REGISTRATION
        RIGHTS AGREEMENT

       

      This
        Registration Rights Agreement (this “Agreement”)
        is
        made and entered into as of October 14, 2005, among Gentium S.p.A., an Italian
        corporation (the “Company”),
        and
        the purchasers signatory hereto (each such purchaser is a “Purchaser”
        and
        collectively, the “Purchasers”).

       

      This
        Agreement is made pursuant to the Securities Subscription Agreement, dated
        as of
        October 2, 2005, among the Company and the Purchasers (the “Purchase
        Agreement”).

       

      The
        Company and the Purchasers hereby agree as follows:

       

      1.  Definitions.
        Capitalized terms used and not otherwise defined herein that are defined
        in the
        Purchase Agreement shall have the meanings given such terms in the Purchase
        Agreement. As used in this Agreement, the following terms shall have the
        following meanings:

       

      “ADSs”
        means
        American Depository Shares, each a security representing one share of Common
        Stock deposited with The Bank of New York pursuant to the terms of the Deposit
        Agreement, issued by The Bank of New York pursuant to the terms of the Deposit
        Agreement.

       

      “Advice”
        shall
        have the meaning set forth in Section 6(d).

       

      “Effectiveness
        Date”
        means,
        with respect to the initial Registration Statement required to be filed
        hereunder, the 120th
        calendar
        day following the date hereof (the 150th
        calendar
        day in the case of a “full review” by the Commission) and, with respect to any
        additional Registration Statements which may be required pursuant to Section
        3(c) that the Company must file on Form F-1, the 120th
        calendar
        day following the date on which the Company first knows, or reasonably should
        have known, that such additional Registration Statement is required hereunder,
        and, with respect to any additional Registration Statements which may be
        required pursuant to Section 3(c) that the Company is eligible to file on
        Form
        F-3, the 90th
        calendar
        day following the date on which the Company first knows, or reasonably should
        have known, that such additional Registration Statement is required hereunder;
        provided,
        however,
        in the
        event the Company is notified by the Commission that one of the above
        Registration Statements will not be reviewed or is no longer subject to further
        review and comments, the Effectiveness Date as to such Registration Statement
        shall be the fifth Trading Day following the date on which the Company is
        so
        notified if such date precedes the dates required above.

       

      “Effectiveness
        Period”
        shall
        have the meaning set forth in Section 2(a).

       

      “Event”
        shall
        have the meaning set forth in Section 2(b).

       

      “Event
        Date”
        shall
        have the meaning set forth in Section 2(b).

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      

      “Filing
        Date”
        means,
        with respect to the initial Registration Statement required hereunder, the
        90th
        calendar
        day following the date hereof, with respect to any additional Registration
        Statements which may be required pursuant to Section 3(c) that the Company
        must
        file on Form F-1, the 90th
        day
        following the date on which the Company first knows, or reasonably should
        have
        known that such additional Registration Statement is required hereunder,
        and
        with respect to any additional Registration Statements which may be required
        pursuant to Section 3(c) that the Company is eligible to file on Form F-3,
        the
        30th
        day
        following the date on which the Company first knows, or reasonably should
        have
        known that such additional Registration Statement is required
        hereunder.

       

      “Holder”
        or
“Holders”
        means
        the holder or holders, as the case may be, from time to time of Registrable
        Securities.

       

      “Indemnified
        Party”
        shall
        have the meaning set forth in Section 5(c).

       

      “Indemnifying
        Party”
        shall
        have the meaning set forth in Section 5(c).

       

      “Losses”
        shall
        have the meaning set forth in Section 5(a).

       

      “Plan
        of Distribution”
        shall
        have the meaning set forth in Section 2(a). 

       

      “Proceeding”
        means
        an action, claim, suit, investigation or proceeding (including, without
        limitation, an investigation or partial proceeding, such as a deposition),
        whether commenced or threatened.

       

      “Prospectus”
        means
        the prospectus included in a Registration Statement (including, without
        limitation, a prospectus that includes any information previously omitted
        from a
        prospectus filed as part of an effective registration statement in reliance
        upon
        Rule 430A promulgated under the Securities Act), as amended or supplemented
        by
        any prospectus supplement, with respect to the terms of the offering of any
        portion of the Registrable Securities covered by a Registration Statement,
        and
        all other amendments and supplements to the Prospectus, including post-effective
        amendments, and all material incorporated by reference or deemed to be
        incorporated by reference in such Prospectus.

       

      “Registrable
        Securities”
        means
        all of (i) the Shares issuable pursuant to the Securities Subscription
        Agreement, (ii) the Warrant Shares issuable upon the exercise of the Warrants,
        (iii) ADSs representing shares of Common Stock issued or issuable upon any
        stock
        split, dividend or other distribution, recapitalization or similar event
        with
        respect to the foregoing and (iv) the 93,068 shares issuable to the placement
        agent pursuant to the exercise of the warrant issuable to such placement
        agent.


       

      “Registration
        Statement”
        means
        the registration statements required to be filed hereunder and any additional
        registration statements contemplated by Section 3(c), including (in each
        case)
        the Prospectus, amendments and supplements to such registration statement
        or
        Prospectus, including pre- and post-effective amendments, all exhibits thereto,
        and all material incorporated by reference or deemed to be incorporated by
        reference in such registration statement.

       

      
        
           

        

        
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      “Rule
        415”
        means
        Rule 415 promulgated by the Commission pursuant to the Securities Act, as
        such
        Rule may be amended from time to time, or any similar rule or regulation
        hereafter adopted by the Commission having substantially the same purpose
        and
        effect as such Rule.

