Document:

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                                                                    Exhibit 10.4

                                                                  WARRANT NO. __

THIS WARRANT AND THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE OFFERED, SOLD,
ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
UNDER SAID ACT OR UNLESS THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
REASONABLY SATISFACTORY TO THE COMPANY (WHICH SHALL BE IN FORM AND SUBSTANCE
REASONABLY SATISFACTORY TO THE COMPANY) THAT REGISTRATION UNDER SAID ACT IS NOT
REQUIRED.

                                SERIES A WARRANT

              To Purchase [____________] Shares of Common Stock of

                                 ORTHOVITA, INC.

               THIS IS TO CERTIFY THAT [_______________], or registered assigns
(the "Holder"), is entitled, at any time prior to the Expiration Date (as
hereinafter defined), to purchase from Orthovita, Inc. a Pennsylvania
corporation (the "Company"), the Warrant Stock (as hereinafter defined and
subject to adjustment as provided herein), in whole or in part, at a purchase
price of $1.612 per share, all on and subject to the terms and conditions
hereinafter set forth.

               1.   Definitions. As used in this Warrant, the following terms
have the respective meanings set forth below:

               "Additional Shares of Common Stock" means any shares of Common
Stock issued by the Company after the Closing Date other than: (i) Warrant
Stock; (ii) shares issued or issuable pursuant to anti-dilution provisions of
the Series A Convertible Preferred Stock; (iii) shares issued or issuable upon
the conversion of the Series A Convertible Preferred Stock; (iv) shares issued
or issuable as payment(s) of dividends to holders of Series A Convertible
Preferred Stock, (v) shares issued or issuable upon the exercise of any warrants
or options outstanding as of the Closing Date, (vi) Common Stock, stock awards
or options under, or the exercise of any options granted pursuant to, any
currently authorized plan for the issuance of options or capital stock of the
Company including, without limitation, stock purchase plans or (vii) shares
issuable upon the exercise of any warrants that are issuable pursuant to the
terms of the Preferred Stock Purchase Agreement.

               "Affiliate" means any person or entity that, directly or
indirectly through one or more intermediaries, controls or is controlled by or
is under common control with a person or entity, as such terms are used in and
construed under Rule 144 under the Securities Act. With

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respect to a Holder of Warrants, any investment fund or managed account that is
managed on a discretionary basis by the same investment manager as such holder
will be deemed to be an Affiliate of such Holder.

               "Aggregate Warrants" means this Warrant together with all other
warrants issued by the Company pursuant to the Preferred Stock Purchase
Agreement.

               "Appraised Value" means, in respect of any share of Common Stock
on any date herein specified, the fair saleable value of such share of Common
Stock (determined without giving effect to the discount for (i) a minority
interest or (ii) any lack of liquidity of the Common Stock or to the fact that
the Company may have no class of equity registered under the Exchange Act) as of
the last day of the most recent fiscal month ending prior to such date
specified, based on the value of the Company on a fully-diluted basis, as
determined by a nationally recognized investment banking firm selected by the
Company's Board of Directors and having no prior relationship with the Company.

               "Business Day" means any day that is not a Saturday or Sunday or
a day on which banks are required or permitted to be closed in the Commonwealth
of Pennsylvania.

               "Change of Control" means the (i) acquisition by an individual or
legal entity or group (as defined in Rule 13-d of the Exchange Act) of more than
one-half of the voting rights or equity interests in the Company; or (ii) sale,
conveyance, or other disposition of all or substantially all of the assets,
property or business of the Company or the merger into or consolidation with any
other corporation (other than a wholly owned subsidiary corporation) or
effectuation of any transaction or series of related transactions where holders
of the Company's voting securities prior to such transaction or series of
transactions fail to continue to hold at least 50% of the voting power of the
Company.

               "Closing Date" means July __, 2002.

               "Commission" means the Securities and Exchange Commission or any
other federal agency then administering the Securities Act and other federal
securities laws.

               "Common Stock" means (except where the context otherwise
indicates) the Common Stock, $0.01 par value per share, of the Company as
constituted on the Closing Date, and any capital stock into which such Common
Stock may thereafter be changed or converted, and shall also include (i) capital
stock of the Company of any other class (regardless of how denominated) issued
to the holders of shares of Common Stock upon any reclassification thereof which
is also not preferred as to dividends or assets on liquidation over any other
class of stock of the Company and which is not subject to redemption and (ii)
shares of common stock of any successor or acquiring corporation received by or
distributed to the holders of Common Stock of the Company in the circumstances
contemplated by Section 4.8.

               "Current Market Price" means, in respect of any share of Common
Stock on any date herein specified, if there shall not then be a public market
for the Common Stock, the higher of (a) the book value per share of Common Stock
on such date and (b) the Appraised Value per

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share of Common Stock at such date, or if there shall then be a public market
for the Common Stock, the higher of (a) the book value per share of Common Stock
on such date, and (b) the average of the daily market prices for 20 consecutive
Trading Days immediately preceding such date. The daily market price for each
such Trading Day shall be (i) the last sale price on such day on the principal
stock exchange on which such Common Stock is then listed or admitted to trading,
(ii) if no sale takes place on such day on any such exchange, the average of the
last reported closing bid and asked prices on such day as officially quoted on
any such exchange, (iii) if the Common Stock is not then listed or admitted to
trading on any stock exchange, the average of the last reported closing bid and
asked prices on such day in the over-the-counter market, as furnished by the
National Association of Securities Dealers Automatic Quotation System or the
National Quotation Bureau, Inc., (iv) if neither such corporation at the time is
engaged in the business of reporting such prices, as furnished by any similar
firm then engaged in such business, or (v) if there is no such firm, as
furnished by any member of the NASD selected mutually by the holder of this
Warrant and the Company or, if they cannot agree upon such selection, as
selected by two such members of the NASD, one of which shall be selected by
holder of this Warrant and one of which shall be selected by the Company.

               "Current Warrant Price" means, in respect of a share of Common
Stock at any date herein specified, the price at which a share of Common Stock
may be purchased pursuant to this Warrant on such date. Until the Current
Warrant Price is adjusted pursuant to the terms herein, the initial Current
Warrant Price shall be $1.612 per share.

               "Exchange Act" means the Securities Exchange Act of 1934, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect from time to time.

               "Exercise Period" means the period during which this Warrant is
exercisable pursuant to Section 2.1.

               "Expiration Date" means July __, 2007 or such earlier date to
which the Expiration Date has been shortened pursuant to the terms of Section
4.8(a) hereof.

               "GAAP" means generally accepted accounting principles in the
United States of America as from time to time in effect.

               "NASD" means the National Association of Securities Dealers,
Inc., or any successor corporation thereto.

               "Other Property" has the meaning set forth in Section 4.8.

               "Person" means any individual, sole proprietorship, partnership,
joint venture, trust, incorporated organization, association, corporation,
limited liability company, institution, public benefit corporation, entity or
government (whether federal, state, county, city, municipal or otherwise,
including, without limitation, any instrumentality, division, agency, body or
department thereof).

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               "Preferred Stock Purchase Agreement" means that certain Preferred
Stock and Warrant Purchase Agreement dated as of July 19, 2002 among the Company
and the other parties named therein, pursuant to which this Warrant was
originally issued.

               "Restricted Common Stock" means shares of Common Stock which are,
or which upon their issuance upon the exercise of any Warrant would be required
to be, evidenced by a certificate bearing the restrictive legend set forth in
Section 3.2.

               "Securities Act" means the Securities Act of 1933, as amended, or
any similar federal statute, and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

               "Series A Convertible Preferred Stock" shall mean the Company's
Series A 6% Cumulative Convertible Voting Preferred Stock, par value $0.01 per
share.

               "Trading Day" means any day on which the primary market on which
shares of Common Stock are listed is open for trading.

               "Transfer" means any disposition of any Warrant or Warrant Stock
or of any interest in either thereof, which would constitute a sale thereof
within the meaning of the Securities Act.

               "Warrants" means this Warrant and all warrants issued upon
transfer, division or combination of, or in substitution for, any thereof. All
Warrants shall at all times be identical as to terms and conditions and date,
except as to the number of shares of Common Stock for which they may be
exercised.

               "Warrant Price" means an amount equal to (i) the number of shares
of Common Stock being purchased upon exercise of this Warrant pursuant to
Section 2.1, multiplied by (ii) the Current Warrant Price.

               "Warrant Stock" means the [_____________] shares of Common Stock
to be purchased upon the exercise hereof, subject to adjustment as provided
herein.

               2.   Exercise Of Warrant.

               2.1. Manner of Exercise. From and after the Closing Date, and
until 5:00 P.M., New York time, on the Expiration Date (the "Exercise Period"),
the Holder may exercise this Warrant, on any Business Day, for all or any part
of the number of shares of Warrant Stock purchasable hereunder.

               In order to exercise this Warrant, in whole or in part, the
Holder shall deliver to the Company at its principal office or at the office or
agency designated by the Company pursuant to Section 12, (i) a written notice of
Holder's election to exercise this Warrant, which notice shall specify the
number of shares of Warrant Stock to be purchased, (ii) payment of the Warrant
Price as provided herein, and (iii) this Warrant. Such notice shall be
substantially in the

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form of the subscription form appearing at the end of this Warrant as Exhibit A,
duly executed by the Holder or its agent or attorney. Upon receipt thereof, the
Company shall, as promptly as practicable, and in any event within five Business
Days thereafter, execute or cause to be executed and deliver or cause to be
delivered to the Holder a certificate or certificates representing the aggregate
number of full shares of Warrant Stock issuable upon such exercise, together
with cash in lieu of any fraction of a share, as hereinafter provided. The stock
certificate or certificates so delivered shall be, to the extent possible, in
such denomination or denominations as the Holder shall request in the notice and
shall be registered in the name of the Holder or such other name as shall be
designated in the notice. This Warrant shall be deemed to have been exercised
and such certificate or certificates shall be deemed to have been issued, and
the Holder or any other Person so designated to be named therein shall be deemed
to have become a Holder of record of such shares for all purposes, as of the
date when the notice, together with the payment of the Warrant Price and this
Warrant, is received by the Company as described above. If this Warrant shall
have been exercised in part, the Company shall, at the time of delivery of the
certificate or certificates representing Warrant Stock, deliver to the Holder a
new Warrant evidencing the rights of the Holder to purchase the unpurchased
shares of Common Stock called for by this Warrant, which new Warrant shall in
all other respects be identical with this Warrant, or at the request of the
Holder, appropriate notation may be made on this Warrant and the same returned
to the Holder.

                     Payment of the Warrant Price may be made at the option of
the Holder by: (i) certified or official bank check payable to the order of the
Company, (ii) wire transfer to the account of the Company or (iii) commencing
one year following the Closing Date, the surrender and cancellation of a portion
of shares of Common Stock then held by the Holder or issuable upon such exercise
of this Warrant, which shall be valued and credited toward the total Warrant
Price due the Company for the exercise of the Warrant based upon the Current
Market Price of the Common Stock. All shares of Common Stock issuable upon the
exercise of this Warrant pursuant to the terms hereof shall be validly issued
and, upon payment of the Warrant Price, shall be fully paid and nonassessable
and not subject to any preemptive rights.

               2.2.  Fractional Shares. The Company shall not be required to
issue a fractional share of Common Stock upon exercise of any Warrant. As to any
fraction of a share which the Holder of one or more Warrants, the rights under
which are exercised in the same transaction, would otherwise be entitled to
purchase upon such exercise, the Company shall pay an amount in cash equal to
the Current Market Price per share of Common Stock on the date of exercise
multiplied by such fraction.

               2.3.  Continued Validity. A Holder of shares of Common Stock
issued upon the exercise of this Warrant, in whole or in part (other than a
Holder who acquires such shares after the same have been publicly sold pursuant
to a Registration Statement under the Securities Act or sold pursuant to Rule
144 thereunder), shall continue to be entitled with respect to such shares to
all rights to which it would have been entitled as the Holder under Sections 10
and 13 of this Warrant.

               2.4.  Restrictions on Exercise Amount.

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               (i)   Except as provided otherwise in Section 2.4(ii), unless a
Holder delivers to the Company irrevocable written notice that this Section
2.4(i) shall not apply to such Holder, the Holder may not acquire a number of
shares of Warrant Stock to the extent that, upon such exercise, the number of
shares of Common Stock then beneficially owned by such holder and its Affiliates
and any other persons or entities whose beneficial ownership of Common Stock
would be aggregated with the Holder's for purposes of Section 13(d) of the
Exchange Act (including shares held by any "group" of which the holder is a
member) exceeds 4.95% of the total number of shares of Common Stock of the
Company then issued and outstanding. For purposes hereof, "group" has the
meaning set forth in Section 13(d) of the Exchange Act and applicable
regulations of the Securities and Exchange Commission, and the percentage held
by the holder shall be determined in a manner consistent with the provisions of
Section 13(d) of the Exchange Act. Each delivery of a notice of exercise by a
Holder will constitute a representation by such Holder that it has evaluated the
limitation set forth in this paragraph and determined, based on the most recent
public filings by the Company with the Commission, that the issuance of the full
number of shares of Warrant Stock requested in such notice of exercise is
permitted under this paragraph.

               (ii)  The provisions of Section 2.4(i) shall not apply if an
OrbiMed Entity forces an exercise of the Warrants pursuant to Section 4.8(a)
below.

               (iii) Notwithstanding any contrary or inconsistent provision
hereof, if the Company is prohibited by Rule 4350(i) of the National Association
of Securities Dealers, Inc. (the "NASD"), or any successor or similar rule, or
the rules or regulations of any other securities exchange on which the Common
Stock is then listed or traded, from issuing a number of shares of Common Stock
upon exercise of this Warrant (together with any shares of Common Stock, or
securities convertible into or exercisable for Common Stock, issued or issuable
pursuant to the Preferred Stock and Warrant Purchase Agreement (the "Preferred
Stock Purchase Agreement") dated as the Closing Date among the Company, the
Holder and the other parties thereto, or other agreements entered into in
connection therewith, including, without limitation, shares of Common Stock
issued or issuable as payment of dividends on the Series A Convertible Preferred
Stock) in excess of a prescribed amount (the "Issuance Cap Amount"), then the
Company shall not issue shares upon exercise of this Warrant in excess of the
Issuance Cap Amount. Assuming solely for purposes of this Section 2.4(ii) that
such Rule 4350(i) or similar rule is applicable, the Issuance Cap Amount shall
be 4,003,904 shares.

                     In the event the Company is prohibited from issuing shares
of Common Stock as a result of the operation of this Section 2.4(iii), the
Company shall seek the approval of its shareholders to authorize the issuance of
the full number of shares of Common Stock which would be issuable upon the
exercise of the then outstanding Warrants but for the Issuance Cap Amount to
eliminate any prohibitions under applicable law or the rules or regulations of
any stock exchange, interdealer quotation system or other self-regulatory
organization with jurisdiction over the Company or any of its securities on the
Company's ability to issue shares of Common Stock in excess of the Issuance Cap
Amount.

