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                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON, D.C. 20549
                            ------------------------
                                   FORM 10-K
 
                                AMENDMENT NO. 1
 
  /X/     ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                               EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1998
                                       or
 
  / /        TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                                    SECURITIES
                               EXCHANGE ACT OF 1934
 
        FOR THE TRANSITION PERIOD FROM ______________ TO ______________
 
                                    0-25250
                             COMMISSION FILE NUMBER
                         ------------------------------
 
                           OSTEX INTERNATIONAL, INC.
 
              EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER
 
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<CAPTION>
             STATE OF WASHINGTON                                91-1450247
---------------------------------------------  ---------------------------------------------
<S>                                            <C>
STATE OR OTHER JURISDICTION OF INCORPORATION       I.R.S. EMPLOYER IDENTIFICATION NUMBER
                OR ORGANIZATION
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          2203 AIRPORT WAY SOUTH, SUITE 400, SEATTLE, WASHINGTON 98134
                                  206-292-8082
          ADDRESS AND TELEPHONE NUMBER OF PRINCIPAL EXECUTIVE OFFICES
                         ------------------------------
 
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<CAPTION>
 Securities registered pursuant to    Securities registered pursuant to Section
           Section 12(b)                                12(g)
            of the Act:                              of the Act:
<S>        <C>                        <C>
 (none)             (none)                  COMMON STOCK, $.01 PAR VALUE
TITLE OF    EACH EXCHANGE ON WHICH                 TITLE OF CLASS
  CLASS           REGISTERED
</TABLE>
 
                            ------------------------
 
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<S>                                                                                <C>
    Indicate by check mark whether the registrant (1) has filed all reports        YES [X]
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of      NO [ ]
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.
 
    Indicate by check mark if disclosure of delinquent filers pursuant to Item     [X]
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.
</TABLE>
 
                            ------------------------
 
    The aggregate market value of the voting and non-voting stock held by
non-affiliates of the registrant was approximately $13,775,000 on March 19,
1999, based on the per-share closing price of $1.38 on the Nasdaq National
Market.
 
   The number of shares of Common Stock outstanding as of March 22, 1999 was
                                  12,542,500.
                            ------------------------
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
(1) Portions of the Registrant's Annual Report to Shareholders for the fiscal
    year ended December 31, 1998 is incorporated by reference into Part I, Part
    II and Part III of this Form 10-K.
 
(2) Portions of the Registrant's Proxy Statement for the Registrant's Annual
    Shareholders Meeting to be held Thursday, June 3, 1999, to be filed pursuant
    to Regulation 14A is incorporated by reference into Part III of this Form
    10-K.
 
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                           OSTEX INTERNATIONAL, INC.
                               INDEX TO FORM 10-K
 
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                                                         PART I
 
ITEM 1        BUSINESS.....................................................................................           2
ITEM 1A       RISK FACTORS.................................................................................           5
ITEM 1B       EXECUTIVE OFFICERS OF THE REGISTRANT.........................................................           9
ITEM 2        PROPERTIES...................................................................................          10
ITEM 3        LEGAL PROCEEDINGS............................................................................          10
ITEM 4        SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS..........................................          10
 
                                                        PART II
 
ITEM 5        MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED SHAREHOLDER MATTERS........................          11
ITEM 6        SELECTED FINANCIAL DATA......................................................................          11
ITEM 7        MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS........          11
ITEM 7A       QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK...................................          11
ITEM 8        FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA..................................................          11
ITEM 9        CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE.........          11
 
                                                        PART III
 
ITEM 10       DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT...........................................          12
ITEM 11       EXECUTIVE COMPENSATION.......................................................................          12
ITEM 12       SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT...............................          12
ITEM 13       CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS...............................................          12
 
                                                        PART IV
 
ITEM 14       EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K.............................          13
SIGNATURES.................................................................................................          16
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    For the purpose of this Form 10-K, the following capitalized terms shall
have the following meanings:
 
    "Company" or "Ostex" shall mean Ostex International, Inc., a Washington
corporation;
 
    "Annual Report to Shareholders" shall mean the annual report to shareholders
of Ostex International, Inc. for the year ended December 31, 1998; and
 
    "Proxy Statement" shall mean the proxy statement for the 1998 shareholders
meeting of Ostex International, Inc. to be held Thursday, June 3, 1999, to be
filed with the Securities and Exchange Commission (the "Commission") pursuant to
Regulation 14A.
 
                            ------------------------
 
                                     PART I
 
    When used in this report and in the Company's Annual Report to Shareholders
(which discussion has been incorporated herein by reference), the words
"believes," "intends, "anticipates," "plans to" and "expects" and similar
expressions are intended to qualify as forward-looking statements. Such
statements are subject to certain risks and uncertainties and there are a number
of important factors that could cause actual results to differ materially from
those projected. These factors include, among others, the factors described
under "Management's Discussion and Analysis of Financial Condition and Results
of Operations--Other Factors that May Affect Operating Results" in the Company's
Annual Report to Shareholders and the risk factors included herein. Readers are
cautioned not to place undue reliance on such forward-looking statements, which
speak only as of the date hereof. The Company undertakes no obligation to
release publicly the results of any revisions to such forward-looking statements
that may be made to reflect events or circumstances after the date hereof or to
reflect the occurrence of unanticipated events.
 
ITEM 1. BUSINESS
 
    Ostex was incorporated in the State of Washington in 1989. The Company is
engaged in the discovery and commercialization of products associated with
osteoporosis and other collagen-related diseases. The Company believes that its
lead product, the OSTEOMARK-Registered Trademark- test, incorporates
breakthrough and patented technology in the area of bone resorption measurement.
Ostex has formed collaborative relationships with leading diagnostic and
pharmaceutical companies to aid in the commercialization of Osteomark. As of
December 31, 1998, the Company had 35 employees.
 
    Osteoporosis is a significant health problem. According to the National
Osteoporosis Foundation (the "NOF"), osteoporosis afflicts approximately 30
million people in the U.S. alone. Additionally millions of people are at risk of
skeletal degradation associated with Paget's disease of bone, cancer that
metastasizes to bone, hyperparathyroidism (overactivity of the parathyroid
gland, characterized by a reduction of bone mass) and renal osteodystrophy. In
spite of the serious human and economic consequences of these diseases
(according to the NOF, the direct healthcare and indirect lost productivity
costs of osteoporosis exceed $10 billion annually in the U.S. alone), medical
intervention usually commences only after pain, immobility, fractures, or other
symptoms have appeared. The Company expects the osteoporosis therapeutic market
will increase significantly. The Company also believes new therapeutic products
are under development for osteoporosis, some of which are in late-stage clinical
trials, and that the Osteomark test can be used to effectively predict a
patient's response to osteoporosis therapy and monitor existing therapies and
other therapies which may be developed.
 