       

      “Rule
        424”
        means
        Rule 424 promulgated by the Commission pursuant to the Securities Act, as
        such
        Rule may be amended from time to time, or any similar rule or regulation
        hereafter adopted by the Commission having substantially the same purpose
        and
        effect as such Rule.

       

      “Selling
        Shareholder Questionnaire”
        shall
        have the meaning set forth in Section 3(a).

       

      2.    
Shelf
        Registration.

       

      (a)  On
        or
        prior to each Filing Date, the Company shall prepare and file with the
        Commission a Registration Statement covering the resale of 130% of the
        Registrable Securities (including the ADSs) on such Filing Date for an offering
        to be made on a continuous basis pursuant to Rule 415. The initial Registration
        Statement shall be on Form F-1, and any subsequent Registration Statements
        shall
        be on Form F-3 (except if the Company is not then eligible to register for
        resale the Registrable Securities on Form F-3, in which case such registration
        shall be on another appropriate form in accordance herewith) and shall contain
        (unless otherwise directed by the Holders) substantially the “Plan
        of Distribution”
        attached hereto as Annex
        A.
        Subject
        to the terms of this Agreement, the Company shall use its best efforts to
        cause
        a Registration Statement to be declared effective under the Securities Act
        as
        promptly as possible after the filing thereof, but in any event prior to
        the
        applicable Effectiveness Date, and shall use its best efforts to keep such
        Registration Statement continuously effective under the Securities Act until
        all
        Registrable Securities covered by such Registration Statement have been sold
        or
        may be sold without volume restrictions pursuant to Rule 144(k) as determined
        by
        the counsel to the Company pursuant to a written opinion letter to such effect,
        addressed and acceptable to the Company’s transfer agent and the affected
        Holders (the “Effectiveness
        Period”).
        The
        Company shall telephonically request effectiveness of a Registration Statement
        as of 10:00 AM Eastern Time on the Effectiveness Date which shall be a Trading
        Day. The Company shall immediately notify the Holders via facsimile or
        electronic mail of the effectiveness of a Registration Statement on the same
        Trading Day that the Company telephonically confirms effectiveness with the
        Commission, which shall be the date requested for effectiveness of a
        Registration Statement. The Company shall, by 9:30 AM Eastern Time on the
        Trading Day after the Effective Date (as defined in the Purchase Agreement),
        file a Form 424(b)(5) with the Commission. Failure to so notify the Holder
        within 1 Trading Day of such notification shall be deemed an Event under
        Section
        2(b).

       

      
        
           

        

        
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      (b)  If:
        (i) a
        Registration Statement is not filed on or prior to its Filing Date (if the
        Company files a Registration Statement without affording the Holders the
        opportunity to review and comment on the same as required by Section 3(a),
        the
        Company shall not be deemed to have satisfied this clause (i)), or (ii) the
        Company fails to file with the Commission a request for acceleration in
        accordance with Rule 461 promulgated under the Securities Act, within five
        Trading Days of the date that the Company is notified (orally or in writing,
        whichever is earlier) by the Commission that a Registration Statement will
        not
        be “reviewed,” or not subject to further review, or (iii) prior to its
        Effectiveness Date, the Company fails to file a pre-effective amendment and
        otherwise respond in writing to comments made by the Commission in respect
        of
        such Registration Statement within 10 calendar days after the receipt of
        comments by or notice from the Commission that such amendment is required
        in
        order for a Registration Statement to be declared effective, or (iv) a
        Registration Statement filed or required to be filed hereunder is not declared
        effective by the Commission by the Effectiveness Date, or (v) after the
        Effectiveness Date, a Registration Statement ceases for any reason to remain
        continuously effective as to all Registrable Securities for which it is required
        to be effective, or the Holders are not permitted to utilize the Prospectus
        therein to resell such Registrable Securities for 10 consecutive calendar
        days
        but no more than an aggregate of 15 calendar days during any 12-month period
        (which need not be consecutive Trading Days) (any such failure or breach
        being
        referred to as an “Event”,
        and
        for purposes of clause (i) or (iv) the date on which such Event occurs, or
        for
        purposes of clause (ii) the date on which such five Trading Day period is
        exceeded, or for purposes of clause (iii) the date which such 10 calendar
        day
        period is exceeded, or for purposes of clause (v) the date on which such
        10 or
        15 calendar day period, as applicable, is exceeded being referred to as
“Event
        Date”),
        then
        in addition to any other rights the Holders may have hereunder or under
        applicable law, on each such Event Date and on each monthly anniversary of
        each
        such Event Date (if the applicable Event shall not have been cured by such
        date)
        until the applicable Event is cured, the Company shall pay to each Holder
        an
        amount in cash, as partial liquidated damages and not as a penalty, equal
        to 2%
        of the aggregate purchase price paid by such Holder pursuant to the Purchase
        Agreement for any Registrable Securities then held by such Holder. If the
        Company fails to pay any partial liquidated damages pursuant to this Section
        in
        full within seven days after the date payable, the Company will pay interest
        thereon at a rate of 18% per annum (or such lesser maximum amount that is
        permitted to be paid by applicable law) to the Holder, accruing daily from
        the
        date such partial liquidated damages are due until such amounts, plus all
        such
        interest thereon, are paid in full. The partial liquidated damages pursuant
        to
        the terms hereof shall apply on a daily pro-rata basis for any portion of
        a
        month prior to the cure of an Event.

