Positive Results for Peplin`s First Phase III AK Trial

* Met primary and secondary efficacy endpoints with statistically significant
clearance of AK lesions vs. vehicle
* First topical treatment to demonstrate statistically significant benefit over
vehicle across non-head anatomical locations, including back of hand
* Median reduction in overall lesion count of 66.7%

EMERYVILLE, Calif. & BRISBANE, Australia--(Business Wire)--
Peplin, Inc. (ASX:PLI) today announced positive results for PEP005 (ingenol
mebutate) Gel in REGION-I, its Australian and US based Phase III actinic (solar)
keratosis (AK) clinical trial for the treatment of lesions on non-head
locations, which include the trunk and extremities. AK is a common pre-cancerous
skin condition caused by sun exposure, which can develop into skin cancers if
left untreated.

Peplin`s Chief Executive Officer, Tom Wiggans, is pleased with the positive
results and said: "Once again, our team has done an excellent job of obtaining
great clinical results while completing our first Phase III trial within the
expected timeframe."

He continues, "These strong results achieve an important step towards
commercialisation. In addition, they confirm efficacy signals with prior trials
and market need, since no currently marketed product has proven efficacy for
this range of locations for non-head lesions, especially with a 2-day course of
therapy. PEP005 Gel continues to provide patients the potential for a compelling
alternative."

REGION-I tested a 0.05% concentration of PEP005 Gel applied once a day for only
two consecutive days. This resulted in a median reduction in the number of AK
lesions of 66.7% (p-value<0.0001), a total clearance rate across all anatomical
non-head sites, including the extremely difficult-to-treat back of hand and arm
locations, equal to 27.4% (p-value<0.0001) and a partial clearance rate of 44.4%
(p-value <0.0001). In addition, statistical significance was established in back
of hand, arm and chest locations. These highly statistically significant
results, as evidenced in the favourable p-values, suggest that the drug has
significant benefit over vehicle.

As anticipated, the inclusion of treatment sites for all non-head AK lesions
contributed to the lower clearance rates when compared to previous trials, but
the total clearance rates ranged from 16% to 89%by anatomical location with
chest, back of hand and arms achieving statistical significance. The other areas
did not show statistical significance due to the low number of patients that
enrolled with these types of AK lesions.

Dr. Robert Rosen, a Sydney dermatologist and scientific advisor to Peplin, who
has also been involved in the PEP005 clinical trial program, said that current
treatment options for solar keratosis have a number of shortfalls, including
pain, persisting skin irritation and redness during prolonged treatment periods.

"As a result, patients are often unwilling to use their medications," he said.
"A topical agent like PEP005 Gel, which can effectively and conveniently treat
lesions in two days, will be of significant benefit to doctors and their
patients."

Brian Berman, M.D., Ph.D., Professor of Dermatology and Internal Medicine at the
University of Miami, Miller School of Medicine, states: "Practicing
dermatologists recognise that the successful treatment of AK lesions found on
the arms or back of hands is a challenge generally unmet by topical treatments
currently on the market. PEP005 Gel`s strong results across these difficult
treatment areas provide the opportunity to satisfy our AK patients` unmet need."

As seen in previous non-head trials, the local skin responses (LSRs) peaked at
Day 8 and returned to baseline by Day 29. The most frequent LSRs included
erythema, flaking and scaling with no significant adverse effects reported.

Peplin will conduct its End-of-Phase II meeting with the FDA on June 3, 2009.
Peplin was notified by the FDA of their need to postpone the meeting by two
weeks from the originally scheduled date due to internal scheduling conflicts at
the FDA. Peplin will initiate the Phase III program for patients with AK lesions
on the head, an estimated 70% of the AK market, in the second quarter of 2009.

REGION-I Trial Details

Design and treatment method: REGION-I was a 250-patient, Australian and US
multi-centre, randomised, parallel group, double-blind, vehicle-controlled
clinical trial to evaluate the safety and efficacy of a 0.05% concentration
applied for 2 consecutive days for Peplin`s patented product, PEP005 Gel in
patients with AK lesions on non-head sites, including arm, back, back of hand,
chest, leg and shoulder.

The study was conducted at 19 study centers within the United States and
Australia. All eligible patients were centrally randomised to either active
(PEP005 Gel, 0.05%) or vehicle gel in a 1:1 ratio. Randomisation was stratified
by study site and anatomical location. This field-directed therapy was applied
to a 25 cm2 contiguous AK treatment area containing four to eight clinically
typical AK lesions. Study medication was patient-applied, at home, to the
selected treatment area. Patients returned to the clinic for study follow-up
visits on Days 3, 8, 15, 29 and 57 (study exit) following study medication
application.

Evaluation criteria: This Phase III trial aimed to evaluate the safety and
efficacy of Peplin`s proprietary product, PEP005 (ingenol mebutate) Gel, in
patients with AK lesions on non-head locations. The primary efficacy objective
was complete clearance of AK lesions.Complete clearance was defined as the
proportion of patients at the Day 57 visit with no clinically visible AK lesions
in the selected treatment area.

The secondary objectives were partial clearance and percent median reduction of
AK lesions. Partial clearance was defined as the proportion of patients at the
Day 57 visit with a 75% or greater reduction in the number of AK lesions
identified at Baseline in the selected treatment area. Percent median reduction
was defined as the median number of AK lesions within the selected treatment
area no longer clinically visible for any given patient at the Day 57 visit.

