This document discusses angiogenesis in cancer and anti-angiogenic drugs. It explains that angiogenesis is the formation of new blood vessels that is important for tumor growth and metastasis. The document reviews how angiogenesis is regulated by activators and inhibitors, and discusses several anti-angiogenic drugs that have been developed to inhibit new blood vessel formation and thereby treat cancer.

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This project has been submitted under planning and guidance of
Mr.Tathagata Roy(Assistant professor in Pharmacology),Bharat
Technology, under Maulana Abul Kalam Azad University Of
Technology(MAKAUT)Formly known as West Bengal University
Of Technology(WBUT),Kolkata-700064 in consonance with
regulation of West Bengal University Of Technology for the award
of Bachelor in Pharmacy(B.Pharm) degree.

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BHARAT TECHNOLOGY, RATHTALA, ULUBERIA, HOWRAH
(WEST BENGAL)
CERTIFICATE OF ORIGINALITY OF WORK
I Univ. Roll No.
Student of Branch Year, have undergone the
theory based study at Bharat Technology, Uluberia, Howrah.
I hereby declare that the report is an original one and has not been submitted
earlier to this institute for fulfillment of the requirement of bachelor degree of a course of study.
(Project Guide) Student’s Signature
Mr.Tathagoto Roy Indranil Chatterjee
Assistant Professor Pharmacology
Bharat Technology Branch:
Semester:
Rath Tala, Uluberia (Howrah)
DATE :
PLACE:

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_____________________________________
This is to certify that the dissertation entitled-“Angiogenesis in cancer and
Anti angiogenic Drugs” is the bonafied theory based work done by Mr.
Indranil Chatterjee in partial fulfillment of the requirement for the degree of
Bachelor of Pharmacy in Pharmacology at Bharat Technology under the
supervision and guidance of myself.
I certify that he has carried out his survey work independently with proper
care. I hereby recommend that this dissertation he accepted in partial
fulfillment of requirement for the degree of Bachelor of Pharmacy in
pharmacology. I am pleased to forward this thesis for evaluation. This
dissertation partially or fully has not been submitted for any other degree of
this University or any other University.
Mr.Tathagata Roy, M.Pharm
Pharmacology
Bharat Technology,
Jadurberia, Uluberia, Howrah

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_____________________________________
This is to certify that the dissertation entitled-“
Angiogenesis in cancer and Anti angiogenic Drugs” is the
bonafied theory based work done by Mr. Indranil
Chatterjee in partial fulfillment of the requirement for
the degree of Bachelor of Pharmacy in Pharmacology
at Bharat Technology under the supervision and
guidance of myself.
I certify that he has carried out his survey work
independently with proper care. I hereby recommend
that this dissertation he accepted in partial fulfillment
of requirement for the degree of Bachelor of
Pharmacy in pharmacology. I am pleased to forward
this thesis for evaluation. This dissertation partially or
fully has not been submitted for any other degree of
this University or any other University.

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Prof (Dr.) Beduin Mahanti
M.Pharm, PhD, DPPM, CFN
Principal, Bharat Technology,
Jadurberia, Uluberia, Howrah
I hereby declare that the work in cooperate in this thesis has
been carried out by the Department of Pharmacology,Bharat
Technology,Banitabla,Uluberia,Howrah, under the guidance
of assistant professor Mr.Tathagata Roy.
The work embodied in this thesis is original and has not been
submitted to any other universities.

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PLACE: ------------------------------------------
SIGNATURE
DATE:
To carry a project work needs a lot of patients, dedication and also to
avail the guidance from a proper guide. Words can hardly substitute the immense depth
of gratitude and ineptness that I own to my reverend Teacher Mr.Tathagata Roy,
Assistantprofessor of Bharat Technology for his valuable guidance. I also provide my
hearty thanks to him for his criticism, encouragement and inspiration through the course
of the work.
It is my privilege to offer deep sense of gratitude, respect and thanks
from the bottom of my heart to Prof. (Dr.) R.Debnath, the director of Bharat
Consortium Institutes, for his support, encouragement and facilities provided to carry
out my project work.
I also express my gratitude towards Mr.B.Mohanty, Principal of
Bharat Technology, for his valuable suggestions, support, blessings and encouragement
throughout my course of the project work.
A project is always a collective effort of so many persons having
different ideas, advices, suggestions and constructive criticism which built up a good
project. I am thankful to Mr. M.Jana, Mr. S.Mandal, Mr. S.K Pahari and Mr. S Saha
encouragement, support and valuable technical advices during my project work.
I express my sincere thanks to our librarian Mr. C.R Khatua and Mr.
P.Mandal for providing me every facility for literature review and other for my project
work.

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I offer my cordial thanks to all my batch mates for helping me throughout the course of
my project work.
I am thankful to the Management of Bharat Technology, Uluberia,
and Howrah for providing facilities for continuation of my project work.
Finally, I convey my deepest regards to my parents for their consent and
moral support without whom would not have been here.
INDRANIL CHATTERJEE
Dedicated to my beloved parents and to
my respected Teacher and
Guide…………………….
Mr.Tathagata Roy
(Assistant professor)
Department of Pharmacology
Bharat Technology

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ANGIOGENESIS
IN
CANCER

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&
Anti Angiogenic drugs
New growth in the vascular network is important since the proliferation, as
well as metastatic spread, of cancer cells depends on an adequate supply of oxygen and
nutrients and the removal of waste products. New blood and lymphatic vessels form
through processes called angiogenesis and lymphangiogenesis, respectively.
Angiogenesis is regulated by both activator and inhibitor molecules. More than a dozen
different proteins have been identified as angiogenic activators and inhibitors. Levels of
expression of angiogenic factors reflect the aggressiveness of tumor cells. The discovery
of angiogenic inhibitors should help to reduce both morbidity and mortality from
carcinomas. Thousands of patients have received antiangiogenic therapy to date. Despite
their theoretical efficacy, antiangiogeic treatments have not proved beneficial in terms of
long-term survival. There is an urgent need for a new comprehensive treatment strategy
combining antiangiogenic agents with conventional cytoreductive treatments in the
control of cancer.