       

      (c)  Prior
        to
        the Effective Date of any given Registration Statement the Company is required
        to file hereunder, the Company will file a Form F-6 if necessary to register
        or
        list any of the Registrable Securities thereunder, and will file such an
        F-6 in
        enough time so that such F-6 is effective on or prior to the Effective Date
        of
        such Registration Statement. 

       

      3.  Registration
        Procedures

       

      In
        connection with the Company’s registration obligations hereunder, the Company
        shall:

       

      
        
           

        

        
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      (a)  Not
        less
        than five Trading Days prior to the filing of each Registration Statement
        or any
        related Prospectus or any amendment or supplement thereto (including any
        document that would be incorporated or deemed to be incorporated therein
        by
        reference), the Company shall, (i) furnish to each Holder copies of all such
        documents proposed to be filed, which documents (other than those incorporated
        or deemed to be incorporated by reference) will be subject to the review
        of such
        Holders, and (ii) cause its officers and directors, counsel and independent
        certified public accountants to respond to such inquiries as shall be necessary,
        in the reasonable opinion of respective counsel to conduct a reasonable
        investigation within the meaning of the Securities Act. The Company shall
        not
        file a Registration Statement or any such Prospectus or any amendments or
        supplements thereto to which the Holders of a majority of the Registrable
        Securities shall reasonably object in good faith, provided that the Company
        is
        notified of such objection in writing no later than 5 Trading Days after
        the
        Holders have been so furnished copies of such documents. Each Holder agrees
        to
        furnish to the Company a completed Questionnaire in the form attached to
        this
        Agreement as Annex B (a “Selling
        Shareholder Questionnaire”)
        not
        less than two Trading Days prior to the Filing Date or by the end of the
        fourth
        Trading Day following the date on which such Holder receives draft materials
        in
        accordance with this Section.

       

      (b)  (i)
        Prepare and file with the Commission such amendments, including post-effective
        amendments, to a Registration Statement and the Prospectus used in connection
        therewith as may be necessary to keep a Registration Statement continuously
        effective as to the applicable Registrable Securities for the Effectiveness
        Period and prepare and file with the Commission such additional Registration
        Statements in order to register for resale under the Securities Act all of
        the
        Registrable Securities; (ii) cause the related Prospectus to be amended or
        supplemented by any required Prospectus supplement (subject to the terms
        of this
        Agreement), and as so supplemented or amended to be filed pursuant to Rule
        424;
        (iii) respond as promptly as reasonably possible to any comments received
        from
        the Commission with respect to a Registration Statement or any amendment
        thereto
        and as promptly as reasonably possible provide the Holders true and complete
        copies of all correspondence from and to the Commission relating to a
        Registration Statement; and (iv) comply in all material respects with the
        provisions of the Securities Act and the Exchange Act with respect to the
        disposition of all Registrable Securities covered by a Registration Statement
        during the applicable period in accordance (subject to the terms of this
        Agreement) with the intended methods of disposition by the Holders thereof
        set
        forth in such Registration Statement as so amended or in such Prospectus
        as so
        supplemented.

       

      (c)  If
        during
        the Effectiveness Period, the number of Registrable Securities at any time
        exceeds 90% of the number of ADSs then registered in a Registration Statement,
        then the Company shall file as soon as reasonably practicable but in any
        case
        prior to the applicable Filing Date, an additional Registration Statement
        covering the resale by the Holders of not less than 130% of the number of
        such
        Registrable Securities (including the ADSs).

       

      
        
           

        

        
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      (d)  Notify
        the Holders of Registrable Securities to be sold (which notice shall, pursuant
        to clauses (ii) through (v) hereof, be accompanied by an instruction to suspend
        the use of the Prospectus until the requisite changes have been made) as
        promptly as reasonably possible (and, in the case of (i)(A) below, not less
        than
        two Trading Days prior to such filing) and (if requested by any such Person)
        confirm such notice in writing no later than one Trading Day following the
        day
        (i)(A) when a Prospectus or any Prospectus supplement or post-effective
        amendment to a Registration Statement is proposed to be filed; (B) when the
        Commission notifies the Company whether there will be a “review” of such
        Registration Statement and whenever the Commission comments in writing on
        such
        Registration Statement (the Company shall provide true and complete copies
        thereof and all written responses thereto to each of the Holders); and (C)
        with
        respect to a Registration Statement or any post-effective amendment, when
        the
        same has become effective; (ii) of any request by the Commission or any other
        Federal or state governmental authority for amendments or supplements to
        a
        Registration Statement or Prospectus or for additional information; (iii)
        of the
        issuance by the Commission or any other federal or state governmental authority
        of any stop order suspending the effectiveness of a Registration Statement
        covering any or all of the Registrable Securities or the initiation of any
        Proceedings for that purpose; (iv) of the receipt by the Company of any
        notification with respect to the suspension of the qualification or exemption
        from qualification of any of the Registrable Securities for sale in any
        jurisdiction, or the initiation or threatening of any Proceeding for such
        purpose; and (v) of the occurrence of any event or passage of time that makes
        the financial statements included in a Registration Statement ineligible
        for
        inclusion therein or any statement made in a Registration Statement or
        Prospectus or any document incorporated or deemed to be incorporated therein
        by
        reference untrue in any material respect or that requires any revisions to
        a
        Registration Statement, Prospectus or other documents so that, in the case
        of a
        Registration Statement or the Prospectus, as the case may be, it will not
        contain any untrue statement of a material fact or omit to state any material
        fact required to be stated therein or necessary to make the statements therein,
        in light of the circumstances under which they were made, not misleading;
        provided
        that any
        and all of such information shall remain confidential to each Holder until
        such
        information otherwise becomes public, unless disclosure by a Holder is required
        by law; provided,
        further,
        notwithstanding each Holder’s agreement to keep such information confidential,
        the Holders make no acknowledgement that any such information is material,
        non-public information.

