ROCKVILLE, Md.–(Business Wire)–
Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN), a clinical stage pharmaceutical
company commercializing potential best in class oncology and CNS therapeutics,
today announced that it has submitted a Phase II protocol to the U.S. Food and
Drug Administration (FDA) for the clinical study of Serdaxin® for the treatment
of Parkinson`s disease (PD).

“Serdaxin has demonstrated an ability to prevent neuronal deaths in PD models,
and the drug`s positive Phase IIa results in depression further enhance its
promise as a treatment for PD,” said Rexahn Chief Executive Officer, Dr. Chang
Ahn. “Although there are currently various treatment options for PD, a
meaningful cure is overdue. Based on Serdaxin`s novel action as a dual serotonin
and dopamine enhancer, we believe it has the potential to be the first drug of
its kind to target both the classic symptoms of PD and treat the depression so
often associated with this disease.”

The Phase II study will assess Serdaxin`s efficacy as a treatment for
Parkinson`s disease in approximately 300 subjects. The planned double blind,
randomized, placebo-controlled trial will include the Unified Parkinson`s
Disease Rating Scale (UPDRS) and quality of life instruments as study endpoints
and will be conducted at multiple sites.

Rexahn also has formed a Parkinson`s Scientific Advisory Board (SAB) composed of
leading medical researchers in the field of neurology who will advise on the
design and development of the Serdaxin clinical trials. Commenting on the
protocol submission, Dr. William Weiner, Chairman of the SAB, and head of the
Maryland Parkinson`s Disease and Movement Disorders Center, and Professor and
Chair of the Department of Neurology at the University of Maryland School of
Medicine, said, “We believe that Serdaxin’s properties in animal models open
exciting possibilities as a new treatment for patients with PD. All the members
of the SAB will be actively engaged in Serdaxin’s clinical development, which we
hope will further establish the drug’s efficacy in treating PD.”

About Serdaxin®

Serdaxin® is a potential market-leading CNS neuroprotective agent and
antidepressant. Rexahn is currently investigating Serdaxin as a treatment for
depression in Phase II clinical trials. Serdaxin may achieve greater and broader
therapeutic coverage and appears to have no serious side effects such as nausea,
vomiting, insomnia, weight gain, sexual dysfunction, cognitive deficit or motor
impairment that are linked to existing antidepressant drugs. Serdaxin has a
well-established, excellent human safety profile. In preclinical studies,
Serdaxin had onset of action in less than two days. Based on its novel mechanism
as a dual serotonin and dopamine enhancer, it is a potential treatment for
multiple CNS disorders where these neurotransmitters are depleted or implicated
in CNS-based illnesses, such as Parkinson`s disease (PD). Serdaxin has the
potential to address both non-motor and motor events of PD by serving as a
neuroprotective agent and addressing loss of dopaminergic neurons that lead to
loss of control of movements; and further, enhancing serotonin and dopamine
levels that are involved in depression and mood disorders. Rexahn has multiple
clinical programs planned for investigating Serdaxin in the treatment of anxiety
disorders, Parkinson`s disease, Alzheimer`s disease and neurodegenerative
illnesses, neuroprotection and biodefense uses.

About Parkinson`s Disease

Parkinson`s disease (PD) is the most common movement disorder, affecting more
than 5 million patients worldwide. Age is the most important risk factor for PD,
and the aging world population is expected to push the number of the afflicted
to over 10 million by 2030. In addition, its chronic and debilitating nature
warrants high socio-economic impacts. PD is characterized by the progressive
loss of dopaminergic neurons in the brain. The resulting dopamine depletion
leads to its cardinal motor symptoms, such as rigidity (muscle stiffness),
bradykinesia (slowing of movement), postural instability and resting tremor.
These impairments are accompanied by non-motor disabilities, including dementia,
depression, and sleep disturbance. The current standard treatment options target
the dopaminergic pathway, either by supplementing the molecule or stimulating
dopamine receptors (binding partners of dopamine). While these strategies
ameliorate symptoms in early stages, they become less effective over the course
of the disease. In addition, dopamine therapies fail to tackle the underlying
causes of the disease, and therefore, do not slow the progression of PD or
extend the life expectancy of patients. Serdaxin is a new class of CNS disorder
therapeutics that has prevented neuronal deaths in PD models. In contrast to
other PD drugs, Serdaxin directly targets the disease mechanism by slowing or
halting the progression of the disease, fulfilling unmet needs in Parkinson`s
disease treatment.

About Rexahn Pharmaceuticals, Inc.

Rexahn Pharmaceuticals is a clinical stage pharmaceutical company dedicated to
commercializing first in class and market leading therapeutics for cancer, CNS
disorders, sexual dysfunction and other unmet medical needs. Rexahn currently
has three drug candidates in Phase II clinical trials, Archexin®, Serdaxin®, and
Zoraxel – all potential best in class therapeutics – and a robust pipeline of
preclinical compounds to treat multiple cancers and CNS disorders. Rexahn also
operates key R&D programs of nano-medicines, 3D-GOLD, and TIMES drug discovery
platforms. For more information, please visit www.rexahn.com.

Safe Harbor

This press release contains forward-looking statements. Rexahn’s actual results
may differ materially from anticipated results, and expectations expressed in
these forward-looking statements, as a result of certain risks and
uncertainties, including Rexahn’s lack of profitability, and the need for
additional capital to operate its business to develop its product candidates;
the risk that Rexahn’s development efforts relating to its product candidates
may not be successful; the possibility of being unable to obtain regulatory
approval of Rexahn’s product candidates; the risk that the results of clinical
trials may not be completed on time or support Rexahn’s claims; demand for and
market acceptance of Rexahn’s drug candidates; Rexahn’s reliance on third party
researchers and manufacturers to develop its product candidates; Rexahn’s
ability to develop and obtain protection of its intellectual property; and other
risk factors set forth from time to time in our filings with the Securities and
Exchange Commission. Rexahn assumes no obligation to update these
forward-looking statements.

Rexahn Pharmaceuticals, Inc.
Investor Relations
Stern Investor Relations, Inc.
Stephanie Ascher, 212-362-1200
stephanie@sternir.com
or
Base Pair Communications
Constantine Theodoropulos, 617-401-3116
constantine@basepaircomm.com

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