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Background Angiogenesis, the formation of new blood vessels from the
endothelium of the existing vasculature, is fundamental in tumor growth, progression,
and metastasis. Inhibiting tumor angiogenesis is a promising strategy for treatment of
cancer and has been successfully transferred from preclinical to clinical application in
recent years. Whereas conventional therapeutic approaches, e.g. chemotherapy and
radiation, are focusing on tumor cells, antiangiogenic therapy is directed against the
tumor supplying blood vessels. Materials and methods. This review will summarize
important molecular mechanisms of tumor angiogenesis and advances in the design of
antiangiogenic drugs. Furthermore, clinical implications of antiangiogenic therapy in
surgical oncology will be discussed. Results First antiangiogenic drugs have been
approved for treatment of advanced solid tumors in several countries. Leading
antiangiogenic drugs are designed to inhibit vascular endothelial growth factor-mediated
tumor angiogenesis. Combining antiangiogenic agents with conventional chemotherapy
or radiation is currently investigated clinically with great emphasis to realize a
multimodal the last 30 years, numerous pro- and antiangiogenic molecules, their ligands,
and intracellular signaling pathways have been identified. Enormous efforts have been
undertaken to develop antiangiogenic strategies for clinical cancer treatment. Despite
numerous promising results in preclinical models, several initial clinical trials gave no
convincing evidence for efficient antitumoral therapy by classical antiangiogenic agents
as monotherapy. This has led to the development of new antiangiogenic compounds and
successful combination of angiogenesis inhibitors with classical cytotoxic chemotherapy
and radiotherapy. Combined with chemotherapy, antiangiogenesis has proven its clinical
efficiency in patients suffering from advanced colorectal cancer leading to an improved
patient survival time [1]. In 2004, the first antiangiogenic compound bevacizumab
(Avastin) was therefore approved by the Food and Drug Administration (FDA) as first-
line therapy in combination with standard 5-fluorouracil-based chemotherapy in patients
with advanced colorectal cancer. In this review, we will outline pathophysiological and
molecular mechanism of tumor angiogenesis, and we will focus on the clinical impact of
recently developed antiangiogenic therapies.
Cancer has the ability to spread to adjacent or distant organs, which makes
it life threatening. Tumor cells can penetrate blood or lymphatic vessels, circulate
through the intravascular stream, and then proliferate at another site: metastasis [2]. For
the metastatic spread of cancer tissue, growth of the vascular network is important. The
processes whereby new blood and lymphatic vessels form are called angiogenesis and
lymphangiogenesis, respectively. Both have an essential role in the formation of a new
vascular network to supply nutrients, oxygen and immune cells, and also to remove
waste products [2]. Angiogenic and lymphangiogenic factors are increasingly receiving
attention, especially in the field of neoplastic vascularization.

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Angiogenesis in cancer
Tumor growth and metastasis depend on angiogenesis and
lymphangiogenesis triggered by chemical signals from tumor cells in a phase of rapid
growth [2]. In a previous study, [3] compared the behavior of cancer cells infused into
different regions of the same organ. One region was the iris with blood circulation;
another was the anterior chamber without
circulation. The cancer cells without blood
circulation grew to 1–2 mm3 in diameter and then
stopped, but grew beyond 2 mm3 . When placed in
an area where angiogenesis was possible. In the
absence of vascular support, tumors may become
necrotic or even apoptotic [4]. Therefore,
angiogenesis is an important factor in the
progression of cancer. Neovascularization, including
tumor angiogenesis, is basically a four-step process.
First, the basement membrane in tissues is injured
locally. There is immediate destruction and hypoxia.
Second, endothelial cells activated by angiogenic
factors migrate. Third, endothelial cells proliferate and stabilize. Fourth, angiogenic
factors continue to influence the angiogenic process. Vascular endothelial cells divide
only about every 1000 days on average [5]. Angiogenesis is stimulated when tumor
tissues require nutrients and oxygen. Angiogenesis is regulated by both activator and
inhibitor molecules. However, up-regulation of the activity of angiogenic factors is itself
not sufficient for angiogenesis of the neoplasm. Negative regulators or inhibitors of
vessel growth need to also be down-regulated [6].
are the fundamental processes by
which new blood vessels are formed [7][8][9]. Vasculogenesis is defined as the
differentiation of precursor cells (angioblasts) into endothelial cells and the de novo
formation of a primitive vascular network, whereas angiogenesis is defined as the
growth of new capillaries from pre-existing blood vessels [8]. In the embryo, blood
vessels form through both vasculogenesis and angiogenesis. In the adult, the transient
formation of new blood vessels is only observed under certain physiological situations
(e.g., in the female reproductive tract under control of the oestrous cycle, in the placenta
during pregnancy, or during wound healing), and occurs mainly through angiogenesis.
Dysregulated angiogenesis has been implicated in the pathogenesis of numerous diseases
including vascular retinopathies, rheumatoid arthritis, and cancer [10].The pioneering
work of Folkman and his colleagues has convincingly established the concept that tumor
development is dependent upon neoangiogenesis and has paved the way for the
identification of several angiogenic molecules, including the fibroblast growth factor

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(FGF) and vascular endothelial growth factor (VEGF) families [11]. However, the recent
characterization of circulating bone marrow-derived endothelial progenitor cells in the
blood of adult animals and the demonstration of their incorporation into pathological
neovascular foci indicate that vasculogenesis may also participate in pathological
neovascularization [12]. Although major progress has been made during the last decade,
our understanding of the molecular mechanisms of these processes is still incomplete.
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66. Dingcheng Gao, Nolan DJ, Mellick AS, et al. (January 11, 2008). "Endothelial Progenitor Cells Control the
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9369.PMC 1891431. PMID 17575055.
Vascular endothelial growth factor A (VEGF-A) is the best known agent that induce
angiogenesis. It is a vascular permeability factor that belongs to the platelet-derived
growth factor (PDGF) superfamily, which also includes VEGF-B, VEGF-C, VEGF-D,
VEGF-E, and placental growth factor (PlGF) [13]. Hypoxia induces VEGF expression
through the mediation of hypoxia-inducible factor (HIF-1α) [14]. There are many other
factors involved in angiogenesis, such as epidermal growth factor (EGF), PDGF,
prostaglandins, COX-2, and IL-6 [15]. The VEGF family of ligands plays its role through
cell surface receptor tyrosine kinases, VGFR-1, VGFR-2, and VGFR-3 [16]. VEGFR-2 is
the most important one through which VEGF exerts its mitogenic, chemotactic, and
vascular permeabilizing effects on endothelial cell . Moreover, VEGF interacts with a
family of coreceptors called neuropilins (NRP-1 and NRP-2) [17] that strengthen the link
between VEGF and its receptors increasing their biological activity.

20. 20 | P a g e
Overexpression of VEGF in HNSCC is associated with more advanced disease,
increased resistance to cytotoxic agents, and poor prognosis [18–24]. In a meta-analysis of
12 studies including 1002 patients affected by cancer of oral cavity (70.8% of patients),
pharynx (15.2%), and larynx (14%), VEGF expression was evaluated, and its positivity
was associated with a twofold higher risk of death at 2 years [25][26] demonstrated that
there are different
molecular mechanisms by
which each tumor induce
angiogenesis. Using
sample collected from
patients affected by
HNSCC and sample of
normal and dysplastic
mucosa, they conducted
an immunohistochemical
analysis and gene
expression profiling
Fig. 1-Endothelial precursors(angioblasts)inthe embryoassemble inaprimitivenetwork(vasculogenesis) that
expandsandremodels(angiogenesis).Smoothmuscle cellscoverendothelialcellsduringvascular myogenesis,
and stabilize vessels duringarteriogenesis.CL,collagen;EL,elastin;Fib,fibrillin. With permission from Ref. [21]
.
Studies. They studied the expression of cytokines (CK) such as VEGF, IL-8/CXCL8,
HGF, and FGF-2 in normal, dysplastic, and pathological tissues. These CK are well-
known mediators of HNSCC angiogenesis. The authors observed that normal mucosa
generally does not express VEGF, IL-8/CXCL8, FGF-2, and HGF and that, where
present, the levels of these CKs are very low compared to dysplastic and pathological
mucosa. The same CKs are more frequently expressed and at a higher levels in
dysplastic oral mucosa.[18][19][20] The incidence and the intensity of expression of VEGF,
IL-8/CXCL8, FGF-2, and HGF are highest in HNSCC samples. Moreover, they
validated the presence of two different clusters in relation to angiogenesis in HNSCC
samples: tumors in Cluster A express high levels of VEGF and FGF-2 and low levels of
IL-8/CXCL8 and HGF and are characterized by higher levels of micro vessel density
than tumors in Cluster B, expressing on the contrary low levels of VEGF and FGF-2 and
higher levels of IL-8/CXCL8 and HGF[21]. These data suggest that there are at least two
different pathways in inducing angiogenesis in HNSCC. This hypothesis has an
important therapeutic implication. In fact we can argue that the inhibition of a specific
molecular pathways can block the angiogenesis process, and consequently the tumor
growth, only if the target of the therapy is expressed by the tumor cells. In the same
study the authors used three different HNSCC cell lines with different levels of
expression of VEGF that were inoculated in nude mice. Then they treated the
experimental models with anti-VEGF antibody, with nonspecific human IgG antibody,
or with PBS,(Phosphate-buffered saline, a buffer solution isotonic and nontoxic to cells).

