Edoxaban Demonstrates Superior Efficacy Compared With Enoxaparin Sodium in Preventing VTE After Total Knee Replacement

TOKYO, July 12, 2010 - Daiichi Sankyo Company, Limited announced that its investigational
once-daily oral, direct factor Xa inhibitor, edoxaban, was shown to be
superior to enoxaparin in preventing venous thromboembolic (VTE) events in
patients following total knee replacement (TKR), a type of major orthopedic
surgery. Results from the Phase III STARS E-3 (Studying Thrombosis After
Replacement Surgery) study were presented at the 21st International Congress
on Thrombosis (ICT) in Milan, Italy.[i]

This multicenter, double-blind, double dummy, centrally randomized trial
evaluated the efficacy and safety of edoxaban compared with enoxaparin in
patients undergoing TKR in Japan and Taiwan. A total of 716 patients received
either 30 mg once-daily oral dose of edoxaban or subcutaneous injection of
enoxaparin 2,000 international units (equivalent to 20 mg) twice-daily for 11
to 14 days. The primary efficacy endpoint of the trial was the incidence of
symptomatic pulmonary embolism (PE) and symptomatic and asymptomatic deep
vein thrombosis (DVT). The primary safety endpoint was the incidence of major
bleeding and clinically relevant non-major bleeding.

DVT occurred in 7.4 percent of patients receiving edoxaban once-daily
compared with 13.9 percent of patients who received enoxaparin (relative risk
reduction of 46.8 percent; p=0.01). There were no PE events observed in
either treatment group. There was no statistically significant difference in
major and clinically relevant non-major bleeding (p=0.13). There were no
cases of intracranial hemorrhage or death in either treatment group.

Indicators for potential liver damage in both treatment groups were
carefully monitored during this trial by measuring bilirubin and serum
aminotransferase levels.[ii] Elevations greater than three times the upper
limit of the normal range of serum aminotransferase levels occurred in 1.4
percent of patients taking edoxaban compared with 8.0 percent of those taking
enoxaparin.

"The combination of efficacy, tolerability and convenient once-daily oral
dosing in this clinical setting further supports the potential role of
edoxaban in helping patients and physicians avoiding thrombotic events," said
Dr. Takeshi Fuji, Head of Orthopedic Surgery, Osaka Koseinenkin Hospital.
"These results are encouraging as they demonstrate superior efficacy of
once-daily edoxaban compared with twice daily subcutaneous enoxaparin, the
current standard of care for this patient population."

In March 2010, Daiichi Sankyo submitted a New Drug Application to the
Ministry of Health, Labor and Welfare in Japan seeking approval of edoxaban
for the prevention of VTE after major orthopedic surgery.

Global Development of Edoxaban

The global clinical development program for edoxaban comprises several
indications, including the prevention of stroke and systemic embolic events
in patients with atrial fibrillation, as well as the acute treatment and
long-term secondary prevention of VTE.

Global studies include:

    - ENGAGE AF-TIMI 48: Investigates two different doses of once-daily
      edoxaban versus warfarin in approximately 20,500 patients with atrial
      fibrillation for the prevention of stroke and systemic embolic events.
      ENGAGE AF-TIMI 48 began enrollment in late 2008 and is expected to be
      completed in 2012.

    - HOKUSAI VTE: To date, the largest single trial for the secondary
      prevention of recurrent VTE in approximately 7,500 patients with deep
      vein thrombosis and/or pulmonary embolism as well as for the acute
      treatment of VTE. HOKUSAI VTE trial enrollment began in early 2010.

Both HOKUSAI VTE and ENGAGE AF-TIMI 48 are Phase III, multi-national,
randomized, double-blind studies.

About Edoxaban

Edoxaban is a once-daily oral anticoagulant that directly inhibits factor
Xa, an important factor in the coagulation process. Daiichi Sankyo is
developing edoxaban as a potential new treatment for the prevention of both
arterial and venous thromboembolism. Notably, Daiichi Sankyo has more than 25
years experience conducting research in the area of factor Xa inhibition, and
was the first company to study these compounds in humans. Edoxaban is being
developed solely by Daiichi Sankyo.

About DAIICHI SANKYO

DAIICHI SANKYO is a global pharmaceutical company that focuses
on researching and marketing innovative medications. The company was created
in 2005 through the merger of two traditional Japanese enterprises, Daiichi
and Sankyo. With net sales of nearly 7.3 billion EUR in fiscal year 2009 (as
of March 31st), DAIICHI SANKYO is one of the world's 20 leading
pharmaceutical companies. The company's world headquarters is in Tokyo, its
European base is located in Munich. DAIICHI SANKYO has affiliates in 12
European countries and has been one of the strongest Japanese pharmaceutical
companies located in Europe since it set up European production facilities
and marketing offices in 1990. The company's research activities focus on the
areas of cardiovascular diseases, hematology, anti-infectives and cancer. Its
aim is to develop medications that are "best" in their class or to create new
classes of pharmaceutical drugs.

Forward-looking statements

This press release contains forward-looking statements and information
about future developments in the sector, and the legal and business
conditions of DAIICHI SANKYO, Co. Ltd, DAIICHI SANKYO, Inc., and DAIICHI
SANKYO EUROPE GmbH. Such forward-looking statements are uncertain and are
subject at all times to the risks of change, particularly to the usual risks
faced by a global pharmaceutical company, including the impact of the prices
for products and raw materials, medication safety, changes in exchange rates,
government regulations, employee relations, taxes, political instability and
terrorism as well as the results of independent demands and governmental
inquiries that affect the affairs of the company. All forward-looking
statements contained in this release hold true as of the date of publication.
They do not represent any guarantee of future performance. Actual events and
developments could differ materially from the forward-looking statements that
are explicitly expressed or implied in these statements. DAIICHI SANKYO, Co.
Ltd, DAIICHI SANKYO, Inc., and DAIICHI SANKYO EUROPE GmbH assume no
responsibility for the updating of such forward-looking statements about
future developments of the sector, legal and business conditions and the
company.

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[i]T. Fuji et al., Edoxaban versus enoxaparin for thromboprophylaxis
after total knee replacement: The STARS E-3 trial 21st International Congress
of Thrombosis, July 6 - 9 2010, Milano.

[ii] Liver Blood Tests. Available at:
www.medicinenet.com/liver_blood_tests/page2.htm. Accessed June 18,
2010.

For more information, please contact: Toshiaki Sai, Daiichi Sankyo, Co., Ltd. (Japan), +81-3-6225-1126 (office). Dr. Michaela Paudler-Debus, Daiichi Sankyo Europe GmbH, +49-(0)89-78-08-685 (office), +49-(0)172-845 8974 (mobile)