Cempra, Inc., Provides Update on Clinical Development of Solithromycin and Taksta(TM)

Cempra, Inc., Provides Update on Clinical Development of Solithromycin and
Taksta(TM)

Conference Call at 4:30 p.m. EST, Today

CHAPEL HILL, N.C., Dec. 16, 2013 (GLOBE NEWSWIRE) -- Cempra, Inc.
(Nasdaq:CEMP), today provided an update on the clinical development of
solithromycin and Taksta(TM). Prabhavathi Fernandes, Ph.D., president and
chief executive officer of Cempra, will host a conference call and webcast at
4:30 p.m. EST, today, to discuss the current status of the company's clinical
programs.

Solithromycin

The company has recently initiated Solitaire-IV, the company's global
solithromycin intravenous (IV)-to-oral Phase 3 clinical trial, in patients
with community-acquired bacterial pneumonia (CABP). Solitaire-IV joins
Solitaire-Oral, the first global Phase 3 study of solithromycin in CABP
patients, which initiated enrollment in December 2012.

"Cempra is focused on developing truly differentiated antibiotics for the
acute care and community settings that we believe will offer significant
benefit to patients, payors and providers," said Dr. Fernandes. "The goal of
Solitaire-IV is to provide evidence of safety and efficacy of an IV-to-oral
step down regimen that we believe will provide clinicians and their patients a
better therapeutic option to treat CABP. Currently, hospital-admitted patients
spend seven to 10 days in the hospital receiving a combination of different
oral and IV antibiotics. Future treatment with IV solithromycin would be
monotherapy and it would enable the option to switch to the oral form and
leave the hospital sooner, which should save money for the provider and payor
and improve patient quality of life. We look forward to presenting results on
this study when available as well as reporting top-line results of
Solitaire-Oral, which we expect in mid-2014."

Solitaire-IV is a double-blind, placebo-controlled and global multi-center
study in which approximately 800 patients with PORT-II to PORT-IV CABP will be
randomized to initially receive intravenous administration of either 400 mg of
solithromycin or 400 mg of moxifloxacin. Patients can switch to oral dosing of
the drug they started on (800 mg loading dose followed by 400 mg once daily
for a total of five days for solithromycin or once-daily oral administration
of 400 mg of moxifloxacin for seven days) based on a decision by the
physician. The primary endpoint is non-inferiority of early response at 72
hours in the intent to treat (ITT) population, which is specified by the
proposed FDA guidance.

CABP is one of the most common bacterial infections resulting in five to 10
million cases and 1.1 million hospitalizations per year in the U.S. It is the
number one cause of death from an infection, particularly for the very young
and old. Patients hospitalized for CABP face a mortality rate of 23%.
Recognizing the importance of this disease, pneumococcus, the primary pathogen
in CABP, was elevated to qualified infectious diseases pathogen status by the
FDA and both oral and IV solithromycin were designated Qualified Infectious
Products.

Solithromycin is Cempra's fourth-generation macrolide/fluoroketolide with
potential for broad use. Cempra is developing oral capsules, intravenous
formulation and a pediatric suspension for planned use in all age groups, both
in the hospital as well as in outpatient use. Solithromycin is the first new
antibiotic in over 20 years being developed in dosing formulations suitable
for all populations.

Taksta(TM) – Phase 2 results to date

The Phase 2 study is an open-label randomized clinical trial in which 50
patients with prosthetic joint infection (PJI) will be randomized to receive
either oral Taksta plus rifampin or current standard of care, which is
intravenous antibiotic therapy with antibiotics such as vancomycin, nafcillin
or cefazolin.The primary outcome measure is demonstration of infection-free
status at 12 weeks following initiation of therapy.To date, 31 subjects with
PJI have been screened, at 14 sites, of which 21 subjects were enrolled on
Taksta plus rifampin. Of these 21, 13 patients were dropped from the study for
various reasons including not growing a positive culture. The remaining eight
were randomized into the trial. Three of the subjects that received Taksta
plus rifampin completed the 12-week regimen. One of the patients was declared
a success at re-implantation with a negative culture. The other two are doing
well and are awaiting surgery. One patient did not tolerate the
Taksta-rifampin combination. Of the four patients in the standard of care arm,
one patient has completed IV therapy and surgery is pending, the second
patient was successfully treated but was switched from IV vancomycin to IV
daptomycin mid-stream during the course of treatment, the third patient was
successfully treated but another bacterium was isolated, which may be a
possible contaminant and the fourth patient is still on intravenous therapy.
Enrollment is continuing.