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               3.   Transfer, Division and Combination.

               3.1. Transfer. The Warrants and the Warrant Stock shall be freely
transferable, subject to compliance with all applicable laws, including, but not
limited to the Securities Act; provided, however, that a Holder must obtain the
prior written consent of the Company in order to transfer Warrants representing
the right to purchase less than 100,000 shares of Warrant Stock. If, at the time
of the surrender of this Warrant in connection with any transfer of this Warrant
or the Warrant Stock, this Warrant or the Warrant Stock, as applicable, shall
not be registered under the Securities Act and under applicable state securities
or blue sky laws, the Company may require, as a condition of allowing such
transfer that the Holder or transferee of this Warrant or the Warrant Stock as
the case may be, furnish to the Company a written opinion of counsel that is
reasonably acceptable to the Company to the effect that such transfer may be
made without registration under the Securities Act and under applicable state
securities or blue sky laws, (ii) that the Holder or transferee execute and
deliver to the Company an investment letter in form and substance acceptable to
the Company and substantially in the form attached as Exhibit C hereto and (iii)
that the transferee be an "accredited investor" as defined in Rule 501(a)
promulgated under the Securities Act. Transfer of this Warrant and all rights
hereunder, in whole or in part, shall be registered on the books of the Company
to be maintained for such purpose, upon surrender of this Warrant at the
principal office of the Company referred to in Section 2.1 or the office or
agency designated by the Company pursuant to Section 12, together with a written
assignment of this Warrant substantially in the form of Exhibit B hereto duly
executed by the Holder or its agent or attorney and funds sufficient to pay any
transfer taxes payable upon the making of such transfer. Upon such surrender
and, if required, such payment, the Company shall execute and deliver a new
Warrant or Warrants in the name of the assignee or assignees and in the
denomination specified in such instrument of assignment, and shall issue to the
assignor a new Warrant evidencing the portion of this Warrant not so assigned,
and this Warrant shall promptly be cancelled. Notwithstanding anything herein to
the contrary, this Warrant may not be transferred or assigned in whole or in
part without compliance with applicable federal and state securities laws.
Following a transfer that complies with the requirements of this Section 3.1,
the Warrant may be exercised by a new Holder for the purchase of shares of
Common Stock regardless of whether the Company issued or registered a new
Warrant on the books of the Company.

               3.2. Restrictive Legend. Each certificate for Warrant Stock
initially issued upon the exercise of this Warrant, and each certificate for
Warrant Stock issued to any subsequent transferee of any such certificate, shall
be stamped or otherwise imprinted with a legend in substantially the following
form:

               "THE SECURITIES REPRESENTED BY THIS CERTIFICATE
               HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
               OF 1933 AS AMENDED, AND MAY NOT BE OFFERED, SOLD,
               ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN
               EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT OR
               UNLESS THE COMPANY HAS RECEIVED AN OPINION OF
               COUNSEL REASONABLY SATISFACTORY TO THE COMPANY
               (WHICH SHALL BE IN FORM AND

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               SUBSTANCE REASONABLY SATISFACTORY TO THE COMPANY)
               THAT REGISTRATION UNDER SAID ACT IS NOT REQUIRED."

               "THE SALE, TRANSFER OR ASSIGNMENT OF THE
               SECURITIES REPRESENTED BY THIS CERTIFICATE ARE
               SUBJECT TO THE TERMS AND CONDITIONS OF A CERTAIN
               INVESTOR RIGHTS AGREEMENT DATED AS OF JULY 19,
               2002, AS AMENDED FROM TIME TO TIME, AMONG THE
               COMPANY AND CERTAIN HOLDERS OF ITS OUTSTANDING
               SECURITIES. COPIES OF SUCH AGREEMENT MAY BE
               OBTAINED AT NO COST BY WRITTEN REQUEST MADE BY THE
               HOLDER OF RECORD OF THIS CERTIFICATE TO THE
               SECRETARY OF THE COMPANY."

               3.3. Division and Combination; Expenses; Books. This Warrant may
be divided or combined with other Warrants upon presentation hereof at the
aforesaid office or agency of the Company, together with a written notice
specifying the names and denominations in which new Warrants are to be issued,
signed by the Holder or its agent or attorney. Subject to compliance with
Section 3.1 as to any transfer which may be involved in such division or
combination, the Company shall execute and deliver a new Warrant or Warrants in
exchange for the Warrant or Warrants to be divided or combined in accordance
with such notice. The Company shall prepare, issue and deliver at its own
expense the new Warrant or Warrants under this Section 3. The Company agrees to
maintain, at its aforesaid office or agency, books for the registration and the
registration of transfer of the Warrants.

               4.   Adjustments. The number of shares of Common Stock for which
this Warrant is exercisable, and the price at which such shares may be purchased
upon exercise of this Warrant, shall be subject to adjustment from time to time
as set forth in this Section 4. The Company shall give the Holder notice of any
event described below which requires an adjustment pursuant to this Section 4 in
accordance with Sections 5.1 and 5.2.

               4.1  Stock Dividends, Subdivisions and Combinations. If at any
time while this Warrant is outstanding the Company shall:

                    i.   declare a dividend or make a distribution on its
               outstanding shares of Common Stock in shares of Common Stock,

                    ii.  subdivide its outstanding shares of Common Stock into a
               larger number of shares of Common Stock, or

                    iii. combine its outstanding shares of Common Stock into a
               smaller number of shares of Common Stock,

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then:

                    (1)  the number of shares of Common Stock acquirable upon
                         exercise of this Warrant immediately after the
                         occurrence of any such event shall be adjusted to equal
                         the number of shares of Common Stock which a record
                         holder of the same number of shares of Common Stock
                         that would have been acquirable under this Warrant
                         immediately prior to the record date for such dividend
                         or distribution or the effective date of such
                         subdivision or combination would own or be entitled to
                         receive after such record date or the effective date of
                         such subdivision or combination, as applicable, and

                    (2)  the Warrant Price shall be adjusted to equal:

                         (A)  the Current Warrant Price in effect at the time of
                              the record date for such dividend or distribution
                              or of the effective date of such subdivision or
                              combination, multiplied by the number of shares of
                              Common Stock into which this Warrant is
                              exercisable immediately prior to the adjustment,
                              divided by

                         (B)  the number of shares of Common Stock into which
                              this Warrant is exercisable immediately after such
                              adjustment.

Any adjustment made pursuant to clause (i) of this paragraph shall become
effective immediately after the record date for the determination of
shareholders entitled to receive such dividend or distribution, and any
adjustment pursuant to clauses (ii) or (iii) of this paragraph shall become
effective immediately after the effective date of such subdivision or
combination.

               4.2  Certain Other Distributions. If at any time while this
Warrant is outstanding the Company shall cause the holders of its Common Stock
to be entitled to receive any dividend or other distribution of:

                    i.   cash (other than a cash dividend payable out of
               earnings or earned surplus legally available for the payment of
               dividends under the laws of the jurisdiction of incorporation of
               the Company),

                    ii.  any evidences of its indebtedness, any shares of stock
               of any class or any other securities or property of any nature
               whatsoever (other than cash, convertible securities or additional
               shares of Common Stock), or

                    iii. any warrants or other rights to subscribe for or
               purchase any evidences of its indebtedness, any shares of stock
               of any class or any other

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               securities or property of any nature whatsoever (other than cash,
               convertible securities or additional shares of Common Stock),

then:

                    (1)  the number of shares of Common Stock acquirable upon
                         exercise of this Warrant shall be adjusted to equal the
                         product of the number of shares of Common Stock
                         acquirable upon exercise of this Warrant immediately
                         prior to the record date for such dividend or
                         distribution, multiplied by a fraction (x) the
                         numerator of which shall be the Current Warrant Price
                         per share of Common Stock at the date of taking such
                         record and (y) the denominator of which shall be such
                         Current Warrant Price minus the amount allocable to one
                         share of Common Stock of any such cash so distributable
                         and of the fair value (as determined in good faith by
                         the Board of Directors of the Company) of any and all
                         such evidences of indebtedness, shares of stock, other
                         securities or property or warrants or other
                         subscription or purchase rights so distributable; and

                    (2)  the Current Warrant Price in effect immediately prior
                         to the record date fixed for determination of
                         shareholders entitled to receive such distribution
                         shall be adjusted to equal (x) the Current Warrant
                         Price multiplied by the number of shares of Common
                         Stock acquirable upon exercise of this Warrant
                         immediately prior to the adjustment, divided by (y) the
                         number of shares of Common Stock acquirable upon
                         exercise of this Warrant immediately after such
                         adjustment. A reclassification of the Common Stock
                         (other than a change in par value, or from par value to
                         no par value or from no par value to par value) into
                         shares of Common Stock and shares of any other class of
                         stock shall be deemed a distribution by the Company to
                         the holders of its Common Stock of such shares of such
                         other class of stock within the meaning of this Section
                         4.2 and, if the outstanding shares of Common Stock
                         shall be changed into a larger or smaller number of
                         shares of Common Stock as a part of such
                         reclassification, such change shall be deemed a
                         subdivision or combination, as the case may be, of the
                         outstanding shares of Common Stock within the meaning
                         of this Section 4.2.

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               4.3   Issuance of Additional Shares of Common Stock.

                     i.  If at any time while this Warrant is outstanding the
               Company shall issue or sell any Additional Shares of Common Stock
               in exchange for consideration in an amount per Additional Share
               of Common Stock less than the Current Warrant Price at the time
               the additional shares of Common Stock are issued or sold, then:

                         (A)  the Current Warrant Price immediately prior to
                              such issue or sale shall be reduced to a price
                              determined by dividing

                              (1)  an amount equal to the sum of

                                   (a)   the number of shares of Common Stock
                                   outstanding immediately prior to such issue
                                   or sale multiplied by the then existing
                                   Current Warrant Price, plus

                                   (b)   the consideration, if any, received by
                                   the Company upon such issue or sale, by

                              (2)  the total number of shares of Common Stock
                                   outstanding immediately after such issue or
                                   sale; and

                         (B)  the number of shares of Common Stock acquirable
                              upon exercise of this Warrant shall be adjusted to
                              equal the amount obtained by

                              (1)  multiplying the Current Warrant Price in
                                   effect immediately prior to such issue or
                                   sale by the number of shares of Common Stock
                                   acquirable upon exercise of this Warrant
                                   immediately prior to such issue or sale and

                              (2)  dividing the product thereof by the Current
                                   Warrant Price resulting from the adjustment
                                   made pursuant to clause (A).

                     ii. The provisions of paragraph 4.3(i) shall not apply to
               any issuance of additional shares of Common Stock for which an
               adjustment is provided under Section 4.1 or 4.2. No adjustment of
               the number of shares of Common Stock acquirable upon exercise of
               this Warrant shall be made under paragraph 4.3(i) upon the
               issuance of any additional shares of Common Stock which are
               issued pursuant to the exercise of any warrants or other
               subscription or purchase rights or pursuant to the exercise of
               any conversion or exchange rights in any convertible

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               securities, if any such adjustment shall previously have been
               made upon the issuance of such warrants or other rights or upon
               the issuance of such convertible securities (or upon the issuance
               of any warrant or other rights therefor) pursuant to Section 4.4.

               4.4   Issuance of Common Stock Equivalents. If at any time while
this Warrant is outstanding the Company shall issue or sell any warrants or
other rights to subscribe for or purchase any additional shares of Common Stock
or any securities convertible into shares of Common Stock (other than the
Additional Shares of Common Stock) (collectively, "Common Stock Equivalents"),
whether or not the rights to exchange or convert thereunder are immediately
exercisable, and the effective price per share for which Common Stock is
issuable upon the exercise, exchange or conversion of such Common Stock
Equivalents shall be less than the Current Warrant Price in effect immediately
prior to the time of such issue or sale, then the number of shares of Warrant
Stock acquirable upon the exercise of this Warrant and the Current Warrant Price
shall be adjusted as provided in Section 4.3 on the basis that the maximum
number of additional shares of Common Stock issuable pursuant to all such Common
Stock Equivalents shall be deemed to have been issued and outstanding and the
Company shall have received all of the consideration payable therefor, if any,
as of the date of the actual issuance of such Common Stock Equivalents. No
further adjustments to the current Warrant Price shall be made under this
Section 4.4 upon the actual issue of such Common Stock upon the exercise,
conversion or exchange of such Common Stock Equivalents.

               4.5   Intentionally omitted.

               4.6   Superseding Adjustment.

                    i.   If, at any time after any adjustment of the number of
shares of Common Stock into which this Warrant is exercisable and the Current
Warrant Price shall have been made pursuant to Section 4.4 as the result of any
issuance of Common Stock Equivalents, (x) the right to exercise, convert or
exchange all or a portion of such Common Stock Equivalents shall expire
unexercised, or (y) the conversion rate or consideration per share for which
shares of Common Stock are issuable pursuant to such Common Stock Equivalents
shall be increased solely by virtue of provisions therein contained for an
automatic increase in such conversion rate or consideration per share upon the
occurrence of a specified date or event, then any such previous adjustments to
the Current Warrant Price and the number of shares of Common Stock for which
this Warrant is exercisable shall be rescinded and annulled and the additional
shares of Common Stock which were deemed to have been issued by virtue of the
computation made in connection with the adjustment so rescinded and annulled
shall no longer be deemed to have been issued by virtue of such computation.

                    ii.  Upon the occurrence of an event set forth in Section
4.6(i) above there shall be a recomputation made of the effect of such Common
Stock Equivalents on the basis of: (i) treating the number of additional shares
of Common Stock or other property, if any, theretofore actually issued or
issuable pursuant to the previous exercise, conversion or exchange of such
Common Stock Equivalents, as having been issued on the date or dates of any such
exercise, conversion or exchange and for the consideration actually received and
receivable

                                       12

<PAGE>

therefor, and (ii) treating any such Common Stock Equivalents which then remain
outstanding as having been granted or issued immediately after the time of such
increase of the conversion rate or consideration per share for which shares of
Common Stock or other property are issuable under such Common Stock Equivalents;
whereupon a new adjustment to the number of shares of Common Stock for which
this Warrant is exercisable and the Current Warrant Price shall be made, which
new adjustment shall supersede the previous adjustment so rescinded and
annulled.

