RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY OF THE, EFFICACY, SAFETY AND TOLERABILITY OF EPA-FFA GASTRO-RESISTANT CAPSULES, IN PATIENTS WITH FAMILIAL ADENOMATOUS POLYPOSIS (FAP)

Familial Adenomatous Polyposis (FAP) is an inherited susceptibility to diffuse
colorectal adenomas and colorectal carcinoma, occurring in close to 100% of
unresected colons, and caused by a germline mutation in the APC gene located on
the long arm of chromosome 5 [Kinzler et al 1996]. To prevent cancer
development, it is recommended that patients with FAP undergo colectomy with
ileo-anal or ileo-rectal anastomosis (or colectomy and end-ileostomy) at a
socially convenient time before polyp progression to malignancy and before the
age of 25. Patients with the attenuated FAP phenotype, often associated with
mutations at the 5* terminus (exon 4 and proximally) [Spiro et al 1993], have
fewer polyps and may often delay colectomy.

The molecular events leading to the development of CRC from polyps are
characterised by an imbalance in cell proliferation and apoptosis (natural cell
death) from alterations in those genes involved in colonic mucosal homeostasis.
Furthermore, evidence exists to show that differences are present in the cell
kinetics of the colonic mucosa of patients who are polyp formers and those who
are not. Those patients who have a predisposition to form colonic adenomas are
thought to have a generalised decreased level of apoptosis and higher rates of
cell proliferation throughout the colon [Steinbach et al 1946-1953].

Colectomy removes the bulk of the polyps in FAP, therefore significantly
reducing the cancer risk, yet retains the native rectum in situ allowing a good
functional outcome and avoiding stoma formation. Subsequent proctectomy is
indicated when polyp burden is frequently high in the remaining rectum, if
large highly dysplastic polyps occur, or if frank malignancy develops.
Proctocolectomy also significantly reduces the cancer risk with the removal of
the colon and rectum. A pouch fashioned from the terminal ileum can be created,
and anastomosed to the anus. Routine endoscopic surveillance is also required
with timings dependent on the extent of the disease, with polyp ablation as
necessary.

It has been suggested that omega-3 PUFAs in fish oil can modulate the high
levels of colonicmucosal cell proliferation rates associated with sporadic
colonic adenomas [Anti M et al 1994] and furthermore, work at St George*s
Hospital Medical School, London, has shown significant beneficial effects of
cell proliferation and apoptosis rates on the colonic mucosa of patients with a
history of colonic adenomas using a highly purified, form of EPA as the free
fatty acid [Courtney et al 2005].

Fatty acids are either saturated, monounsaturated or polyunsaturated. Some
omega-6 and omega-3 polyunsaturated fatty acids; are *essential* fatty acids,
i.e. they cannot be made in the human body and therefore must be obtained from
dietary sources. The Western diet is abundant in omega-6 fatty acids (e.g. corn
oil, sunflower oil). Humans lack the necessary enzyme to synthesise
certainomega-3 fatty acids and so they must be obtained from separate dietary
sources. Whilst *-linolenic acid can be obtained from certain vegetable
sources, the two main omega-3 fatty acids, docosahexaenoic acid (DHA) and
eicosapentaenoic acid (EPA) are obtained principally from fish and fish oils.
There is evidence of the benefit of fish oils in the prevention of
cardiovascular disease [Gerdes et al 1994] and there is also the suggestion
that they may be useful in the prevention of other conditions such as prostatic
cancer and colorectal cancer [Boyle and Langman 2000].

The mechanism(s) of the anti-neoplastic activity of EPA-FFA is not fully
understood. Several mechanisms have been postulated including modulation of
cyclooxygenase (COX) activity,
promotion of apoptosis by increasing reactive oxygen species production and
alteration of cellsurface receptor function by changing lipid raft behaviour.
EPA can act as an alternative, poorly utilised substrate (rather than
arachidonic acid prevalent in Western diets) for the COX enzymes (including
COX-2) leading to decreased pro-tumorigenic prostaglandin E2 production.
Recently, EPA treatment has been demonstrated to reduce PGE2 levels in rodent
colorectal mucosa and in mouse colorectal cancer liver metastases (Hawcroft et
al 2010). In this respect, it has similar activity to the coxibs. However, EPA
drives 3-series prostaglandin and thromboxane production by COX-1 which is
believed to explain the anti-platelet activity of EPA, in contrast to the
coxibs which promote a thrombogenic state secondary to endothelial cell COX-2
inhibition and unopposed thromboxane A2 activity in platelets.

