Daiichi Sankyo Submits First New Drug Application for Oral Factor Xa Inhibitor, Edoxaban

Innovative Once-Daily Oral Factor Xa Inhibitor Submitted for Approval in Japan

TOKYO, April 6, 2010 - Daiichi Sankyo Company, Limited announced today that it has
submitted a New Drug Application to the Ministry of Health, Labor and Welfare
in Japan seeking approval of the anticoagulant, edoxaban, for the prevention
of venous thromboembolism (VTE) after major orthopedic surgery.

Edoxaban, being developed solely by Daiichi Sankyo, is an oral
anticoagulant that directly and specifically inhibits Factor Xa, a clotting
factor in the blood. Results from pivotal Phase III studies showed that
once-daily oral administration of edoxaban reduced the incidence of VTE in
patients undergoing total knee replacement or total hip replacement, and the
non-inferiority to injectable enoxaparin sodium was confirmed.

"Upon approval, we believe that edoxaban, with its simple once-daily oral
dosing, will be a significant improvement for patients undergoing orthopedic
surgery in Japan," said Dr. Kazunori Hirokawa, Head of the R&D Division of
Daiichi Sankyo, Co., Ltd.

The pivotal Phase III studies conducted to support this first application
in Japan - one in knee surgery and the other in hip surgery - were
randomized, double-blind, parallel group, multi-center trials comparing a
once-daily, 30 mg oral dose of edoxaban to 2,000 IU (20 mg) twice-daily
subcutaneous injections of enoxaparin sodium. Treatment was provided for 11
to 14 days in both trials.

The primary efficacy endpoint in both trials was to confirm
non-inferiority of edoxaban to enoxaparin sodium for the prevention of
asymptomatic and symptomatic deep vein thrombosis and symptomatic pulmonary
embolism. The primary safety endpoint in both trials was to compare the
incidence of major and clinically relevant non-major bleeding between
edoxaban and enoxaparin sodium groups.

Full trial results will be submitted for presentation and publication in
peer-reviewed settings.

Global Development of Edoxaban

The global clinical development program for edoxaban includes 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.

"Early phase data show that edoxaban is an innovative anticoagulant with
direct, specific and reversible activity on Factor Xa, which is being
investigated as a treatment for a variety of medical conditions, such as
atrial fibrillation and VTE, as an alternative to current oral and injectable
products," said Dr. Hirokawa.

    Global studies include:

    - ENGAGE AF-TIMI 48: Investigating once-daily edoxaban versus warfarin in
      more than 16,500 patients with atrial fibrillation for the prevention
      of stroke and systemic embolic events. ENGAGE AF-TIMI 48 began
      enrollment in late 2008.
    - HOKUSAI VTE: To date, the largest single trial for the secondary
      prevention of recurrent VTE in patients with deep vein thrombosis and
      pulmonary embolism as well as for the acute treatment of VTE. HOKUSAI
      VTE began enrollment in early 2010.

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

About Daiichi Sankyo

In keeping with its vision of becoming a "Global Pharma Innovator," the
Daiichi Sankyo Group is dedicated to the creation and supply of innovative
pharmaceutical products to address the diversified, unmet medical needs of
customers in both developed and emerging markets. While maintaining its
portfolio of marketed pharmaceuticals for hypertension, hyperlipidemia, and
bacterial infections, the Group is engaged in the development of treatments
for thrombotic disorders and focused on the discovery of novel oncology and
cardiovascular-metabolic therapies. Furthermore, the Daiichi Sankyo Group has
created a "Hybrid Business Model," which will respond to market and customer
diversity and optimize growth opportunities across the value chain.

For more information, please visit www.daiichisankyo.com

Daiichi Sankyo, Inc., headquartered in Parsippany, New Jersey, is the
U.S. subsidiary of Daiichi Sankyo Company, Ltd. For more information on
Daiichi Sankyo, Inc., please visit www.dsi.com.

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.

For more information, please contact: Toshiaki Sai, Daiichi Sankyo, Co., Ltd.(Japan), +81-3-6225-1126 (office); Kimberly Wix, Daiichi Sankyo, Inc. (US), +1-973-944-2338 (office), +1-908-656-5447 (mobile); Dr. Michaela Paudler-Debus, Daiichi Sankyo Europe GmbH, +49(0)89-78-08-685 (office), +49(0)172-845-8974 (mobile)