       

      (e)  Use
        its
        best efforts to avoid the issuance of, or, if issued, obtain the withdrawal
        of
        (i) any order suspending the effectiveness of a Registration Statement, or
        (ii)
        any suspension of the qualification (or exemption from qualification) of
        any of
        the Registrable Securities for sale in any jurisdiction, at the earliest
        practicable moment.

       

      (f)  Furnish
        to each Holder, without charge, at least one conformed copy of each such
        Registration Statement and each amendment thereto, including financial
        statements and schedules, all documents incorporated or deemed to be
        incorporated therein by reference to the extent requested by such Person,
        and
        all exhibits to the extent requested by such Person (including those previously
        furnished or incorporated by reference) promptly after the filing of such
        documents with the Commission.

       

      (g)  Promptly
        deliver to each Holder, without charge, as many copies of the Prospectus
        or
        Prospectuses (including each form of prospectus) and each amendment or
        supplement thereto as such Persons may reasonably request in connection with
        resales by the Holder of Registrable Securities. Subject to the terms of
        this
        Agreement, the Company hereby consents to the use of such Prospectus and
        each
        amendment or supplement thereto by each of the selling Holders in connection
        with the offering and sale of the Registrable Securities covered by such
        Prospectus and any amendment or supplement thereto, except after the giving
        on
        any notice pursuant to Section 3(d).

       

      
        
           

        

        
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      (h)  If
        NASDR
        Rule 2710 requires any broker-dealer to make a filing prior to executing
        a sale
        by a Holder, the Company shall (i) make an Issuer Filing with the NASDR,
        Inc.
        Corporate Financing Department pursuant to NASDR Rule 2710(b)(10)(A)(i),
        (ii)
        respond within five Trading Days to any comments received from NASDR in
        connection therewith, and (iii) pay the filing fee required in connection
        therewith.

       

      (i)  Prior
        to
        any resale of Registrable Securities by a Holder, use its commercially
        reasonable efforts to register or qualify or cooperate with the selling Holders
        in connection with the registration or qualification (or exemption from the
        Registration or qualification) of such Registrable Securities for the resale
        by
        the Holder under the securities or Blue Sky laws of such jurisdictions within
        the United States as any Holder reasonably requests in writing, to keep each
        registration or qualification (or exemption therefrom) effective during the
        Effectiveness Period and to do any and all other acts or things reasonably
        necessary to enable the disposition in such jurisdictions of the Registrable
        Securities covered by each Registration Statement; provided that the Company
        shall not be required to qualify generally to do business in any jurisdiction
        where it is not then so qualified, subject the Company to any material tax
        in
        any such jurisdiction where it is not then so subject or file a general consent
        to service of process in any such jurisdiction.

       

      (j)  If
        requested by the Holders, cooperate with the Holders to facilitate the timely
        preparation and delivery of certificates representing Registrable Securities
        to
        be delivered to a transferee pursuant to a Registration Statement, which
        certificates shall be free, to the extent permitted by the Purchase Agreement,
        of all restrictive legends, and to enable such Registrable Securities to
        be in
        such denominations and registered in such names as any such Holders may
        request.

       

      (k)  Upon
        the
        occurrence of any event contemplated by this Section 3, as promptly as
        reasonably possible under the circumstances taking into account the Company’s
        good faith assessment of any adverse consequences to the Company and its
        stockholders of the premature disclosure of such event, prepare a supplement
        or
        amendment, including a post-effective amendment, to a Registration Statement
        or
        a supplement to the related Prospectus or any document incorporated or deemed
        to
        be incorporated therein by reference, and file any other required document
        so
        that, as thereafter delivered, neither a Registration Statement nor such
        Prospectus will contain an untrue statement of a material fact or omit to
        state
        a material fact required to be stated therein or necessary to make the
        statements therein, in light of the circumstances under which they were made,
        not misleading. If the Company notifies the Holders in accordance with clauses
        (ii) through (v) of Section 3(d) above to suspend the use of any Prospectus
        until the requisite changes to such Prospectus have been made, then the Holders
        shall suspend use of such Prospectus. The Company will use its best efforts
        to
        ensure that the use of the Prospectus may be resumed as promptly as is
        practicable. The Company shall be entitled to exercise its right under this
        Section 3(k) to suspend the availability of a Registration Statement and
        Prospectus, subject to the payment of partial liquidated damages pursuant
        to
        Section 2(b), for a period not to exceed 60 days (which need not be consecutive
        days) in any 12 month period.

       

      
        
           

        

        
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      (l)  Comply
        with all applicable rules and regulations of the Commission and the Trading
        Market.

       

      (m)  The
        Company may require each selling Holder to furnish to the Company a certified
        statement as to the number of shares of Common Stock or ADSs beneficially
        owned
        by such Holder and, if required by the Commission, the person thereof that
        has
        voting and dispositive control over the Shares. During any periods that the
        Company is unable to meet its obligations hereunder with respect to the
        registration of the Registrable Securities solely because any Holder fails
        to
        furnish such information within three Trading Days of the Company’s request, any
        liquidated damages that are accruing at such time as to such Holder only
        shall
        be tolled and any Event that may otherwise occur solely because of such delay
        shall be suspended as to such Holder only, until such information is delivered
        to the Company.

