Cempra Announces Partial Exercise of Over-Allotment Option and Completion of the Public Offering of Common Stock

Cempra Announces Partial Exercise of Over-Allotment Option and Completion of
the Public Offering of Common Stock

CHAPEL HILL, N.C., June 19, 2013 (GLOBE NEWSWIRE) -- Cempra, Inc.
(Nasdaq:CEMP), a clinical-stage pharmaceutical company focused on developing
differentiated antibiotics to meet critical medical needs in the treatment of
bacterial infections, today announced that it has completed its previously
announced underwritten public offering of 7,250,000 shares of common stock,
plus an additional 1,023,938 shares issued pursuant to the partial exercise by
the underwriters of their over-allotment option, at a public offering price of
$7.00 per share. The partial exercise of the over-allotment option increases
the net proceeds to the company, after underwriting discounts and commissions
and estimated offering expenses, from approximately $47.5 million to
approximately $54.2 million.

Barclays, Stifel and Cowen and Company are acting as joint book-running
managers for the offering. Needham & Company and SunTrust Robinson Humphrey
are acting as co-managers.

Cempra has filed a registration statement on Form S-3, as well as a final
prospectus supplement and accompanying prospectus, with the Securities and
Exchange Commission. The final prospectus supplement and accompanying
prospectus relating to the offering may be obtained by sending a request to
Barclays Capital Inc. by calling 1-888-603-5847, or by mail at Barclays
Capital Inc. c/o Broadridge Financial Solutions, 1155 Long Island Avenue,
Edgewood, NY 11717, or by e-mail at Barclaysprospectus@broadridge.com; from
Stifel, Nicolaus & Company, Incorporated by mail at One Montgomery Street,
36^th Fl, San Francisco, CA 94104, by telephone at 415-364-2720 or by e-mail
at syndprospectus@stifel.com; and from Cowen and Company, LLC c/o Broadridge
Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, Attn:
Prospectus Department or by telephone at 631-274-2806.

This press release does not constitute an offer to sell or a solicitation of
an offer to buy the securities in this offering.

About Cempra, Inc.

Founded in 2006, Cempra, Inc. is a clinical-stage pharmaceutical company
focused on developing antibiotics to meet critical medical needs in the
treatment of bacterial infectious diseases. Cempra's two lead product
candidates are currently in advanced clinical development.Solithromycin
(CEM-101) is in a Phase 3 clinical trial 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.Both 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: risks
relating to the use of the proceeds from the offering; the results, timing,
costs and regulatory review of our studies and clinical trials; 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; the results of studies of our product
candidates conducted by others; the possible impairment of, or inability to
obtain, intellectual property rights and the costs of obtaining such rights
from third parties; our ability to obtain FDA approval of our product
candidates; our dependence on the success of solithromycin and Taksta; 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 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
        
         Media Contact:
         Karine Kleinhaus, M.D.
         Russo Partners, LLC
         (646) 942-5632
         Karine.kleinhaus@russopartnersllc.com