    The Company is the exclusive licensee of the Osteomark technology, known
clinically as the NTx test, which is available in urine and serum formats that
can aid in healthcare decision-making at early menopause and beyond. The
Osteomark test is a non-invasive diagnostic test which quantitatively indicates
the level of bone resorption. Individuals who are losing bone collagen at
accelerated rates may indicate a condition which typically results in
osteoporosis. The Company believes that early identification of high
 
                                       2
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levels of bone resorption provides the opportunity to predict skeletal response
(bone mineral density) to hormonal antiresorptive and other osteoporosis
therapies in postmenopausal women and helps prevent the onset of osteoporosis.
The Company also believes that the Osteomark test aids clinicians in monitoring
the effects of antiresorptive therapies in postmenopausal women, as well as in
older patients who have already lost significant bone mass.
 
    On May 8, 1995, the Company's Osteomark test became commercially available
in the United States as a urinary test that provides a quantitative measure of
the excretion of cross-linked N-telopeptides of Type I collagen (NTx) as an
indicator of human bone resorption, and in July 1996 the Company received
expanded claims from the Food and Drug Administration (the "FDA") for the test.
The 1996 claims allow that an Osteomark test measurement, if taken prior to the
initiation of hormonal antiresorptive therapy, can be utilized to predict a
patient's response to that therapy, in terms of its effect on bone mineral
density. Additionally, the claims allow that the test can be used for
therapeutic monitoring of antiresorptive therapies in postmenopausal women, as
well as individuals diagnosed with osteoporosis and Paget's disease, and for
therapeutic monitoring of estrogen-suppressing therapies. In March 1998, the
claims were further expanded by allowing that, in addition to the 1996 claims,
an Osteomark test measurement can identify the probability for a decrease in
bone mineral density in postmenopausal women taking calcium supplements relative
to those treated with hormonal antiresorptive therapy. The Company is
manufacturing and marketing the Osteomark test in an Enzyme-linked Immunosorbent
Assay ("ELISA") format for testing urine or serum samples.
 
    In February 1999, the Company received clearance to market Osteomark NTx
Serum. Osteomark NTx Serum is the first and only commercially available test in
the United States that measures specific bone breakdown by osteoclasts using a
blood sample. The Company believes that the use of a serum NTx test provides a
number of advantages to testing laboratories, including the elimination of the
requirement to normalize NTx values to creatinine concentration.
 
    Worldwide promotion of the Osteomark urine test kits is also supported by
Johnson & Johnson Clinical Diagnostics, Inc. ("Johnson & Johnson"). In 1995 the
Company entered into research, development, license and supply agreements with
Johnson & Johnson. These agreements grant Johnson & Johnson a license to
manufacture, sell and distribute certain products using Ostex's bone resorption
technology. Currently, Johnson & Johnson distributes in the United States and
certain foreign countries the Osteomark test in the existing microtiter plate
format and is adapting the urine test for use with its automated analyzer. Ostex
will receive royalties on Johnson & Johnson's sales of products incorporating
the Ostex technology.
 
    Under the Johnson & Johnson license agreement, the Company has the right to
license its technology for use on automated instruments to one other company in
addition to Johnson & Johnson. The Company is currently evaluating other
potential collaborators to adapt the Osteomark test to other high-speed
automated instruments.
 
    In the year ended December 31, 1998, the Company's largest customer, Johnson
& Johnson, accounted for approximately 16% of the Company's product sales. The
termination of the Company's relationship with Johnson & Johnson could have a
material adverse effect on the Company's results of operations. See "Risk
Factors--Reliance on Collaborative Agreements and Certain Relationships".
 
    In 1992, Ostex entered into a research and development agreement and a
license agreement with Mochida Pharmaceutical Co., Ltd. ("Mochida"), a Japanese
pharmaceutical company, for the commercialization of the Osteomark test in
Japan. Under the research and development agreement, Mochida has an option to
license the NTx serum test and has paid Ostex $3,350,000 in development fees to
date. Future payments of $750,000 under the agreement are contingent upon
Mochida's decision to exercise its option. Under the license agreement, Ostex
granted Mochida exclusive marketing and distribution rights to certain Ostex
products in Japan. Since 1992, Mochida has paid Ostex $2,500,000 in licensing
fees for the Osteomark test. In January 1998, Mochida launched the Osteomark
test in Japan for the management of
 
                                       3
<PAGE>
patients with hyperparathyroidism and for patients with metastatic bone tumors.
Ostex sells Mochida the critical reagents to be assembled into finished products
in Japan by Mochida.
 
    The Company also plans to develop the Osteomark test in other formats,
including formats suitable for use in the physician's office. The Company has an
agreement with Metrika, Inc. ("Metrika"), a diagnostic device company, to
develop a physician's office "point-of-care" Osteomark test device. The Company
and Metrika are developing this fully disposable point-of-care NTx test as an
indicator of bone resorption that computes NTx values and displays them
digitally.
 
    OSTEOMARK and OSTEX are registered United States ("U.S.") trademarks of the
Company. The Company has also registered its OSTEOMARK trademark in 46 other
countries. Additional trademark applications are pending.
 
    The Company's collagen breakdown test technology is covered by 20 U. S.
patents, 3 European patents, 3 Japanese patents, and patents in Australia,
Canada, Ireland, Spain, Hong Kong, and Singapore. Two of the European patents
and one of the Japanese patents are in opposition proceedings. Additional patent
applications are pending. See "Risk Factors--Dependence on Licensed Patents and
Proprietary Rights".
 
    The Company's research and development expenditures, all of which were
funded by the Company, totaled $2,901,000, $4,470,000, and $3,163,000, in 1998,
1997 and 1996, respectively.
 
    The Company's foreign product sales, all to non-affiliates, totaled
$517,000, $652,000, and $370,000, in 1998, 1997 and 1996, respectively. Foreign
sales were primarily to Europe, Canada and South America.
 
    The Company's international business is subject to risks of currency
fluctuations, governmental actions and other governmental proceedings abroad.
The Company does not regard these risks as a deterrent to further expansions of
its operations abroad. However, the Company closely reviews its methods of
operations and adopts strategies responsive to changing economic and political
conditions.
 