       

      4.  Registration
        Expenses.
        All
        fees and expenses incident to the performance of or compliance with this
        Agreement by the Company shall be borne by the Company whether or not any
        Registrable Securities are sold pursuant to a Registration Statement. The
        fees
        and expenses referred to in the foregoing sentence shall include, without
        limitation, (i) all registration and filing fees (including, without limitation,
        fees and expenses (A) with respect to filings required to be made with the
        Trading Market on which the ADSs are then listed for trading, (B) in compliance
        with applicable state securities or Blue Sky laws reasonably agreed to by
        the
        Company in writing (including, without limitation, fees and disbursements
        of
        counsel for the Company in connection with Blue Sky qualifications or exemptions
        of the Registrable Securities and determination of the eligibility of the
        Registrable Securities for investment under the laws of such jurisdictions
        as
        requested by the Holders) and (C) if not previously paid by the Company in
        connection with an Issuer Filing, with respect to any filing that may be
        required to be made by any broker through which a Holder intends to make
        sales
        of Registrable Securities with NASD Regulation, Inc. pursuant to the NASD
        Rule
        2710, so long as the broker is receiving no more than a customary brokerage
        commission in connection with such sale, (ii) printing expenses (including,
        without limitation, expenses of printing certificates for Registrable Securities
        and of printing prospectuses if the printing of prospectuses is reasonably
        requested by the holders of a majority of the Registrable Securities included
        in
        a Registration Statement), (iii) messenger, telephone and delivery expenses
        related to the Company's obligations hereunder, (iv) fees and disbursements
        of
        counsel for the Company, (v) Securities Act liability insurance, if the Company
        so desires such insurance, and (vi) fees and expenses of all other Persons
        retained by the Company in connection with the consummation of the transactions
        contemplated by this Agreement. In addition, the Company shall be responsible
        for all of its internal expenses incurred in connection with the consummation
        of
        the transactions contemplated by this Agreement (including, without limitation,
        all salaries and expenses of its officers and employees performing legal
        or
        accounting duties), the expense of any annual audit and the fees and expenses
        incurred in connection with the listing of the Registrable Securities on
        any
        securities exchange as required hereunder, including all fees and expenses
        of
        the Depositary. In no event shall the Company be responsible for any broker
        or
        similar commissions or, except to the extent provided for in the Transaction
        Documents, including Section 4 hereof, any legal fees or other costs of the
        Holders.

       

      
        
           

        

        
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      5.  Indemnification

       

      (a)  Indemnification
        by the Company.
        The
        Company shall, notwithstanding any termination of this Agreement, indemnify
        and
        hold harmless each Holder, the officers, directors, agents, brokers (including
        brokers who offer and sell Registrable Securities as principal as a result
        of a
        pledge or any failure to perform under a margin call of Common Stock),
        investment advisors and employees of each of them, each Person who controls
        any
        such Holder (within the meaning of Section 15 of the Securities Act or Section
        20 of the Exchange Act) and the officers, directors, agents and employees
        of
        each such controlling Person, to the fullest extent permitted by applicable
        law,
        from and against any and all losses, claims, damages, liabilities, costs
        (including, without limitation, reasonable attorneys’ fees) and expenses
        (collectively, “Losses”),
        as
        incurred, arising out of or relating to any untrue or alleged untrue statement
        of a material fact contained in a Registration Statement, any Prospectus
        or any
        form of prospectus or in any amendment or supplement thereto or in any
        preliminary prospectus, or arising out of or relating to any omission or
        alleged
        omission of a material fact required to be stated therein or necessary to
        make
        the statements therein (in the case of any Prospectus or form of prospectus
        or
        supplement thereto, in light of the circumstances under which they were made)
        not misleading, except to the extent, but only to the extent, that (i) such
        untrue statements or omissions are based solely upon information regarding
        such
        Holder furnished in writing to the Company by such Holder expressly for use
        therein, or to the extent that such information relates to such Holder or
        such
        Holder’s proposed method of distribution of Registrable Securities as set forth
        in Annex A hereto or any changes to Annex A hereto that are expressly approved
        in writing by such Holder expressly for use in a Registration Statement,
        such
        Prospectus or such form of Prospectus or in any amendment or supplement thereto
        or (ii) in the case of an occurrence of an event of the type specified in
        Section 3(d)(ii)-(v), the use by such Holder of an outdated or defective
        Prospectus after the Company has notified such Holder in writing that the
        Prospectus is outdated or defective and prior to the receipt by such Holder
        of
        the Advice contemplated in Section 6(d). The Company shall notify the Holders
        promptly of the institution, threat or assertion of any Proceeding arising
        from
        or in connection with the transactions contemplated by this Agreement of
        which
        the Company is aware.