21. 21 | P a g e
The growth of tumor with high levels of VEGF was inhibited by anti-VEGF treatment
while not influenced by nonspecific IgG or PBS[22]. On the other hand anti-VEGF
treatment had limited effects on the growth of tumor with low levels of VEGF. In this
case no difference in tumor volume was found compared to those treated with
nonspecific IgG or PBS. These data may have very important implications in clinical
practice and support the need of better understanding the molecular alterations in each
specific tumor in order to better select patients for targeted therapies [23].
It is clear that for vasculogenesis and angiogenesis to effectively proceed during
physiological and pathological conditions, it is essential that a complex array of
angiogenic and anti-angiogenic factors, interacting with multiple cells and tissues, be
tightly regulated. Although endothelial cells have attracted the most attention, they alone
cannot complete the process of vessel growth and development, as peri-endothelial cells
and matrix components play essential roles[24][25][26].
Fig. 2 VEGF initiates assembly of endothelial cells (EC), PDGF-BB recruits pericytes (PC) and smooth muscle
cells (SMC), whereas angiopoietin-1 (Ang1) and TGF-β1 stabilize the nascent vessel. Angiopoietin-2 (Ang2)
destabilizesthe vessel,resultinginangiogenesisinthe presence of angiogenicstimuli or in vessel regression in
the absence of endothelial survival factors. With permission from Ref.
Angiogenesis is a vital process that facilitates tumor growth and survival.[27,28] Tumor
angiogenesis refers to the ability of a tumor to stimulate new blood
vessel formation. This critical step in development enables tumor expansion, local
invasion, and dissemination through
 Delivery of oxygen, nutrients, and survival factors
 Production of growth factors that benefit tumor cells
 Formation of a route for tumor cell egress

22. 22 | P a g e

23. 23 | P a g e
Mechanical stimulation of angiogenesis is not well characterized. There is a significant
amount of controversy with regard to shear stress acting on capillaries to cause
angiogenesis, although current knowledge suggests that increased muscle contractions

24. 24 | P a g e
may increase angiogenesis.[29] This may be due to an increase in the production of nitric
oxide during exercise. Nitric oxide results in vasodilation of blood vessels.
Chemical stimulation of angiogenesis is performed by various angiogenic proteins,
including several growth factors.
(Secretion ofproteases,resolution of
Basal lamina, migration towards
Chemotactic gradient,proliferation,
Tube formation)
VEGF is factor largely specific for
endothelial cells,
bFGF can also induce,
not specific for EC)
Mouse cornea:
Wounding induces
Angiogenesis,
Chemotactic
Response to
Angiogenic factors

25. 25 | P a g e
FGF[30] Promotes proliferation & differentiation of endothelial
cells, smooth muscle cells, and fibroblasts
VEGF Affects permeability
VEGFR and NRP-1 Integrate survival signals
Ang1 and Ang2 Stabilize vessels
PDGF (BB-homodimer)
and PDGFR
recruit smooth muscle cells
TGF-β, endoglin and TGF-β
receptors
↑extracellular matrix production
MCP-1
Histamine
Integrins αVβ3, αVβ5
[31]
)
and α5β1
Bind matrix macromolecules and proteinases
VE-cadherin and CD31 endothelial junctional molecules
ephrin Determine formation of arteries or veins
plasminogen activators
remodels extracellular matrix, releases and activates
growth factors
plasminogen activator
inhibitor-1
stabilizes nearby vessels
eNOS and COX-2
AC133 regulates angioblast differentiation
ID1/ID3
Regulates endothelial trans differentiation

26. 26 | P a g e
Activators Function Inhibitors Function
VEGF, VEGF-C,
PlGF
Stimulate
angiogenesis,
permeability; VEGF-C:
VEGFR-1,
soluble
Sink for VEGF,
VEGF-B, PlGF
(VEGFR-1)
and homologuesb
stimulates
lymphangiogenesis;
PlGF: role in
VEGFR-1 and
neuropilin-
and for
VEGF165 (NP-1)
pathologic
angiogenesis 1 (NP-1)
VEGF receptors
(VEGFR)
VEGFR-2: angiogenic
signaling receptor;
VEGFR- Angiopoietin-2
Antagonist of
Ang1: induces
vessel
regression
3: (lymph)angiogenic
signaling receptor;
in the absence
of angiogenic
signals
neuropilin-1 (NP-1):
binds specifically
VEGF165;
coreceptor ofVEGFR-2
Angiopoietin-1
(Ang1) and
Ang1: stabilizes
vessels by tightening
endothelial-
Thrombospondin-
1 (TSP-
Extracellular
matrix protein;
Type I repeats
Tie2-receptorb
smooth muscle
interaction; inhibits
permeability; 1)
inhibit
endothelial
migration,
growth,

27. 27 | P a g e
Activators Function Inhibitors Function
adhesion,
Ang2: destabilizes
vessels before
sprouting
survival; related
TSP-2 also
inhibits
angiogenesis
PDGF-BB and
receptors
Recruit smooth muscle
cells Meth-1, Meth-2
Inhibitors
containing
metalloprotease,
thrombospondin
and disintegrin
domains
TGF-β1c, endoglin,
TGF-β
Stabilize vessels by
stimulating extracellular
Angiostatin and
related
Proteolytic
fragments of
plasminogen;
inhibit
receptors matrix production
plasminogen
kringles
endothelial
migration and
survival
FGF, HGF, MCP-1
Stimulate
angiogenesis
(FGF, HGF) and Endostatin
Fragment of
type XVIII
collagen;
inhibits
arteriogenesis
(FGF, MCP-1)
endothelial
survival and
migration

28. 28 | P a g e
Activators Function Inhibitors Function
Integrins αvβ3, αvβ5
Receptors for
matrix
macromolecules
and
Vasostatin,
calreticulin
Calreticulin
and N-
terminal
fragment
proteinases
(MMP2)
(vasostatin)
inhibit
endothelial
growth
VE-cadherin,
PECAM
Endothelial
junctional
molecules;
essential for Platelet factor-4
Heparin-
binding CXC
chemokine
inhibits
(CD31)
endothelial survival
effect; antibodies block
tumor
binding ofbFGF
and VEGF
Angiogenesis
Ephrins
Regulate
arterial/venous
specification
Tissue-inhibitors
of MMP
Suppress
pathologic
angiogenesis;
(TIMPs), MMP-
PEX: proteolytic
fragment of
MMP2, blocks
inhibitors, PEX
binding of
MMP2 to αvβ3
Plasminogen Proteinases involved in Tissue-inhibitors
Suppress
pathological