    The Company is developing an assay for Type II collagen degradation. Type II
collagen is a primary constituent of joint cartilage. Osteoarthritis, a
degenerative disease of joint cartilage, affects over 15 million people in the
United States alone. The disease first appears in a limited number of joints.
The first symptom, joint pain, occurs after substantial cartilage damage has
taken place. Eventually, pain and tenderness increase and the joint motion
becomes diminished. The Ostex Type II collagen degradation test under
development has been designed to allow reliable monitoring of joint cartilage
changes for validating the effectiveness of drugs under development and for
identifying patients with early-stage disease. In addition, similar to the
Osteomark test used in connection with osteoporosis, the Company believes that
the Type II collagen degradation test will aid in the clinical management of
osteoarthritis patients by monitoring the effectiveness of therapy.
 
    Ostex is investigating the use of its NTx test in cancer patient management.
Independent researchers have shown that the level of bone resorption increases
significantly when cancer metastasizes to bone. A patient's NTx level may be
useful to identify cancer patients with elevated bone turnover who might warrant
a bone scan to detect metastatic bone disease.
 
    Ostex is also in the early stages of developing an assay for measuring Type
III collagen degradation. Type III collagen is a significant constituent of
blood vessels such as coronary arteries. Measuring degradation of this type of
collagen may be useful in identifying cardiovascular disease.
 
                                       4
<PAGE>
ITEM 1A. RISK FACTORS
 
UNCERTAINTY OF MARKET ACCEPTANCE
 
    The Company's lead product, the Osteomark test, became commercially
available in May 1995 in the U.S. and sales have not been significant enough to
generate net income. There can be no assurance that the Company's Osteomark test
or any of its other products will gain acceptance from the medical community,
clinical or hospital laboratories, physicians or patients as readily as other
forms of diagnosis or any newly developed diagnostic. There can be no assurance
that the Company will be able to develop significant market share for its
products, or any market share at all. Inability of the Company to achieve market
acceptance for its products would have a material adverse effect on the
Company's business, financial condition and results of operation.
 
DEPENDENCE ON CORE TECHNOLOGY; UNCERTAINTY OF ADAPTATION TO DIFFERENT FORMATS
 
    The Company currently relies exclusively upon its core technology for the
development of diagnostic products associated with osteoporosis and other
collagen-related diseases. There can be no assurance that competitors of the
Company will not be successful in developing new or more efficient or
cost-effective diagnostics that are more readily accepted than the Company's
products. The Company is in the process of undertaking ongoing and additional
research and development to adapt its core technology to different formats,
instruments and other delivery platforms that currently exist or may be
developed. In particular, additional research and development will be required
to adapt its core technology to high-speed, high-volume automated instruments
typically used in large clinical laboratories or companies through which the
Company may seek to expand the market for its products. There can be no
assurance that the Company will be successful in adapting and further developing
its core technology to meet such needs. The Company is developing physician
office adaptations of its core technology. There can be no assurance that the
Company or its development partner will either successfully develop or obtain
required regulatory approval for a cost-effective instrument for physician
office use. In addition, technological changes or medical advancements could
diminish or eliminate the commercial viability of the Osteomark test or future
products based upon the Company's core technology. The failure to adapt the
Company's core technology to different formats, instruments and other delivery
platforms, or otherwise to commercialize such core technology, would have a
material adverse effect on the Company's business, financial condition and
results of operation.
 
RELIANCE ON COLLABORATIVE AGREEMENTS AND CERTAIN RELATIONSHIPS
 
    The Company has entered into collaborative or co-promotional agreements with
several partners, including, among others, Johnson & Johnson, Mochida and
Wyeth-Ayerst Laboratories, and intends to appoint a second international
distributor for its automated instrument application. The level of each
partner's involvement and support and the amount and timing of resources that
these collaborators devote to these activities are not within the control of the
Company and can significantly impact the Company's ability to achieve its
objectives. There can be no assurance that these collaborators will perform
their contractual obligations as expected or that the Company will derive any
additional revenue from such arrangements. Moreover, the agreements may be
terminated under certain circumstances. The Company expects to rely on these and
additional agreements to develop and commercialize its future products. There
can be no assurance that the Company will be able to negotiate acceptable
collaborative agreements in the future or that such new agreements or existing
agreements will be successful. In addition, there can be no assurance that the
parties to the agreements will not pursue alternative technologies.
 
LIMITED SALES AND MARKETING EXPERIENCE
 
    The Company has limited experience in sales, marketing and distribution. To
market any of its products directly, the Company must develop and implement a
substantial marketing and sales effort with
 
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technical expertise and supporting distribution capability. The Company intends
to continue to market and sell its products in the U.S. through research and
clinical laboratories, other companies, and collaborative arrangements and sell
its products in other markets through distributors or collaborative
arrangements. There can be no assurance that the Company will be able to
establish effective sales and distribution capabilities or that its
collaborators will be successful in gaining market acceptance for the Company's
products or that the Company will achieve or maintain significant market share
for its products.
 
DEPENDENCE ON LICENSED PATENTS AND PROPRIETARY RIGHTS
 
    The Company's success depends, in large part, on its current and future
patent position relating to its core technology. The Company's patent position
involves complex legal and factual questions. The Company is the exclusive
licensee of certain patents within and outside of the U.S. relating to the
Company's core technology. Claims made under patent applications may be denied
or significantly narrowed, and issued patents may not provide significant
commercial protection to the Company. There is no assurance that the Company's
patents will not be successfully challenged or circumvented by others. The
Company could incur substantial costs in proceedings before the U.S. Patent
Office, including interference proceedings. These proceedings could also result
in adverse decisions as to the patentability of the Company's licensed or
assigned inventions. There can be no assurance that the Company's products do
not or will not infringe on the patent or proprietary rights of others. The
Company may be required to obtain additional licenses to the patents or other
proprietary rights of others. The Company may also require licenses from the
inventors of certain processes, technologies and assay formats in order to
successfully market certain products. There can be no assurance that any such
licenses would be made available on terms acceptable to the Company, if at all.
If the Company needs and cannot or does not obtain such licenses, it could
encounter delays in product introductions while it attempts to circumvent such
patents or the development, manufacture, or sale of products requiring such
licenses could be precluded. The Company believes there will continue to be
significant litigation in the industry regarding patent and other intellectual
property rights.
 
    The Company is aware of competitors that are developing products that may be
covered by claims made in patents or patent applications of the Company. Because
certain foreign patents are subject to third-party opposition following the date
of grant of such patents, there can be no assurance that claims of the Company's
foreign patents, once granted, will survive such opposition without cancellation
or significant modification. Because U.S. applications are confidential until a
patent issues, the Company cannot be assured that its patent claims have
priority in the U.S. or will be entitled to patent protection.
 