The effects of EPA-FFA on polyps have been investigated in the Multiple
intestinal neoplasia (Min) mouse. The Min mouse has a mutation of the tumour
suppressor gene (APC). This confers a predisposition to form polyps in the
small and large intestines which develop rapidly within the first 12 weeks of
life. It thus provides an animal model of FAP in which the effects of potential
chemopreventative interventions can be examined. ApcMin/+ and corresponding
wild-type mice were fed control diet (Ctrl) or diets containing either EPA-FFA
2.5% or EPA-FFA 5%, for 12 weeks while monitoring food intake and body weight.
Tissues were collected for macroscopic, microscopic, immunohistochemical and
mucosal fatty acids analyses. Blood was collected to measure lipid peroxidation
levels. Both EPA-FFA diets protected from the cachexia observed among ApcMin/+
animals fed Ctrl diet (P < 0.0054), in conjunction with a significant decrease
in lipid peroxidation in the treated arms. Compared to Ctrl, EPA-FFA 2.5% and
5% dramatically repressed polyp formation (by 71.5% and 78.6%, respectively, P
< 0.0001) and reduced polyp load (by 82.5% and 93.4%, respectively, P <
0.0001). Polyps <1mm were predominantly found in the 5% EPA-FFA treatment
arm while those measuring 1-3 mm were more frequent in the Ctrl group (P <
0.0001). In the EPAFFA treated mice, arachidonic acid in gastrointestinal
mucosa was replaced by EPA (P < 0.0001), this was associated with a significant
reduction of COX-2. In the EPA-FFA treated arms, *-catenin nuclear
translocation was reduced (small intestine) or absent (colon), while a
significant decrease in proliferation was observed in the entire intestine with
a concomitant increase in apoptosis (Fini et al 2010).

A chemoprevention trial in FAP patients has been conducted using the EPA-FFA
gastro resistant capsules. This was a single-centre, double-blind, randomised,
placebo-controlled study conducted in adult subjects with a confirmed diagnosis
of FAP and previous colectomy with ileo-rectal anastomosis. Consenting
subjects, aged 18 or older, with a diagnosis of FAP and an evaluable rectal
segment having 3 or more rectal polyps *2mm in size (within an area of the
rectum that could be tattooed) were recruited. Subjects satisfying the entry
criteria were randomised (1:1) to receive one of two treatments: placebo twice
daily or 500mg EPA, as the free fatty acid, twice daily (total daily dose 2g)
for 6 months. In total, 58 subjects were randomised, 29 to the placebo group
and 29 to the EPA treatment group. Few subjects withdrew prematurely from the
study, (3 in placebo and 2 in the EPA treatment group). For all subjects in the
placebo group the reason for withdrawal was adverse events or clinically
significant laboratory result requiring discontinuation. In the EPA group
failure to tolerate study drug and other (specifically that the subject did not
attend the 6 months visit) were the reasons given. The study demonstrated a
statistically significant reduction in number of
polyps (p=0.0046 Full analysis set) in a focal area of the rectum following six
months treatment with EPA compared to placebo. Statistically significant
differences between the EPA treatment group and placebo group were found for
percentage change in number of polyps, percentage change in total polyp
diameter and global rectal polyp burden (as assessed by the expert review
panel). Treatment with EPA resulted in an increase in rectal mucosal content of
EPA and DPA relative toother fatty acids. This is in keeping with the
proposition that increased levels of EPA lead to a change in production of
local mediators involved in the development of polyps. Overall, EPA was
well-tolerated in this population (West et al 2010).

extracted from protocol 5.1

Primary Objective
* To determine the efficacy of EPA-FFA gastro-resistant capsules in patients
with FAP in reducing polypectomy.

Secondary Objectives
* To evaluate the clinical disease progression.
* To evaluate the long-term safety and tolerability of EPA-FFA.

2 year randomised, double-blind, placebo-controlled, parallel group study to
determine the safety and efficacy of EPA-FFA gastro resistant
capsules in FAP.

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