29. 29 | P a g e
Activators Function Inhibitors Function
activators, cellular migration and of MMP angiogenesis
matrix
metalloproteinases
matrix remodeling;
liberate bFGF and
VEGF from
(TIMPs), MMP-
inhibitors
the matrix; activate
TGF-β1; generate
angiostatin
Plasminogen
activator
Stabilizes nascent
vessels by preventing
matrix
Interferon (IFN)
α, β, γ;
Cytokines and
chemokines,
inhibiting
inhibitor-1
dissolution; poor
cancer prognosis
IP-10, IL-4, IL-
12, IL-18
endothelial
migration; IFNα
downregulates
bFGF
Nitric oxide
synthase,
Nitric oxide and
prostaglandins
stimulate
Prothrombin
kringle-2,
Fragments of
the hemostatic
factors suppress
cyclooxygenase-2
angiogenesis and
vasodilation; Cox2
inhibitors
anti-thrombin III
fragment
endothelial
growth
suppress tumor
angiogenesis
Other activators
AC133 (orphan
receptor involved in
Other inhibitors
16 kDa-prolactin
(inhibits

30. 30 | P a g e
Activators Function Inhibitors Function
angioblast bFGF/VEGF);
differentiation);
chemokinesc(pleiotropic
role in
canstatin
(fragment of the
α2-chain of
collagen
angiogenesis);
inhibitors of
differentiation (Id1/Id3;
IV); maspin
(serpin);
troponin-I
(inhibits
helix-loop-helix
transcriptional
repressors)
actomyosin
ATPase); VEGI
(member ofTNF
family); restin
(NC10 domain
of collagen XV);
fragment of
SPARC (inhibits
endothelial
binding and
activity of
VEGF);
osteopontin
fragment
(contains RGD
sequence)

31. 31 | P a g e
 FGF
The fibroblastgrowth factor (FGF) family with its prototypemembers FGF-1 (acidic FGF)
and FGF-2 (basic FGF) consists to date of at least 22 known members.[32]
Most are
single-chain peptides of 16-18 kDa and display high affinity to heparin and heparin
sulfate. In general, FGFs stimulate a variety of cellular functions by binding to cell
surface FGF-receptors in the presence of heparin proteoglycans. The FGF-receptor
family is composed of seven members, and all the receptor proteins are single-chain
receptor tyrosinekinases that become activated through auto phosphorylation induced
by a mechanism of FGF-mediated receptor dimerization. Receptor activation gives rise
to a signal transduction cascade that leads to gene activation and diverse biological
responses, including cell differentiation, proliferation, and matrix dissolution, thus
initiating a process of mitogenic activity critical for the growth of endothelial cells,
fibroblasts, and smooth muscle cells. FGF-1, unique among all 22 members of the FGF
family, can bind to all seven FGF-receptor subtypes, making it the broadest-acting
member of the FGF family, and a potent mitogen for the diverse cell types needed to
mount an angiogenic response in damaged (hypoxic) tissues, where up regulation of
FGF-receptors occurs.[33]
FGF-1 stimulates the proliferation and differentiation of all cell
types necessary for building an arterial vessel, including endothelial cells and smooth
muscle cells; this fact distinguishes FGF-1 from other pro-angiogenic growth factors,
such as vascular endothelial growth factor (VEGF), which primarily drives the formation
of new capillaries.[34][35]
Until 2007, three human clinical trials have been successfully completed with FGF-1, in
which the angiogenic protein was injected directly into the damaged heart muscle. Also,
one additional human FGF-1 trial has been completed to promote wound healing in
diabetics with chronic wounds.
Besides FGF-1, one of the most important functions of fibroblast growth factor-2 (FGF-
2 or bFGF) is the promotion of endothelial cell proliferation and the physical
organization of endothelial cells into tube-like structures, thus promoting angiogenesis.
FGF-2 is a more potent angiogenic factor than VEGF or PDGF (platelet-derived growth
factor); however, it is less potent than FGF-1. As well as stimulating blood vessel
growth, aFGF (FGF-1) and bFGF (FGF-2) are important players in wound healing. They
stimulate the proliferation of fibroblasts and endothelial cells that give rise to
angiogenesis and developing granulation tissue; both increase blood supply and fill up a
wound space/cavity early in the wound-healing process.
VEGF
Vascular endothelial growth factor (VEGF) has been demonstrated to be a major
contributor to angiogenesis, increasing the number of capillaries in a given network.

32. 32 | P a g e
Initial in vitro studies demonstrated bovine capillary endothelial cells will proliferate and
show signs of tube structures upon stimulation by VEGF and bFGF, although the results
were more pronounced with VEGF.[36] Up regulation of VEGF is a major component of
the physiological response to exercise and its role in angiogenesis is suspected to be a
possible treatment in vascular injuries.[37][38][39][40] In vitro studies clearly demonstrate
that VEGF is a potent stimulator of angiogenesis because, in the presence of this growth
factor, plated endothelial cells will proliferate and migrate, eventually forming tube
structures resembling capillaries. VEGF causes a massive signaling cascade
in endothelial cells. Binding to VEGF receptor-2 (VEGFR-2) starts a tyrosine kinase
signaling cascade that stimulates the production of factors that variously stimulate vessel
permeability (eNOS, producing NO), proliferation/survival (bFGF), migration
(ICAMs/VCAMs/MMPs) and finally differentiation into mature blood vessels.
Mechanically, VEGF is up regulated with muscle contractions as a result of increased
blood flow to affected areas. The increased flow also causes a large increase in
the mRNA production of VEGF receptors 1 and 2. The increase in receptor production
means muscle contractions could cause up regulation of the signaling cascade relating to
angiogenesis. As part of the angiogenic signaling cascade, NO is widely considered to
be a major contributor to the angiogenic response because inhibition of NO significantly
reduces the effects of angiogenic growth factors. However, inhibition of NO during
exercise does not inhibit angiogenesis, indicating there are other factors involved in the
angiogenic response.

33. 33 | P a g e
VEGF-A production can be induced in cells that are not receiving
enough oxygen.[41] When a cell is deficient in oxygen, it produces HIF, hypoxia-
inducible factor, a transcription factor. HIF stimulates the release of VEGF-A, among
other functions (including modulation of erythropoiesis). Circulating VEGF-A then
binds to VEGF Receptors on endothelial cells, triggering a Tyrosine Kinase Pathway
leading to angiogenesis. The expression of angiopoietin-2 in the absence of VEGF leads
to endothelial cell death and vascular regression.[42] Conversely, a German study done in
vivo found that VEGF concentrations actually decreased after a 25% reduction in oxygen
intake for 30 minutes.[43] HIF1 alpha and HIF1 beta are constantly being produced but
HIF1 alpha is highly O2 labile, so, in aerobic conditions, it is degraded. When the cell
becomes hypoxic, HIF1 alpha persists and the HIF1alpha/beta complex stimulates
VEGF release.