    The Company also relies on trade secrets and other unpatented proprietary
technology. No assurance can be given that the Company can meaningfully protect
its rights in such unpatented technology or that others will not independently
develop substantially equivalent products and processes or otherwise gain access
to the Company's technology. The Company seeks to protect its trade secrets and
proprietary know-how, in part, with confidentiality agreements with its
employees and consultants. There can be no assurance that these agreements will
not be breached, that the Company will have adequate remedies for any breach, or
that the Company's trade secrets will not otherwise become known or be
independently developed by competitors. In addition, protracted and costly
litigation may be necessary to enforce and determine the scope and validity of
the Company's proprietary rights.
 
LENGTHY REGULATORY PROCESSES AND UNCERTAINTY OF REGULATORY APPROVALS
 
    The process of obtaining FDA and other required regulatory approvals can be
lengthy and expensive. The time required for approvals is uncertain, and often
depends on the type, complexity and novelty of the product. There can be no
assurance that regulatory agencies will act favorably or quickly in their review
of any submission by the Company, and significant difficulties or costs may be
encountered by the Company in its efforts to obtain approvals that could delay
or preclude the Company from marketing its products. Furthermore, there can be
no assurance that the agency will not request the development of additional
 
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data following original submissions, causing the Company to incur further cost
and delay. Nor can there be any assurance that the FDA will not restrict the
intended use of a submitted product as a condition for clearance.
 
    If the FDA concludes that a device is not substantially equivalent to
another legally marketed device, submission of a premarket approval ("PMA")
application will be required. If the FDA indicates that a PMA is required for
any product of the Company, the application will require submission of results
of clinical studies and manufacturing information, and likely a review by a
panel of experts outside of the FDA. Clinical studies would need to be conducted
in accordance with FDA requirements. The failure to comply would result in the
FDA's refusal to accept the data or the imposition of regulatory sanctions. FDA
review of a PMA application can take significantly longer than that for a
premarket notification "510(k)" application to demonstrate "substantial
equivalence" to a legally marketed product. Further, if a company wishes to
propose modifications to a product subsequent to FDA approval of a PMA
application, including changes in indications or other significant modifications
to labeling, or modifications to the manufacturing process, or if a company
wishes to change its manufacturing facility, a PMA supplement must first be
submitted to the FDA for its review and approval.
 
EXTENSIVE CONTINUING GOVERNMENT REGULATION
 
    The research, development, manufacturing and marketing of the Company's
products are subject to extensive continuing regulation by numerous governmental
authorities in the U.S. and certain other countries, and the Company, its
products, and its manufacturing facilities are subject to continual review and
periodic inspection. The regulatory standards for manufacturing are applied
stringently by the FDA. Discovery of previously unknown problems with a product,
manufacturer, or facility may result in restrictions on such product or
manufacturer or facility, including warning letters, fines, suspensions of
regulatory approvals, product recalls, operating restrictions, delays in
obtaining new product approvals, withdrawal of the product from the market, and
criminal prosecution. Other violations of FDA requirements can result in similar
penalties. The Company is also subject to numerous environmental, health and
workplace safety laws and regulations, including those governing laboratory
procedures, exposure to blood-borne pathogens, and the handling of biohazardous
materials. Any violation of, and the cost of compliance with, these laws and
regulations could adversely impact the Company's operations. The Company is
unable to predict the extent or likelihood of adverse government regulation that
might arise from future U.S. or foreign government action.
 
LIMITED MANUFACTURING EXPERIENCE
 
    The Company is developing adaptations of its core technology for use in
physicians' offices and depends upon the efforts of collaborators for this
development. Such adaptations have not been fully completed and there can be no
assurance that, if developed, such adaptations could be manufactured in a
commercially viable manner. Unless the Company develops additional in-house
manufacturing capability for such products, it will be dependent upon outside
sources for the manufacture of such products. There can be no assurance that the
Company's reliance on others for the manufacture of its products will not result
in problems with product supply. Interruptions in the availability of products
could delay or prevent the development and commercial marketing of the Company's
products.
 
HISTORY OF LOSSES AND LIMITED OPERATING HISTORY
 
    The Company has a limited operating history and had a retained deficit
through December 31, 1998 of $32,223,000. For the year-end December 31, 1998,
the Company had a net loss of $8,095,000. The Company expects to incur
additional costs as it continues with its operations, marketing efforts,
research and development activities, and clinical trials. The Company expects to
continue to incur losses in future periods and the Company is unable to predict
when, if at all, it will achieve profitability.
 
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FUTURE CAPITAL NEEDS AND UNCERTAINTY OF ADDITIONAL FINANCING
 
    The Company will continue to require substantial funds for research and
development, general and administration, and the marketing of its products. The
amount of the Company's future capital requirements will depend on many factors,
including the status of the development of its products, the time and costs
involved in obtaining regulatory approvals, the costs involved in filing,
prosecuting and enforcing patent claims, competing technological and market
developments, the ability of the Company to maintain existing collaborative and
licensing arrangements, and the ability of the Company to establish new
collaborative and licensing arrangements. The Company expects that its existing
capital resources will be sufficient to fund the Company's activities through
1999. However, the Company may be required to seek additional financing. There
can be no assurance that additional funds, whether through additional
financings, collaborative arrangements with corporate sponsors or other sources,
will be available, if at all, in a timely manner or on terms acceptable to the
Company. If adequate funds are not available, the Company may be required to
delay, scale back or eliminate one or more of its programs or obtain funds
through arrangements that are unfavorable to the Company.
 
INTENSE COMPETITIVE ENVIRONMENT
 
    Competition from biotechnology companies, diagnostic companies,
pharmaceutical companies and research and academic institutions is intense and
is based on price as well as product performance. A number of diagnostic tests
and procedures, and other non-invasive tests for osteoporosis and other bone
disorders currently exist and others are in development, and the manufacturers
of these tests will continue to improve them. In addition, the diagnostic
industry is subject to rapid technological change. There can be no assurance
that the Company's competitors will not succeed in developing products that are
more effective or less expensive than those which have been or are being
developed by the Company or which would render the Company's core technology
obsolete or non-competitive. Many of the Company's competitors have
substantially greater financial, technical and human resources than the Company.
In addition, many of these competitors have significantly greater experience and
resources than the Company in undertaking clinical trials and other regulatory
approval procedures as well as in marketing and achieving manufacturing
efficiencies. There are also small companies, academic institutions,
governmental agencies and other research organizations that are conducting
research in the area of osteoporosis and other collagen-related diseases. These
entities may also market commercial products either on their own or through
collaborative efforts. The Company's competitors may develop technologies and
products that are available for sale prior to the Company's products or at a
lower cost or with better technical characteristics rendering the Company's
products less competitive.
 