               4.7  Other Provisions Applicable to Adjustments. The following
provisions shall be applicable to the making of adjustments of the number of
shares of Common Stock into which this Warrant is exercisable and the Current
Warrant Price provided for in Section 4:

                    a.   Computation of Consideration. To the extent that any
additional shares of Common Stock or any convertible securities or any warrants
or other rights to subscribe for or purchase any additional shares of Common
Stock or any convertible securities shall be issued for cash consideration, the
consideration received by the Company therefor shall be the amount of the cash
received by the Company therefor, or, if such additional shares of Common Stock
or convertible securities are offered by the Company for subscription, the
subscription price, or, if such additional shares of Common Stock or convertible
securities are sold to underwriters or dealers for public offering without a
subscription offering, the initial public offering price (in any such case
subtracting any amounts paid or receivable for accrued interest or accrued
dividends and without taking into account any compensation, discounts or
expenses paid or incurred by the Company for and in the underwriting of, or
otherwise in connection with, the issuance thereof). To the extent that such
issuance shall be for a consideration other than cash, then, except as herein
otherwise expressly provided, the amount of such consideration shall be deemed
to be the fair value of such consideration at the time of such issuance as
determined in good faith by the Board of Directors of the Company. In case any
additional shares of Common Stock or any convertible securities or any warrants
or other rights to subscribe for or purchase such additional shares of Common
Stock or convertible securities shall be issued in connection with any merger in
which the Company issues any securities, the amount of consideration therefor
shall be deemed to be the fair value, as determined in good faith by the Board
of Directors of the Company, of such portion of the assets and business of the
nonsurviving corporation as such Board in good faith shall determine to be
attributable to such additional shares of Common Stock, convertible securities,
warrants or other rights, as the case may be. The consideration for any
additional shares of Common Stock issuable pursuant to any warrants or other
rights to subscribe for or purchase the same shall be the consideration received
by the Company for issuing such warrants or other rights plus the additional
consideration payable to the Company upon exercise of such warrants or other
rights. The consideration for any additional shares of Common Stock issuable
pursuant to the terms of any convertible securities shall be the consideration
received by the Company for issuing warrants or other rights to subscribe for or
purchase such convertible securities, plus the consideration paid or payable to
the Company in respect of the subscription for or purchase of such convertible
securities, plus the additional consideration, if any, payable to the Company
upon the exercise of the right of conversion or exchange in such convertible
securities. In case of the issuance at any time of any additional shares of
Common Stock or convertible securities in payment or satisfaction of any
dividends upon any class of stock other than Common Stock, the Company shall be
deemed to

                                       13

<PAGE>

have received for such additional shares of Common Stock or convertible
securities a consideration equal to the amount of such dividend so paid or
satisfied.

                    b.  When Adjustments to Be Made. The adjustments required by
Section 4 shall be made whenever and as often as any specified event requiring
an adjustment shall occur, except that any that would otherwise be required may
be postponed (except in the case of a subdivision or combination of shares of
the Common Stock, as provided for in Section 4.1) up to, but not beyond the date
of exercise if such adjustment either by itself or with other adjustments not
previously made adds or subtracts less than 1% of the shares of Common Stock
into which this Warrant is exercisable immediately prior to the making of such
adjustment. Any adjustment representing a change of less than such minimum
amount (except as aforesaid) which is postponed shall be carried forward and
made as soon as such adjustment, together with other adjustments required by
this Section 4 and not previously made, would result in a minimum adjustment or
on the date of exercise. For the purpose of any adjustment, any specified event
shall be deemed to have occurred at the close of business on the date of its
occurrence.

                    c.  Fractional Interests. In computing adjustments under
this Section 4, fractional interests in Common Stock shall be taken into account
to the nearest 1/100th of a share.

                    d.  When Adjustment Not Required. If the Company undertakes
a transaction contemplated under this Section 4 and as a result takes a record
of the holders of its Common Stock for the purpose of entitling them to receive
a dividend or distribution or subscription or purchase rights or other benefits
contemplated under this Section 4 and shall, thereafter and before the
distribution to shareholders thereof, legally abandon its plan to pay or deliver
such dividend, distribution, subscription or purchase rights or other benefits
contemplated under this Section 4, then thereafter no adjustment shall be
required by reason of the taking of such record and any such adjustment
previously made in respect thereof shall be rescinded and annulled.

                    e.  Escrow of Stock. If after any property becomes
distributable pursuant to Section 4 by reason of the taking of any record of the
holders of Common Stock, but prior to the occurrence of the event for which such
record is taken, a holder of this Warrant exercises the Warrant during such
time, then such holder shall continue to be entitled to receive any shares of
Common Stock issuable upon exercise hereunder by reason of such adjustment and
such shares or other property shall be held in escrow for the holder of this
Warrant by the Company to be issued to holder of this Warrant upon and to the
extent that the event actually takes place. Notwithstanding any other provision
to the contrary herein, if the event for which such record was taken fails to
occur or is rescinded, then such escrowed shares shall be canceled by the
Company and escrowed property returned to the Company.

               4.8  Reorganization, Reclassification, Merger, Consolidation
or Disposition of Assets.

                    a.  If, during the Exercise Period, the Company authorizes
or approves, enters into any agreement contemplating or solicits shareholder
approval for, any

                                       14

<PAGE>

Change of Control, then any of OrbiMed Advisors LLC, OrbiMed Associates LLC, PW
Juniper Crossover Fund LLC or Caduceus Private Investment L.P. (each, an
"OrbiMed Entity" and collectively, the "OrbiMed Entities") may, at its election,
cause the Expiration Date to be shortened to any date that is prior to the
consummation of the Change of Control, by giving the Holder written notice of
such election no later than 15 days prior to the new Expiration Date specified
in such notice (the "New Expiration Date"). Any Warrants that remain unexercised
as of the New Expiration Date shall be null and void as of 5:00 p.m. EST on the
New Expiration Date; provided however, that the Warrants shall be reinstated on
the same terms as existed immediately prior to such nullification if the Change
of Control transaction is abandoned by the Company. Notwithstanding anything to
the contrary contained herein, the OrbiMed Entities shall have no rights under
this Section 4.8(a) unless they collectively own at least 25% of the Aggregate
Warrants.

                    b.  If, during the Exercise Period, there shall occur a
Change of Control that did not result in an election by an OrbiMed Entity to
force an exercise of the Warrants pursuant to Section 4.8(a) above, and,
pursuant to the terms of such Change of Control, shares of common stock of the
successor or acquiring corporation, or any cash, shares of stock or other
securities or property of any nature whatsoever (including warrants or other
subscription or purchase rights) in addition to or in lieu of common stock of
the successor or acquiring corporation ("Other Property"), are to be received by
or distributed to the holders of Common Stock of the Company, then the Holder of
this Warrant shall have the right thereafter to receive, upon the exercise of
the Warrant, the number of shares of common stock of the successor or acquiring
corporation or of the Company, if it is the surviving corporation, and the Other
Property receivable upon or as a result of such Change of Control by a holder of
the number of shares of Common Stock into which this Warrant is exercisable
immediately prior to such event.

                    c.  In case of any such Change of Control described in
Section 4.8(b) above, unless the Warrants are redeemed pursuant to Section 15.2
hereof, the successor or acquiring corporation (if other than the Company) shall
expressly assume the due and punctual observance and performance of each and
every covenant and condition of contained in this Warrant to be performed and
observed by the Company and all the obligations and liabilities hereunder,
subject to such modifications as may be deemed appropriate (as determined by
resolution of the Board of Directors of the Company) in order to provide for
adjustments of shares of the Common Stock into which this Warrant is exercisable
which shall be as nearly equivalent as practicable to the adjustments provided
for in Section 4. For purposes of Section 4, common stock of the successor or
acquiring corporation shall include stock of such corporation of any class which
is not preferred as to dividends or assets on liquidation over any other class
of stock of such corporation and which is not subject to redemption and shall
also include any evidences of indebtedness, shares of stock or other securities
which are convertible into or exchangeable for any such stock, either
immediately or upon the arrival of a specified date or the happening of a
specified event and any warrants or other rights to subscribe for or purchase
any such stock. The foregoing provisions of this Section 4 shall similarly apply
to successive Change of Control transactions.

               4.9  Other Action Affecting Common Stock. In case at any time or
from time to time the Corporation shall take any action in respect of its Common
Stock, other than the

                                       15

<PAGE>

payment of dividends permitted by Section 4 or any other action described in
Section 4, then, unless such action will not have a materially adverse effect
upon the rights of the holder of this Warrant, the number of shares of Common
Stock or other stock into which this Warrant is exercisable and/or the purchase
price thereof shall be adjusted in such manner as may be equitable in the
circumstances.

               4.10  Certain Limitations. Notwithstanding anything herein to the
contrary, the Company agrees not to enter into any transaction which, by reason
of any adjustment hereunder, would cause the Current Warrant Price to be less
than the par value per share of Common Stock.

               4.11  Stock Transfer Taxes. The issue of stock certificates upon
exercise of this Warrant shall be made without charge to the holder for any tax
in respect of such issue. The Company shall not, however, be required to pay any
tax which may be payable in respect of any transfer involved in the issue and
delivery of shares in any name other than that of the holder of this Warrant,
and the Company shall not be required to issue or deliver any such stock
certificate unless and until the person or persons requesting the issue thereof
shall have paid to the Company the amount of such tax or shall have established
to the satisfaction of the Company that such tax has been paid.

               5.    Notices to Warrant Holders.

               5.1.  Certificate as to Adjustments. Upon the occurrence of each
adjustment or readjustment of the Current Warrant Price, the Company, at its
expense, shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and prepare and furnish to the Holder of this Warrant a
certificate setting forth such adjustment or readjustment and showing in detail
the facts upon which such adjustment or readjustment is based. The Company
shall, upon the written request at any time of the Holder of this Warrant,
furnish or cause to be furnished to such Holder a like certificate setting forth
(i) such adjustments and readjustments, (ii) the Current Warrant Price at the
time in effect and (iii) the number of shares of Common Stock and the amount, if
any, or other property which at the time would be received upon the exercise of
Warrants owned by such Holder.

               5.2.  Notice of Corporate Action. If at any time:

                     (a)  the Company shall take a record of the holders of its
          Common Stock for the purpose of entitling them to receive a dividend
          (other than a cash dividend payable out of earnings or earned surplus
          legally available for the payment of dividends under the laws of the
          jurisdiction of incorporation of the Company) or other distribution,
          or any right to subscribe for or purchase any evidences of its
          indebtedness, any shares of stock of any class or any other securities
          or property, or to receive any other right, or

                     (b)  there shall be any capital reorganization of the
          Company, any reclassification or recapitalization of the capital stock
          of the Company or any consolidation or merger of the Company with, or
          any sale, transfer or other disposition of all or substantially all
          the property, assets or business of the Company to, another
          corporation, or

                                       16

<PAGE>

                     (c)  there shall be a voluntary or involuntary dissolution,
          liquidation or winding up of the Company; then, in any one or more of
          such cases, the Company shall give to the Holder (i) at least 20 days'
          prior written notice of the date on which a record date shall be
          selected for such dividend, distribution or right or for determining
          rights to vote in respect of any such reorganization,
          reclassification, merger, consolidation, sale, transfer, disposition,
          dissolution, liquidation or winding up, and (ii) in the case of any
          such reorganization, reclassification, merger, consolidation, sale,
          transfer, disposition, dissolution, liquidation or winding up, at
          least 20 days' prior written notice of the date when the same shall
          take place. Such notice in accordance with the foregoing clause also
          shall specify (i) the date on which any such record is to be taken for
          the purpose of such dividend, distribution or right, the date on which
          the holders of Common Stock shall be entitled to any such dividend,
          distribution or right, and the amount and character thereof, and (ii)
          the date on which any such reorganization, reclassification, merger,
          consolidation, sale, transfer, disposition, dissolution, liquidation
          or winding up is to take place and the time, if any such time is to be
          fixed, as of which the holders of Common Stock shall be entitled to
          exchange their shares of Common Stock for securities or other property
          deliverable upon such reorganization, reclassification, merger,
          consolidation, sale, transfer, disposition, dissolution, liquidation
          or winding up. Each such written notice shall be sufficiently given if
          addressed to the Holder at the last address of the Holder appearing on
          the books of the Company and delivered in accordance with Section
          16.2.

               5.3.  No Rights as Shareholder. This Warrant does not entitle the
Holder to any voting or other rights as a shareholder of the Company prior to
exercise and payment for the Warrant Price in accordance with the terms hereof.

               6.    No Impairment. The Company shall not by any action,
including, without limitation, amending its articles of incorporation or through
any reorganization, transfer of assets, consolidation, merger, dissolution,
issue or sale of securities or any other voluntary action, avoid or seek to
avoid the observance or performance of any of the terms of this Warrant, but
will at all times in good faith assist in the carrying out of all such terms and
in the taking of all such actions as may be necessary or appropriate to protect
the rights of the Holder against impairment. Without limiting the generality of
the foregoing, the Company will (a) not increase the par value of any shares of
Common Stock receivable upon the exercise of this Warrant above the amount
payable therefor upon such exercise immediately prior to such increase in par
value, (b) take all such action as may be necessary or appropriate in order that
the Company may validly and legally issue fully paid and nonassessable shares of
Common Stock upon the exercise of this Warrant, and (c) use its best efforts to
obtain all such authorizations, exemptions or consents from any public
regulatory body having jurisdiction thereof as may be necessary to enable the
Company to perform its obligations under this Warrant. Upon the request of the
Holder, the Company will at any time during the period this Warrant is
outstanding acknowledge in writing, in form satisfactory to the Holder, the
continuing validity of this Warrant and the obligations of the Company
hereunder.

               7.    Reservation and Authorization of Common Stock: Registration
With Approval of Any Governmental Authority. From and after the Closing Date,
the Company

                                       17

<PAGE>

shall at all times reserve and keep available for issue upon the exercise of
Warrants such number of its authorized but unissued shares of Common Stock as
will be sufficient to permit the exercise in full of all outstanding Warrants.
All shares of Common Stock which shall be so issuable, when issued upon exercise
of any Warrant and payment therefor in accordance with the terms of such
Warrant, shall be duly and validly issued and fully paid and nonassessable, and
not subject to preemptive rights. Before taking any action which would cause an
adjustment reducing the Current Warrant Price below the then par value, if any,
of the shares of Common Stock issuable upon exercise of the Warrants, the
Company shall take any corporate action which may be necessary in order that the
Company may validly and legally issue fully paid and non-assessable shares of
such Common Stock at such adjusted Current Warrant Price. Before taking any
action which would result in an adjustment in the number of shares of Common
Stock for which this Warrant is exercisable or in the Current Warrant Price, the
Company shall obtain all such authorizations or exemptions thereof, or consents
thereto, as may be necessary from any public regulatory body or bodies having
jurisdiction thereof. If any shares of Common Stock required to be reserved for
issuance upon exercise of Warrants require registration or qualification with
any governmental authority under any federal or state law before such shares may
be so issued (other than as a result of a prior or contemplated distribution by
the Holder of this Warrant), the Company will in good faith and as expeditiously
as possible and at its expense endeavor to cause such shares to be duly
registered.

               8.   Taking of Record; Stock and Warrant Transfer Books. In the
case of all dividends or other distributions by the Company to the holders of
its Common Stock with respect to which any provision of Section 4 refers to the
taking of a record of such holders, the Company will in each such case take such
a record and will take such record as of the close of business on a Business
Day. The Company will not at any time, except upon dissolution, liquidation or
winding up of the Company, close its stock transfer books or Warrant transfer
books so as to result in preventing or delaying the exercise or transfer of any
Warrant.