34. 34 | P a g e
Angiopoietins
The Angiopoietins, Ang1 and Ang2, are required for the formation of mature blood
vessels, as demonstrated by mouse knock out studies.[44] Ang1 and Ang2 are protein
growth factors which act by binding their receptors,Tie-1 and Tie-2; while this is
somewhat controversial, it seems that cell signals are transmitted mostly by Tie-2;
though some papers show physiologic signaling via Tie-1 as well. These receptors
are tyrosine kinases. Thus, they can initiate cell signaling when ligand binding causes a
dimerization that initiates phosphorylation on key tyrosine.
MMP

35. 35 | P a g e
Another major contributor to angiogenesis is matrix metalloproteinase (MMP). MMPs
help degrade the proteins that keep the vessel walls solid. This proteolysis allows
the endothelial cells to escape into the interstitial matrix as seen in sprouting
angiogenesis. Inhibition of MMPs prevents the formation of
new capillaries.[45] These enzymes are highly regulated during the vessel formation
process because destruction of the extracellular matrix would decrease the integrity of
the microvasculature.[30]
DII4
Delta-like ligand 4 (DII4) is a protein with a negative regulatory effect on
angiogenesis.[45] Dll4 is a Trans membrane ligand, for the notch family of receptors.
Epidermal growth factor domain–like 7 (EGFL7) is an extracellular matrix
protein that supports endothelial cell adhesion, promotes cell survival under stress, and
forms perivascular tracks that regulate blood vessel formation[46][47][48]. EGFL7 is
selectively expressed in nascent blood vessels in tumors and other proliferating tissues,
but is absent or expressed at low levels in healthy quiescent vessels. Preclinical studies
also report that EGFL7 may promote tumor escape from immunity.
Platelet-derived growth factor
The PDGF family of dimeric growth factors shares a significant degree of sequence
similarity to VEGF, yet its expression patterns and functional properties are clearly
distinct. PDGFs and their tyrosine kinase receptors are expressed and impact a large
number of tissues including fibroblasts, smooth muscle cells, neurons and endothelium
[49] This expression pattern explains why deregulation of this pathway has been
associated with a myriad of human diseases, including atherosclerosis, fibrosis and
cancers.
TGF-beta signaling
Transforming growth factor-beta is a member of a large superfamily that includes: bone
morphogenetic proteins, activins, inhibits and Mullerian inhibitory substance all relevant
to developmental processes [50].Three members of the TGF-beta family (TGF-beta1-3)
gave been identified all with partially overlapping expression, but distinct functions. The
growth factors are secreted as latent forms and its activation is dependent on either
proteolytic processingor binding to thrombospondin-1. Signal transduction by TGF-beta
requires a series of serine/threonine receptors, accessory receptors, Smad proteins and
Smad transcription factors that convey these signals to specific genes.

36. 36 | P a g e
Establishment of a functional circulatory system during development is
crucial for delivery of nutrients and oxygen to the embryo. Defects in the development
of blood vessels result in death before birth or in congenital cardiovascular
abnormalities. Our main focus is to examine the molecular and genetic pathways that
regulate the three principal processes of vascular development and homeostasis:
endothelial cell lineage determination, vasculogenesis and angiogenesis. More recently,
we have extended our studies to investigating the molecular underpinning of certain
vascular diseases. We focus on the mouse model and the embryonic stem cell (ESC) in

37. 37 | P a g e
vitro differentiation system because of the ready availability of genetic and experimental
tools, and because of physiological similarities between mice and humans. Using an
expression-based "gene trap" screen in mouse ESCs and embryos, we previously
identified two novel genes that are involved in vascular system
development, Vezf1 and Egfl7 [51].
Angiogenesis is the formation of new blood vessels. This process is a normal part
of growth and healing. It is also connected to the development of several diseases,
including cancer.
Once a tumor grows to a certain size, it requires nutrients and oxygen found in the
blood to help it grow, invade nearby tissues, and spread, called metastasis. The tumor
sends chemical signals out that stimulate the growth of new blood vessels that carry the
blood to it. As a result, each part of the angiogenesis process is a potential target for new
cancer treatments. The idea is that if a drug can stop the tumor from receiving a blood
supply, the tumor will "starve" and die [52].
Drugs that block angiogenesis, which are called angiogenesis inhibitors or anti-
angiogenics, have become an important part of treatment for many types of cancer.
DEVELOPMENT OF SUSTAINED ANGIOGENESIS
Tumors stimulate the growth of host blood vessels, a process called
angiogenesis, which is essential for supplying nutrients to the tumor.[53]
Even with
genetic abnormalities that dysregulated growth and survival of individual cells, tumors
cannot enlarge beyond 1 to 2 mm in diameter or thickness unless they are
vascularized.[54]
Presumably the 1- to 2-mm zone represents the maximal distance
across which oxygen and nutrients can diffuse from blood vessels. Beyond this

38. 38 | P a g e
Size, the tumor fails to enlarge without
vascularization because of hypoxia-induced
cell death [55].
Neovascularization has a dual effect
on tumor growth: perfusion supplies
nutrients and oxygen, and newly formed
endothelial cells stimulate the growth of
adjacent tumor cells by secreting
polypeptide growth factors such as insulin-
like growth factors and PDGF.[56]
Angiogenesis is a requisite not only for
continued tumor growth, but also for
metastasis. Without access to the
vasculature, the tumor cells cannot readily
spread to distant sites.
How do growing tumors develop a
blood supply?
Several studies indicate that tumors
produce factors that are capable of
triggering the entire series of events
involved in the formation of new capillaries.
Tumor angiogenesis can occur by
recruitment of endothelial cell precursors or
by sprouting of existing capillaries, as in
physiologic angiogenesis.
Figure 3: The metastatic cascade. Schematic illustration of the sequential steps involved
In the hematogenous spread of a tumor.
However, tumor blood vessels differ from the normal vasculature by being tortuous
and irregularly shaped and by being leaky. The leakiness is attributed largely to the
increased production of VEGF. [57]
In contrast to normal mature vessels, which are
quiescent structures, tumor vessels may grow continuously. Tumor cells may, in some
special cases, line structures that resemble capillaries, a phenomenon called
vasculogenic mimicry [58].

39. 39 | P a g e
A cancer needs a good blood supply to bring food and oxygen and remove
waste products. When it has reached 1 to 2mm across, a tumor needs to grow its own
blood vessels in order to continue to get bigger. Some cancer cells make a protein called
vascular endothelial growth factor (VEGF). The VEGF protein attaches to receptors on
cells that line the walls of blood vessels within the tumour. The cells are called
endothelial cells. This triggers the blood vessels to grow so the cancer can then grow.[59]
Angiogenesis means the growth of new blood vessels. If we can stop cancers from
growing blood vessels we can slow the growth of the cancer or sometimes shrink it. Anti
angiogenic drugs are treatments that stop tumors from growing their own blood
vessels.[60]
There are different types of drugs that block blood vessel growth, including
 Drugs that block blood vessel growth factor
 Drugs that block signalling within the cell
 Drugs that affect signals between cells
Some drugs block vascular endothelial growth factor (VEGF) from attaching to the
receptors on the cells that line the blood vessels. This stops the blood vessels from
growing.
A drug that blocks VEGF is bevacizumab (Avastin). It is also a monoclonal
antibody.[61]
Some drugs stop the VEGF receptors from sending growth signals into the blood
vessel cells. These treatments are also called cancer growth blockers or tyrosine
kinase inhibitors (TKIs). Sunitinib (Sutent) is a type of TKI that blocks the growth
signals inside blood vessel cells. It is used to treat kidney cancer and a rare type of
stomach cancer called gastrointestinal stromal tumour (GIST)[62].