DEPENDENCE ON THERAPEUTICS DEVELOPED BY OTHERS
 
    Acceptance of and demand for the diagnostic products that the Company is
developing will be affected by the need perceived by physicians to diagnose
bone, cartilage and connective tissue disorders for the purposes of treatment.
There are currently a limited number of therapies that are effective in
preventing osteoporosis or other bone, cartilage or connective tissue disorders,
or in treating these disorders once diagnosed. In the event new therapies do not
receive regulatory approval or experience delayed market acceptance, the Company
could be adversely affected. Unfavorable publicity concerning a product of the
Company or therapeutic products for osteoporosis could also have an adverse
effect on the Company's ability to obtain regulatory approvals or to achieve
market acceptance.
 
UNCERTAINTY OF HEALTHCARE REIMBURSEMENT
 
    The Company's ability to commercialize its products will depend in part on
the extent to which reimbursement for the cost of such products and related
treatment will be available from third-party payors, such as government health
administration authorities, private health coverage insurers and other
organizations. The status of the scope of healthcare programs worldwide is
uncertain and there can be no
 
                                       8
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assurance that adequate third-party coverage will be available for the Company
to maintain price levels sufficient for realization of an appropriate return on
its investment in product development. Third-party payors are increasingly
challenging the price and cost effectiveness of medical products and services.
If the Company succeeds in bringing one or more products to the market, there
can be no assurance that these products will be considered cost effective and
that reimbursement to the consumer will be available or sufficient to allow the
Company to sell its products on a competitive basis.
 
VOLATILITY OF STOCK PRICE
 
    The volatility of the Company's stock price has been significant since it
first became publicly traded in January 1995. The stock market may experience
significant price and volume fluctuations unrelated to the operating performance
of particular companies. Factors such as any loss of key management, the results
of the Company's clinical trials or those of its competitors, adverse regulatory
actions or decisions, evidence regarding the safety or efficacy of the Company's
products or those of its competitors, announcements of technological innovations
or new products by the Company or its competitors, governmental regulation,
developments with respect to patents or other proprietary rights, product or
patent litigation or public concern as to the safety of products developed by
the Company may have a volatile effect on the market price of the Company's
Common Stock.
 
ITEM 1B. EXECUTIVE OFFICERS OF THE REGISTRANT
 
    The executive officers of the Company and their ages are as follows:
 
<TABLE>
<CAPTION>
NAME                                                       AGE                            POSITION
-----------------------------------------------------  -----------  -----------------------------------------------------
<S>                                                    <C>          <C>
 
Thomas A. Bologna....................................          50   President and Chief Executive Officer
 
Thomas F. Broderick..................................          50   Vice President, Patent and General Counsel
 
J. Daniel Clemens....................................          42   Vice President, Product Development
 
Donna J. DeLong......................................          50   Vice President, Marketing
 
Nancy J.S. Mallinak..................................          37   Vice President, Regulatory and Clinical Affairs
 
Cory J. Smith........................................          48   Vice President, Manufacturing
</TABLE>
 
    There were no family relationships between any executive officers of the
Company.
 
    THOMAS A. BOLOGNA joined the Company in July 1997 as the President and Chief
Executive Officer and as a member of the Board of Directors. From January 1996
until July 1997 Mr. Bologna was a principal in Healthcare Venture Associates, a
consulting firm. From January 1994 to January 1996 Mr. Bologna was President and
Chief Executive Officer for Scriptgen Pharmaceuticals, Inc., a biotechnology
company with proprietary drug screening and development technology that is
developing orally active drugs to regulate gene expression, and from July 1987
to January 1994 Mr. Bologna was the Chairman of the Board of Directors and
President and Chief Executive Officer of Gen-Probe Incorporated, a biotechnology
company commercializing genetic-probe-based technology for diagnostic and
therapeutic applications.
 
    THOMAS F. BRODERICK was named the Vice President, Patent and General Counsel
in November 1997. Mr. Broderick was Vice President, Intellectual Property from
March 1997 to November 1997 and was Patent Counsel for the Company from April
1996 to March 1997. From 1989 to March 1996, Mr. Broderick was a partner at the
patent law firm of Christensen, O'Connor, Johnson & Kindness in Seattle,
Washington.
 
    J. DANIEL CLEMENS was named the Vice President, Product Development in
September 1998. Mr. Clemens was Director of Research & Development for the
Company from May 1992 to September 1998 and Manager of Product Development from
October 1990 to May 1992. Prior to joining Ostex,
 
                                       9
<PAGE>
Mr. Clemens was Senior Research & Development Scientist from February 1987 to
October 1990 at Genetic Systems Corporation/Sanofi.
 
    DONNA J. DELONG joined the Company in February 1998 as Vice President,
Marketing. From May 1996 to February 1998, Ms. DeLong was Senior Director of
Marketing at Chiron Diagnostics, a division of Chiron Corporation, a healthcare
company; from October 1993 to April of 1996, Ms. DeLong was the Director of
Marketing at Neopath Inc., a medical diagnostics company; and from May 1990 to
October 1993 Ms. DeLong was the Director of Marketing at Sanofi Diagnostics
Pasteur, a medical diagnostics company.
 
    NANCY J.S. MALLINAK was named Vice President, Regulatory and Clinical
Affairs of the Company in February 1997. Ms. Mallinak was Director, Regulatory
and Clinical Affairs for the Company from June 1995 to February 1997 and was
Manager, Regulatory and Clinical Affairs for the Company from December 1992 to
June 1995. From June 1989 to December 1992, Ms. Mallinak was Manager, Clinical
Product Development in the Diagnostics Group of Baxter International, Inc., a
general healthcare company.
 
    CORY J. SMITH was named Vice President, Manufacturing in September 1998. Mr.
Smith was Director of Manufacturing for the Company from October 1993 to
September 1998 and was the Manufacturing Engineer for the Company from September
1992 to October 1993. Prior to joining Ostex, Mr. Smith was the Quality
Assurance Manager from June 1991 to September 1992 at Genetic Systems
Corporation/ Sanofi.
 
ITEM 2. PROPERTIES
 
    The Company's research laboratories, manufacturing operations, and
administrative offices are located in Seattle, Washington. The Company leases
approximately 32,000 square feet of space in Seattle under a lease that will
expire in 2005. The Seattle facility has adequate capacity for the Company's
present needs.
 
ITEM 3. LEGAL PROCEEDINGS
 
    Information regarding Legal Proceedings is incorporated herein by reference
to note 10 in the "Notes to Financial Statements" on page 28 of the Annual
Report to Shareholders.
 
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
    No matters were submitted to a vote of shareholders during the fourth
quarter ended December 31, 1998.
 