               9.   Registration Rights. The Warrant Stock shall be registered
in accordance with the terms and conditions contained in that certain Investor
Rights Agreement dated of even date hereof, among the Holder, the Company and
the other parties named therein (the "Investor Rights Agreement"). The Holder
acknowledges that pursuant to the Investor Rights Agreement, the Company has the
right to request that the Holder furnish information regarding such Holder and
the distribution of the Warrant Stock as is required by law or the Commission to
be disclosed in the Registration Statement (as such term is defined in the
Investor Rights Agreement), and the Company may exclude from such registration
the shares of Warrant Stock acquirable hereunder if Holder fails to furnish such
information within a reasonable time prior to the filing of each Registration
Statement, supplemented prospectus included therein and/or amended Registration
Statement.

               10.  Supplying Information. Upon any default by the Company of
its obligations hereunder or under the Investor Rights Agreement, the Company
shall cooperate with the Holder in supplying such information as may be
reasonably necessary for such Holder to complete and file any information
reporting forms presently or hereafter required by the Commission as a condition
to the availability of an exemption from the Securities Act for the sale of any
Warrant or Restricted Common Stock.

                                       18

<PAGE>

               11.   Loss or Mutilation. Upon receipt by the Company from the
Holder of evidence reasonably satisfactory to it of the ownership of and the
loss, theft, destruction or mutilation of this Warrant and indemnity or security
reasonably satisfactory to it and reimbursement to the Company of all reasonable
expenses incidental thereto and in case of mutilation upon surrender and
cancellation hereof, the Company will execute and deliver in lieu hereof a new
Warrant of like tenor to the Holder; provided, however, that in the case of
mutilation, no indemnity shall be required if this Warrant in identifiable form
is surrendered to the Company for cancellation.

               12.   Office of the Company. As long as any of the Warrants
remain outstanding, the Company shall maintain an office or agency (which may be
the principal executive offices of the Company) where the Warrants may be
presented for exercise, registration of transfer, division or combination as
provided in this Warrant.

               13.   Financial and Business Information.

               13.1. Quarterly Information. The Company will deliver to the
Holder, as soon as available and in any event within 45 days after the end of
each of the first three quarters of each fiscal year of the Company, one copy of
an unaudited consolidated balance sheet of the Company and its subsidiaries as
at the end of such quarter, and the related unaudited consolidated statements of
income, retained earnings and cash flow of the Company and its subsidiaries for
such quarter and, in the case of the second and third quarters, for the portion
of the fiscal year ending with such quarter, setting forth in each case in
comparative form the figures for the corresponding periods in the previous
fiscal year. Such financial statements shall be prepared by the Company in
accordance with GAAP and accompanied by the certification of the Company's chief
executive officer or chief financial officer that such financial statements
present fairly the consolidated financial position, results of operations and
cash flow of the Company and its subsidiaries as at the end of such quarter and
for such year-to-date period, as the case may be; provided, however, that the
Company shall have no obligation to deliver such quarterly information under
this Section 13.1 to the extent it is publicly available.

               13.2. Annual Information. The Company will deliver to the Holder
as soon as available and in any event within 90 days after the end of each
fiscal year of the Company, one copy of an audited consolidated balance sheet of
the Company and its subsidiaries as at the end of such year, and audited
consolidated statements of income, retained earnings and cash flow of the
Company and its subsidiaries for such year; setting forth in each case in
comparative form the figures for the corresponding periods in the previous
fiscal year; all prepared in accordance with GAAP, and which audited financial
statements shall be accompanied by an opinion thereon of the independent
certified public accountants regularly retained by the Company, or any other
firm of independent certified public accountants of recognized national standing
selected by the Company; provided, however, that the Company shall have no
obligation to deliver such annual information under this Section 13.2 to the
extent it is publicly available.

               13.3. Filings. The Company will file on or before the required
date all regular or periodic reports (pursuant to the Exchange Act) with the
Commission and will deliver to

                                       19

<PAGE>

Holder promptly upon their becoming available one copy of each report, notice or
proxy statement sent by the Company to its shareholders generally.

               14.   Limitation of Liability. No provision hereof, in the
absence of affirmative action by the Holder to purchase shares of Common Stock,
and no enumeration herein of the rights or privileges of the Holder hereof,
shall give rise to any liability of the Holder for the purchase price of any
Common Stock, whether such liability is asserted by the Company or by creditors
of the Company.

               15.   Redemption

               15.1  The Company may at the option of the Board of Directors of
the Company redeem this Warrant, in whole or in part, at any time (a) in lieu of
effecting an adjustment under Section 4.3 hereof, or (b) provided that (i) the
Current Market Price on a particular date is at least 200% of the Current
Warrant Price at such time and (ii) (x) all of the Warrant Stock underlying the
Warrants to be redeemed is then registered under an effective registration
statement in accordance with the terms and conditions of the Investor Rights
Agreement and the Company is in compliance in all material respects with the
Investor Right Agreement or (y) may be sold without restriction pursuant to Rule
144(k) promulgated by the Commission under the Securities Act. The amount
payable in redemption of the rights to purchase the Warrant Stock pursuant to
this Section 15.1 shall be cash equal to $0.10 multiplied by the number of
Warrants being redeemed. If the Current Warrant Price has been adjusted under
Section 4, the redemption price per share shall be adjusted to equal 6.35% of
the Current Warrant Price.

               15.2  The Company may at the option of the Board of Directors of
the Company redeem this Warrant, in whole or in part, upon or after the
consummation by the Company of a Change in Control. The amount payable in
redemption of the rights to purchase the Warrant Stock pursuant to this Section
15.2 shall be cash equal to the value of the rights to purchase such shares of
Warrant Stock calculated using the Black-Scholes Option Pricing Model, using the
following assumptions: (i) that no dividends will be paid on the Warrant Stock
prior to the Expiration Date, (ii) the volatility is equal to 60%, and (iii) the
risk-free interest rate is equal to the rate available for U.S. Government
Treasury Bills with 30 days left until maturity as of the date of the Redemption
Notice. The redemption price payable pursuant to Section 15.1 and 15.2, as
applicable, is referred to herein as the "Redemption Price."

               15.3  The Company shall effect a redemption as follows:

                    i.  The number of warrants subject to redemption (including
the Warrants) shall be allocated pro rata among the holders of all of the
warrants to purchase Common Stock issued by the Company pursuant to the
Preferred Stock Purchase Agreement (collectively, the "Redemption Warrants"),
based upon the number of Redemption Warrants then outstanding that are held by
each such holder.

                    ii. The Company shall pay the Redemption Price in cash for
the Redemption Warrants to be redeemed.

                                       20

<PAGE>

                    iii.  At least 15 but no more than 60 days prior to the date
fixed for any redemption of any Redemption Warrants (the "Redemption Date"),
written notice shall be given to each holder of record of Redemption Warrants to
be redeemed, notifying such holder of the redemption to be effected, specifying
the Redemption Date, the Redemption Price, the place at which payment may be
obtained and calling upon such holder to surrender to the Company, in the manner
and at the place designated, its certificate or certificates representing the
Redemption Warrants to be redeemed (the "Redemption Notice"). Except as provided
in Section 15.2(iv), on or after the Redemption Date, each holder of Redemption
Warrants to be redeemed shall surrender to the Company the certificate or
certificates representing such warrants, in the manner and at the place
designated in the Redemption Notice, and thereupon the Redemption Price therefor
shall be paid to the person whose name appears on such certificate or
certificates as the owner thereof, and upon such payment, each surrendered
certificate shall be canceled. In the event less than all the warrants
represented by any such certificate are redeemed, a new certificate shall be
issued representing the unredeemed warrants.

                    iv.   Three days prior to the Redemption Date, the Company
shall deposit the Redemption Price for all outstanding Redemption Warrants
designated for redemption in the Redemption Notice, and not yet redeemed, with a
bank or trust company having aggregate capital and surplus in excess of
$50,000,000 as a trust fund for the benefit of the respective holders of the
Redemption Warrants designated for redemption and not yet redeemed.
Simultaneously, the Company shall deposit irrevocable instructions and authorize
such bank or trust company to pay, on and after the date fixed for redemption or
prior thereto, the Redemption Price of the Redemption Warrants to the holders
thereof upon surrender of their certificates. The balance of any monies
deposited by the Company pursuant to this paragraph remaining unclaimed at the
expiration of two years following the Redemption Date shall thereafter be
returned to the Company, provided that the holder to which such monies would be
payable hereunder shall be entitled, upon proof of its ownership of the Warrant,
to receive such monies but without interest from the Redemption Date.

               16.   Miscellaneous.

               16.1. Nonwaiver and Expenses. No course of dealing or any delay
or failure to exercise any right hereunder on the part of the Holder shall
operate as a waiver of such right or otherwise prejudice Holder's rights, powers
or remedies. If the Company fails to make, when due, any payments provided for
hereunder, or fails to comply with any other provision of this Warrant, the
Company shall pay to the Holder such amounts as shall be sufficient to cover any
third party costs and expenses including, but not limited to, reasonable
attorneys' fees, including those of appellate proceedings, incurred by the
Holder in collecting any amounts due pursuant hereto or in otherwise enforcing
any of its rights, powers or remedies hereunder.

               16.2. Notice Generally. All notices, requests, demands or other
communications provided for herein shall be in writing and shall be deemed to
have been given the next Business Day after being deposited with a nationally
recognized overnight courier such as Federal Express, or when personally
delivered, or successfully sent by facsimile transmission as evidenced by a fax
machine confirmation report thereof, addressed, as the case may be, to the
Holder at the address on the books and records of the Company, with a copy to
Wollmuth Maher

                                       21

<PAGE>

& Deutsch LLP, 500 Fifth Avenue, New York, New York 10110, Attention: Ellen H.
Clark, Esq., Facsimile No. (212) 382-0050, if to an OrbiMed Entity and with a
copy, if the Holder is not an OrbiMed Entity, to Kane Kessler, P.C., 1350 Avenue
of the Americas, New York, New York 10019, Attention: Robert L. Lawrence, Esq.,
Facsimile No. (212) 245-3009; or to the Company, Orthovita, Inc., at 45 Great
Valley Parkway, Malvern, Pennsylvania 19355, Att'n: Joseph M. Paiva, Chief
Financial Officer, Facsimile no. 610-640-2603; with a copy to Morgan, Lewis &
Bockius LLP, 1701 Market Street, Philadelphia, Pennsylvania 19103, Att'n:
Christine Arasin, Esq., Facsimile no. 215-963-5299, or to such other person or
address as either party shall designate to the other from time to time in
writing forwarded in like manner.

               16.3. Successors and Assigns. Subject to compliance with the
provisions of Section 3.1, this Warrant and the rights evidenced hereby shall
inure to the benefit of and be binding upon the successors of the Company and
the successors and assigns of the Holder. The provisions of this Warrant are
intended to be for the benefit of all Holders from time to time of this Warrant,
and shall be enforceable by any such Holder.

               16.4. Amendment. This Warrant may be modified or amended or the
provisions of this Warrant waived with the written consent of the Company and
the Holder.

               16.5. Severability. Wherever possible, each provision of this
Warrant shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Warrant shall be prohibited by or
invalid under applicable law, such provision shall be modified to the extent of
such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of this Warrant.

               16.6. Headings. The headings used in this Warrant are for the
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant.

               16.7. Governing Law. This Warrant and the transactions
contemplated hereby shall be deemed to be consummated in the State of New York
and shall be governed by and interpreted in accordance with the local laws of
the State of New York without regard to the provisions thereof relating to
conflict of laws. The Company hereby irrevocably consents to the exclusive
jurisdiction of the State and Federal courts located in New York City, New York
in connection with any action or proceeding arising out of or relating to this
Warrant. In any such litigation the Company agrees that the service thereof may
be made by certified or registered mail directed to the Company at its address
set forth in Section 16.2.

                            (Signature Page Follows)

                                       22

<PAGE>

               IN WITNESS WHEREOF, Orthovita, Inc. has caused this Warrant to be
executed by its duly authorized officer and attested by its Secretary.

Dated: ___________________, 2002

                                           ORTHOVITA, INC.

                                           By:______________________________
                                                 Name:
                                                 Title:

Attest:

By:______________________________
   Name:
   Title: Secretary

Agreed and Acknowledged:

[NAME OF HOLDER]

By:______________________________
   Name:
   Title:

                                       23

<PAGE>

                                    EXHIBIT A

                                SUBSCRIPTION FORM

                 [To be executed only upon exercise of Warrant]

The undersigned registered owner of this Warrant exercises this Warrant for the
purchase of shares of Common Stock of Orthovita, Inc., and herewith makes
payment therefor, all at the price and on the terms and conditions specified in
this Warrant and requests that certificates for the shares of Common Stock
hereby purchased (and any securities or other property issuable upon such
exercise) be issued in the name of and delivered to and whose address is . [And,
if such shares of Common Stock shall not include all of the shares of Common
Stock issuable as provided in this Warrant, that a new Warrant of like tenor and
date for the balance of the shares of Common Stock issuable hereunder be
delivered to the undersigned.]

                 (Name of Registered Owner)

                 (Signature of Registered Owner)

                 (Street Address)

                 (State) (Zip Code)

NOTICE:   The signature on this subscription must correspond with the name as
          written upon the face of the Warrant in every particular, without
          alteration or enlargement or any change whatsoever.

<PAGE>

                                    EXHIBIT B

                                 ASSIGNMENT FORM

FOR VALUE RECEIVED the undersigned registered owner of this Warrant for the
purchase of shares of Orthovita, Inc. hereby sells, assigns and transfers unto
the Assignee named below all of the rights of the undersigned under this
Warrant, with respect to the number of shares of common Stock set forth below:

Name and Address of Assignee

No. of Shares of Common Stock

and does hereby irrevocably constitute and appoint ____________ attorney-in-fact
to register such transfer on the books of the Company, maintained for the
purpose, with full power of substitution in the premises.

Dated: Print Name:

Signature:

Witness:

NOTICE: The signature on this assignment must correspond with the name as
written upon the face of the Warrant in every particular, without alteration or
enlargement or any change whatsoever.

<PAGE>

                                    EXHIBIT C
                    FORM OF INVESTMENT REPRESENTATION LETTER

                        Investment Representation Letter

     In connection with the acquisition of [warrants (the "Warrants") to
purchase ____ shares of common stock of Orthovita, Inc. (the "Company"), par
value $.01 per share (the "Common Stock")][___shares of common stock of
Orthovita, Inc. (the "Company"), par value $.01 per share (the "Common Stock")
upon the exercise of warrants by ________], by _______________ (the "Holder")
from _____________, the Holder hereby represents and warrants to the Company as
follows:

     The Holder (i) is an "Accredited Investor" as that term is defined in Rule
501 of Regulation D promulgated under the Securities Act of 1933, as amended
(the "Act"); and (ii) has the ability to bear the economic risks of such
Holder's prospective investment, including a complete loss of Holder's
investment in the Warrants and the shares of Common Stock issuable upon the
exercise thereof (collectively, the "Securities"). The Holder, by acceptance of
the Warrants, represents and warrants to the Company that the Warrants and all
securities acquired upon any and all exercises of the Warrants are purchased for
the Holder's own account for investment, and not with view to distribution of
either the Warrants or any securities purchasable upon exercise thereof.

