Nuvelo Announces Positive Phase 1b Proof-of-Concept Data With Anticoagulant NU172

       - Phase 2 development to begin in late 2008 or in early 2009 -



    SAN CARLOS, Calif., Aug. 14 /EMWNews/ -- Nuvelo, Inc.

(Nasdaq: NUVO) today announced positive results from the Phase 1b

proof-of-concept trial of NU172, demonstrating that the direct thrombin

inhibitor rapidly produced and maintained anticoagulation with a rapid

return toward baseline after the infusion ended with a favorable safety

profile.



    "NU172 has the potential to address many of the limitations of

currently available anticoagulants given the profile we have seen to date

in preclinical and Phase 1 testing, including its ability to produce rapid

and predictable onset and offset of anticoagulation without the need for an

antidote, its potential ability to work in stagnant blood, its

predominately non-renal clearance, and the option to stop and restart

anticoagulation as needed during or after surgery," said A. Michael

Lincoff, M.D., vice chairman of the department of cardiovascular medicine

and an interventional cardiologist at the Cleveland Clinic. "Because of

these characteristics, NU172 could potentially offer an improved approach

to anticoagulation for procedures such as coronary artery bypass graft

(CABG) surgery, kidney dialysis, and percutaneous coronary intervention

(PCI)."



    The single-center, Phase 1b trial examined the safety, tolerability and

pharmacokinetics of intravenous bolus plus infusion dosing of NU172, in 24

healthy male volunteers. Volunteers were given a 2 mg/kg bolus dose

followed by escalating infusion doses of NU172 for four hours. In all four

cohorts, NU172 produced dose-dependent increases in anticoagulation,

measured by activated clotting time (ACT), prothrombin time (PT) and

activated partial thromboplastin time (aPTT). The highest infusion dose

rate tested, 6.0 mg/kg/hr, resulted in an average ACT per subject ranging

from 373 to 414 seconds and an increase of approximately three times

baseline. Average PT values per subject ranged from 56 to 92 seconds and

had an increase of approximately five times baseline. Average aPTT values

per subject ranged from 130 to 178 seconds and had an increase of

approximately five times baseline. All measurements were maintained stably

throughout the four-hour infusion. Once the infusion ended, the ACT and

other coagulation parameters showed a rapid return toward baseline,

consistent with the short plasma half-life of NU172 observed in the Phase

1a trial. In addition, NU172 was well-tolerated with no serious adverse

events.



    "In this study, we were able to identify a dose that meets or exceeds

the level of anticoagulation needed for the indications we plan to

evaluate, including CABG surgery," said Dr. Ted W. Love, chairman and chief

executive officer of Nuvelo. "In addition to supporting our previous

proof-of-concept data, the Phase 1b study shows that anticoagulation with

NU172 can be maintained for four hours, which is longer than a typical CABG

procedure. We are on track to launch a Phase 2 study evaluating NU172 in

the fourth quarter of 2008 or the first quarter of 2009."



    Approximately 450,000 CABG procedures, 50 million dialysis procedures,

and 1.2 million PCIs are performed annually in the U.S. During these

procedures, anticoagulants are given to prevent blood clotting. In CABG

procedures and often in dialysis, the anticoagulation effect of heparin

must be reversed with protamine once the procedure has been completed.

    About Aptamers and NU172



    Aptamers are chemically synthesized single-stranded nucleic acids that

form well-defined three-dimensional shapes, allowing them to bind target

molecules in a manner that is conceptually similar to antibodies.

Characteristics of aptamers include high specificity and affinity, and the

ability to target protein-protein interactions.



    NU172 is an aptamer designed to directly inhibit thrombin's ability to

stimulate blood clot formation in the setting of medical procedures where

human blood is exposed to foreign materials. Specifically, NU172 is being

studied for use as a potential short-acting anticoagulant during procedures

such as coronary artery bypass graft surgery, kidney dialysis and

percutaneous coronary interventions. Data from the Phase 1 trial and

preclinical studies suggest that NU172 has the potential to produce rapid

and predictable onset and offset of anticoagulation, work in stagnant

blood, avoid thrombocytopenia, and has the potential for non-renal

clearance.



    About Nuvelo and Archemix's Joint Collaborative Effort



    In August 2006, Nuvelo expanded its collaboration with Archemix to

develop and commercialize aptamers that have a short-acting anticoagulant

effect. Under the agreement, Archemix is responsible for discovery of

short-acting aptamers for use in medical procedures, and Nuvelo leads

development and worldwide commercialization of these aptamers.



    About Nuvelo



    Nuvelo, Inc. is dedicated to improving the lives of patients through

the discovery, development and commercialization of novel drugs for acute

cardiovascular disease, cancer and other debilitating medical conditions.

Nuvelo's development pipeline includes NU172, a direct thrombin inhibitor

which has completed Phase 1 development for use as a potential short-acting

anticoagulant during medical or surgical procedures; and NU206, a Wnt

pathway modulator in Phase 1 development for the potential treatment of

chemotherapy/radiation therapy-induced mucositis and inflammatory bowel

disease. In addition, Nuvelo is pursuing research programs in leukemia and

lymphoma therapeutic antibodies and Wnt signaling pathway therapeutics to

further expand its pipeline and create additional partnering and licensing

opportunities.



    Information about Nuvelo is available at our website at

http://www.nuvelo.com or by phoning 650-517-8000.



    This press release contains "forward-looking statements," which include

statements regarding the timing, progress and anticipated completion of

Nuvelo's clinical stage and research programs, and the potential benefits

that patients may experience from the use of our clinical stage compounds,

which statements are hereby identified as "forward-looking statements" for

purposes of the safe harbor provided by the Private Securities Litigation

Reform Act of 1995. Such statements are based on our management's current

expectations and involve risks and uncertainties. Actual results and

performance could differ materially from those projected in the

forward-looking statements as a result of many factors, including, without

limitation, uncertainties relating to drug discovery and the regulatory

approval process; clinical development processes; enrollment rates for

patients in our clinical trials; changes in relationships with strategic

partners and dependence upon strategic partners for the performance of

critical activities under collaborative agreements; and the impact of

competitive products and technological changes. These and other factors are

identified and described in more detail in Nuvelo's filings with the SEC,

including without limitation Nuvelo's quarterly report on Form 10-Q for the

quarter ended June 30, 2008 and subsequent filings. We disclaim any intent

or obligation to update these forward-looking statements.