40. 40 | P a g e
Some drugs act on the chemicals that cells use to signal to each other to grow. This can
block the formation of blood vessels. Drugs that works in this way
include thalidomide and lenalidomide (Revlimid).[63]
Angiogenesis requires the binding of signaling molecules, such as vascular endothelial
growth factor (VEGF), to receptors on the surface of normal endothelial cells. When
VEGF and other endothelial growth factors bind to their receptors on endothelial cells,
signals within these cells are initiated that promote the growth and survival of new blood
vessels.
Angiogenesis inhibitors interfere with various steps in this process. For example,
bevacizumab (Avastin®) is a monoclonal antibody that specifically recognizes and
binds to VEGF . When VEGF is attached to bevacizumab, it is unable to activate the
VEGF receptor. Other angiogenesis inhibitors, including sorafenib and sunitinib, bind to
receptors on the surface of endothelial cells or to other proteins in the downstream
signaling pathways, blocking their activities [64].
Yes. The U.S. Food and Drug Administration (FDA) has approved bevacizumab to
be used alone for glioblastoma that has not improved with other treatments and to be
used in combination with other drugs to treat metastatic colorectal cancer, some non-
small cell lung cancers, and metastatic renal cell cancer. Bevacizumab was the first
angiogenesis inhibitor that was shown to slow tumor growth and, more important, to
extend the lives of patients with some cancers [65].
The FDA has approved other drugs that have antiangiogenic activity,
including sorafenib(Nexavar®), sunitinib (Sutent®), pazopanib (Votrient®),
and everolimus (Afinitor®). Sorafenib is approved for hepatocellular carcinoma and
kidney cancer, sunitinib and everolimus for both kidney cancer and neuroendocrine
tumors, and pazopanib for kidney cancer. Researchers are exploring the use of
angiogenesis inhibitors to treat other types of cancer. In addition, angiogenesis inhibitors
are being used to treat some diseases that involve the development of abnormal blood
vessel growth in noncancerous conditions, such as macular degeneration [66].

41. 41 | P a g e
Angiogenesis inhibitors are unique cancer-fighting agents because they tend to inhibit
the growth of blood vessels rather than tumor cells. In some cancers, angiogenesis
inhibitors are most effective when combined with additional therapies, especially
chemotherapy. It has been hypothesized that these drugs help normalize the blood
vessels that supply the tumor, facilitating the delivery of other anticancer agents, but this
possibility is still being investigated[67].
Angiogenesis inhibitor therapy does not necessarily kill tumors but instead may prevent
tumors from growing. Therefore, this type of therapy may need to be administered over
a long period.
TARGETS AND AGENTS
The possibility of inhibiting angiogenesis as a potential therapeutic intervention in
cancer treatment was first proposed by Folkman. A number of anti-angiogenic drugs are
now either licensed or in clinical trials. In general, four strategies are being used by
investigators to design anti-angiogenesis agents:
 Blocking the ability of the endothelial cells to break down the surrounding matrix
 Inhibiting normal endothelial cells directly
 Blocking factors that stimulate angiogenesis
 Blocking the action of integrin, a molecule on the endothelial cell surface
The following drugs are examples of angiogenesis inhibitors approved by the U.S. Food
and Drug Administration to treat cancer. Typically, these drugs are given with other
types of treatment, such as chemotherapy.
 Bevacizumab (Avastin), a substance called a monoclonal antibody
produced in the laboratory, is used to treat colorectal, kidney cancer,
and lung cancer. It is injected into a vein.

42. 42 | P a g e
 Everolimus (Afinitor) is used to treat kidney cancer, advanced breast
cancer, a rare type of noncancerous brain tumor called sub ependymal
giant cell astrocytoma, and pancreatic neuroendocrine tumors (PNETs).
It is a pill taken by mouth.
 Lenalidomide (Revlimid) is used to treat multiple myeloma; tumors
involving cells that normally produce antibodies; and mantle cell
lymphoma, a type of non-Hodgkin lymphoma. It is a pill taken by
mouth.
 Pazopanib (Votrient) is used to treat kidney cancer and advanced soft
tissue sarcoma. It is a pill taken by mouth.
 Ramucirumab (Cyramza) is used to treat advanced stomach
cancer and gastro-esophageal junction adenocarcinoma, a form of
cancer located where the stomach joins to the esophagus. It is injected
into a vein.
 Sorafenib (Nexavar), which works in many ways, including blocking
angiogenesis, is used to treat kidney cancer, liver cancer, and thyroid
cancer. It is a pill taken by mouth.
 Sunitinib (Sutent) is used to treat kidney cancer, PNET,
and gastrointestinal stromal tumor. It is a pill taken by mouth.

43. 43 | P a g e
 Thalidomide (Thalomid) appears to stop cells called endothelial cells
that line blood vessels from forming new blood vessels and is a
treatment for multiple myeloma. Thalidomide should not be taken by
women who are pregnant or plan to become pregnant because it is
harmful to fetuses. It is a pill taken by mouth.
Many of these drugs are also being studied for use in other types of cancer that may not
be listed here. Talk with your doctor to get more information about these and other
angiogenesis inhibitors, as well as ones that are being evaluated in clinical trials.
Because angiogenesis is important to many of the body’snormal processes, angiogenesis
inhibitors can cause a wide range of side effects, including:
 High blood pressure
 A rash and/or dry, itchy skin
 Hand-foot syndrome (tender, thickened areas on the skin, sometimes with blisters,
on palms and soles)
 Diarrhea
 Fatigue
 Low blood counts
 Problems with wound healing or cuts re-opening
 Appetite Loss
 Bleeding and Bruising (Thrombocytopenia)
 Constipation
 Diarrhea
 Edema
 Fatigue
 Hair Loss (Alopecia)

44. 44 | P a g e
 Infection and Neutropenia
 Lymphedema
 Memory or Concentration Problems
 Mouth and Throat Problems
 Nausea and Vomiting
 Nerve Problems (Peripheral Neuropathy)
 Pain
 Sexual and Fertility Problems (Men)
 Sexual and Fertility Problems (Women)
 Skin and Nail Changes
 Sleep Problems
 Urinary and Bladder Problems
Although some of these side effects may be common, they do not happen with every
drug or with every person. In addition, they can often be treated with medication.
Rarely, angiogenesis inhibitors may cause serious bleeding, heart attacks, heart
failure, or blood clots. People at higher risk for these conditions should discuss the risks
and benefits of these treatments and ways to monitor these risks. [For example, patients
who had chemotherapy with a class of drugs called anthracyclines or radiation
therapy to the chest wall have a higher risk of heart failure with bevacizumab].
Another rare side effect is bowel perforations (holes) in the intestines, which usually
require surgery to correct [68].
Anti-angiogenesis
agent
Description
Bevacizumab (Avastin) Humanized anti-VEGF-A monoclonal antibody
Ranibizumab (Lucentis) Anti-VEGF-A antibody Fab fragment

45. 45 | P a g e
Anti-angiogenesis
agent
Description
Pegaptanib (Macugen) RNA aptamer of 165-amino acid VEGF-A
IMC-1121B Human anti-VEGFR-2 monoclonal antibody
DC101 Mouse VEGFR-2-specific monoclonal antibody
VEGF-Trap Fusion protein including immunoglobulin domain of VEGFR-1
and VEGFR-2 and human IgG1 Fc fragment
AEE788 VEGFR-2 and EGFR inhibitor
Axitinib (AG-013736) VEGFR-1 and VEGFR-2 inhibitor, also inhibits VEGFR-3,
PDGFR-β, and c-KIT
AG-013925 VEGFR and PDGFR inhibitor
Imatinib Bcr-Abl fusion protein inhibitor, also inhibits PDGFR-β and c-
KIT
Vatalanib (PTK787/ZK22258) VEGFR-2 inhibitor, also inhibits VEGFR-1, VEGFR-3 and
PDGFR-β

