MacroChem Acquires Rights to Pexiganan, a Novel Topical Anti-Infective for Treatment of Diabetic Foot Infections, From Genaera

Wellesley Hills, Massachusetts (ots/PRNewswire) -

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

MacroChem Corporation (OTC Bulletin Board: MACM) today announced
that it has exercised the option it acquired in July, 2007 to acquire
exclusive worldwide license rights for drug uses of pexiganan, a
novel, small peptide anti-infective for treatment of patients with
mild diabetic foot infection (DFI), from Genaera Corporation.

"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 and that fits our strategic focus and
complements our lead product candidate, EcoNail(R) for treatment of
nail fungus," stated Robert J. DeLuccia, President and CEO of
MacroChem. "Both drugs would treat diseases of the foot predominantly
treated by the same prescribing specialists, namely podiatrists. Both
EcoNail and pexiganan are potentially of interest to a larger number
of physician specialists and primary care physicians. MacroChem would
ultimately be seeking a partner for marketing to those groups while
retaining rights to market to selected physician specialists."

In clinical trials previously conducted by Genaera, over 1000
human subjects were exposed to pexiganan without safety concerns,
including 418 patients who received pexiganan in two Phase 3 clinical
trials submitted in a New Drug Application to the U.S. Food and Drug
Administration (FDA) in 1998. The primary clinical endpoint of one of
the two Phase 3 trials was judged by the FDA to have been achieved.
The other Phase 3 clinical trial, which did not meet its specified
endpoint, provided strong supportive data indicative of the clinical
benefit of pexiganan. At that time, difficulties with Chemistry
Manufacturing & Controls (CMC) and an FDA request for one additional
controlled trial precluded approval. MacroChem believes that since
that time, significant improvements have been made in peptide
manufacturing processes as well as in clinical trial design and
execution. MacroChem plans to implement a program to address the
previously identified CMC issues and resume formal dialogue with the
FDA to determine the appropriate clinical development path.

"We are pleased to enter into an agreement with MacroChem
Corporation for the therapeutic rights to pexiganan. This agreement
reflects a first step in the execution of Genaera's strategy to
divest its non-core-assets, including Squalamine and LOMUCIN(TM). We
believe pexiganan has significant potential to treat infected
diabetic foot ulcers and that MacroChem is dedicated to the
commercialization of this asset," stated Dr. Henry Wolfe, Executive
Vice President and Chief Scientific Officer of Genaera.

Mr. DeLuccia further noted, "We are 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 peptide
manufacturing, 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."

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
millions of diabetic foot infections annually with a potential
estimated half billion dollar market."

Benjamin Lipsky, M.D., Professor of Medicine, University of
Washington School of Medicine and Chairman of the Infectious Disease
Society of America (IDSA) Guidelines Committee on Diabetic Foot
Infection, commented, "I think there is a clear need for a topical
antimicrobial compound for treatment of mild diabetic foot
infections. Why expose the entire body to the potential toxic and
microbial-altering effects of systemic therapy when the infection is
limited to a superficial wound? With the growing problem of
resistance of microorganisms to antibiotics, new types of
antimicrobial agents and novel routes of treatment that allow lower
doses of these agents would be welcomed. There are currently very few
topical antimicrobial compounds available, none of which has been
specifically proved to be effective for diabetic foot infections."

Under the terms of the license agreement, MacroChem will pay
Genaera an initial fee of US$1 million through February 1, 2008. The
deal terms also include payments of US$7 million to Genaera upon the
achievement of certain clinical and regulatory milestones through
approval, sales-based milestones of up to US$35 million, and 10%
royalty payments on net sales. In addition, MacroChem will assume all
clinical development, manufacturing and regulatory activities for
pexiganan. MacroChem will require additional funding to fully develop
the product.

