as described in WO 02/45746 patent filed December 6,
2001.
4
Her1 and Her2 รีเซปเตอร์ have been targets of different vaccine candidates evaluated in preclinical and clinical studies. In the design of vaccines based on Her2, DCs vaccines (Czerniecki BJ et al, (2007) Cancer Res 67 (4): 1842-1852), Her2 peptides and ECD-Her2
have been used. (Ladjemi MZ et al, (2010) Cancer Immunol Immunother 59 (9): 1295-1312). 5 In phase II clinical studies with breast cancer patients, active immunization with peptide
p369-377 (peptide E75) derived from the Her2 ECD and presented by MHC-I, using colony
stimulating factor granulocyte-macrophage (GM-CSF) as adjuvant was evaluated. This
vaccine is able to generate specific Citotoxic T Lymphocytes (CTL) in vivo against cells