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Contact:  Peyton Marshall or                Justin Jackson (Media) or
          Jill Sawdon                       John Nugent (Investors)
          The Medicines Company             Burns McClellan
          (617) 225-9099 (ph)               (212) 213-0006 (ph)
          (617) 225-2397 (fx)               (212) 213-4447 (fx)

FOR IMMEDIATE RELEASE


            THE MEDICINES COMPANY REPORTS RESULTS FROM HERO-2 TRIAL:
            AN INTERNATIONAL CLINICAL STUDY IN HEART ATTACK PATIENTS

   TREATMENT WITH ANGIOMAX(R)(BIVALIRUDIN) REDUCES THE COMBINED RISK OF DEATH
                             OR SECOND HEART ATTACK

CAMBRIDGE, MA, September 2, 2001 - The Medicines Company (NASDAQ: MDCO)
announced today the results from HERO-2, an international trial studying the
effects of ANGIOMAX(R) (bivalirudin) as a potential new treatment among patients
receiving fibrinolysis for myocardial infarction (heart attack). Professor
Harvey White, principal investigator in the trial, reported to the European
Society of Cardiology meeting in Stockholm on Sunday, September 2nd 2001 that in
the trial ANGIOMAX reduced the combined incidence of death or
investigator-reported second myocardial infarction compared to heparin at 30
days by 1.3% (14.2% in patients treated with heparin vs. 12.9% in patients
treated with ANGIOMAX [p value = 0.023]). Professor White also reported the
overall clinical benefit of ANGIOMAX compared to heparin. The combined incidence
of death, reinfarction or non-fatal disabling stroke was significantly reduced
by ANGIOMAX (p-value 0.049) - saving 11 patients from these catastrophic events
for every 1000 patients treated.

The investigators observed that patients treated with ANGIOMAX had a 30%
reduction in second myocardial infarction at 96 hours compared to heparin
(p-value 0.001). The reduction in second myocardial infarction was also
statistically significant at 30 days both when the second myocardial infarctions
were determined by the treating clinician (p-value 0.001) and when adjudicated
by an independent panel of experts (p-value 0.004). HERO-2 was the first
myocardial infarction trial to perform systematic, blinded adjudication of
repeat heart attacks by an independent, expert panel. Since the diagnosis of a
second heart attack is often clinically uncertain, the use of a blinded
independent adjudication panel was designed to improve the accuracy of the
treatment effect seen in this trial.

With 17,073 patients at 539 hospitals in 46 countries, the trial was designed to
be large enough to assess clinically important differences in 30-day mortality
and second myocardial infarction as individual endpoints. Patients in the trial
were treated with either heparin or ANGIOMAX, alongside fibrinolytic therapy
with streptokinase and platelet inhibition with aspirin

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Patients treated with ANGIOMAX in the trial also showed a 4% lower risk of death
than those treated with heparin, a level that did not reach conventional levels
of statistical significance. The data indicated that ANGIOMAX-based treatment
was at least as effective (and therefore non-inferior) to standard (heparin)
therapy in terms of mortality with an odds ratio of 0.96 (95% confidence
interval 0.86-1.07). The overall death rates of 10.8% at 30 days reflected the
countries involved (approximately 70% of patients enrolled in the trial were
treated in Russia or Eastern European countries) and the risk profile of the
patients enrolled in the study. Death rates were lowest in Western countries
(6.7%) and highest in Russia (13.2%).

The overall incidence rate of intra-cranial hemorrhage - the most important side
effect associated with anticoagulation and fibrinolysis for heart attack - was
0.5%. This was lower than the incidence rate of 0.7-1.1% reported in other
recent "clot buster" trials, and there was not a significant increase in the
incidence in patients treated with ANGIOMAX compared to patients treated with
heparin. Furthermore there was not a significant increase in other severe
bleeding or blood transfusions in ANGIOMAX patients compared to heparin
patients.

Professor White commented, "These results validate the idea that new
anti-thrombin agents such as ANGIOMAX will move us forward in the quest to
improve treatments for heart attack worldwide. The results are consistent with
data from other recent trials such as GUSTO-V and ASSENT-3 where mortality has
not been significantly reduced, but where second heart attacks have also been
prevented using new drugs. ANGIOMAX is therefore added to a short list of drugs
inhibiting platelets, such as abciximab, and drugs indirectly inhibiting
thrombin, such as enoxaparin, which have recently become part of our treatment
options."

Dr. Eric Topol, the Chairman of Cardiovascular Medicine at the Cleveland Clinic
performed an independent review of the data in HERO-2. "The results of this
trial are clinically meaningful," said Dr. Topol. "HERO-2 validates ANGIOMAX as
an important drug in management of acute ischemic heart disease. The finding of
substantial reductions in second heart attacks without significant increases in
intracranial hemorrhage provides a significant step forward in patient care."

"This is yet another demonstration that ANGIOMAX is better than heparin in
ischemic heart disease patients," stated Clive Meanwell, Chief Executive Officer
and President of The Medicines Company. "Future work with ANGIOMAX will build on
the striking reduction in reinfarction rates seen in this trial - particularly
in the field of catheter-based reperfusion in the cardiac catheterization
laboratory."

