Safety Study of DA-9801 to Treat Diabetic Neuropathy

This is a double-blind, randomized, parallel group, dose ranging, placebo-controlled study
where eligible subjects (age 18 to 75 years) will have an average pain score ≥ 4 on an
11-point Likert numerical rating scale (NRS) for at least four days each week prior to
randomization as assessed by daily pain diaries. Eligible subjects will be randomized to a
1:1:1:1 ratio to receive 300mg, 600mg, 900mg of DA-9801, or placebo three times a day for 12
weeks. During and at the end of the 12-week treatment period subjects will be evaluated for
safety and efficacy parameters. A follow-up visit for safety will occur two weeks after the
last treatment visit (TV).

The Screening Phase (2 weeks) is designed to determine whether subjects are eligible to
proceed to the Treatment Phase of the study and consists of a series of screening
assessments designed to determine eligibility. Eligible subjects will undergo a two-week
washout period for medications and therapies administered for pain management.

At or up to 21 days before the Screening Visit, written informed consent from (ICF) the
subject will be obtained by the Investigator or a suitably qualified designee before the
performance of any protocol specific procedure. At the Screening Visit, the subject will be
issued a daily diary in order to record daily pain level during the screening phase.

The Treatment Phase (TV0 to TV12) begins with a series of assessments designed to confirm
the subjects' continued eligibility. The site will collect the daily diary and the subject's
pain score will be determined. Only subjects whose average pain score is ≥ 4 for at least
four days each week will be randomized to any of the four treatment groups.

DA-9801 administration schedule is three times per day, starting from TV0 to TV12.

During this study phase subjects will be evaluated on a weekly basis. Efficacy evaluations
each week will include the subject's global impression of improvement and CGI of pain.
Safety evaluations during the Treatment Phase will consist of adverse event assessments at
each visit.

The Follow-up Visit (two weeks after last TV) The Follow-up Visit is designed to assess
safety and will occur 14 days after the last TV. If the subject is withdrawn from the study
prior to TV12, the subject should be exited from the study AFTER completing the specified
assessments for that visit.

Inclusion Criteria:

- Must be 18 to 75 years of age

- Diagnosed with Type I or Type II diabetes

- HbA1c ≤ 12% at the time of screening

- Has diabetic neuropathic pain (numbness, soreness, shooting or poking pain) in the
lower extremities for more than 3 months prior to screening and with no adequate
relief from other treatments

- Has an average pain score of ≥ 4 for 24 hours at least 4 days out of the week prior
to randomization as assessed by the 11-point Likert NRS.

- If female of childbearing potential, subject must have a negative serum pregnancy
test at screening

- Understands and is willing to participate in the clinical study and can comply with
study procedures and visits.

- Normal cognitive and communicative ability as judged by clinical assessment and
ability to complete self-reported questionnaires

- Subject is willing and able to give informed consent

Exclusion Criteria:

- Evidence of another type of neuropathic pain caused by a condition other than
diabetes

- Pain from another source as severe or greater than the pain under study

- BMI (Body Mass Index) > 37 kg/m2

- Clinical signs of infection related to sores of any type on the legs

- Subjects on any investigational drug(s) or therapeutic device(s) within 30 days
preceding screening; or subject or physician anticipates use of any of these
therapies by the subject during the course of the study

- Previous participation in the Treatment Phase of this Protocol

- History of drug or alcohol abuse, within the past 6 months

- Malignant disease not in remission for 5 years or more that has been medically or
surgically treated without evidence of metastases

- Presence of one or more medical conditions, as determined by medical history, which
seriously compromises the subject's ability to complete the study, including history
of poor adherence with medical treatment, renal, hepatic, hematologic, active
auto-immune or immune diseases that, in the opinion of the Investigator, would make
the subject an inappropriate candidate for this study: c) One or more abnormal blood
biochemistry analyte result that is ≥ 3 times that of the upper limit of the normal
range; d) For laboratory results that are significantly lower than the normal range,
specific criteria will be used to judge subject eligibility for randomization for
Total protein, Albumin, and Hemoglobin or Platelets.

- Known history of having Acquired Immunodeficiency Syndrome (AIDS) or with a history
known to be infected with Human Immunodeficiency Virus (HIV)

- New York Heart Association (NYHA) Class III and IV congestive heart failure (CHF), as
defined by the following criteria: a)Class III: Symptoms with moderate exertion
b)Class IV: Symptoms at rest

- Pregnant or breast feeding

- Women of child-bearing potential not using an effective birth control method. Women
of child-bearing potential are defined as women physiologically capable of becoming
pregnant, UNLESS they meet the following criteria:

d) Post-menopausal: 12 months of natural (spontaneous) amenorrhea or 6 months of
spontaneous amenorrhea with serum Follicle Stimulating Hormone (FSH) levels >
40mIU/m, OR; e) 6 weeks post surgical bilateral oophorectomy with or without
hysterectomy, OR; f) Are using one or more of the following acceptable methods of
contraception: surgical sterilization, hormonal contraception, and double-barrier
methods. Reliable contraception should be maintained throughout the study and for 7
days after study discontinuation.

- Subjects with a diagnosis of psychiatric disorders such as major depressive disorder,
bipolar disorder, obsessive compulsive disorder, generalized anxiety, dysthymia or
suicidality/suicide ideation

- Administration of local anesthetic shot or systemic steroids within two months of
screening

- Subjects not willing to undergo a two-week washout period for pharmacologic and
non-pharmacologic pain management techniques