EXHIBIT 99

                                  AMGEN INC.

Factors That May Affect Amgen

         Amgen operates in a rapidly changing environment that involves a number
of risks, some of which are beyond our control. The following discussion
highlights some of these risks and others are discussed elsewhere herein.

     Product development

         We intend to continue an aggressive product development program.
Successful product development in the biotechnology industry is highly
uncertain, and very few research and development projects produce a commercial
product. Product candidates that appear promising in the early phases of
development, such as in early human clinical trials, may fail to reach the
market for a number of reasons, such as:

-    the product candidate did not demonstrate acceptable clinical trial results
     even though it demonstrated positive preclinical trial results
-    the product candidate was not effective in treating a specified condition
     or illness
-    the product candidate had harmful side effects on humans
-    the necessary regulatory bodies (such as the FDA) did not approve our
     product candidate for an indicated use
-    the product candidate was not economical for us to manufacture it
-    other companies or people have or may have proprietary rights to our
     product candidate (e.g. patent rights) and will not let us sell it on
     reasonable terms, or at all
-    the product candidate is not cost effective in light of existing
     therapeutics

         Several product candidates have failed at various stages in the product
development process, including BDNF, Megakaryocyte Growth and Development Factor
(MGDF) and GDNF. For example, in 1997, we announced the failure of BDNF (for the
treatment of ALS by subcutaneous injection administration route), because the
product candidate, as administered, did not produce acceptable clinical results
in a specific indication after a phase 3 trial, even though BDNF had progressed
successfully through preclinical and earlier clinical trials. Of course, there
may be other factors that prevent us from marketing a product. We cannot
guarantee we will be able to produce commercially successful products. Further,
clinical trial results are frequently susceptible to varying interpretations by
scientists, medical personnel, regulatory personnel, statisticians and others
which may delay, limit or prevent further clinical development or regulatory
approvals of a product candidate. Also, the length of time that it takes for us
to complete clinical trials and obtain regulatory approval for product marketing
has in the past

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varied by product and by the indicated use of a product. We expect that this
will likely be the case with future product candidates and we cannot predict the
length of time to complete necessary clinical trials and obtain regulatory
approval. See "- Regulatory matters."

     Regulatory matters

         Our research, preclinical testing, clinical trials, facilities,
manufacturing, pricing and sales and marketing are subject to extensive
regulation by numerous state and federal governmental authorities in the U.S.,
such as the FDA and the Health Care Financing Administration ("HCFA"), as well
as by foreign countries and the European Union (the "EU"). Currently, we are
required in the U.S. and in foreign countries to obtain approval from those
countries' regulatory authorities before we can market and sell our products in
those countries. The success of our current and future products will depend in
part upon obtaining and maintaining regulatory approval to market products in
approved indications in the U.S. and foreign markets. In our experience, the
regulatory approval process is a lengthy and complex process, both in the U.S.
and in foreign countries, including countries in the EU. Even if we obtain
regulatory approval, both our manufacturing processes and our marketed products
are subject to continued review. Later discovery of previously unknown problems
with our products or manufacturing processes may result in restrictions on such
products or manufacturing processes, including withdrawal of the products from
the market. Our failure to obtain necessary approvals, or the restriction,
suspension or revocation of any approvals, or our failure to comply with
regulatory requirements could prevent us from manufacturing or selling our
products which could have a material adverse effect on us and our results of
operations.

     Reimbursement; Third party payors

         In both domestic and foreign markets, sales of our products are
dependent, in part, on the availability of reimbursement from third party payors
such as state and federal governments (for example, under Medicare and Medicaid
programs in the U.S.) and private insurance plans. In certain foreign markets,
the pricing and profitability of our products generally are subject to
government controls. In the U.S., there have been, and we expect there will
continue to be, a number of state and federal proposals that limit the amount
that state or federal governments will pay to reimburse the cost of drugs. In
addition, we believe the increasing emphasis on managed care in the U.S. has and
will continue to put pressure on the price and usage of our products, which may
impact product sales. Further, when a new therapeutic is approved, the
reimbursement status and rate of such a product is uncertain. In addition,
current reimbursement policies for existing products may change at any time.
Changes in reimbursement or our failure to obtain reimbursement for our products
may reduce the demand for, or the price of, our products, which could result in
lower product sales or revenues which could have a material adverse effect on us
and our results of operations. For example, in the U.S. the use of

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EPOGEN(R) in connection with treatment for end stage renal disease is funded
primarily by the U.S. federal government. Therefore, as in the past, EPOGEN(R)
sales could be affected by future changes in reimbursement rates or the basis
for reimbursement by the federal government. For example, in early 1997, HCFA
instituted a reimbursement change for EPOGEN(R) which adversely affected the
Company's EPOGEN(R) sales, until the policies were revised. See "Item 7.
Management's Discussion and Analysis of Financial Condition and Results of
Operations - Results of Operations - Product sales - EPOGEN(R) (Epoetin alfa)."