46. 46 | P a g e
Anti-angiogenesis
agent
Description
Sorafenib (BAY 43-9006,
Nexavar)
Raf, VEGFR-2, VEGFR-3 inhibitor, also inhibits PDGFR-β and
c- KIT
Semaxanib (SU5416) VEGFR-2 inhibitor, also inhibits PDGFR
SU6668 VEGFR-2 inhibitor, also inhibits PDGFR-β, FGFR-1, and c-KIT
SU11657 VEGFR-1 and VEGFR-2 inhibitor, also inhibits PDGFR-α,
PDGFR-β, and c-KIT
Sunitinib (SU11248, Sutent) VEGFR-1 and VEGFR-2 inhibitor, also inhibits PDGFR-α,
PDGFR-β, and c-KIT
Vandetanib (ZD6474, Zactima) VEGFR-2 inhibitor, also inhibits VEGFR-3 and EGFR
ZD2171 VEGFR-2 inhibitor, also inhibits VEGFR-1, VEGFR-3, c-KIT,
and PDGFR-β
Angiostatin Cleavage fragment of plasminogen
Endostatin Cleavage fragment of collagen XVIII

47. 47 | P a g e
Anti-angiogenesis
agent
Description
Thrombospondin-1 Extracellular glycoprotein
Anti-VEGF therapies are important in the treatment of certain cancers and in age-related
macular degeneration. They can involve monoclonal antibodies such
as bevacizumab (Avastin), antibody derivatives such as ranibizumab (Lucentis), or
orally-available small molecules that inhibit the tyrosine kinases stimulated by
VEGF: lapatinib (Tykerb/Tyverb), sunitinib (Sutent), sorafenib (Nexavar), axitinib
, andpazopanib. (Some of these therapies target VEGF receptors rather than the
VEGFs.) THC and cannabidiol both inhibit VEGF and slow Glioma growth [69].
Both antibody-based compounds are commercialized. The first three orally available
compounds are commercialized, as well. The latter two (axitinib and pazopanib) are in
clinical trials.
Bergers and Hanahan concluded in 2008 that anti-VEGF drugs can show therapeutic
efficacy in mouse models of cancer and in an increasing number of human cancers. But,
"the benefits are at best transitory and are followed by a restoration of tumour growth
and progression."[70]
Later studies into the consequences of VEGF inhibitor use have shown that, although
they can reduce the growth of primary tumours, VEGF inhibitors can concomitantly
promote invasiveness and metastasis of tumours.[71][72]
AZ2171 (cediranib), a multi-targeted tyrosine kinase inhibitor has been shown to have
anti-edema effects by reducing the permeability and aiding in vascular normalization.
A 2014 Cochrane Systematic Review studied the effectiveness of ranibizumab
and pegaptanib, on patients suffering from macular edema caused by central retinal vein
occlusion.[73] Participants on both treatment groups showed improvement in visual acuity
measures and a reduction in macular edema symptoms over six months.[73]

48. 48 | P a g e
MECHANISM OF ACTION: It is the first selectively targeted drug to be introduced
for treatment of malignancy. It inhibits a specific tyrosine protein kinase labeled ‘Bcr-
Abl’ tyrosine kinase expressed by chronic myeloid leukemia (CML) cells and related
receptor tyrosine kinases including platelet derived growth factors (PDGF) receptors
that is actively act on stem cell receptor and c-kit receptor active in gastro-intestinal
stromal tumour (GIST).[74]
PHARMACOKINETICS: It is well absorbed orally, metabolized in liver, one active
metabolite is produced. The major degrading enzyme CYP3A4 and potential interaction
may occur with inducers and inhibitors of this isoenzyme. All metabolites are excreted
in faeces through bile. Its t1/2 is 18 hours while that of its active metabolite is
doubled [74].
ADVERSE EFFECTS: abdominal pain, vomiting, fluid retention, periorbital edema,
pleural effusion, myalgia, liver damage and CHF [74].
DOSE: 400 mg/day with meals; accelerated phase of CML 600-800 mg/day [74].
MECHANISM OF ACTION: It is second generation ‘Bcr-Abl’ PDGF-
receptors β and c-kit receptor tyrosine kinase inhibitor with 20-50 folds higher
affinity than Imatinib [74]..
DRUG PROFILE: It is only 30% absorbed orally.Absorbion may be increased
with food [74]..
ADVERSE EFFECTS: abdominal pain, vomiting, fluid retention, periorbital
edema, pleural effusion, myalgia, liver damage and CHF [74]..
DOSE: 400 mg/day with meals [74]..

49. 49 | P a g e
MECHANISM OF ACTION: It is humanized monoclonal antibody that binds to
VEGF-A and hinders its access to the VEGF receptor, interrupting angiogenic
signaling[74]..
DRUG PROFILE: combined with 5-FU, Bevacizumab is used in colorectal
cancer[74]..
ADVERSE EFFECTS: rise in BP, arterial thromboembolism leading to heart
attack and stroke, vessel injury, haemorrhages, heart failure, healing defects,
proteinuria, gastrointestinal perorations[74]..
DOSE: i.v infusion every 2-3 weeks[74]..
2. [74].
MECHANISM OF ACTION: This is a small molecular synthetic VEGF
receptor-2 inhibitor, which enters cells and comparatively blocks ATP binding to
the tyrosine kinase domain, thereby preventing phosphorylation of angiogenic
regulatory proteins. It also inhibits PDGF receptor α and β,c- KIT,RET
etc[74]..
ADVERSE EFFECTS: hypertension, proteinuria, rashes, diarrhea, weakness,
bleeding, neutropenia, rarely CHF, hypothyroidism[74]..
DOSE: Orally daily in 4 week cycles[74]..
1.

50. 50 | P a g e
The small-molecule-kinase inhibitor sorafenib targets wild-type and mutated B-Raf,
VEGFR2, VEGFR3, PDGFR-β, c-KIT, FLT-3 and p38. It induces growth arrest and
apoptosis of endothelial cells and some tumor cell types. Activity was first reported in a
phase II randomized discontinuation trial in patients with RCC, whereby PFS was
prolonged compared with placebo (24 weeks versus 6 weeks). Patients were treated for
12 weeks (run-in treatment) and at the end of that period those with stable disease were
subsequently randomized to sorafenib or placebo. In a phase III, randomized,
doubleblind, first-line placebo-controlled trial, sorafenib prolonged PFS of patient with
metastatic RCC and was approved by the FDA and European Medicines Evaluation
Agency (EMEA) for the treatment of advanced and metastatic RCC. Retrospective
analysis showed that high basal VEGF levels (>131 pg/ml) correlated with a poor
prognosis and a trend towards greater PFS benefit in sorafenib versus placebo-treated
patients.
2.
Temsirolimus inhibits mTOR, an Akt-target kinase downstream of VEGFR2, which
controls cell proliferation, cellular metabolism and survival. Activity was demonstrated
in a phase I trial in patients with RCC, and was confirmed in phase II studies, improving
outcomes when administered either as single agent or in combination with IFNα. A
three-arm, randomized, phase III trial compared temsirolimus, IFNα and a combination
of the two drugs as first-line treatment in aggressive RCC. Patients who received
temsirolimus alone had longer OS and PFS than did patients in either of the other two
treatment arms.
In addition to the angiogenesis inhibitors that have already been approved by the FDA,
others that target VEGF or other angiogenesis pathways are currently being tested in
clinical (research studies involving patients). If these angiogenesis inhibitors prove to be
both safe and effective in treating human cancer, they may be approved by the FDA and
made available for widespread use.
In addition, phase I and II clinical trials are testing the possibility of combining
angiogenesis inhibitor therapy with other treatments that target blood vessels, such as
tumor-vascular disrupting agents, which damage existing tumor blood vessels [75].