"Our randomized open-label Phase 2 study was designed to evaluate Taksta
compared to the standard of care in patients with prosthetic joint
infections," said Dr. Fernandes. "Despite the small number of patients that
completed the trial so far due to the original exclusive entry criteria, the
results to date are consistent with a positive effect of Taksta in this
indication. Along with the very strong results from studies world wide of
fusidic acid in PJI, the active antibiotic of Taksta, we are optimistic that
this study will lay the groundwork for a defined Phase 3 study.

"A very important milestone, which we previously announced in October 2013,
was Taksta's Orphan drug designation granted by the U.S. Food and Drug
Administration. This was a significant event for Cempra for a number of
reasons. It may provide a 50% clinical cost tax credit and allow for a PDUFA
fee waiver along with seven years statutory market exclusivity. In addition,
orphan drug designation gives us an opportunity to develop a path to a new
drug application (NDA) concurrently while running our Phase 2 study rather
than waiting for completion of the trial to discuss the path toward an NDA. We
have designed an innovative Phase 3 study that may be a path toward an NDA. We
plan to submit the proposed Phase 3 study protocol to the FDA early next year
and discuss our strategy with the FDA in the first half of 2014."

PJIs occur in about 1% of hip replacements and 2% of knee replacements, with
an overall incidence rate of about 20,000 per year in the U.S. at current hip
and knee arthroplasty rates. There are few good options to treat these serious
staphylococcal, often MRSA, infections, which require long-term antibiotic
treatment. Current therapy in the U.S. is with intravenous antibiotics such as
vancomycin and multiple surgeries. An oral drug that can be safely
administered for a long period of time could improve care and quality of life
for these patients. In addition to the Orphan designation, the Office of Rare
Diseases Research has recognized and listed PJI as a rare disease in December
2013.

Conference call and webcast information

The conference call may be accessed by dialing 877-377-7553 for domestic
callers and 253-237-1151 for international callers. Please specify to the
operator that you would like to join the "Cempra, Inc., Clinical Update call,
conference ID#: 24949034." The conference call will be webcast live under the
investor relations section ofCempra's website atwww.cempra.com, and will be
archived there for 30 days following the call. Please visitCempra's website
several minutes prior to the start of the broadcast to ensure adequate time
for any software download that may be necessary.

About Cempra, Inc.

Founded in 2006, Cempra, Inc. is a late clinical-stage pharmaceutical company
focused on developing antibiotics to treat critical bacterial infections in
patients in both acute and primary care settings.Cempra's two lead product
candidates are currently in advanced clinical development.Solithromycin
(CEM-101) is in two Phase 3 clinical trials for community-acquired bacterial
pneumonia (CABP) and is licensed to strategic commercial partner Toyama
Chemical Co., Ltd., a subsidiary of FUJIFILM Holdings Corporation, for certain
exclusive rights in Japan. TAKSTA™ (CEM-102) is Cempra's second product
candidate currently in a Phase 2 clinical trial for prosthetic joint
infections. TAKSTA was recently granted orphan drug designation for this
indication. Both product candidates seek to address the need for new
treatments targeting drug-resistant bacterial infections in the hospital and
in the community. The company also intends to use its series of proprietary
lead compounds from its novel macrolide library for uses such as the treatment
of chronic inflammatory diseases, endocrine diseases and gastric motility
disorders. Additional information about Cempra can be found at www.cempra.com.

Please Note: This press release contains forward-looking statements regarding
future events. These statements are just predictions and are subject to risks
and uncertainties that could cause the actual events or results to differ
materially. These risks and uncertainties include, among others: the results,
timing, costs and regulatory review of our studies and clinical trials; the
results of studies of our product candidates conducted by others; our need to
obtain additional funding and our ability to obtain future funding on
acceptable terms; our anticipated capital expenditures and our estimates
regarding our capital requirements; our ability to obtain FDA approval of our
product candidates; our dependence on the success of solithromycin and Taksta;
the possible impairment of, or inability to obtain, intellectual property
rights and the costs of obtaining such rights from third parties; and
innovation by our competitors. The reader is referred to the documents that we
file from time to time with the Securities and Exchange Commission.

CONTACT: Investor and Media Contacts:
         Robert E. Flamm, Ph.D.
         Russo Partners, LLC
         (212) 845-4226
         Robert.flamm@russopartnersllc.com
        
         Andreas Marathovouniotis
         Russo Partners LLC
         (212) 845-4235
         Andreas.marathis@russopartnersllc.com