Macrochem Acquires Option To License Pexiganan, a Novel Topical Anti-Infective for Treatment of Diabetic Foot Infection, from Genaera

WELLESLEY HILLS, Massachusetts, July 10 /PRNewswire/ --

- Broadens late-stage product development portfolio building on lead
product candidate EcoNail in Phase 2 trial for onychomycosis

MacroChem Corporation (OTCBB: MACM) today announced that it has signed an
exclusive option to acquire exclusive worldwide license rights for drug uses
of pexiganan, a novel, small peptide anti-infective for topical treatment of
patients with mild diabetic foot infection (DFI), from Genaera Corporation
(Genaera).

"We believe this is a unique opportunity for MacroChem to broaden its
product portfolio with a product that has already completed two Phase 3
clinical trials. It also fits our strategic focus and complements our lead
product candidate, EcoNail(TM) for treatment of nail fungus currently in a
fully enrolled Phase 2 trial and progressing on track with an interim
assessment of clinical data later this year after all patients have been
treated for twenty four weeks," said Robert J. DeLuccia, President and CEO of
MacroChem.

Clinical trials with pexiganan previously conducted by Genaera include
two Phase 3 trials submitted in a New Drug Application (NDA) to the U.S. Food
and Drug Administration (FDA) in 1998. At that time, outstanding issues with
CMC (Chemistry, Manufacturing and Controls) and an FDA request for one
additional controlled trial precluded approval.

Mr. DeLuccia further noted, "We would be pleased to have pexiganan in our
hands since we believe that, if approved, it would be welcomed by physicians
and patients for the treatment of diabetic foot infection. In recent years,
there have been many advances in the manufacturing of peptides, a better
understanding of the treatment of diabetic foot infection, improvements in
clinical trial design and execution, and more clarity concerning regulatory
requirements for topical anti-infectives with the potential market being even
more attractive than before."

WELLESLEY HILLS, Massachusetts, July 10 /PRNewswire/ --

He added, "There continues to be a very large and growing incidence of
diabetes and, as a result, a growing number of diabetic foot infections in
the U.S. Diabetic foot ulcers in the approximately 20 million diabetics in
the US alone are a major concern and burden to both patients and healthcare
system. There is also a lack of effective topical anti-infectives to treat
diabetic foot infection. Accordingly, we believe that pexiganan could fill an
important unmet medical need for a topical anti-infective treatment and
provide a significant commercial opportunity in an addressable market of
approximately 3.5 million diabetic foot infections annually."

The option agreement gives MacroChem a 90-day exclusive right to enter
into a license agreement with Genaera. MacroChem paid Genaera US$250,000 on
execution of the option agreement.

Both EcoNail and pexiganan would be developed to treat diseases of the
foot predominantly treated by the same prescribing specialists, namely
podiatrists. Both products would potentially be of interest to a larger
number of physician specialists and primary care physicians as well. EcoNail
is the company's patented lacquer which contains the antifungal econazole and
MacroChem's enhancer SEPA(R). Patients participating in the EcoNail study
will receive 48 weeks of treatment and will undergo efficacy assessments
using standard criteria of nail appearance and mycology. However, the Company
will collect and evaluate 24-week interim data later this year. This trial
was specifically designed, with the assistance of well-known onychomycosis
experts, to address three important objectives: to assess early signs of
efficacy, to maintain robust clinical endpoints in the full study, and, if
successful, to facilitate advancement to Phase 3 as soon as possible.

About MacroChem

MacroChem Corporation is a specialty pharmaceutical company with two
clinical development stage products containing our proprietary enhancer,
SEPA(R): EcoNail, to treat fungal infection of the nail and Opterone(R), to
treat male hypogonadism. In addition to our SEPA technology, we are also
evaluating applications for MacroDerm(TM), our patented series of polymers
that impede penetration of active ingredients through the skin. For more
information visit our website, http://www.macrochem.com .

Forward-Looking Statements

With the exception of historical information contained in this press
release, the matters described herein are forward-looking statements that
involve risks and uncertainties. MacroChem's actual results may differ
significantly from the results discussed in the forward-looking statements.
Factors that might cause such a difference include, but are not limited to,
those discussed or referred to in the section entitled "Risk Factors" in
MacroChem's Annual Report on Form 10-K, as well as those discussed elsewhere
therein, and include, without limitation, risks regarding product
development, the timing and results of clinical trials, the regulatory
approval process, capital requirements, financial condition, patent
protection and dependence on third parties for development and licensing
arrangements. Readers are cautioned not to place undue reliance on these
forward-looking statements, which speak only as of the date hereof. MacroChem
undertakes no obligation to update publicly any forward-looking statements,
whether as a result of new information, future events or otherwise. For more
information visit our website, http://www.macrochem.com .

MacroChem Corporation: Bernard Patriacca - VP/CFO +1-781-489-7310

    Investor Relations:    The Investor Relations Group, Inc.
                           Jordan Silverstein/Christine Berni +1-212-825-3210

    Media:                 The Investor Relations Group, Inc.
                           Bill Douglass +1-212-825-3210

Web site: http://www.macrochem.com