                            ------------------------
 
                                       10
<PAGE>
                                    PART II
 
ITEM 5. MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED SHAREHOLDER MATTERS
 
    The Company's Common Stock is traded on the Nasdaq National Market under the
symbol "OSTX". Information regarding the Common Stock trading activity for 1998
and 1997 is incorporated herein by reference to the "Shareholder
Information--Price Range of Common Stock" on page 32 of the Annual Report to
Shareholders, which is included as Exhibit 13.0 to this Annual Report on Form
10-K.
 
    As of March 22, 1999, there were 12,542,500 shares of Common Stock
outstanding held of record by approximately 131 shareholders. The Company
believes there are approximately 3,700 additional owners of Common Stock who own
shares held in street name.
 
    The Company has never paid cash dividends and has no present intention of
paying dividends in the foreseeable future.
 
    TRANSFER AGENT AND REGISTRAR--The transfer agent and registrar for the
Common Stock is ChaseMellon Shareholder Services, L.L.C., Seattle, Washington.
 
ITEM 6. SELECTED FINANCIAL DATA
 
    The information required by this item is incorporated herein by reference to
"Selected Financial Data" on page 16 of the Annual Report to Shareholders, which
is included as Exhibit 13.0 to this Annual Report on Form 10-K.
 
ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
  OF OPERATIONS
 
    The information required by this item is incorporated herein by reference to
pages 17-19 of the Annual Report to Shareholders, which is included as Exhibit
13.0 to this Annual Report on Form 10-K.
 
ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
 
    Not Applicable
 
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
 
    The information required by this item is incorporated herein by reference to
the Financial Statements and "Notes to Financial Statements" on pages 20-29, and
"Report of Independent Public Accountants" on page 30, of the Annual Report to
Shareholders, which is included as Exhibit 13.0 to this Annual Report on Form
10-K.
 
ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
  FINANCIAL DISCLOSURE
 
    None.
 
                            ------------------------
 
                                       11
<PAGE>
                                    PART III
 
ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
 
    a. Directors
 
    The information contained in the section entitled "Election of Directors and
Director Information" of the Proxy Statement is incorporated herein by reference
in response to this item.
 
    b. Executive Officers of the Registrant
 
    Information required by this item is contained in Part I of this Annual
Report on Form 10-K in the section entitled "Executive Officers of the
Registrant."
 
    c. Compliance With Section 16(a)
 
    Information contained in the section entitled "Compliance with Section 16(a)
of the Exchange Act" of the Proxy Statement is incorporated herein by reference
in response to this item.
 
ITEM 11. EXECUTIVE COMPENSATION
 
    The information contained in the section entitled "Executive Compensation"
of the Proxy Statement is incorporated herein by reference in response to this
item.
 
ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
    The information contained in the section entitled "Security Ownership of
Certain Beneficial Owners and Management" of the Proxy Statement is incorporated
herein by reference in response to this item.
 
ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
    The information contained in the section entitled "Compensation Committee
Interlocks and Insider Participation" of the Proxy Statement is incorporated
herein by reference in response to this item.
 
                            ------------------------
 
                                       12
<PAGE>
                                    PART IV
 
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K
 
    (A) FINANCIAL STATEMENTS, FINANCIAL STATEMENT SCHEDULES AND EXHIBITS
 
    The information contained in the Financial Statements and "Notes to
Financial Statements" are located on pages 20-29 of the Annual Report to
Shareholders and are listed below. This information is included as Exhibit 13.0
to this Annual Report on Form 10-K.
 
<TABLE>
<CAPTION>
                                                                                     PAGE WITHIN
FINANCIAL STATEMENTS                                                                ANNUAL REPORT
-------------------------------------------------------------------------------  -------------------
<S>                                                                              <C>
Balance Sheets.................................................................              20
Statements of Operations.......................................................              21
Statements of Cash Flows.......................................................              22
Statements of Shareholders' Equity.............................................              23
Notes to Financial Statements..................................................              24
Report of Independent Public Accountants.......................................              30
</TABLE>
 
    (B) REPORTS ON FORM 8-K
 
    None
 
    (C) EXHIBIT INDEX (14)
 
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
EXHIBIT NUMBER                                            DESCRIPTION
--------------------  -----------------------------------------------------------------------------------
<S>        <C>        <C>
 
(8)        3.1        Articles of Incorporation, as amended, dated January 1997
 
(1)        3.2        Bylaws, as amended
 
(1)        4.1        Specimen Common Stock Certificate
 
(1)        10.1A      Amended and Restated Stock Option Plan*
 
(1)        10.1B      Form of Employee Stock Option Agreement*
 
(1)        10.1C      Form of Director's Stock Option Agreement*
 
(9)        10.2       Amended and Restated Directors' Nonqualified Stock Option Plan dated July 16, 1997*
 
(9)        10.3       Amended and Restated 1994 Stock Option Plan*
 
                      Agreements with Hologic, Inc.
(3)(12)    10.4A      Co-Promotion and Sales Representation Agreement dated January 14,   1997
 
(3)(12)    10.4B      Joint Development, License and Supply Agreement dated January 14,   1997
 
(1)        10.5       Form of Indemnification Agreement with officers and directors*
 
                      Agreement with Thomas A. Bologna
(13)       10.7       Executive Employment Agreement dated July 16, 1997*
 
                      Agreements with Mochida Pharmaceutical Co., Ltd.
(1)        10.12A     Research and Development Agreement dated August 1992
 
(1)        10.12B     Osteomark License Agreement Dated August 1992
</TABLE>
 
                                       13
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NUMBER                                            DESCRIPTION
--------------------  -----------------------------------------------------------------------------------
<S>        <C>        <C>
(3)        10.12D     Second Amendment to Osteomark License Agreement dated   December 24, 1997
 
                      Agreements with the Washington Research Foundation
(1)        10.13A     Restated Exclusive License Agreement effective June 19, 1992 (Urinary   Assay for
                        Measuring Bone Resorption)
 
(1)        10.13B     Amendment to Restated Exclusive License Agreement effective   January 1, 1993
 
(1)        10.13C     Second Amendment effective June 2, 1994
 
(1)        10.14      Exclusive License Agreement dated February 10, 1994 (O-CSF)
 
                      Agreements with the University of Washington
(3)(12)    10.15A     Research Agreement dated July 1, 1996 (Molecular Markers of   Connective Tissue
                        Degradation)
 
(3)(12)    10.15B     Research Agreement dated October 1, 1996 (Role of O-CSF in   Osteoclast Regulation)
 
(1)        10.16A     Know-How Transfer and Consulting Agreement dated September 18, 1989 with David R.
                        Eyre, Ph.D.*
 
(1)        10.16B     Extension and Amendment dated May 1, 1992*
 
(1)        10.19      Osteomark EIA Exclusive Distribution License Agreement dated March 28, 1994 with
                        Technogenetics S.R.L.
 