51. 51 | P a g e
Our understanding of the mechanisms of angiogenesis and their modification by
antiangiogenic treatments in human cancer are still rudimentary. Analysis is mostly
focused in understanding the role of individual molecules or pathways, while we lack an
integrated view and understanding of the functional association between apparently
distinct events and their modification during angiogenesis and antiangiogenesis therapy.
For example, a growing amount of evidence indicates that tumors react to therapy by up
regulating angiogenic factors and mobilizing bone-marrow-derived CECP. In spite of
the obvious clinical relevance of these observations, we still have little knowledge of
how tumors adapt to, and possibly escape from, angiogenesis inhibition. To address
these and many other outstanding questions, it will be important to associate clinical
studies not only with pharmacodynamics measurements, but also with relevant
preclinical experimental models [76].
Table 3…….
Subject Anti-
angiogenesis
Treatment
Chemotherapy Median
Survival
(months)
Reference
Previously – Irinotecan/fluorouracil/leucovorin 15.6

52. 52 | P a g e
Subject Anti-
angiogenesis
Treatment
Chemotherapy Median
Survival
(months)
Reference
untreated
metastatic
colorectal cancer,
phase III
Bevacizumab (5
mg/kg)
Irinotecan/fluorouracil/leucovorin 20.3a
Recurrent or
advanced NSCLC,
phase III
– Paclitaxel/carboplatin 10.3
Bevacizumab (15
mg/kg)
Paclitaxel/carboplatin 12.3a
Metastatic breast
cancer, phase III
– Paclitaxel 25.2
Bevacizumab (10
mg/kg)
Paclitaxel 26.7b, c
Previously
untreated
metastatic
colorectal cancer,
phase II
– Fluorouracil/leucovorin 13.8
Bevacizumab (5
mg/kg)
Fluorouracil/leucovorin 21.5d, e
Bevacizumab (10
mg/kg)
Fluorouracil/leucovorin 16.1d

53. 53 | P a g e
Subject Anti-
angiogenesis
Treatment
Chemotherapy Median
Survival
(months)
Reference
Previously treated
metastatic
colorectal cancer,
phase III
– Oxaliplatin/fluorouracil/leucovorin 10.8
Bevacizumab (10
mg/kg)
10.2b
Bevacizumab (10
mg/kg)
Oxaliplatin/fluorouracil/leucovorin 12.9a
Previously treated
metastatic
colorectal cancer,
phase III
– Oxaliplatin/fluorouracil/leucovorin 11.8
Vatalanib (1250
mg)
Oxaliplatin/fluorouracil/leucovorin 12.1b
Previously
untreated NSCLC
cancer, phase III
– Carboplatin/paclitaxel No significant
difference
Sorafenib (400 mg) Carboplatin/paclitaxel
aMedian survival significantly different from chemotherapy alone treatment group.
bNo significant increase in overall survival compared to chemotherapy alone treatment
group.
cProgression-free survival significantly different from chemotherapy alone treatment
group.

54. 54 | P a g e
dA trend of increased survival compared to chemotherapy alone treatment group.
eA trend of increased survival compared to chemotherapy + bevacizumab (10 mg/kg)
treatment group.
1) Four antiangiogenic drugs, bevacizumab, sorafenib, sunitinib and
temsirolimus, have been approved for clinical use on the basis of results from
randomized phase III clinical trials without significant contributions from
biomarkers [77].
2) No validated biomarkers of angiogenesis or antiangiogenic activity are available
for routine clinical use.

55. 55 | P a g e
3) Biomarkers of angiogenesis might be useful for monitoring angiogenesis,
assessing drug activity and distinguishing between active and inactive drugs,
predicting clinical outcome and response to therapy, defining the optimum
biological dose, facilitating development of combination therapies, and rapidly
identifying resistance to treatment [78].
4) Biomarkers under consideration for clinical use include circulating cells, proteins
(e.g. angiogenic factors, angiogenesis-associated molecules; protein expression
profiles), nucleic acids (e.g. gene-expression patterns) and functional parameters
(e.g. tumor perfusion, metabolism)[79].
5) The association of laboratory investigations with clinical trials will be
instrumental for the validation of biomarkers of angiogenesis and for improving
the design, monitoring and evaluation of antiangiogenic treatments.
Currently, the use and the understanding of antiangiogenic therapies in
oncology are at different stages of development: on the one hand, four drugs extending
patient survival in some cancers are available for clinical use, while on the other we are

56. 56 | P a g e
not able to sufficiently monitor the activity of these drugs, identify those patients
responding to them or predict therapy outcome. Improved clinical use of these drugs and
the successful development of new ones will depend heavily on our ability to monitor
angiogenesis and drug activity in patients.
First, we should take advantage of the availability of these drugs to study
how individual biomarkers behave in patients in response to treatment, how changes in
these parameters relate to each other, and how they correlate with treatment outcome.
Lastly, in spite of the indisputable success of angiogenesis and
antiangiogenesis research in deciphering mechanisms, delivering new drugs and
introducing a new therapy paradigm in clinical oncology, many important questions
remain unanswered. New questions are emerging, such as how tumors adapt to and
escape from antiangiogenic therapy. To accelerate the validation of available biomarkers
and the discovery of new ones, and to address questions emerging from clinical studies,
it will be important to associate relevant preclinical models to clinical studies. The
development of biomarkers of angiogenesis represents a unique opportunity for clinical
oncologists and laboratory scientists to join forces to address relevant questions and
design meaningful studies.
Tumor angiogenesis is a tumor micro environmental process that
promotes tumor cell survival, growth, invasion and metastasis, and its inhibition is
emerging as a new therapeutic approach to control tumor progression. Hundreds of

57. 57 | P a g e
molecules with antiangiogenic activity in preclinical models have been reported, and
many of them have entered clinical testing in oncology.
Initially, antiangiogenic molecules were discovered on the basis of
their ability to inhibit endothelial cell proliferation in vitro and angiogenesis in vivo.
Subsequently, the identification of molecular mediators of angiogenesis, such as
vascular endothelial growth factor (VEGF), opened the possibility of selectively
targeting specific pathways. To date, four antiangiogenic drugs have been approved for
human use in solid tumors: Avastin®(Genentech, San Francisco, CA;
bevacizumab), Nexavar® (Bayer Aktiengesellschaft, Leverkusen-Bayerwerk, Germany;
sorafenib), Sutent® (C.P. Pharmaceuticals International, New York, NY; sunitinib), and
Torisel® (Wyeth Corporation, Madison, NJ; temsirolimus). The successful clinical
development of these drugs is in contrast to the plethora of molecules that failed to
replicate in clinical trials the efficacy that was seen in preclinical models.
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