       

      
        
           

        

        
          9

          
            

          

        

        
           

        

      

      (b)  Indemnification
        by Holders.
        Each
        Holder shall, severally and not jointly, indemnify and hold harmless the
        Company, its directors, officers, agents and employees, each Person who controls
        the Company (within the meaning of Section 15 of the Securities Act and Section
        20 of the Exchange Act), and the directors, officers, agents or employees
        of
        such controlling Persons, to the fullest extent permitted by applicable law,
        from and against all Losses, as incurred, to the extent arising out of or
        based
        solely upon: (x) such Holder’s failure to comply with the prospectus delivery
        requirements of the Securities Act or (y) any untrue or alleged untrue statement
        of a material fact contained in any Registration Statement, any Prospectus,
        or
        any form of prospectus, or in any amendment or supplement thereto or in any
        preliminary prospectus, or arising out of or relating to any omission or
        alleged
        omission of a material fact required to be stated therein or necessary to
        make
        the statements therein not misleading (i) to the extent, but only to the
        extent,
        that such untrue statement or omission is contained in any information so
        furnished in writing by such Holder to the Company specifically for inclusion
        in
        such Registration Statement or such Prospectus or (ii) to the extent that
        (1)
        such untrue statements or omissions are based solely upon information regarding
        such Holder furnished in writing to the Company by such Holder expressly
        for use
        therein, or to the extent that such information relates to such Holder or
        such
        Holder’s proposed method of distribution of Registrable Securities as set forth
        in Annex
        A
        hereto
        or any changes to Annex
        A
        hereto
        that are expressly approved in writing by such Holder expressly for use in
        a
        Registration Statement, such Prospectus or such form of Prospectus or in
        any
        amendment or supplement thereto or (2) in the case of an occurrence of an
        event
        of the type specified in Section 3(d)(ii)-(v), the use by such Holder of
        an
        outdated or defective Prospectus after the Company has notified such Holder
        in
        writing that the Prospectus is outdated or defective and prior to the receipt
        by
        such Holder of the Advice contemplated in Section 6(d). In no event shall
        the
        liability of any selling Holder hereunder be greater in amount than the dollar
        amount of the net proceeds received by such Holder upon the sale of the
        Registrable Securities giving rise to such indemnification
        obligation.

       

      (c)  Conduct
        of Indemnification Proceedings.
        If any
        Proceeding shall be brought or asserted against any Person entitled to indemnity
        hereunder (an “Indemnified
        Party”),
        such
        Indemnified Party shall promptly notify the Person from whom indemnity is
        sought
        (the “Indemnifying
        Party”)
        in
        writing, and the Indemnifying Party shall have the right to assume the defense
        thereof, including the employment of counsel reasonably satisfactory to the
        Indemnified Party and the payment of all fees and expenses incurred in
        connection with defense thereof; provided, that the failure of any Indemnified
        Party to give such notice shall not relieve the Indemnifying Party of its
        obligations or liabilities pursuant to this Agreement, except (and only)
        to the
        extent that it shall be finally determined by a court of competent jurisdiction
        (which determination is not subject to appeal or further review) that such
        failure shall have prejudiced the Indemnifying Party.

       

      An
        Indemnified Party shall have the right to employ separate counsel in any
        such
        Proceeding and to participate in the defense thereof, but the fees and expenses
        of such counsel shall be at the expense of such Indemnified Party or Parties
        unless: (1) the Indemnifying Party has agreed in writing to pay such fees
        and
        expenses; (2) the Indemnifying Party shall have failed promptly to assume
        the
        defense of such Proceeding and to employ counsel reasonably satisfactory
        to such
        Indemnified Party in any such Proceeding; or (3) the named parties to any
        such
        Proceeding (including any impleaded parties) include both such Indemnified
        Party
        and the Indemnifying Party, and such Indemnified Party shall reasonably believe
        that a material conflict of interest is likely to exist if the same counsel
        were
        to represent such Indemnified Party and the Indemnifying Party (in which
        case,
        if such Indemnified Party notifies the Indemnifying Party in writing that
        it
        elects to employ separate counsel at the expense of the Indemnifying Party,
        the
        Indemnifying Party shall not have the right to assume the defense thereof
        and
        the reasonable fees and expenses of one separate counsel shall be at the
        expense
        of the Indemnifying Party). The Indemnifying Party shall not be liable for
        any
        settlement of any such Proceeding effected without its written consent, which
        consent shall not be unreasonably withheld. No Indemnifying Party shall,
        without
        the prior written consent of the Indemnified Party, effect any settlement
        of any
        pending Proceeding in respect of which any Indemnified Party is a party,
        unless
        such settlement includes an unconditional release of such Indemnified Party
        from
        all liability on claims that are the subject matter of such
        Proceeding.

       

      
        
           

        

        
          10

          
            

          

        

        
           

        

      

      All
        reasonable and documented fees and expenses of the Indemnified Party (including
        reasonable fees and expenses to the extent incurred in connection with
        investigating or preparing to defend such Proceeding in a manner not
        inconsistent with this Section) shall be paid to the Indemnified Party, as
        incurred, within ten Trading Days of written notice thereof to the Indemnifying
        Party; provided,
        that
        the Indemnified Party shall promptly reimburse the Indemnifying Party for
        that
        portion of such fees and expenses applicable to such actions for which such
        Indemnified Party is not entitled to indemnification hereunder, determined
        based
        upon the relative faults of the parties.

