16-JAN-08

RESEARCH TRIANGLE PARK, NC, January 16, 2008 -- CeNeRx BioPharma, Inc., a clinical stage
company developing and commercializing innovative treatments for diseases of the central nervous
system, today announced the successful completion of the Phase l clinical program for Tyrima™, its
lead candidate for the treatment of depression and anxiety. Tyrima is a selective and reversible
member of a novel class of drugs known as RIMAs, or reversible inhibitors of monoamine oxidase A.
The Phase l program included acute dose, repeat dose and fed-fasted studies. The results of all
studies were favorable, showing that Tyrima was safe and well tolerated and exhibited good
pharmacokinetic properties.

“Tyrima has the potential to be the first triple-action antidepressant capable of treating a broad
patient population, and we are very pleased with the safety and tolerability observed in the Phase
l clinical program,” said Dr. Daniel Burch, R&D head and chief medical officer of CeNeRx.
“Monoamine oxidase A inhibitors (MAOI) have demonstrated efficacy advantages over
conventional antidepressants, but their use has been limited by their potential for serious adverse
food effects. In these Phase l studies, Tyrima demonstrated good safety and excellent drug-like
properties, with a positive pharmacokinetic profile at all doses tested and minimal signs of fed-
fasted effects. We look forward to initiating the Phase ll program in the second quarter of 2008.”

Like conventional MAOI agents, the triple-action mechanism of Tyrima elevates the levels of three
key neurotransmitters (serotonin, norepinephrine and dopamine) that positively affect mood and
anxiety. In contrast, most of the current leading antidepressant drugs affect only the single
neurotransmitter serotonin. However, unlike older MAOIs, the unique selectivity and reversibility of
CeNeRx’s Tyrima should enable patients to benefit from the efficacy advantages of the class while
avoiding the food-associated cardiovascular side effects of older MAOIs. The potential for these
adverse effects has greatly restricted the use of conventional MAOI agents.

The Phase l program evaluated a range of Tyrima doses in 65 subjects. The repeat dose study
results confirmed the positive findings of the acute dose trial that were reported previously. Tyrima
was well tolerated, with no clinically significant adverse events reported at any dose. It achieved
high plasma concentrations and exhibited a favorable pharmacokinetic half-life consistent with
once- or twice-daily dosing.

“Successful completion of the Phase l program is a major milestone for our third-generation RIMA
agents, whose triple-action mechanism has the potential to provide greater antidepressant efficacy
to the many patients who do not obtain adequate relief from currently available therapies,” said
Barry Brand, chief executive officer of CeNeRx. “Tyrima offers a mechanism of action that is well-
precedented and it has novel safety advantages. We look forward to rapidly advancing the Phase
ll program.”

CeNeRx has worldwide rights to develop and commercialize Tyrima. This compound, which could
be the first RIMA antidepressant available in the U.S. market, has patent protection beyond 2027.

About CeNeRx BioPharma
CeNeRx (SEN-er-ex) is a privately held clinical stage biopharmaceutical company developing and
commercializing innovative treatments for diseases of the central nervous system. CeNeRx’s most
advanced compounds, reversible inhibitors of monoamine oxidase, or RIMAs, are in late preclinical
and Phase I development for the treatment of major depressive disorder. RIMAs may have
efficacy advantages over current agents for depression and are expected to have a good safety
profile. The company is also developing its preclinical pipeline of selective cannabinoid compounds
for the treatment of pain, glaucoma and obesity. More information about CeNeRx BioPharma can
be found at www.cenerx.com.