     The Holder acknowledges that (i) the Securities have not been registered
under the Act, (ii) the Securities are "restricted securities" and the
certificate(s) representing the Securities shall bear the following legend, or a
similar legend to the same effect, until (i) in the case of the shares of Common
Stock underlying the Warrants, such shares shall have been registered for resale
by the Holder under the Act and effectively been disposed of in accordance with
a registration statement that has been declared effective; or (ii) in the
opinion of counsel for the Company such Securities may be sold without
registration under the Act or any applicable "Blue Sky" or state securities
laws:

          "[NEITHER] THE SECURITIES REPRESENTED BY THIS CERTIFICATE
     [NOR THE SECURITIES INTO WHICH THEY ARE EXERCISABLE] HAVE [NOT]
     BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
     "ACT"), AND ALL SUCH SECURITIES ARE SUBJECT TO RESTRICTIONS ON
     TRANSFERABILITY AS SET FORTH IN THIS CERTIFICATE. [NEITHER] THE
     SECURITIES REPRESENTED HEREBY [NOR THE SECURITIES INTO WHICH THEY
     ARE EXERCISABLE] MAY [NOT] BE SOLD, TRANSFERRED, OR OTHERWISE
     DISPOSED OF IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
     UNDER THE ACT OR AN OPINION OF COUNSEL, REASONABLY ACCEPTABLE TO
     COUNSEL FOR THE COMPANY, TO THE EFFECT THAT THE PROPOSED SALE,
     TRANSFER, OR DISPOSITION MAY BE EFFECTUATED WITHOUT REGISTRATION
     UNDER THE ACT."

<PAGE>

     IN WITNESS WHEREOF, the Holder has caused this Investment
Representation Letter to be executed in its corporate name by its duly
authorized officer this __ day of ____ 200_.

                              [Name]

                               By: ______________________________
                                   Name:
                                   Title:<PAGE>

                                                                    Exhibit 10.5

                                                                  WARRANT NO. __

THIS WARRANT AND THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE OFFERED, SOLD,
ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
UNDER SAID ACT OR UNLESS THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
REASONABLY SATISFACTORY TO THE COMPANY (WHICH SHALL BE IN FORM AND SUBSTANCE
REASONABLY SATISFACTORY TO THE COMPANY) THAT REGISTRATION UNDER SAID ACT IS NOT
REQUIRED.

                                SERIES A WARRANT

              To Purchase [____________] Shares of Common Stock of

                                 ORTHOVITA, INC.

                  THIS IS TO CERTIFY THAT [_______________], or registered
assigns (the "Holder"), is entitled, at any time prior to the Expiration Date
(as hereinafter defined), to purchase from Orthovita, Inc. a Pennsylvania
corporation (the "Company"), the Warrant Stock (as hereinafter defined and
subject to adjustment as provided herein), in whole or in part, at a purchase
price of $1.706 per share, all on and subject to the terms and conditions
hereinafter set forth.

                  1.       Definitions. As used in this Warrant, the following
terms have the respective meanings set forth below:

                  "Additional Shares of Common Stock" means any shares of Common
Stock issued by the Company after the Closing Date other than: (i) Warrant
Stock; (ii) shares issued or issuable pursuant to anti-dilution provisions of
the Series A Convertible Preferred Stock; (iii) shares issued or issuable upon
the conversion of the Series A Convertible Preferred Stock; (iv) shares issued
or issuable as payment(s) of dividends to holders of Series A Convertible
Preferred Stock, (v) shares issued or issuable upon the exercise of any warrants
or options outstanding as of the Closing Date, (vi) Common Stock, stock awards
or options under, or the exercise of any options granted pursuant to, any
currently authorized plan for the issuance of options or capital stock of the
Company including, without limitation, stock purchase plans or (vii) shares
issuable upon the exercise of any warrants that are issuable pursuant to the
terms of the Preferred Stock Purchase Agreement.

                  "Affiliate" means any person or entity that, directly or
indirectly through one or more intermediaries, controls or is controlled by or
is under common control with a person or entity, as such terms are used in and
construed under Rule 144 under the Securities Act. With

<PAGE>

respect to a Holder of Warrants, any investment fund or managed account that is
managed on a discretionary basis by the same investment manager as such holder
will be deemed to be an Affiliate of such Holder.

                  "Aggregate Warrants" means this Warrant together with all
other warrants issued by the Company pursuant to the Preferred Stock Purchase
Agreement.

                  "Appraised Value" means, in respect of any share of Common
Stock on any date herein specified, the fair saleable value of such share of
Common Stock (determined without giving effect to the discount for (i) a
minority interest or (ii) any lack of liquidity of the Common Stock or to the
fact that the Company may have no class of equity registered under the Exchange
Act) as of the last day of the most recent fiscal month ending prior to such
date specified, based on the value of the Company on a fully-diluted basis, as
determined by a nationally recognized investment banking firm selected by the
Company's Board of Directors and having no prior relationship with the Company.

                  "Business Day" means any day that is not a Saturday or Sunday
or a day on which banks are required or permitted to be closed in the
Commonwealth of Pennsylvania.

                  "Change of Control" means the (i) acquisition by an individual
or legal entity or group (as defined in Rule 13-d of the Exchange Act) of more
than one-half of the voting rights or equity interests in the Company; or (ii)
sale, conveyance, or other disposition of all or substantially all of the
assets, property or business of the Company or the merger into or consolidation
with any other corporation (other than a wholly owned subsidiary corporation) or
effectuation of any transaction or series of related transactions where holders
of the Company's voting securities prior to such transaction or series of
transactions fail to continue to hold at least 50% of the voting power of the
Company.

                  "Closing Date" means July __, 2002.

                  "Commission" means the Securities and Exchange Commission or
any other federal agency then administering the Securities Act and other federal
securities laws.

                  "Common Stock" means (except where the context otherwise
indicates) the Common Stock, $0.01 par value per share, of the Company as
constituted on the Closing Date, and any capital stock into which such Common
Stock may thereafter be changed or converted, and shall also include (i) capital
stock of the Company of any other class (regardless of how denominated) issued
to the holders of shares of Common Stock upon any reclassification thereof which
is also not preferred as to dividends or assets on liquidation over any other
class of stock of the Company and which is not subject to redemption and (ii)
shares of common stock of any successor or acquiring corporation received by or
distributed to the holders of Common Stock of the Company in the circumstances
contemplated by Section 4.8.

                   "Current Market Price" means, in respect of any share of
Common Stock on any date herein specified, if there shall not then be a public
market for the Common Stock, the higher of (a) the book value per share of
Common Stock on such date and (b) the Appraised Value per

                                       2

<PAGE>

share of Common Stock at such date, or if there shall then be a public market
for the Common Stock, the higher of (a) the book value per share of Common Stock
on such date, and (b) the average of the daily market prices for 20 consecutive
Trading Days immediately preceding such date. The daily market price for each
such Trading Day shall be (i) the last sale price on such day on the principal
stock exchange on which such Common Stock is then listed or admitted to trading,
(ii) if no sale takes place on such day on any such exchange, the average of the
last reported closing bid and asked prices on such day as officially quoted on
any such exchange, (iii) if the Common Stock is not then listed or admitted to
trading on any stock exchange, the average of the last reported closing bid and
asked prices on such day in the over-the-counter market, as furnished by the
National Association of Securities Dealers Automatic Quotation System or the
National Quotation Bureau, Inc., (iv) if neither such corporation at the time is
engaged in the business of reporting such prices, as furnished by any similar
firm then engaged in such business, or (v) if there is no such firm, as
furnished by any member of the NASD selected mutually by the holder of this
Warrant and the Company or, if they cannot agree upon such selection, as
selected by two such members of the NASD, one of which shall be selected by
holder of this Warrant and one of which shall be selected by the Company.

                  "Current Warrant Price" means, in respect of a share of Common
Stock at any date herein specified, the price at which a share of Common Stock
may be purchased pursuant to this Warrant on such date. Until the Current
Warrant Price is adjusted pursuant to the terms herein, the initial Current
Warrant Price shall be $1.706 per share.

                  "Exchange Act" means the Securities Exchange Act of 1934, as
amended, or any similar federal statute, and the rules and regulations of the
Commission thereunder, all as the same shall be in effect from time to time.

                  "Exercise Period" means the period during which this Warrant
is exercisable pursuant to Section 2.1.

                  "Expiration Date" means July __, 2007 or such earlier date to
which the Expiration Date has been shortened pursuant to the terms of Section
4.8(a) hereof.

                  "GAAP" means generally accepted accounting principles in the
United States of America as from time to time in effect.

                  "NASD" means the National Association of Securities Dealers,
Inc., or any successor corporation thereto.

                  "Other Property" has the meaning set forth in Section 4.8.

                   "Person" means any individual, sole proprietorship,
partnership, joint venture, trust, incorporated organization, association,
corporation, limited liability company, institution, public benefit corporation,
entity or government (whether federal, state, county, city, municipal or
otherwise, including, without limitation, any instrumentality, division, agency,
body or department thereof).

                                       3

<PAGE>

                  "Preferred Stock Purchase Agreement" means that certain
Preferred Stock and Warrant Purchase Agreement dated as of July 19, 2002 among
the Company and the other parties named therein.

                  "Restricted Common Stock" means shares of Common Stock which
are, or which upon their issuance upon the exercise of any Warrant would be
required to be, evidenced by a certificate bearing the restrictive legend set
forth in Section 3.2.

                  "Securities Act" means the Securities Act of 1933, as amended,
or any similar federal statute, and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

                  "Series A Convertible Preferred Stock" shall mean the
Company's Series A 6% Cumulative Convertible Voting Preferred Stock, par value
$0.01 per share.

                  "Trading Day" means any day on which the primary market on
which shares of Common Stock are listed is open for trading.

                  "Transfer" means any disposition of any Warrant or Warrant
Stock or of any interest in either thereof, which would constitute a sale
thereof within the meaning of the Securities Act.

                  "Warrants" means this Warrant and all warrants issued upon
transfer, division or combination of, or in substitution for, any thereof. All
Warrants shall at all times be identical as to terms and conditions and date,
except as to the number of shares of Common Stock for which they may be
exercised.

                  "Warrant Price" means an amount equal to (i) the number of
shares of Common Stock being purchased upon exercise of this Warrant pursuant to
Section 2.1, multiplied by (ii) the Current Warrant Price.

                  "Warrant Stock" means the [_____________] shares of Common
Stock to be purchased upon the exercise hereof, subject to adjustment as
provided herein.

                  2.       Exercise Of Warrant.

                  2.1.     Manner of Exercise.  From and after the Closing Date,
and until 5:00 P.M., New York time, on the Expiration Date (the "Exercise
Period"), the Holder may exercise this Warrant, on any Business Day, for all or
any part of the number of shares of Warrant Stock purchasable hereunder.

                  In order to exercise this Warrant, in whole or in part, the
Holder shall deliver to the Company at its principal office or at the office or
agency designated by the Company pursuant to Section 12, (i) a written notice of
Holder's election to exercise this Warrant, which notice shall specify the
number of shares of Warrant Stock to be purchased, (ii) payment of the Warrant
Price as provided herein, and (iii) this Warrant. Such notice shall be
substantially in the

                                       4

<PAGE>

form of the subscription form appearing at the end of this Warrant as Exhibit A,
duly executed by the Holder or its agent or attorney. Upon receipt thereof, the
Company shall, as promptly as practicable, and in any event within five Business
Days thereafter, execute or cause to be executed and deliver or cause to be
delivered to the Holder a certificate or certificates representing the aggregate
number of full shares of Warrant Stock issuable upon such exercise, together
with cash in lieu of any fraction of a share, as hereinafter provided. The stock
certificate or certificates so delivered shall be, to the extent possible, in
such denomination or denominations as the Holder shall request in the notice and
shall be registered in the name of the Holder or such other name as shall be
designated in the notice. This Warrant shall be deemed to have been exercised
and such certificate or certificates shall be deemed to have been issued, and
the Holder or any other Person so designated to be named therein shall be deemed
to have become a Holder of record of such shares for all purposes, as of the
date when the notice, together with the payment of the Warrant Price and this
Warrant, is received by the Company as described above. If this Warrant shall
have been exercised in part, the Company shall, at the time of delivery of the
certificate or certificates representing Warrant Stock, deliver to the Holder a
new Warrant evidencing the rights of the Holder to purchase the unpurchased
shares of Common Stock called for by this Warrant, which new Warrant shall in
all other respects be identical with this Warrant, or at the request of the
Holder, appropriate notation may be made on this Warrant and the same returned
to the Holder.

                       Payment of the Warrant Price may be made at the option of
the Holder by: (i) certified or official bank check payable to the order of the
Company, (ii) wire transfer to the account of the Company or (iii) commencing
one year following the Closing Date, the surrender and cancellation of a portion
of shares of Common Stock then held by the Holder or issuable upon such exercise
of this Warrant, which shall be valued and credited toward the total Warrant
Price due the Company for the exercise of the Warrant based upon the Current
Market Price of the Common Stock. All shares of Common Stock issuable upon the
exercise of this Warrant pursuant to the terms hereof shall be validly issued
and, upon payment of the Warrant Price, shall be fully paid and nonassessable
and not subject to any preemptive rights.

                  2.2. Fractional Shares. The Company shall not be required to
issue a fractional share of Common Stock upon exercise of any Warrant. As to any
fraction of a share which the Holder of one or more Warrants, the rights under
which are exercised in the same transaction, would otherwise be entitled to
purchase upon such exercise, the Company shall pay an amount in cash equal to
the Current Market Price per share of Common Stock on the date of exercise
multiplied by such fraction.

                  2.3. Continued Validity. A Holder of shares of Common Stock
issued upon the exercise of this Warrant, in whole or in part (other than a
Holder who acquires such shares after the same have been publicly sold pursuant
to a Registration Statement under the Securities Act or sold pursuant to Rule
144 thereunder), shall continue to be entitled with respect to such shares to
all rights to which it would have been entitled as the Holder under Sections 10
and 13 of this Warrant.