There will be a conference call with management on Tuesday, September 4 at 8:30
AM (Eastern Time) to discuss these results. To listen in, please dial
800-593-7038. If you are calling from outside the United States, please dial
1.847.619.6820. If you are unable to participate in the live


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call, an electronic recording will be available through September 11. To listen
to the recording, please dial 888.843.8954 or 1.630.652.3043 from outside the
United States. The passcode for the call is 4611267.

ABOUT HEART ATTACK

According to the American Heart Association, an estimated 7.3 million Americans
age 20 and older have a history of heart attacks. This year, approximately 1.1
million Americans will have a new or recurrent heart attack (about 450,000 of
these will be recurrent attacks).

A major cause of heart attack is a thrombus, or blood clot, that obstructs the
flow of blood to the heart, thereby depriving it of oxygen and nutrients. Blood
clots are composed of fibrin, platelets and thrombin. While fibrinoloytic agents
such as streptokinase break up only the fibrin element of the clot, ANGIOMAX
targets thrombin. Since ANGIOMAX is a small-molecule, direct inhibitor of
thrombin, it can inhibit both fluid-phase (inactive) or clot-bound (active)
thrombin, whereas heparin, an indirect thrombin inhibitor, can only inhibit
fluid-phase thrombin and its action can be impaired by other elements found in
blood. A previous trial (HERO-1) showed that ANGIOMAX was more effective than
heparin in achieving and maintaining blood flow in the coronary artery following
myocardial infarction.

ABOUT ANGIOMAX

ANGIOMAX is a small-molecule, reversible, direct thrombin inhibitor that has
been shown to reduce the incidence of death, myocardial infarction, and the need
for revascularization in patients undergoing balloon angioplasty. In addition,
ANGIOMAX has been associated with a significant reduction in bleeding
complications in this patient group. Its benefits remain consistent in high-risk
patients, unlike other agents that show reduced efficacy in such patient groups.
Reductions in these complications not only represent the opportunity for better
patient care, but also for cost-savings by institutions.


ANGIOMAX is indicated for use as an anticoagulant in patients with unstable
angina undergoing percutaneous transluminal coronary angioplasty (PTCA).
ANGIOMAX is intended for use with aspirin. The most common (=>10%) adverse
events for ANGIOMAX were back pain, pain, nausea, headache, and hypotension. The
incidence of these adverse events was comparable in both the ANGIOMAX and
heparin groups. ANGIOMAX is contraindicated in patients with active major
bleeding or hypersensitivity to ANGIOMAX or its components. An unexplained fall
in blood pressure or hematocrit, or any unexplained symptom, should lead to
serious consideration of a hemorrhagic event and cessation of ANGIOMAX
administration.



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ABOUT THE MEDICINES COMPANY

The Medicines Company was founded in 1996 to acquire, develop and commercialize
selected pharmaceutical products in late stages of development and approved
products. In December 2000, the Company received marketing approval from the
U.S. Food and Drug Administration for ANGIOMAX for use as an anticoagulant in
combination with aspirin in patients with unstable angina undergoing coronary
balloon angioplasty. The Company began selling ANGIOMAX in the United States in
January 2001. The Company expects ANGIOMAX to be the cornerstone product of a
planned acute hospital franchise. Ongoing clinical programs with ANGIOMAX
include the REPLACE studies of ANGIOMAX in coronary angioplasty. The Company is
also developing ANGIOMAX for additional potential applications for use in the
treatment of ischemic heart disease. ANGIOMAX is being examined in patients
undergoing angioplasty with heparin-induced thrombocytopenia and heparin-induced
thrombocytopenia and thrombosis. The Company is also developing a second
product, CTV-05, a proprietary biotherapeutic agent with a potentially broad
range of applications in the treatment of gynecological and reproductive
infections. CTV-05 is currently being studied in a double-blind placebo
controlled trial supported by NIH examining the safety and effectiveness of the
compound as an adjunct to antibiotic therapy in the treatment of bacterial
vaginosis. Additional information about the company and its products can be
found at www.themedicinescompany.com.

This press release contains forward-looking statements that involve a number of
risks and uncertainties. For this purpose, any statements contained herein that
are not statements of historical fact may be deemed to be forward-looking
statements. Without limiting the foregoing, the words, "believes,"
"anticipates," "plans," "expects," "intends," and similar expressions are
intended to identify forward-looking statements. Important factors that could
cause actual results to differ materially from the expectations described in
these forward-looking statements are set forth under the caption "Risk Factors "
in the Company's Quarterly Report on Form 10-Q filed with the Securities and
Exchange Commission on August 13, 2001 and incorporated herein by reference.
These risk factors include risks as to the commercial success of ANGIOMAX(R)
(bivalirudin); how long the Company will be able to operate on its existing
capital resources; whether the Company's products (other than ANGIOMAX for its
approved indication) will advance in the clinical trials process, the timing of
such clinical trials, whether the clinical trial results will warrant continued
product development, whether and when, if at all, the Company's products will
receive approval from the U.S. Food and Drug Administration or equivalent
regulatory agencies, and for which indications, and, if such products receive
approval, whether they will be successfully marketed; the Company's history of
net losses; and the Company's dependence on third parties, including
manufacturers, suppliers, sales agents and collaborators.


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