(1)        10.20      Osteomark EIA Distribution License Agreement dated July 12, 1994 with BRAHMS
                        Diagnostic (formerly Henning Berlin GmbH)
 
(1)        10.23      Osteomark Agreement dated February 12, 1993, as amended May 10, 1994, with Nichols
                        Institute Reference Laboratory
 
                      Lease Agreements
(4)        10.27A     Lease Agreement dated October 2, 1995, with David A. Sabey and   Sandra L. Sabey
 
(8)        10.27B     First Amendment of Lease dated October 15, 1996, with the City of   Seattle,
                        successor-in-interest to David A. Sabey and Sandra L. Sabey
 
                      Agreements with Johnson & Johnson Clinical Diagnostics, Inc.
(5)        10.28A     Distribution Agreement dated June 7, 1995
 
(5)        10.28B     Research, Development, License and Supply Agreement dated June 7,   1995
 
(4)        10.29      Clinical Laboratory Services License and Supply Agreement dated October 25, 1995,
                        with SmithKline Beecham Clinical Laboratories, Inc.
 
(13)       10.30      Promotion Agreement dated September 30, 1997 with Wyeth-Ayerst Laboratories
 
(6)        10.31      Agreement with Laboratory Corporation of America-TM- Holdings (LabCorp), dated
                        January 11, 1996
 
(7)        10.32A     Joint Development, License and Co-Marketing Agreement dated April 10, 1997 with
                        Metrika, Inc.
 
(10)       10.33      Form of CS First Boston Corporation Warrant
 
(11)       10.34      Form of Invemed Associates, Inc. Warrant
</TABLE>
 
                                       14
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NUMBER                                            DESCRIPTION
--------------------  -----------------------------------------------------------------------------------
<S>        <C>        <C>
(2)        10.35      Shareholder Rights Agreement dated January 21, 1997
 
**         13.0       Selected Financial Data, Management's Discussion and Analysis of Financial
                        Condition and Results of Operations, Financial Statements and Notes to the
                        Financial Statements from the Company's Annual Report to Shareholders for the
                        year ended December 31, 1998
 
           23.1       Consent of Arthur Andersen LLP
 
           27.1       Financial Data Schedule
</TABLE>
 
------------------------
 
     *  Management contract or compensatory plan or agreement.
 
    **  Filed Herewith in.
 
     (1) Incorporated herein by reference from Item 16(a) of Registrant's Form
       S-1 Registration Statement as declared effective January 24, 1995 (No.
       33-86118).
 
     (2) Incorporated herein by reference to exhibit number 4.5 filed with Form
       8-A with the Commission in January 1997.
 
     (3) Confidential treatment requested. Exhibit omits information that has
       been filed separately with the Commission.
 
     (4) Incorporated herein by reference to exhibit of the same number filed
       with Form 10-K with the Commission for the year ended December 31, 1995.
 
     (5) Incorporated herein by reference to exhibit of the same number filed
       with Form 10-Q with the Commission for the quarter ended June 30, 1995.
 
     (6) Incorporated herein by reference to exhibit of the same number filed
       with Form 10-Q with the Commission for the quarter ended March 31, 1996.
 
     (7) Incorporated herein by reference to exhibit of the same number filed
       with Form 10-Q with the Commission for the quarter ended September 30,
       1997.
 
     (8) Incorporated herein by reference to exhibit of the same number filed
       with Form 10-K with the Commission for the year ended December 31, 1996.
 
     (9) Incorporated herein by reference to exhibit of the same number filed
       with Form S-8 with the Commission on January 13, 1998.
 
    (10) Incorporated herein by reference to exhibit number 1.1A filed with the
       Registrant's Form S-1 Registration Statement as declared effective
       January 24, 1995 (No. 33-86118).
 
    (11) Incorporated herein by reference to exhibit number 1.1B filed with the
       Registrant's Form S-1 Registration Statement as declared effective
       January 24, 1995 (No. 33-86118).
 
    (12) Incorporated herein by reference to exhibits of the same number filed
       with Form 10-K with the Commission for the year ended December 31, 1996,
       and as amended with Form 10-K/A on October 17, 1997.
 
    (13) Incorporated herein by reference to exhibits of the same number filed
       with Form 10-K with the Commission for the year ended December 31, 1997.
 
    (14) Copies of exhibits may be obtained at prescribed rates from the Public
       Reference Section of the Commission at 450 5th Street NW, Room 1024,
       Washington, D.C. 20549, or through the Commission's Edgar system located
       on the internet at www.sec.gov.
 
                                       15
<PAGE>
                                   SIGNATURES
 
    Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized on March 22, 1999.
 
                                OSTEX INTERNATIONAL, INC.
 
                                BY             /S/ THOMAS A. BOLOGNA
                                     -----------------------------------------
                                                 Thomas A. Bologna
                                                PRESIDENT AND CHIEF
                                           EXECUTIVE OFFICER AND DIRECTOR
 
    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.
 
          SIGNATURE                     CAPACITIES                  DATE
------------------------------  ---------------------------  -------------------
 
                                President and Chief
    /s/ THOMAS A. BOLOGNA         Executive Officer
------------------------------    (principal executive         March 22, 1999
      Thomas A. Bologna           officer and principal
                                  financial officer)
 
     /s/ THOMAS J. CABLE        Chairman of the Board of
------------------------------    Directors                    March 22, 1999
       Thomas J. Cable
 
    /s/ ELISABETH L. EVANS      Director
------------------------------                                 March 22, 1999
      Elisabeth L. Evans
 
      /s/ DAVID R. EYRE         Director
------------------------------                                 March 22, 1999
        David R. Eyre
 
    /s/ FREDRIC J. FELDMAN      Director
------------------------------                                 March 22, 1999
      Fredric J. Feldman
 
    /s/ GREGORY D. PHELPS       Director
------------------------------                                 March 22, 1999
      Gregory D. Phelps
 
     /s/ JOHN H. TRIMMER        Director
------------------------------                                 March 22, 1999
       John H. Trimmer
 
                                       16
<PAGE>
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
EXHIBIT NUMBER                                                 DESCRIPTION
---------------------  -------------------------------------------------------------------------------------------
<S>        <C>         <C>
 