                  2.4. Restrictions on Exercise Amount.

                                       5

<PAGE>

                    (i)   Except as provided otherwise in Section 2.4(ii),
     unless a Holder delivers to the Company irrevocable written notice that
     this Section 2.4(i) shall not apply to such Holder, the Holder may not
     acquire a number of shares of Warrant Stock to the extent that, upon such
     exercise, the number of shares of Common Stock then beneficially owned by
     such holder and its Affiliates and any other persons or entities whose
     beneficial ownership of Common Stock would be aggregated with the Holder's
     for purposes of Section 13(d) of the Exchange Act (including shares held by
     any "group" of which the holder is a member) exceeds 4.95% of the total
     number of shares of Common Stock of the Company then issued and
     outstanding. For purposes hereof, "group" has the meaning set forth in
     Section 13(d) of the Exchange Act and applicable regulations of the
     Securities and Exchange Commission, and the percentage held by the holder
     shall be determined in a manner consistent with the provisions of Section
     13(d) of the Exchange Act. Each delivery of a notice of exercise by a
     Holder will constitute a representation by such Holder that it has
     evaluated the limitation set forth in this paragraph and determined, based
     on the most recent public filings by the Company with the Commission, that
     the issuance of the full number of shares of Warrant Stock requested in
     such notice of exercise is permitted under this paragraph.

                    (ii)  The provisions of Section 2.4(i) shall not apply if an
     OrbiMed Entity forces an exercise of the Warrants pursuant to Section
     4.8(a) below.

                    (iii) Notwithstanding any contrary or inconsistent provision
     hereof, if the Company is prohibited by Rule 4350(i) of the National
     Association of Securities Dealers, Inc. (the "NASD"), or any successor or
     similar rule, or the rules or regulations of any other securities exchange
     on which the Common Stock is then listed or traded, from issuing a number
     of shares of Common Stock upon exercise of this Warrant (together with any
     shares of Common Stock, or securities convertible into or exercisable for
     Common Stock, issued or issuable pursuant to the Preferred Stock and
     Warrant Purchase Agreement (the "Preferred Stock Purchase Agreement") dated
     as the Closing Date among the Company, the Holder and the other parties
     thereto, or other agreements entered into in connection therewith,
     including, without limitation, shares of Common Stock issued or issuable as
     payment of dividends on the Series A Convertible Preferred Stock) in excess
     of a prescribed amount (the "Issuance Cap Amount"), then the Company shall
     not issue shares upon exercise of this Warrant in excess of the Issuance
     Cap Amount. Assuming solely for purposes of this Section 2.4(ii) that such
     Rule 4350(i) or similar rule is applicable, the Issuance Cap Amount shall
     be 4,003,904 shares.

                          In the event the Company is prohibited from issuing
     shares of Common Stock as a result of the operation of this Section
     2.4(iii), the Company shall seek the approval of its shareholders to
     authorize the issuance of the full number of shares of Common Stock which
     would be issuable upon the exercise of the then outstanding Warrants but
     for the Issuance Cap Amount to eliminate any prohibitions under applicable
     law or the rules or regulations of any stock exchange, interdealer
     quotation system or other self-regulatory organization with jurisdiction
     over the Company or any of its securities on the Company's ability to issue
     shares of Common Stock in excess of the Issuance Cap Amount.

                                       6

<PAGE>

               3.   Transfer, Division and Combination.

               3.1. Transfer. The Warrants and the Warrant Stock shall be freely
transferable, subject to compliance with all applicable laws, including, but not
limited to the Securities Act; provided, however, that a Holder must obtain the
prior written consent of the Company in order to transfer Warrants representing
the right to purchase less than 100,000 shares of Warrant Stock. If, at the time
of the surrender of this Warrant in connection with any transfer of this Warrant
or the Warrant Stock, this Warrant or the Warrant Stock, as applicable, shall
not be registered under the Securities Act and under applicable state securities
or blue sky laws, the Company may require, as a condition of allowing such
transfer that the Holder or transferee of this Warrant or the Warrant Stock as
the case may be, furnish to the Company a written opinion of counsel that is
reasonably acceptable to the Company to the effect that such transfer may be
made without registration under the Securities Act and under applicable state
securities or blue sky laws, (ii) that the Holder or transferee execute and
deliver to the Company an investment letter in form and substance acceptable to
the Company and substantially in the form attached as Exhibit C hereto and (iii)
that the transferee be an "accredited investor" as defined in Rule 501(a)
promulgated under the Securities Act. Transfer of this Warrant and all rights
hereunder, in whole or in part, shall be registered on the books of the Company
to be maintained for such purpose, upon surrender of this Warrant at the
principal office of the Company referred to in Section 2.1 or the office or
agency designated by the Company pursuant to Section 12, together with a written
assignment of this Warrant substantially in the form of Exhibit B hereto duly
executed by the Holder or its agent or attorney and funds sufficient to pay any
transfer taxes payable upon the making of such transfer. Upon such surrender
and, if required, such payment, the Company shall execute and deliver a new
Warrant or Warrants in the name of the assignee or assignees and in the
denomination specified in such instrument of assignment, and shall issue to the
assignor a new Warrant evidencing the portion of this Warrant not so assigned,
and this Warrant shall promptly be cancelled. Notwithstanding anything herein to
the contrary, this Warrant may not be transferred or assigned in whole or in
part without compliance with applicable federal and state securities laws.
Following a transfer that complies with the requirements of this Section 3.1,
the Warrant may be exercised by a new Holder for the purchase of shares of
Common Stock regardless of whether the Company issued or registered a new
Warrant on the books of the Company.

               3.2. Restrictive Legend. Each certificate for Warrant Stock
initially issued upon the exercise of this Warrant, and each certificate for
Warrant Stock issued to any subsequent transferee of any such certificate, shall
be stamped or otherwise imprinted with a legend in substantially the following
form:

               THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT
               BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AS
               AMENDED, AND MAY NOT BE OFFERED, SOLD, ASSIGNED OR
               TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE
               REGISTRATION STATEMENT UNDER SAID ACT OR UNLESS THE
               COMPANY HAS RECEIVED AN OPINION OF COUNSEL REASONABLY
               SATISFACTORY TO THE COMPANY (WHICH SHALL BE IN FORM AND

                                       7

<PAGE>

               SUBSTANCE REASONABLY SATISFACTORY TO THE COMPANY) THAT
               REGISTRATION UNDER SAID ACT IS NOT REQUIRED."

               "THE SALE, TRANSFER OR ASSIGNMENT OF THE SECURITIES
               REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE
               TERMS AND CONDITIONS OF A CERTAIN INVESTOR RIGHTS
               AGREEMENT DATED AS OF JULY 19, 2002, AS AMENDED FROM
               TIME TO TIME, AMONG THE COMPANY AND CERTAIN HOLDERS OF
               ITS OUTSTANDING SECURITIES. COPIES OF SUCH AGREEMENT
               MAY BE OBTAINED AT NO COST BY WRITTEN REQUEST MADE BY
               THE HOLDER OF RECORD OF THIS CERTIFICATE TO THE
               SECRETARY OF THE COMPANY."

               3.3. Division and Combination; Expenses; Books. This Warrant may
be divided or combined with other Warrants upon presentation hereof at the
aforesaid office or agency of the Company, together with a written notice
specifying the names and denominations in which new Warrants are to be issued,
signed by the Holder or its agent or attorney. Subject to compliance with
Section 3.1 as to any transfer which may be involved in such division or
combination, the Company shall execute and deliver a new Warrant or Warrants in
exchange for the Warrant or Warrants to be divided or combined in accordance
with such notice. The Company shall prepare, issue and deliver at its own
expense the new Warrant or Warrants under this Section 3. The Company agrees to
maintain, at its aforesaid office or agency, books for the registration and the
registration of transfer of the Warrants.

               4.   Adjustments. The number of shares of Common Stock for which
this Warrant is exercisable, and the price at which such shares may be purchased
upon exercise of this Warrant, shall be subject to adjustment from time to time
as set forth in this Section 4. The Company shall give the Holder notice of any
event described below which requires an adjustment pursuant to this Section 4 in
accordance with Sections 5.1 and 5.2.

               4.1  Stock Dividends, Subdivisions and Combinations. If at any
time while this Warrant is outstanding the Company shall:

                    i.   declare a dividend or make a distribution on its
               outstanding shares of Common Stock in shares of Common Stock,

                    ii.  subdivide its outstanding shares of Common Stock into a
               larger number of shares of Common Stock, or

                    iii. combine its outstanding shares of Common Stock into a
               smaller number of shares of Common Stock,

                                       8

<PAGE>

then:

                    (1)   the number of shares of Common Stock acquirable upon
                          exercise of this Warrant immediately after the
                          occurrence of any such event shall be adjusted to
                          equal the number of shares of Common Stock which a
                          record holder of the same number of shares of Common
                          Stock that would have been acquirable under this
                          Warrant immediately prior to the record date for such
                          dividend or distribution or the effective date of such
                          subdivision or combination would own or be entitled to
                          receive after such record date or the effective date
                          of such subdivision or combination, as applicable, and

                    (2)   the Warrant Price shall be adjusted to equal:

                          (A)  the Current Warrant Price in effect at the time
                               of the record date for such dividend or
                               distribution or of the effective date of such
                               subdivision or combination, multiplied by the
                               number of shares of Common Stock into which this
                               Warrant is exercisable immediately prior to the
                               adjustment, divided by

                          (B)  the number of shares of Common Stock into which
                               this Warrant is exercisable immediately after
                               such adjustment.

Any adjustment made pursuant to clause (i) of this paragraph shall become
effective immediately after the record date for the determination of
shareholders entitled to receive such dividend or distribution, and any
adjustment pursuant to clauses (ii) or (iii) of this paragraph shall become
effective immediately after the effective date of such subdivision or
combination.

               4.2  Certain Other Distributions. If at any time while this
Warrant is outstanding the Company shall cause the holders of its Common Stock
to be entitled to receive any dividend or other distribution of:

                    i.   cash (other than a cash dividend payable out of
               earnings or earned surplus legally available for the payment of
               dividends under the laws of the jurisdiction of incorporation of
               the Company),

                    ii.  any evidences of its indebtedness, any shares of stock
               of any class or any other securities or property of any nature
               whatsoever (other than cash, convertible securities or additional
               shares of Common Stock), or

                    iii. any warrants or other rights to subscribe for or
               purchase any evidences of its indebtedness, any shares of stock
               of any class or any other

                                       9

<PAGE>

               securities or property of any nature whatsoever (other than cash,
               convertible securities or additional shares of Common Stock),

then:

                          (1)   the number of shares of Common Stock
                                acquirable upon exercise of this Warrant shall
                                be adjusted to equal the product of the number
                                of shares of Common Stock acquirable upon
                                exercise of this Warrant immediately prior to
                                the record date for such dividend or
                                distribution, multiplied by a fraction (x) the
                                numerator of which shall be the Current Warrant
                                Price per share of Common Stock at the date of
                                taking such record and (y) the denominator of
                                which shall be such Current Warrant Price minus
                                the amount allocable to one share of Common
                                Stock of any such cash so distributable and of
                                the fair value (as determined in good faith by
                                the Board of Directors of the Company) of any
                                and all such evidences of indebtedness, shares
                                of stock, other securities or property or
                                warrants or other subscription or purchase
                                rights so distributable; and

                          (2)   the Current Warrant Price in effect immediately
                                prior to the record date fixed for determination
                                of shareholders entitled to receive such
                                distribution shall be adjusted to equal (x) the
                                Current Warrant Price multiplied by the number
                                of shares of Common Stock acquirable upon
                                exercise of this Warrant immediately prior to
                                the adjustment, divided by (y) the number of
                                shares of Common Stock acquirable upon exercise
                                of this Warrant immediately after such
                                adjustment. A reclassification of the Common
                                Stock (other than a change in par value, or from
                                par value to no par value or from no par value
                                to par value) into shares of Common Stock and
                                shares of any other class of stock shall be
                                deemed a distribution by the Company to the
                                holders of its Common Stock of such shares of
                                such other class of stock within the meaning of
                                this Section 4.2 and, if the outstanding shares
                                of Common Stock shall be changed into a larger
                                or smaller number of shares of Common Stock as a
                                part of such reclassification, such change shall
                                be deemed a subdivision or combination, as the
                                case may be, of the outstanding shares of Common
                                Stock within the meaning of this Section 4.2.

               4.3  Intentionally omitted.

               4.4  Intentionally omitted.

                                       10

<PAGE>

               4.5 Intentionally omitted.

               4.6 Intentionally omitted.

               4.7 Other Provisions Applicable to Adjustments. The following
provisions shall be applicable to the making of adjustments of the number of
shares of Common Stock into which this Warrant is exercisable and the Current
Warrant Price provided for in Section 4:

                   a.  Computation of Consideration. To the extent that any
additional shares of Common Stock or any convertible securities or any warrants
or other rights to subscribe for or purchase any additional shares of Common
Stock or any convertible securities shall be issued for cash consideration, the
consideration received by the Company therefor shall be the amount of the cash
received by the Company therefor, or, if such additional shares of Common Stock
or convertible securities are offered by the Company for subscription, the
subscription price, or, if such additional shares of Common Stock or convertible
securities are sold to underwriters or dealers for public offering without a
subscription offering, the initial public offering price (in any such case
subtracting any amounts paid or receivable for accrued interest or accrued
dividends and without taking into account any compensation, discounts or
expenses paid or incurred by the Company for and in the underwriting of, or
otherwise in connection with, the issuance thereof). To the extent that such
issuance shall be for a consideration other than cash, then, except as herein
otherwise expressly provided, the amount of such consideration shall be deemed
to be the fair value of such consideration at the time of such issuance as
determined in good faith by the Board of Directors of the Company. In case any
additional shares of Common Stock or any convertible securities or any warrants
or other rights to subscribe for or purchase such additional shares of Common
Stock or convertible securities shall be issued in connection with any merger in
which the Company issues any securities, the amount of consideration therefor
shall be deemed to be the fair value, as determined in good faith by the Board
of Directors of the Company, of such portion of the assets and business of the
nonsurviving corporation as such Board in good faith shall determine to be
attributable to such additional shares of Common Stock, convertible securities,
warrants or other rights, as the case may be. The consideration for any
additional shares of Common Stock issuable pursuant to any warrants or other
rights to subscribe for or purchase the same shall be the consideration received
by the Company for issuing such warrants or other rights plus the additional
consideration payable to the Company upon exercise of such warrants or other
rights. The consideration for any additional shares of Common Stock issuable
pursuant to the terms of any convertible securities shall be the consideration
received by the Company for issuing warrants or other rights to subscribe for or
purchase such convertible securities, plus the consideration paid or payable to
the Company in respect of the subscription for or purchase of such convertible
securities, plus the additional consideration, if any, payable to the Company
upon the exercise of the right of conversion or exchange in such convertible
securities. In case of the issuance at any time of any additional shares of
Common Stock or convertible securities in payment or satisfaction of any
dividends upon any class of stock other than Common Stock, the Company shall be
deemed to have received for such additional shares of Common Stock or
convertible securities a consideration equal to the amount of such dividend so
paid or satisfied.

