Prolia(R) (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial

THOUSAND OAKS, California, March 23, 2011 - Amgen (Nasdaq: AMGN) today announced new long-term data showing that
during the fourth and fifth years of Prolia(R) (denosumab) treatment,
postmenopausal women with osteoporosis receiving Prolia continued with
further, statistically significant, year-over-year increases in lumbar spine
and total hip bone mineral density (BMD), a key measurement of bone strength.
The overall adverse event profile was similar for the fourth and fifth years
of consecutive Prolia treatment.

The data, which were presented at the annual European Congress
Osteoporosis and Osteoarthritis (ECCEO11-IOF) in Valencia, Spain, showed that
treatment with Prolia, the first and only approved RANK Ligand inhibitor for
the treatment of postmenopausal osteoporosis, resulted in robust BMD gains
after five continuous years of treatment (13.7 percent for lumbar spine BMD
and 7.0 percent for total hip BMD).

The FREEDOM Study and the 5-Year Prolia Data

The pivotal FREEDOM (Fracture REduction Evaluation of Denosumab in
Osteoporosis every 6 Months) study established the efficacy and safety of
Prolia based on three years of data from approximately 7,800 postmenopausal
women. The open-label extension of FREEDOM is evaluating the long-term (up to
10 years) efficacy and safety of Prolia in 4,550 postmenopausal women.
Seventy percent of eligible women from the FREEDOM study continued enrollment
in the extension study; 2,343 women continued to receive Prolia treatment,
and 2,207 transitioned from placebo to Prolia.

Continued treatment with Prolia resulted in consistent year-over-year
gains in BMD at the lumbar spine and total hip. In years 4 and 5
respectively, women taking Prolia experienced further 1.9 percent and 1.7
percent increases in lumbar spine BMD and further 0.7 percent and 0.6 percent
increases in total hip BMD (all P<0.0001 compared with extension baseline).

The incidences of new osteoporotic fractures also remained low for women
taking Prolia for five years.

The women who transitioned from placebo to Prolia in the extension study
showed significant BMD increases during the first two years of Prolia
treatment: 7.9 percent increase in lumbar spine BMD and 4.1 percent increase
in total hip BMD (all P<0.0001 compared with extension baseline).

Rates of adverse events (AEs) were 83.4 percent for women who continued
on Prolia and 82.8 percent for women transitioned from placebo to Prolia.
Rates of serious AEs were 18.9 percent and 19.4 percent for the two groups
respectively. Two subjects in the group that transitioned from placebo to
Prolia had AEs adjudicated to osteonecrosis of the jaw (ONJ) that healed
without further complications. One of these subjects continued Prolia, and
one subject discontinued. No atypical femoral fractures were reported in
either group.

Osteoporosis: Impact and Prevalence

Referred to as a "silent epidemic" by the International Osteoporosis
Foundation (IOF), osteoporosis is a global problem that is increasing in
significance as the population of the world both increases and ages. The
World Health Organization has officially declared osteoporosis a public
health crisis, and the IOF is urging governments worldwide to make
osteoporosis a healthcare priority.

Osteoporosis-associated fractures are a significant cause of mortality
and morbidity. In 2000, the number of osteoporotic fractures in Europe was
estimated at 3.79 million, of which 890,000 were hip fractures.(1) Since
2001, the incidence of hip fractures in European countries has risen
significantly.(2) In the United States (U.S.), the number of fractures due to
osteoporosis is expected to rise to more than three million by 2025.(3)

The direct medical cost of osteoporotic fractures in Europe is expected
to rise from euro 31.7 billion in 2000 to euro 76.7 billion in 2050.(4) In
2005, osteoporosis-related fractures were responsible for an estimated $19
billion in cost in the U.S., and this cost is expected to rise to
approximately $25 billion by 2025.(5)

About Prolia

Prolia is the first approved therapy that specifically targets RANK
Ligand, an essential regulator of osteoclasts (the cells that break down
bone).

Prolia is approved in the European Union (EU) for the treatment of
osteoporosis in postmenopausal women at increased risk of fractures, and for
the treatment of bone loss associated with hormone ablation in men with
prostate cancer at increased risk of fractures.

Prolia is approved in the U.S. for the treatment of postmenopausal women
with osteoporosis at high risk for fracture, defined as a history of
osteoporotic fracture, or multiple risk factors for fracture; or patients who
have failed or are intolerant to other available osteoporosis therapy.

Prolia is available in 12 European countries, the U.S., Canada and
Australia. Applications in the rest of the world are pending.

Prolia is administered as a single subcutaneous injection of 60mg once
every six months. For further information on Prolia, please visit:
www.prolia.com.

Important EU Safety Information

The most common adverse reactions with Prolia were urinary tract
infection, upper respiratory tract infection, sciatica, cataracts,
constipation, rash, pain in extremity. The most serious adverse reactions
were those of skin infections, predominantly cellulitis, reported more
commonly in the Prolia group compared with placebo (0.4 percent vs. 0.1
percent) in postmenopausal osteoporosis studies. In breast and prostate
cancer studies, serious adverse reactions of skin infection were similar in
the Prolia and placebo groups (0.6 percent vs. 0.6 percent). In the Phase 3
placebo-controlled clinical trial in patients with prostate cancer receiving
ADT, an imbalance in cataract adverse events was observed with Prolia
compared with placebo (4.7 percent vs. 1.2 percent). No imbalance in cataract
adverse events was observed in postmenopausal women with osteoporosis or in
women undergoing aromatase inhibitor therapy for nonmetastatic breast cancer.