(8)        3.1         Articles of Incorporation, as amended, dated January 1997
 
(1)        3.2         Bylaws, as amended
 
(1)        4.1         Specimen Common Stock Certificate
 
(1)        10.1A       Amended and Restated Stock Option Plan*
 
(1)        10.1B       Form of Employee Stock Option Agreement*
 
(1)        10.1C       Form of Director's Stock Option Agreement*
 
(9)        10.2        Amended and Restated Directors' Nonqualified Stock Option Plan dated July 16, 1997*
 
(9)        10.3        Amended and Restated 1994 Stock Option Plan*
 
                       Agreements with Hologic, Inc.
(3)(12)    10.4A       Co-Promotion and Sales Representation Agreement dated January 14, 1997
 
(3)(12)    10.4B       Joint Development, License and Supply Agreement dated January 14, 1997
 
(1)        10.5        Form of Indemnification Agreement with officers and directors*
 
                       Agreement with Thomas A. Bologna
(13)       10.7        Executive Employment Agreement dated July 16, 1997*
 
                       Agreements with Mochida Pharmaceutical Co., Ltd.
(1)        10.12A      Research and Development Agreement dated August 1992
 
(1)        10.12B      Osteomark License Agreement Dated August 1992
 
(3)        10.12D      Second Amendment to Osteomark License Agreement dated December 24,1997
 
                       Agreements with the Washington Research Foundation
(1)        10.13A      Restated Exclusive License Agreement effective June 19, 1992 (Urinary Assay   for Measuring
                         Bone Resorption)
 
(1)        10.13B      Amendment to Restated Exclusive License Agreement effective January 1, 1993
 
(1)        10.13C      Second Amendment effective June 2, 1994
 
(1)        10.14       Exclusive License Agreement dated February 10, 1994 (O-CSF)
 
                       Agreements with the University of Washington
(3)(12)    10.15A      Research Agreement dated July 1, 1996 (Molecular Markers of Connective   Tissue
                         Degradation)
 
(3)(12)    10.15B      Research Agreement dated October 1, 1996 (Role of O-CSF in Osteoclast   Regulation)
 
(1)        10.16A      Know-How Transfer and Consulting Agreement dated September 18, 1989 with David R. Eyre,
                         Ph.D.*
 
(1)        10.16B      Extension and Amendment dated May 1, 1992*
 
(1)        10.19       Osteomark EIA Exclusive Distribution License Agreement dated March 28, 1994 with
                         Technogenetics S.R.L.
 
(1)        10.20       Osteomark EIA Distribution License Agreement dated July 12, 1994 with BRAHMS Diagnostic
                         (formerly Henning Berlin GmbH)
 
(1)        10.23       Osteomark Agreement dated February 12, 1993, as amended May 10, 1994, with Nichols
                         Institute Reference Laboratory
</TABLE>
 
                                       17
<PAGE>
<TABLE>
<CAPTION>
EXHIBIT NUMBER                                                 DESCRIPTION
---------------------  -------------------------------------------------------------------------------------------
<S>        <C>         <C>
                       Lease Agreements
(4)        10.27A      Lease Agreement dated October 2, 1995, with David A. Sabey and Sandra L.   Sabey
 
(8)        10.27B      First Amendment of Lease dated October 15, 1996, with the City of Seattle,
                           successor-in-interest to David A. Sabey and Sandra L. Sabey
 
                       Agreements with Johnson & Johnson Clinical Diagnostics, Inc.
(5)        10.28A      Distribution Agreement dated June 7, 1995
 
(5)        10.28B      Research, Development, License and Supply Agreement dated June 7, 1995
 
(4)        10.29       Clinical Laboratory Services License and Supply Agreement dated October 25, 1995, with
                         SmithKline Beecham Clinical Laboratories, Inc.
 
(13)       10.30       Promotion Agreement dated September 30, 1997 with Wyeth-Ayerst Laboratories
 
(6)        10.31       Agreement with Laboratory Corporation of America-TM- Holdings (LabCorp), dated January 11,
                         1996
 
(7)        10.32A      Joint Development, License and Co-Marketing Agreement dated April 10, 1997 with Metrika,
                         Inc.
 
(10)       10.33       Form of CS First Boston Corporation Warrant
 
(11)       10.34       Form of Invemed Associates, Inc. Warrant
 
(2)        10.35       Shareholder Rights Agreement dated January 21, 1997
 
**         13.0        Selected Financial Data, Management's Discussion and Analysis of Financial Condition and
                         Results of Operations, Financial Statements and Notes to the Financial Statements from
                         the Company's Annual Report to Shareholders for the year ended December 31, 1998
 
           23.1        Consent of Arthur Andersen LLP
 
           27.1        Financial Data Schedule
</TABLE>
 
------------------------
 
 *  Management contract or compensatory plan or agreement.
 
**  Filed Herewith in.
 
 (1) Incorporated herein by reference from Item 16(a) of Registrant's Form S-1
    Registration Statement as declared effective January 24, 1995 (No.
    33-86118).
 
 (2) Incorporated herein by reference to exhibit number 4.5 filed with Form 8-A
    with the Commission in January 1997.
 
 (3) Confidential treatment requested. Exhibit omits information that has been
    filed separately with the Commission.
 
 (4) Incorporated herein by reference to exhibit of the same number filed with
    Form 10-K with the Commission for the year ended December 31, 1995.
 
 (5) Incorporated herein by reference to exhibit of the same number filed with
    Form 10-Q with the Commission for the quarter ended June 30, 1995.
 
 (6) Incorporated herein by reference to exhibit of the same number filed with
    Form 10-Q with the Commission for the quarter ended March 31, 1996.
 
 (7) Incorporated herein by reference to exhibit of the same number filed with
    Form 10-Q with the Commission for the quarter ended September 30, 1997.
 
                                       18
<PAGE>
 (8) Incorporated herein by reference to exhibit of the same number filed with
    Form 10-K with the Commission for the year ended December 31, 1996.
 
 (9) Incorporated herein by reference to exhibit of the same number filed with
    Form S-8 with the Commission on January 13, 1998.
 
(10) Incorporated herein by reference to exhibit number 1.1A filed with the
    Registrant's Form S-1 Registration Statement as declared effective January
    24, 1995 (No. 33-86118).
 
(11) Incorporated herein by reference to exhibit number 1.1B filed with the
    Registrant's Form S-1 Registration Statement as declared effective January
    24, 1995 (No. 33-86118).
 
(12) Incorporated herein by reference to exhibits of the same number filed with
    Form 10-K with the Commission for the year ended December 31, 1996, and as
    amended with Form 10-K/A on October 17, 1997.
 
(13) Incorporated herein by reference to exhibits of the same number filed with
    Form 10-K with the Commission for the year ended December 31, 1997.
 
                                       19