                                       11

<PAGE>

                    b.  When Adjustments to Be Made. The adjustments required by
Section 4 shall be made whenever and as often as any specified event requiring
an adjustment shall occur, except that any that would otherwise be required may
be postponed (except in the case of a subdivision or combination of shares of
the Common Stock, as provided for in Section 4.1) up to, but not beyond the date
of exercise if such adjustment either by itself or with other adjustments not
previously made adds or subtracts less than 1% of the shares of Common Stock
into which this Warrant is exercisable immediately prior to the making of such
adjustment. Any adjustment representing a change of less than such minimum
amount (except as aforesaid) which is postponed shall be carried forward and
made as soon as such adjustment, together with other adjustments required by
this Section 4 and not previously made, would result in a minimum adjustment or
on the date of exercise. For the purpose of any adjustment, any specified event
shall be deemed to have occurred at the close of business on the date of its
occurrence.

                    c.  Fractional Interests. In computing adjustments under
this Section 4, fractional interests in Common Stock shall be taken into account
to the nearest 1/100th of a share.

                    d.  When Adjustment Not Required. If the Company undertakes
a transaction contemplated under this Section 4 and as a result takes a record
of the holders of its Common Stock for the purpose of entitling them to receive
a dividend or distribution or subscription or purchase rights or other benefits
contemplated under this Section 4 and shall, thereafter and before the
distribution to shareholders thereof, legally abandon its plan to pay or deliver
such dividend, distribution, subscription or purchase rights or other benefits
contemplated under this Section 4, then thereafter no adjustment shall be
required by reason of the taking of such record and any such adjustment
previously made in respect thereof shall be rescinded and annulled.

                    e.  Escrow of Stock. If after any property becomes
distributable pursuant to Section 4 by reason of the taking of any record of the
holders of Common Stock, but prior to the occurrence of the event for which such
record is taken, a holder of this Warrant exercises the Warrant during such
time, then such holder shall continue to be entitled to receive any shares of
Common Stock issuable upon exercise hereunder by reason of such adjustment and
such shares or other property shall be held in escrow for the holder of this
Warrant by the Company to be issued to holder of this Warrant upon and to the
extent that the event actually takes place. Notwithstanding any other provision
to the contrary herein, if the event for which such record was taken fails to
occur or is rescinded, then such escrowed shares shall be canceled by the
Company and escrowed property returned to the Company.

               4.8  Reorganization, Reclassification, Merger, Consolidation or
Disposition of Assets.

                    a.  If, during the Exercise Period, the Company authorizes
or approves, enters into any agreement contemplating or solicits shareholder
approval for, any Change of Control, then any of OrbiMed Advisors LLC, OrbiMed
Associates LLC, PW Juniper Crossover Fund LLC or Caduceus Private Investment
L.P. (each, an "OrbiMed Entity" and

                                       12

<PAGE>

collectively, the "OrbiMed Entities") may, at its election, cause the Expiration
Date to be shortened to any date that is prior to the consummation of the Change
of Control, by giving the Holder written notice of such election no later than
15 days prior to the new Expiration Date specified in such notice (the "New
Expiration Date"). Any Warrants that remain unexercised as of the New Expiration
Date shall be null and void as of 5:00 p.m. EST on the New Expiration Date;
provided however, that the Warrants shall be reinstated on the same terms as
existed immediately prior to such nullification if the Change of Control
transaction is abandoned by the Company. Notwithstanding anything to the
contrary contained herein, the OrbiMed Entities shall have no rights under this
Section 4.8(a) unless they collectively own at least 25% of the Aggregate
Warrants.

                    b.  If, during the Exercise Period, there shall occur a
Change of Control that did not result in an election by an OrbiMed Entity to
force an exercise of the Warrants pursuant to Section 4.8(a) above, and,
pursuant to the terms of such Change of Control, shares of common stock of the
successor or acquiring corporation, or any cash, shares of stock or other
securities or property of any nature whatsoever (including warrants or other
subscription or purchase rights) in addition to or in lieu of common stock of
the successor or acquiring corporation ("Other Property"), are to be received by
or distributed to the holders of Common Stock of the Company, then the Holder of
this Warrant shall have the right thereafter to receive, upon the exercise of
the Warrant, the number of shares of common stock of the successor or acquiring
corporation or of the Company, if it is the surviving corporation, and the Other
Property receivable upon or as a result of such Change of Control by a holder of
the number of shares of Common Stock into which this Warrant is exercisable
immediately prior to such event.

                    c.  In case of any such Change of Control described in
Section 4.8(b) above, unless the Warrants are redeemed pursuant to Section 15.2
hereof, the successor or acquiring corporation (if other than the Company) shall
expressly assume the due and punctual observance and performance of each and
every covenant and condition of contained in this Warrant to be performed and
observed by the Company and all the obligations and liabilities hereunder,
subject to such modifications as may be deemed appropriate (as determined by
resolution of the Board of Directors of the Company) in order to provide for
adjustments of shares of the Common Stock into which this Warrant is exercisable
which shall be as nearly equivalent as practicable to the adjustments provided
for in Section 4. For purposes of Section 4, common stock of the successor or
acquiring corporation shall include stock of such corporation of any class which
is not preferred as to dividends or assets on liquidation over any other class
of stock of such corporation and which is not subject to redemption and shall
also include any evidences of indebtedness, shares of stock or other securities
which are convertible into or exchangeable for any such stock, either
immediately or upon the arrival of a specified date or the happening of a
specified event and any warrants or other rights to subscribe for or purchase
any such stock. The foregoing provisions of this Section 4 shall similarly apply
to successive Change of Control transactions.

               4.9  Other Action Affecting Common Stock. In case at any time or
from time to time the Corporation shall take any action in respect of its Common
Stock, other than the payment of dividends permitted by Section 4 or any other
action described in Section 4, then, unless such action will not have a
materially adverse effect upon the rights of the holder of this

                                       13

<PAGE>

Warrant, the number of shares of Common Stock or other stock into which this
Warrant is exercisable and/or the purchase price thereof shall be adjusted in
such manner as may be equitable in the circumstances.

               4.10 Certain Limitations. Notwithstanding anything herein to the
contrary, the Company agrees not to enter into any transaction which, by reason
of any adjustment hereunder, would cause the Current Warrant Price to be less
than the par value per share of Common Stock.

               4.11 Stock Transfer Taxes. The issue of stock certificates upon
exercise of this Warrant shall be made without charge to the holder for any tax
in respect of such issue. The Company shall not, however, be required to pay any
tax which may be payable in respect of any transfer involved in the issue and
delivery of shares in any name other than that of the holder of this Warrant,
and the Company shall not be required to issue or deliver any such stock
certificate unless and until the person or persons requesting the issue thereof
shall have paid to the Company the amount of such tax or shall have established
to the satisfaction of the Company that such tax has been paid.

               5.   Notices to Warrant Holders.

               5.1. Certificate as to Adjustments. Upon the occurrence of each
adjustment or readjustment of the Current Warrant Price, the Company, at its
expense, shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and prepare and furnish to the Holder of this Warrant a
certificate setting forth such adjustment or readjustment and showing in detail
the facts upon which such adjustment or readjustment is based. The Company
shall, upon the written request at any time of the Holder of this Warrant,
furnish or cause to be furnished to such Holder a like certificate setting forth
(i) such adjustments and readjustments, (ii) the Current Warrant Price at the
time in effect and (iii) the number of shares of Common Stock and the amount, if
any, or other property which at the time would be received upon the exercise of
Warrants owned by such Holder.

               5.2. Notice of Corporate Action. If at any time:

                    (a) the Company shall take a record of the holders of its
     Common Stock for the purpose of entitling them to receive a dividend (other
     than a cash dividend payable out of earnings or earned surplus legally
     available for the payment of dividends under the laws of the jurisdiction
     of incorporation of the Company) or other distribution, or any right to
     subscribe for or purchase any evidences of its indebtedness, any shares of
     stock of any class or any other securities or property, or to receive any
     other right, or

                    (b) there shall be any capital reorganization of the
     Company, any reclassification or recapitalization of the capital stock of
     the Company or any consolidation or merger of the Company with, or any
     sale, transfer or other disposition of all or substantially all the
     property, assets or business of the Company to, another corporation, or

                                       14

<PAGE>

                    (c) there shall be a voluntary or involuntary dissolution,
     liquidation or winding up of the Company; then, in any one or more of such
     cases, the Company shall give to the Holder (i) at least 20 days' prior
     written notice of the date on which a record date shall be selected for
     such dividend, distribution or right or for determining rights to vote in
     respect of any such reorganization, reclassification, merger,
     consolidation, sale, transfer, disposition, dissolution, liquidation or
     winding up, and (ii) in the case of any such reorganization,
     reclassification, merger, consolidation, sale, transfer, disposition,
     dissolution, liquidation or winding up, at least 20 days' prior written
     notice of the date when the same shall take place. Such notice in
     accordance with the foregoing clause also shall specify (i) the date on
     which any such record is to be taken for the purpose of such dividend,
     distribution or right, the date on which the holders of Common Stock shall
     be entitled to any such dividend, distribution or right, and the amount and
     character thereof, and (ii) the date on which any such reorganization,
     reclassification, merger, consolidation, sale, transfer, disposition,
     dissolution, liquidation or winding up is to take place and the time, if
     any such time is to be fixed, as of which the holders of Common Stock shall
     be entitled to exchange their shares of Common Stock for securities or
     other property deliverable upon such reorganization, reclassification,
     merger, consolidation, sale, transfer, disposition, dissolution,
     liquidation or winding up. Each such written notice shall be sufficiently
     given if addressed to the Holder at the last address of the Holder
     appearing on the books of the Company and delivered in accordance with
     Section 16.2.

               5.3. No Rights as Shareholder. This Warrant does not entitle the
Holder to any voting or other rights as a shareholder of the Company prior to
exercise and payment for the Warrant Price in accordance with the terms hereof.

               6.   No Impairment. The Company shall not by any action,
including, without limitation, amending its articles of incorporation or through
any reorganization, transfer of assets, consolidation, merger, dissolution,
issue or sale of securities or any other voluntary action, avoid or seek to
avoid the observance or performance of any of the terms of this Warrant, but
will at all times in good faith assist in the carrying out of all such terms and
in the taking of all such actions as may be necessary or appropriate to protect
the rights of the Holder against impairment. Without limiting the generality of
the foregoing, the Company will (a) not increase the par value of any shares of
Common Stock receivable upon the exercise of this Warrant above the amount
payable therefor upon such exercise immediately prior to such increase in par
value, (b) take all such action as may be necessary or appropriate in order that
the Company may validly and legally issue fully paid and nonassessable shares of
Common Stock upon the exercise of this Warrant, and (c) use its best efforts to
obtain all such authorizations, exemptions or consents from any public
regulatory body having jurisdiction thereof as may be necessary to enable the
Company to perform its obligations under this Warrant. Upon the request of the
Holder, the Company will at any time during the period this Warrant is
outstanding acknowledge in writing, in form satisfactory to the Holder, the
continuing validity of this Warrant and the obligations of the Company
hereunder.

               7.   Reservation and Authorization of Common Stock: Registration
With Approval of Any Governmental Authority. From and after the Closing Date,
the Company shall at all times reserve and keep available for issue upon the
exercise of Warrants such number

                                       15

<PAGE>

of its authorized but unissued shares of Common Stock as will be sufficient to
permit the exercise in full of all outstanding Warrants. All shares of Common
Stock which shall be so issuable, when issued upon exercise of any Warrant and
payment therefor in accordance with the terms of such Warrant, shall be duly and
validly issued and fully paid and nonassessable, and not subject to preemptive
rights. Before taking any action which would cause an adjustment reducing the
Current Warrant Price below the then par value, if any, of the shares of Common
Stock issuable upon exercise of the Warrants, the Company shall take any
corporate action which may be necessary in order that the Company may validly
and legally issue fully paid and non-assessable shares of such Common Stock at
such adjusted Current Warrant Price. Before taking any action which would result
in an adjustment in the number of shares of Common Stock for which this Warrant
is exercisable or in the Current Warrant Price, the Company shall obtain all
such authorizations or exemptions thereof, or consents thereto, as may be
necessary from any public regulatory body or bodies having jurisdiction thereof.
If any shares of Common Stock required to be reserved for issuance upon exercise
of Warrants require registration or qualification with any governmental
authority under any federal or state law before such shares may be so issued
(other than as a result of a prior or contemplated distribution by the Holder of
this Warrant), the Company will in good faith and as expeditiously as possible
and at its expense endeavor to cause such shares to be duly registered.

                  8.  Taking of Record; Stock and Warrant Transfer Books. In the
case of all dividends or other distributions by the Company to the holders of
its Common Stock with respect to which any provision of Section 4 refers to the
taking of a record of such holders, the Company will in each such case take such
a record and will take such record as of the close of business on a Business
Day. The Company will not at any time, except upon dissolution, liquidation or
winding up of the Company, close its stock transfer books or Warrant transfer
books so as to result in preventing or delaying the exercise or transfer of any
Warrant.

                  9.  Registration Rights. The Warrant Stock shall be registered
in accordance with the terms and conditions contained in that certain Investor
Rights Agreement dated of even date hereof, among the Holder, the Company and
the other parties named therein (the "Investor Rights Agreement"). The Holder
acknowledges that pursuant to the Investor Rights Agreement, the Company has the
right to request that the Holder furnish information regarding such Holder and
the distribution of the Warrant Stock as is required by law or the Commission to
be disclosed in the Registration Statement (as such term is defined in the
Investor Rights Agreement), and the Company may exclude from such registration
the shares of Warrant Stock acquirable hereunder if Holder fails to furnish such
information within a reasonable time prior to the filing of each Registration
Statement, supplemented prospectus included therein and/or amended Registration
Statement.

                  10. Supplying Information. Upon any default by the Company of
its obligations hereunder or under the Investor Rights Agreement, the Company
shall cooperate with the Holder in supplying such information as may be
reasonably necessary for such Holder to complete and file any information
reporting forms presently or hereafter required by the Commission as a condition
to the availability of an exemption from the Securities Act for the sale of any
Warrant or Restricted Common Stock.

                                       16

<PAGE>

                  11.   Loss or Mutilation. Upon receipt by the Company from the
Holder of evidence reasonably satisfactory to it of the ownership of and the
loss, theft, destruction or mutilation of this Warrant and indemnity or security
reasonably satisfactory to it and reimbursement to the Company of all reasonable
expenses incidental thereto and in case of mutilation upon surrender and
cancellation hereof, the Company will execute and deliver in lieu hereof a new
Warrant of like tenor to the Holder; provided, however, that in the case of
mutilation, no indemnity shall be required if this Warrant in identifiable form
is surrendered to the Company for cancellation.

                  12.   Office of the Company. As long as any of the Warrants
remain outstanding, the Company shall maintain an office or agency (which may be
the principal executive offices of the Company) where the Warrants may be
presented for exercise, registration of transfer, division or combination as
provided in this Warrant.