The primary safety evaluation included:

* Incidence of adverse events (AEs) and serious adverse events (SAEs) recorded
throughout the study
* Incidence and grade of local skin responses (LSRs), and changes in
pigmentation and scarring following study medication

Patients: A total of 255 patients were randomised into the study and included in
the intent to treat (ITT) population. 254 patients received at least one
application of study medication and were included in the safety population.
Twenty patients were excluded from per protocol efficacy analyses due to
protocol deviations, leaving 235 patients to be included in the per protocol
population.

The mean age of patients was 67.1 years (range 36 - 88 years), 62.4% of patients
were male and 37.6% female. Patients were randomised across the six anatomical
locations as follows: 166 (65.1%) arm, 54 (21.2%) back of hand, 17 (6.7%) chest,
2 (0.8%) shoulder, 5 (2.0%) back and 11 (4.3%) leg

REGION-I Results

Efficacy: A 0.05% concentration of PEP005 (ingenol mebutate) Gel applied once
daily for two consecutive days resulted in a total clearance rate in the intent
to treat population equal to 27.4% (p-value<0.0001), a partial clearance rate of
44.4% (p-value<0.0001) and a median reduction in overall lesion count of 66.7%
(p-value<0.0001).

See FIGURE 1:REGION-I Clearance Summary

Safety: The drug suggested a favourable profile. There were no treatment-related
SAEs, and AEs were generally mild to moderate in severity and resolved by Day
57. The most common treatment-related AEs, occurring within the treatment area,
appeared to be application site irritation and pruritus. One patient experienced
pain in the treatment area that led to discontinuation from dosing after one
application.

The local skin responses (LSRs) assessed in this study were as follows:

* erythema
* flaking/scaling
* crusting
* swelling
* vesiculation/pustulation
* erosion/ulceration

Each response was evaluated on a scale of 0 - 4 and then the mean composite
score across responses is calculated.

See FIGURE 2:Composite Local Skin Response

Pigmentation and Scarring: A total of 7 patients in the active group had
pigmentation changes with 4 reporting improvements and 3 patients in active
group reported a worsening of pigmentation. No patients experienced a worsening
of scarring during the study.

ABOUT PEPLIN

Peplin is a development stage specialty pharmaceutical company focused on
advancing and commercialising innovative medical dermatology products. Peplin is
currently developing PEP005 (ingenol mebutate), which is the first in a new
class of compounds and which is derived from the sap of Euphorbia peplus, or E.
peplus, a rapidly growing, readily available plant commonly referred to as petty
spurge or radium weed. E. peplus has a long history of traditional use for a
variety of conditions, including the topical self-treatment of various skin
disorders, including skin cancer and pre-cancerous skin lesions. Peplin`s lead
product candidate is a patient-applied topical gel containing ingenol mebutate,
a compound the use of which Peplin has patented for the treatment of actinic
(solar) keratosis, or AK. This product candidate referred to as PEP005 (ingenol
mebutate) Gel is currently in Phase III clinical trials, having just completed
their first Phase III, known as REGION-I.

ABOUT AK

Actinic keratoses (AK), also known as solar keratosis or sun spots, is generally
considered the most common pre-cancerous skin condition. AK usually appears as
small, rough, scaly areas on the face, lips, ears, back of hands, forearms,
scalp or neck. If left untreated, AK lesions may progress to a form of skin
cancer called squamous cell carcinoma, or SCC. The Lewin Group, Inc., estimates
that the total direct costs for AK in the United States was $1.2 billion in
2004, and in 2002 there were approximately 8.2 million office visits for the
treatment of AK. The Lewin Group also estimated that there were 58 million
people in the United States living with AK in 2004. According to a May 2006
issue of The Journal of Family Practice, in northern hemisphere populations, 11%
to 25% of adults have at least one AK lesion, compared with 40% to 60% of adults
in Australia, which has the highest prevalence of AK worldwide.

FORWARD LOOKING STATEMENTS

This press release contains "forward-looking statements" as defined under U.S.
federal securities laws, including, but not limited to, Peplin`s clinical
development plan and timing of clinical trials referred to herein. These
forward-looking statements can be identified through the use of words such as
"anticipates," "expects," "intends," "plans," "believes," "seeks," "estimates,"
"may," "will," and variations of these words or similar expressions. Forward
looking statements are based on management's current, preliminary expectations
and actual results could differ materially as a result of various risks and
uncertainties, including, but not limited to, delays in clinical trials
resulting from, among other things, ambiguous or negative interim results,
unforeseen safety issues, failure to conduct the clinical trials in accordance
with regulatory requirements or clinical protocols, suspension or termination of
a clinical trial by the FDA or other regulatory authorities, lack of adequate
funding to continue a clinical trial and other important factors disclosed from
time to time in Peplin`s disclosures to the ASX and in its Form 10 Registration
Statement and most recent quarterly report on Form 10-Q filed with the US
Securities and Exchange Commission. Forward-looking statements speak only as of
the date they were made. No undue reliance should be placed on any
forward-looking statements. Such information is subject to change, and we
undertake no obligation to update such statements.

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Peplin, Inc.
Tom Wiggans, +1-510-653 9700
Chief Executive Officer
tom.wiggans@peplin.com
or
Media:
Hill & Knowlton
Camilla Myers, 02-9286 1248
cmyers@hillandknowlton.com.au

Copyright Business Wire 2009