     Guidelines

         Government agencies promulgate regulations and guidelines directly
applicable to us and to our products. However, professional societies, practice
management groups, private health/science foundations and organizations involved
in various diseases may also publish, from time to time, guidelines or
recommendations to the health care and patient communities. These organizations
may make recommendations that affect a patient's usage of certain therapies,
drugs or procedures, including our products. Recommendations of government
agencies or these other groups/organizations may relate to such matters as
usage, dosage, route of administration and use of concomitant therapies.
Recommendations or guidelines that are followed by patients and health care
providers could result in, among other things, decreased use of our products
which could have a material adverse effect on our results of operations. In
addition, the perception by the investment community or stockholders that such
recommendations or guidelines will be followed could adversely affect prevailing
market prices for our common stock.

     Intellectual property and legal matters

         The patent positions of pharmaceutical and biotechnology companies can
be highly uncertain and often involve complex legal, scientific and factual
questions. To date, there has emerged no consistent policy regarding breadth of
claims allowed in such companies' patents. Accordingly, the patents and patent
applications relating to our products, product candidates and technologies may
be challenged, invalidated or circumvented by third parties and might not
protect us against competitors with similar products or technology. For certain
of our product candidates, there are third parties who have patents or pending
patents that they may claim prevent us from commercializing these product
candidates in certain territories. Patent disputes are frequent and can preclude
commercialization of products. We are currently, and in the future may be,
involved in patent litigation. The results of such litigation could subject us
to competition and/or significant liabilities, could require us to enter into
third party licenses or could cause us to cease using the technology or product
in dispute. In addition, we cannot guarantee that such licenses will be
available on terms acceptable to us.

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         The Company is currently involved in arbitration proceedings with Ortho
Pharmaceutical Corporation (which has assigned its rights under the Product
License Agreement to Ortho Biotech, Inc.), a subsidiary of Johnson & Johnson
("Johnson & Johnson"), relating to a license granted by the Company to Johnson &
Johnson for sales of Epoetin alfa in the U.S. for all human therapeutic uses
except dialysis. See Note 4 to the Consolidated Financial Statements,
"Contingencies - Johnson & Johnson arbitrations".

     Competition

         We operate in a highly competitive environment. Our principal
competitors are pharmaceutical and biotechnology companies. Some of our
competitors, mainly large pharmaceutical corporations, have greater clinical,
research, regulatory and marketing resources than we do. In addition, some of
our competitors may have technical or competitive advantages over us for the
development of technologies and processes and may acquire technology from
academic institutions, government agencies and other private and public research
organizations. We cannot guarantee that we will be able to produce or acquire
rights to products that have commercial potential. Even if we achieve successful
product commercialization, we cannot guarantee that one or more of our
competitors will not achieve product commercialization earlier than we do,
obtain patent protection that dominates or adversely affects our activities, or
have significantly greater marketing capabilities.

     Fluctuations in operating results

         Our operating results may fluctuate from period to period for a number
of reasons. In budgeting our operating expenses, some of which are fixed in the
short term, we assume that revenues will continue to grow. Accordingly, even a
relatively small revenue shortfall may cause a period's results to be below our
expectations. A revenue shortfall could arise from any number of factors, such
as:

-    lower than expected demand for our products
-    changes in the government's or private payor's  reimbursement  policies for
     our products
-    changes in wholesaler buying patterns
-    increased competition from new or existing products
-    fluctuations in foreign currency exchange rates
-    changes in our product pricing strategies

         Of course, there may be other factors that affect the Company's
revenues in any given period.

     Rapid growth

         We have an aggressive growth plan that includes substantial and
increasing investments in research and development and facilities. Our plan has
a number of risks, such as:

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-    the need to generate  higher  revenues to cover a higher level of operating
     expenses
-    the need to attract and assimilate a large number of new employees
-    the need to manage complexities associated with a larger and faster growing
     organization
-    the need to accurately  anticipate  demand for the products we  manufacture
     and maintain adequate manufacturing capacity

         Of course, there may be other risks and we cannot guarantee that we
will be able to successfully manage these or other risks.

     Stock price volatility

         Our stock price, like that of other biotechnology companies, is highly
volatile. Our stock price may be affected by, among other things, clinical trial
results and other product-development announcements by us or our competitors,
regulatory matters, announcements in the scientific and research community,
intellectual property and legal matters, changes in reimbursement policies or
medical practices or broader industry and market trends unrelated to our
performance. In addition, if our revenues or earnings in any period fail to meet
the investment community's expectations, there could be an immediate adverse
impact on our stock price.

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