About Pexiganan

Pexiganan is a 22-amino acid linear peptide. It is formulated as a
cream and has a novel mechanism of action based on its ability to
disrupt the integrity of bacterial cell membranes. It has
antimicrobial activity against Gram positive (methycillin resistant
staphylococcus aureus (MRSA)) and Gram negative organisms that
commonly infect skin and soft tissue. It has a low potential for
induction of resistance and no cross-resistance with existing
therapeutic antibiotics as a consequence of its mechanism of action.

About Diabetes and Diabetic Foot Infection

According to the U.S. Centers for Disease Control and Prevention
(CDC), there are about 20.8 million people with diabetes in the U.S.
(in 2005). Current estimates are that about 7% of all Americans have
diabetes, and that prevalence is expected to increase each year.
Among the complications caused by diabetes are foot disorders. It is
estimated that up to about 25% of persons with diabetes will develop
a foot ulcer in their lifetime of which about 60% get infected.
Diabetic foot ulcers generally result from the consequences of
peripheral neuropathy, with loss of protective sensations and foot
deformities. The presence of peripheral vascular disease, increased
biomechanical stress and acute trauma further increase the risk of
foot ulcers. It usually takes several months for an ulcer to heal,
and during this period there is a continual risk of foot infection.
Infected foot ulcers can result in bone infection (osteomyelitis) or
progressive gangrene, and are the major immediate cause of lower limb
amputation. Diabetes is now the top cause of non-traumatic leg
amputations in the developed world. Furthermore, foot ulcers are now
the most frequent cause of diabetes-related hospitalizations. Thus,
diabetic foot ulcers and infection are a major burden to both the
patient and the healthcare system resulting in long-term disabilities
and high demands on the healthcare system.

About MacroChem

MacroChem Corporation is a specialty pharmaceutical company that
develops and seeks to commercialize pharmaceutical products.
Currently, our portfolio of proprietary product candidates is based
on our drug delivery technologies: SEPA(R), MacroDerm(TM) and
DermaPass(TM). Our lead product candidate is EcoNail(TM), a topically
applied SEPA-based econazole lacquer for the treatment of
onychomycosis, a condition commonly known as nail fungus. Our other
clinical stage product candidate, Opterone(R), is a topically applied
SEPA-based testosterone cream designed to treat male hypogonadism. In
addition to EcoNail and Opterone, our pipeline of early-stage product
candidates is based on our SEPA, MacroDerm and DermaPass drug
delivery technologies. For more information visit our website,
http://www.macrochem.com.

About Genaera

Genaera Corporation is focused on advancing the science and
treatment of metabolic diseases. The Company has significant market
opportunities with a first-in-class molecule, trodusquemine
(MSI-1436), that has the potential to redefine the treatment paradigm
for obesity and type 2 diabetes and is presently in a Phase 1 trial
in obesity. In addition, Genaera has a value-driven, fully
out-licensed partnership with MedImmune, Inc. for a second core
program that is presently undergoing Phase 2 clinical testing in
asthma. http://www.genaera.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.

Contact:
MacroChem Corp.: Bernard Patriacca - VP/CFO
bpatriacca@macrochem.com
+1-781-489-7310
Investor Relations: The Investor Relations Group, Inc.
Christine Berni/ Joseph Triunfo, +1-212-825-3210
cberni@investorrelationsgroup.com
jtriunfo@investorrelationsgroup.com
Media:
Bill Douglass/ Michaela Heller, +1-212-825-3210
bdouglass@investorrelationsgroup.com
mheller@investorrelationsgroup.com
Web site: http://www.macrochem.com
http://www.genaera.com

ots Originaltext: MacroChem Corporation
Im Internet recherchierbar: http://www.presseportal.de

Contact:
Bernard Patriacca - VP, CFO of MacroChem Corp., +1-781-489-7310,
bpatriacca@macrochem.com; or Investor Relations, Christine Berni,
cberni@investorrelationsgroup.com, or Joseph Triunfo,
jtriunfo@investorrelationsgroup.com, or Media, Bill Douglass,
bdouglass@investorrelationsgroup.com, or Michaela Heller,
mheller@investorrelationsgroup.com, all of The Investor Relations
Group, Inc., +1-212-825-3210