       

      (d)  Contribution.
        If the
        indemnification under Section 5(a) or 5(b) is unavailable to an Indemnified
        Party or insufficient to hold an Indemnified Party harmless for any Losses,
        then
        each Indemnifying Party shall contribute to the amount paid or payable by
        such
        Indemnified Party, in such proportion as is appropriate to reflect the relative
        fault of the Indemnifying Party and Indemnified Party in connection with
        the
        actions, statements or omissions that resulted in such Losses as well as
        any
        other relevant equitable considerations. The relative fault of such Indemnifying
        Party and Indemnified Party shall be determined by reference to, among other
        things, whether any action in question, including any untrue or alleged untrue
        statement of a material fact or omission or alleged omission of a material
        fact,
        has been taken or made by, or relates to information supplied by, such
        Indemnifying Party or Indemnified Party, and the parties’ relative intent,
        knowledge, access to information and opportunity to correct or prevent such
        action, statement or omission. The amount paid or payable by a party as a
        result
        of any Losses shall be deemed to include, subject to the limitations set
        forth
        in Section 5(c), any reasonable attorneys’ or other reasonable fees or expenses
        incurred by such party in connection with any Proceeding to the extent such
        party would have been indemnified for such fees or expenses if the
        indemnification provided for in this Section was available to such party
        in
        accordance with its terms.

       

      The
        parties hereto agree that it would not be just and equitable if contribution
        pursuant to this Section 5(d) were determined by pro rata allocation or by
        any
        other method of allocation that does not take into account the equitable
        considerations referred to in the immediately preceding paragraph.
        Notwithstanding the provisions of this Section 5(d), no Holder shall be required
        to contribute, in the aggregate, any amount in excess of the amount by which
        the
        proceeds actually received by such Holder from the sale of the Registrable
        Securities subject to the Proceeding exceeds the amount of any damages that
        such
        Holder has otherwise been required to pay by reason of such untrue or alleged
        untrue statement or omission or alleged omission, except in the case of fraud
        by
        such Holder.

       

      
        
           

        

        
          11

          
            

          

        

        
           

        

      

      The
        indemnity and contribution agreements contained in this Section are in addition
        to any liability that the Indemnifying Parties may have to the Indemnified
        Parties.

       

      6.  Miscellaneous

       

      (a)  Remedies.
        In the
        event of a breach by the Company or by a Holder, of any of their obligations
        under this Agreement, each Holder or the Company, as the case may be, in
        addition to being entitled to exercise all rights granted by law and under
        this
        Agreement, including recovery of damages, will be entitled to specific
        performance of its rights under this Agreement. The Company and each Holder
        agree that monetary damages would not provide adequate compensation for any
        losses incurred by reason of a breach by it of any of the provisions of this
        Agreement and hereby further agrees that, in the event of any action for
        specific performance in respect of such breach, it shall waive the defense
        that
        a remedy at law would be adequate.

       

      (b)  No
        Piggyback on Registrations.
        Except
        as set forth on Schedule
        6(b)
        attached
        hereto, neither the Company nor any of its security holders (other than the
        Holders in such capacity pursuant hereto) may include securities of the Company
        in the initial Registration Statement other than the Registrable Securities.
        No
        Person has any right to cause the Company to effect the registration under
        the
        Securities Act of any securities of the Company. The Company shall not file
        any
        other registration statements until the initial Registration Statement required
        hereunder is declared effective by the Commission, provided that this Section
        6(b) shall not prohibit the Company from filing amendments to registration
        statements already filed.

       

      (c)  Compliance.
        Each
        Holder covenants and agrees that it will comply with the prospectus delivery
        requirements of the Securities Act as applicable to it in connection with
        sales
        of Registrable Securities pursuant to a Registration Statement.

       

      (d)  Discontinued
        Disposition.
        Each
        Holder agrees by its acquisition of such Registrable Securities that, upon
        receipt of a notice from the Company of the occurrence of any event of the
        kind
        described in Section 3(d), such Holder will forthwith discontinue disposition
        of
        such Registrable Securities under a Registration Statement until such Holder’s
        receipt of the copies of the supplemented Prospectus and/or amended Registration
        Statement or until it is advised in writing (the “Advice”)
        by the
        Company that the use of the applicable Prospectus may be resumed, and, in
        either
        case, has received copies of any additional or supplemental filings that
        are
        incorporated or deemed to be incorporated by reference in such Prospectus
        or
        Registration Statement. The Company will use its best efforts to ensure that
        the
        use of the Prospectus may be resumed as promptly as it practicable. The
        Company agrees and acknowledges that any periods during which the Holder
        is
        required to discontinue the disposition of the Registrable Securities hereunder
        shall be subject to the provisions of Section 2(b).

       

      (e)  Piggy-Back
        Registrations.
        If at
        any time during the Effectiveness Period there is not an effective Registration
        Statement covering all of the Registrable Securities and the Company shall
        determine to prepare and file with the Commission a registration statement
        relating to an offering for its own account or the account of others under
        the
        Securities Act of any of its equity securities, other than on Form F-4 or
        Form
        F-8 (each as promulgated under the Securities Act) or their then equivalents
        relating to equity securities to be issued solely in connection with any
        acquisition of any entity or business or equity securities issuable in
        connection with the stock option or other employee benefit plans, then the
        Company shall send to each Holder a written notice of such determination
        and, if
        within fifteen days after the date of such notice, any such Holder shall
        so
        request in writing, the Company shall include in such registration statement
        all
        or any part of such Registrable Securities such Holder requests to be
        registered; provided,
        however,
        that,
        the Company shall not be required to register any Registrable Securities
        pursuant to this Section 6(e) that are eligible for resale pursuant to Rule
        144(k) promulgated under the Securities Act or that are the subject of a
        then-effective Registration Statement.