Prolia may lead to hypocalcaemia. Hypocalcaemia must be corrected by
adequate intake of calcium and vitamin D before initiating therapy. ONJ has
been reported rarely in clinical studies in patients receiving denosumab at a
dose of 60 mg every 6 months for osteoporosis.

Important U.S. Safety Information

Prolia is contraindicated in patients with hypocalcemia. Pre-existing
hypocalcemia must be corrected prior to initiating Prolia. Hypocalcemia may
worsen, especially in patients with severe renal impairment. All patients
should be adequately supplemented with calcium and vitamin D.

In the pivotal study, serious infections leading to hospitalizations were
reported more frequently in the Prolia-treated patient group. Serious skin
infections, as well as infections of the abdomen, urinary tract and ear, were
more frequent in patients treated with Prolia. Patients should be advised to
seek prompt medical attention if they develop signs or symptoms of severe
infection, including cellulitis. Endocarditis was reported more frequently in
the Prolia-treated patient group. Epidermal and dermal adverse events such as
dermatitis, rashes, and eczema have been reported. Discontinuation of Prolia
should be considered if severe symptoms develop.

Prolia resulted in significant suppression of bone remodeling. The
significance of these findings is unknown. The long-term consequences of the
degree of suppression of bone remodeling observed with Prolia may contribute
to adverse outcomes such as ONJ, atypical fractures, and delayed fracture
healing. ONJ has been reported in patients with Prolia. Patients should be
monitored for these adverse outcomes. The most common adverse reactions (> 5
percent and more common than placebo) were back pain, pain in extremity,
musculoskeletal pain, hypercholesterolemia, and cystitis. Pancreatitis has
also been reported with Prolia.

Denosumab Commercialization Collaborations

In July 2009, Amgen and GlaxoSmithKline announced a collaboration
agreement to jointly commercialize Prolia for postmenopausal osteoporosis in
Europe, Australia, New Zealand and Mexico once the product is approved in
these countries. Amgen will commercialize Prolia's postmenopausal
osteoporosis and potential oncology indications in the U.S. and Canada and
for all oncology indications in Europe and in other specified markets.

In addition, GlaxoSmithKline will register and commercialize denosumab
for all indications in countries where Amgen does not currently have a
commercial presence, including China, Brazil, India and South Korea but
excluding Japan. The structure of the collaboration allows Amgen the option
of an expanded role in commercialization in both Europe and certain emerging
markets in the future.

Amgen and Daiichi-Sankyo Company Limited have a collaboration and license
agreement for the development and commercialization of denosumab in Japan.

About Amgen

Amgen discovers, develops, manufactures, and delivers innovative human
therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first
companies to realize the new science's promise by bringing safe, effective
medicines from lab to manufacturing plant to patient. Amgen therapeutics have
changed the practice of medicine, helping millions of people around the world
in the fight against cancer, kidney disease, rheumatoid arthritis, bone
disease, and other serious illnesses. With a deep and broad pipeline of
potential new medicines, Amgen remains committed to advancing science to
dramatically improve people's lives. To learn more about our pioneering
science and vital medicines, visit www.amgen.com.

Forward-Looking Statements

This news release contains forward-looking statements that are based on
management's current expectations and beliefs and are subject to a number of
risks, uncertainties and assumptions that could cause actual results to
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noted, Amgen is providing this information as of March 23, 2011 and expressly
disclaims any duty to update information contained in this news release.

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Editor's Note: Prolia(R) (denosumab) currently is not commercialized in
Spain.

    CONTACT: Amgen, Thousand Oaks
    Ashleigh Koss: +1-805-313-6151 (U.S. media)
    Wendy Woods Williams: +41(41)3692-542 (E.U. media)
    Arvind Sood: +1-805-447-1060 (investors)

(1) "Facts and statistics about osteoporosis and its impact."
International Osteoporosis Foundation. Accessed at
www.iofbonehealth.org/facts-and-statistics.html#factsheet-category-22
on 4 February 2011

(2) "Osteoporosis in the European Union in 2008: Ten years of progress
and ongoing challenges." Accessed at
www.iofbonehealth.org/publications/eu-policy-report-of-2008.html on 4
February 2011

(3) Burge R, et al. Incidence and economic burden of osteoporosis-related
fractures in the United States, 2005-2025. J Bone Miner Res. 2007:
22::465-475

(4) "Facts and statistics about osteoporosis and its impact."
International Osteoporosis Foundation. Accessed at
www.iofbonehealth.org/facts-and-statistics.html on 4 February 2011

(5) "Fast Facts" National Osteoporosis Foundation. Accessed at
www.nof.org/node/40 on 4 February 2011

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U.S. media - Ashleigh Koss, +1-805-313-6151; E.U. media - Wendy Woods Williams: +41(41)3692-542; investors, Arvind Sood: +1-805-447-1060