                  13.   Financial and Business Information.

                  13.1. Quarterly Information. The Company will deliver to the
Holder, as soon as available and in any event within 45 days after the end of
each of the first three quarters of each fiscal year of the Company, one copy of
an unaudited consolidated balance sheet of the Company and its subsidiaries as
at the end of such quarter, and the related unaudited consolidated statements of
income, retained earnings and cash flow of the Company and its subsidiaries for
such quarter and, in the case of the second and third quarters, for the portion
of the fiscal year ending with such quarter, setting forth in each case in
comparative form the figures for the corresponding periods in the previous
fiscal year. Such financial statements shall be prepared by the Company in
accordance with GAAP and accompanied by the certification of the Company's chief
executive officer or chief financial officer that such financial statements
present fairly the consolidated financial position, results of operations and
cash flow of the Company and its subsidiaries as at the end of such quarter and
for such year-to-date period, as the case may be; provided, however, that the
Company shall have no obligation to deliver such quarterly information under
this Section 13.1 to the extent it is publicly available.

                  13.2. Annual Information. The Company will deliver to the
Holder as soon as available and in any event within 90 days after the end of
each fiscal year of the Company, one copy of an audited consolidated balance
sheet of the Company and its subsidiaries as at the end of such year, and
audited consolidated statements of income, retained earnings and cash flow of
the Company and its subsidiaries for such year; setting forth in each case in
comparative form the figures for the corresponding periods in the previous
fiscal year; all prepared in accordance with GAAP, and which audited financial
statements shall be accompanied by an opinion thereon of the independent
certified public accountants regularly retained by the Company, or any other
firm of independent certified public accountants of recognized national standing
selected by the Company; provided, however, that the Company shall have no
obligation to deliver such annual information under this Section 13.2 to the
extent it is publicly available.

                  13.3. Filings. The Company will file on or before the required
date all regular or periodic reports (pursuant to the Exchange Act) with the
Commission and will deliver to

                                       17

<PAGE>

Holder promptly upon their becoming available one copy of each report, notice or
proxy statement sent by the Company to its shareholders generally.

                  14.   Limitation of Liability. No provision hereof, in the
absence of affirmative action by the Holder to purchase shares of Common Stock,
and no enumeration herein of the rights or privileges of the Holder hereof,
shall give rise to any liability of the Holder for the purchase price of any
Common Stock, whether such liability is asserted by the Company or by creditors
of the Company.

                  15.   Redemption

                  15.1  The Company may at the option of the Board of Directors
of the Company redeem this Warrant, in whole or in part, at any time, provided
that (i) the Current Market Price on a particular date is at least 200% of the
Current Warrant Price at such time and (ii) (x) all of the Warrant Stock
underlying the Warrants to be redeemed is then registered under an effective
registration statement in accordance with the terms and conditions of the
Investor Rights Agreement and the Company is in compliance in all material
respects with the Investor Right Agreement or (y) may be sold without
restriction pursuant to Rule 144(k) promulgated by the Commission under the
Securities Act. The amount payable in redemption of the rights to purchase the
Warrant Stock pursuant to this Section 15.1 shall be cash equal to $0.10
multiplied by the number of Warrants being redeemed. If the Current Warrant
Price has been adjusted under Section 4, the redemption price per share shall be
adjusted to equal 5.86% of the Current Warrant Price.

                  15.2  The Company may at the option of the Board of Directors
of the Company redeem this Warrant, in whole or in part, upon or after the
consummation by the Company of a Change in Control. The amount payable in
redemption of the rights to purchase the Warrant Stock pursuant to this Section
15.2 shall be cash equal to the value of the rights to purchase such shares of
Warrant Stock calculated using the Black-Scholes Option Pricing Model, using the
following assumptions: (i) that no dividends will be paid on the Warrant Stock
prior to the Expiration Date, (ii) the volatility is equal to 60%, and (iii) the
risk-free interest rate is equal to the rate available for U.S. Government
Treasury Bills with 30 days left until maturity as of the date of the Redemption
Notice. The redemption price payable pursuant to Section 15.1 and 15.2, as
applicable, is referred to herein as the "Redemption Price."

                  15.3  The Company shall effect a redemption as follows:

                        i.  The number of warrants  subject to redemption
(including the Warrants) shall be allocated pro rata among the holders of all of
the warrants to purchase Common Stock issued by the Company pursuant to the
Preferred Stock Purchase Agreement (collectively, the "Redemption Warrants"),
based upon the number of Redemption Warrants then outstanding that are held by
each such holder.

                        ii. The Company shall pay the Redemption Price in cash
for the Redemption Warrants to be redeemed.

                                       18

<PAGE>

                        iii.  At least 15 but no more than 60 days  prior to the
date fixed for any redemption of any Redemption Warrants (the "Redemption
Date"), written notice shall be given to each holder of record of Redemption
Warrants to be redeemed, notifying such holder of the redemption to be effected,
specifying the Redemption Date, the Redemption Price, the place at which payment
may be obtained and calling upon such holder to surrender to the Company, in the
manner and at the place designated, its certificate or certificates representing
the Redemption Warrants to be redeemed (the "Redemption Notice"). Except as
provided in Section 15.2(iv), on or after the Redemption Date, each holder of
Redemption Warrants to be redeemed shall surrender to the Company the
certificate or certificates representing such warrants, in the manner and at the
place designated in the Redemption Notice, and thereupon the Redemption Price
therefor shall be paid to the person whose name appears on such certificate or
certificates as the owner thereof, and upon such payment, each surrendered
certificate shall be canceled. In the event less than all the warrants
represented by any such certificate are redeemed, a new certificate shall be
issued representing the unredeemed warrants.

                        iv.   Three days prior to the Redemption  Date, the
Company shall deposit the Redemption Price for all outstanding Redemption
Warrants designated for redemption in the Redemption Notice, and not yet
redeemed, with a bank or trust company having aggregate capital and surplus in
excess of $50,000,000 as a trust fund for the benefit of the respective holders
of the Redemption Warrants designated for redemption and not yet redeemed.
Simultaneously, the Company shall deposit irrevocable instructions and authorize
such bank or trust company to pay, on and after the date fixed for redemption or
prior thereto, the Redemption Price of the Redemption Warrants to the holders
thereof upon surrender of their certificates. The balance of any monies
deposited by the Company pursuant to this paragraph remaining unclaimed at the
expiration of two years following the Redemption Date shall thereafter be
returned to the Company, provided that the holder to which such monies would be
payable hereunder shall be entitled, upon proof of its ownership of the Warrant,
to receive such monies but without interest from the Redemption Date.

                  16.   Miscellaneous.

                  16.1. Nonwaiver and Expenses. No course of dealing or any
delay or failure to exercise any right hereunder on the part of the Holder shall
operate as a waiver of such right or otherwise prejudice Holder's rights, powers
or remedies. If the Company fails to make, when due, any payments provided for
hereunder, or fails to comply with any other provision of this Warrant, the
Company shall pay to the Holder such amounts as shall be sufficient to cover any
third party costs and expenses including, but not limited to, reasonable
attorneys' fees, including those of appellate proceedings, incurred by the
Holder in collecting any amounts due pursuant hereto or in otherwise enforcing
any of its rights, powers or remedies hereunder.

                  16.2. Notice Generally. All notices, requests, demands or
other communications provided for herein shall be in writing and shall be deemed
to have been given the next Business Day after being deposited with a nationally
recognized overnight courier such as Federal Express, or when personally
delivered, or successfully sent by facsimile transmission as evidenced by a fax
machine confirmation report thereof, addressed, as the case may be, to the
Holder at the address on the books and records of the Company, with a copy to
Wollmuth Maher

                                       19

<PAGE>

& Deutsch LLP, 500 Fifth Avenue, New York, New York 10110, Attention: Ellen H.
Clark, Esq., Facsimile No. (212) 382-0050, if to an OrbiMed Entity and with a
copy, if the Holder is not an OrbiMed Entity, to Kane Kessler, P.C., 1350 Avenue
of the Americas, New York, New York 10019, Attention: Robert L. Lawrence, Esq.,
Facsimile No. (212) 245-3009; or to the Company, Orthovita, Inc., at 45 Great
Valley Parkway, Malvern, Pennsylvania 19355, Att'n: Joseph M. Paiva, Chief
Financial Officer, Facsimile no. 610-640-2603; with a copy to Morgan, Lewis &
Bockius LLP, 1701 Market Street, Philadelphia, Pennsylvania 19103, Att'n:
Christine Arasin, Esq., Facsimile no. 215-963-5299, or to such other person or
address as either party shall designate to the other from time to time in
writing forwarded in like manner.

                  16.3. Successors and Assigns. Subject to compliance with the
provisions of Section 3.1, this Warrant and the rights evidenced hereby shall
inure to the benefit of and be binding upon the successors of the Company and
the successors and assigns of the Holder. The provisions of this Warrant are
intended to be for the benefit of all Holders from time to time of this Warrant,
and shall be enforceable by any such Holder.

                  16.4. Amendment. This Warrant may be modified or amended or
the provisions of this Warrant waived with the written consent of the Company
and the Holder.

                  16.5. Severability. Wherever possible, each provision of this
Warrant shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Warrant shall be prohibited by or
invalid under applicable law, such provision shall be modified to the extent of
such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of this Warrant.

                  16.6. Headings. The headings used in this Warrant are for the
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant

                  16.7. Governing Law. This Warrant and the transactions
contemplated hereby shall be deemed to be consummated in the State of New York
and shall be governed by and interpreted in accordance with the local laws of
the State of New York without regard to the provisions thereof relating to
conflict of laws. The Company hereby irrevocably consents to the exclusive
jurisdiction of the State and Federal courts located in New York City, New York
in connection with any action or proceeding arising out of or relating to this
Warrant. In any such litigation the Company agrees that the service thereof may
be made by certified or registered mail directed to the Company at its address
set forth in Section 16.2.

                            (Signature Page Follows)

                                       20

<PAGE>

                  IN WITNESS WHEREOF, Orthovita, Inc. has caused this Warrant to
be executed by its duly authorized officer and attested by its Secretary.

Dated: ___________________, 2002

                                               ORTHOVITA, INC.

                                               By:______________________________
                                                         Name:
                                                         Title:
Attest:

By:______________________________
   Name:
   Title: Secretary

Agreed and Acknowledged:

[NAME OF HOLDER]

By:______________________________
   Name:
   Title:

<PAGE>

                                    EXHIBIT A

                                SUBSCRIPTION FORM

                 [To be executed only upon exercise of Warrant]

The undersigned registered owner of this Warrant exercises this Warrant for the
purchase of shares of Common Stock of Orthovita, Inc., and herewith makes
payment therefor, all at the price and on the terms and conditions specified in
this Warrant and requests that certificates for the shares of Common Stock
hereby purchased (and any securities or other property issuable upon such
exercise) be issued in the name of and delivered to and whose address is . [And,
if such shares of Common Stock shall not include all of the shares of Common
Stock issuable as provided in this Warrant, that a new Warrant of like tenor and
date for the balance of the shares of Common Stock issuable hereunder be
delivered to the undersigned.]

                           (Name of Registered Owner)

                           (Signature of Registered Owner)

                           (Street Address)

                           (State) (Zip Code)

NOTICE: The signature on this subscription must correspond with the name as
        written upon the face of the Warrant in every particular, without
        alteration or enlargement or any change whatsoever.

<PAGE>

                                    EXHIBIT B

                                 ASSIGNMENT FORM

FOR VALUE RECEIVED the undersigned registered owner of this Warrant for the
purchase of shares of Orthovita, Inc. hereby sells, assigns and transfers unto
the Assignee named below all of the rights of the undersigned under this
Warrant, with respect to the number of shares of common Stock set forth below:

Name and Address of Assignee

No. of Shares of Common Stock

and does hereby irrevocably constitute and appoint _______________
attorney-in-fact to register such transfer on the books of the Company,
maintained for the purpose, with full power of substitution in the premises.

Dated: Print Name:

Signature:

Witness:

NOTICE: The signature on this assignment must correspond with the name as
written upon the face of the Warrant in every particular, without alteration or
enlargement or any change whatsoever.

<PAGE>

                                    EXHIBIT C
                    FORM OF INVESTMENT REPRESENTATION LETTER

                        Investment Representation Letter

         In connection with the acquisition of [warrants (the "Warrants") to
purchase ____ shares of common stock of Orthovita, Inc. (the "Company"), par
value $.01 per share (the "Common Stock")][___shares of common stock of
Orthovita, Inc. (the "Company"), par value $.01 per share (the "Common Stock")
upon the exercise of warrants by ________], by _______________ (the "Holder")
from _____________, the Holder hereby represents and warrants to the Company as
follows:

         The Holder (i) is an "Accredited Investor" as that term is defined in
Rule 501 of Regulation D promulgated under the Securities Act of 1933, as
amended (the "Act"); and (ii) has the ability to bear the economic risks of such
Holder's prospective investment, including a complete loss of Holder's
investment in the Warrants and the shares of Common Stock issuable upon the
exercise thereof (collectively, the "Securities"). The Holder, by acceptance of
the Warrants, represents and warrants to the Company that the Warrants and all
securities acquired upon any and all exercises of the Warrants are purchased for
the Holder's own account for investment, and not with view to distribution of
either the Warrants or any securities purchasable upon exercise thereof.

         The Holder acknowledges that (i) the Securities have not been
registered under the Act, (ii) the Securities are "restricted securities" and
the certificate(s) representing the Securities shall bear the following legend,
or a similar legend to the same effect, until (i) in the case of the shares of
Common Stock underlying the Warrants, such shares shall have been registered for
resale by the Holder under the Act and effectively been disposed of in
accordance with a registration statement that has been declared effective; or
(ii) in the opinion of counsel for the Company such Securities may be sold
without registration under the Act or any applicable "Blue Sky" or state
securities laws:

                  "[NEITHER] THE SECURITIES REPRESENTED BY THIS CERTIFICATE [NOR
         THE SECURITIES INTO WHICH THEY ARE EXERCISABLE] HAVE [NOT] BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"),
         AND ALL SUCH SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY
         AS SET FORTH IN THIS CERTIFICATE. [NEITHER] THE SECURITIES REPRESENTED
         HEREBY [NOR THE SECURITIES INTO WHICH THEY ARE EXERCISABLE] MAY [NOT]
         BE SOLD, TRANSFERRED, OR OTHERWISE DISPOSED OF IN THE ABSENCE OF AN
         EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR AN OPINION OF
         COUNSEL, REASONABLY ACCEPTABLE TO COUNSEL FOR THE COMPANY, TO THE
         EFFECT THAT THE PROPOSED SALE, TRANSFER, OR DISPOSITION MAY BE
         EFFECTUATED WITHOUT REGISTRATION UNDER THE ACT."

<PAGE>

         IN WITNESS WHEREOF, the Holder has caused this Investment
Representation Letter to be executed in its corporate name by its duly
authorized officer this __ day of ____ 200_.

                                             [Name]

                                              By: ______________________________
                                                  Name:
                                                  Title:

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