       

      
        
           

        

        
          12

          
            

          

        

        
           

        

      

      (f)  Amendments
        and Waivers.
        The
        provisions of this Agreement, including the provisions of this sentence,
        may not
        be amended, modified or supplemented, and waivers or consents to departures
        from
        the provisions hereof may not be given, unless the same shall be in writing
        and
        signed by the Company and each Holder of the then outstanding Registrable
        Securities. Notwithstanding the foregoing, a waiver or consent to depart
        from
        the provisions hereof with respect to a matter that relates exclusively to
        the
        rights of Holders and that does not directly or indirectly affect the rights
        of
        other Holders may be given by Holders of all of the Registrable Securities
        to
        which such waiver or consent relates; provided,
        however,
        that
        the provisions of this sentence may not be amended, modified, or supplemented
        except in accordance with the provisions of the immediately preceding
        sentence.

       

      (g)  Notices.
        Any and
        all notices or other communications or deliveries required or permitted to
        be
        provided hereunder shall be delivered as set forth in the Purchase
        Agreement.

       

      (h)  Successors
        and Assigns.
        This
        Agreement shall inure to the benefit of and be binding upon the successors
        and
        permitted assigns of each of the parties and shall inure to the benefit of
        each
        Holder. The Company may not assign its rights or obligations hereunder without
        the prior written consent of all of the Holders of the then-outstanding
        Registrable Securities. Each Holder may assign their respective rights hereunder
        in the manner and to the Persons as permitted under the Purchase
        Agreement.

       

      (i)  No
        Inconsistent Agreements.
        Neither
        the Company nor any of its subsidiaries has entered, as of the date hereof,
        nor
        shall the Company or any of its subsidiaries, on or after the date of this
        Agreement, enter into any agreement with respect to its securities, that
        would
        have the effect of impairing the rights granted to the Holders in this
        Agreement. Except as set forth on Schedule
        6(i),
        neither
        the Company nor any of its subsidiaries has previously entered into any
        agreement granting any registration rights with respect to any of its securities
        to any Person that have not been satisfied in full.

       

      (j)  Execution
        and Counterparts.
        This
        Agreement may be executed in any number of counterparts, each of which when
        so
        executed shall be deemed to be an original and, all of which taken together
        shall constitute one and the same Agreement. In the event that any signature
        is
        delivered by facsimile transmission, such signature shall create a valid
        binding
        obligation of the party executing (or on whose behalf such signature is
        executed) the same with the same force and effect as if such facsimile signature
        were the original thereof.

       

      
        
           

        

        
          13

          
            

          

        

        
           

        

      

      (k)  Governing
        Law.
        All
        questions concerning the construction, validity, enforcement and interpretation
        of this Agreement shall be determined with the provisions of the Purchase
        Agreement.

       

      (l)  Cumulative
        Remedies.
        The
        remedies provided herein are cumulative and not exclusive of any remedies
        provided by law.

       

      (m)  Severability.
        If any
        term, provision, covenant or restriction of this Agreement is held by a court
        of
        competent jurisdiction to be invalid, illegal, void or unenforceable, the
        remainder of the terms, provisions, covenants and restrictions set forth
        herein
        shall remain in full force and effect and shall in no way be affected, impaired
        or invalidated, and the parties hereto shall use their commercially reasonable
        efforts to find and employ an alternative means to achieve the same or
        substantially the same result as that contemplated by such term, provision,
        covenant or restriction. It is hereby stipulated and declared to be the
        intention of the parties that they would have executed the remaining terms,
        provisions, covenants and restrictions without including any of such that
        may be
        hereafter declared invalid, illegal, void or unenforceable.

       

      (n)  Headings.
        The
        headings in this Agreement are for convenience of reference only and shall
        not
        limit or otherwise affect the meaning hereof.

       

      (o)  Independent
        Nature of Holders’ Obligations and Rights.
        The
        obligations of each Holder hereunder are several and not joint with the
        obligations of any other Holder hereunder, and no Holder shall be responsible
        in
        any way for the performance of the obligations of any other Holder hereunder.
        Nothing contained herein or in any other agreement or document delivered
        at any
        closing, and no action taken by any Holder pursuant hereto or thereto, shall
        be
        deemed to constitute the Holders as a partnership, an association, a joint
        venture or any other kind of entity, or create a presumption that the Holders
        are in any way acting in concert with respect to such obligations or the
        transactions contemplated by this Agreement. Each Holder shall be entitled
        to
        protect and enforce its rights, including without limitation the rights arising
        out of this Agreement, and it shall not be necessary for any other Holder
        to be
        joined as an additional party in any proceeding for such purpose.

       

      *************************

      


       

      
        
           

        

        
          14

          
            

          

        

        
           

          
          

        

      



      IN
        WITNESS WHEREOF, the parties have executed this Registration Rights Agreement
        as
        of the date first written above.

       

      
        	 	 	 
	 	
                GENTIUM
                  S.p.A. 

              
	 
 	 
 	 
 
	 	By:  	/s/ Laura
                Ferro 
	 	
                
Name:
                Laura Ferro
	 	Title: Chief
                Executive Officer and President


      

      
 

      [SIGNATURE
        PAGE OF HOLDERS FOLLOWS]


      
        
           

        

        
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      [SIGNATURE
        PAGE OF HOLDERS TO GNT RRA]

      


      Name
        of
        Holder: __________________________

      Signature
        of Authorized Signatory of Holder:
        __________________________

      Name
        of
        Authorized Signatory: _________________________

      Title
        of
        Authorized Signatory: __________________________

      


      


      [SIGNATURE
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