Exhibit 10.5



                            SHARE PURCHASE AGREEMENT

                 (Relating to Ordinary Shares of Gentium S.p.A.)

     THIS SHARE PURCHASE AGREEMENT, dated as of April 4, 2005 (this
"Agreement"), by and between FINSIRTON S.P.A., a corporation incorporated under
the laws of Italy (the "Seller"), and SIGMA TAU FINANZIARIA S.P.A., a
corporation incorporated under the laws of Italy (the "Buyer").

                              W I T N E S S E T H:

     WHEREAS, the Seller is the record and beneficial owner and registered
holder of 4,550,000 outstanding ordinary shares, par value (euro)1 ("Ordinary
Shares"), of Gentium S.p.A., a corporation incorporated under the laws of Italy
(the "Company"); and

     WHEREAS, upon the terms and subject to the conditions of this Agreement the
Seller wishes to transfer and sell to the Buyer, and the Buyer wishes to
purchase from the Seller, up to 940,000 Ordinary Shares and such Repricing
Shares (as defined below) as may become transferable to the Buyer pursuant to
Section 1.7;

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
contained herein and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                   ARTICLE I

                           SALE AND PURCHASE OF SHARES

     1.1. Initial Sale of Shares. Upon the terms and subject to the conditions
of this Agreement, the Seller hereby agrees to sell, assign and transfer to the
Buyer, and the Buyer hereby agrees to purchase from the Seller, 800,000 Ordinary
Shares (the "Initial Shares") at $4.00 per share for an aggregate purchase price
of $3,200,000 (the "Aggregate Purchase Price").

     1.2. Second Sale of Shares. If the Company does not consummate an initial
public offering of its Ordinary Shares by May 31, 2005, the Buyer hereby agrees,
upon the request of the Seller, to purchase up to an additional 140,000 shares
(the "Secondary Shares" and, together with the Initial Shares, the "Shares")
from the Seller at $4.00 per share by June 30, 2005.

     1.3. Registration Rights. In connection with the sale of the Shares, the
Seller hereby agrees to cause the Company to register for resale under the
securities laws of the USA the Shares and any Repricing Shares (as defined
herein), if any, in accordance with the Investors' Rights Agreement in the form
attached hereto as Exhibit A.

     1.4. Initial Closing. The closing of the sale and purchase of the Initial
Shares hereunder (the "Initial Closing") shall take place within one business
day of the mutual execution of the Agreement (the date of such Initial Closing
being the "Initial Closing Date").


<PAGE>

     1.5. Second Closing. The closing of the sale and purchase of the Second
Shares hereunder, if any (the "Second Closing" and each of the Initial Closing
and the Second Closing being a "Closing") shall take place within three business
days of the Seller's request for such sale, and no later than June 30, 2005 (the
date of such Second Closing being the "Second Closing Date" and each of the
Initial Closing Date and the Second Closing Date being a "Closing Date").

     1.6. Closing Deliveries. At each Closing on the applicable Closing Date,
the Buyer shall wire immediately available funds for the purchase price of the
Shares in accordance with Seller's written instructions, and the Seller shall
deliver or cause to be delivered to Orrick, Herrington & Sutcliffe the
certificates for the Shares being sold and transferred by the Seller, duly
endorsed in favor of the Buyer or with appropriate share transfer powers in
favor of the Buyer, duly executed by the Seller, in proper form for transfer, in
the amount being sold by the Seller. The Seller shall cause Orrick, Herrington &
Sutcliffe to deliver the certificates for the Shares to Buyer within five (5)
business days following the receipt by the Seller of the purchase price for the
Shares. The Seller shall pay any and all transfer taxes which may be imposed
with respect to the delivery of the Shares. The parties shall execute and
deliver such other documents as may be required to validly transfer the Shares
to the Buyer and to enable the Buyer to become the registered holder thereof.

     1.7. Repricing Shares. In the event that the Company completes an initial
public offering or if the Company and its shareholders enter into an agreement
to sell all of the outstanding Ordinary Shares of the Company to a third party,
pursuant to which Ordinary Shares (the "Sale Shares") are issued or sold at a
price per share (the "Sale Share Price") less than $5.00 U.S. (such price
subject to equitable adjustments for share splits, share dividends,
combinations, recapitalizations, reclassifications and similar events occurring
after the Closing Date), the Buyer shall be entitled to receive from the Seller
an additional number of fully paid and nonassessable Ordinary Shares equal to
(x) the Aggregate Purchase Price divided by the product determined by
multiplying (i) 0.8 by (ii) the Sale Share Price less (y) the number of Shares
initially delivered to the Buyer on the Initial Closing Date and, if applicable,
the Second Closing Date pursuant to this Agreement (the "Repricing Shares"). If
the issuance would result in the issuance of a fraction of an Ordinary Share,
such fraction of an Ordinary Share shall be rounded down to the nearest whole
share. The Seller's obligation to deliver the certificates for Ordinary Shares
representing the Repricing Shares shall be absolute and unconditional,
irrespective of any action or inaction by the Buyer to enforce the same, any
waiver or consent with respect to any provision hereof, the recovery of any
judgment against any person or any action to enforce the same, any failure or
delay in the enforcement of any other obligation of the Seller to the Buyer, or
any setoff, counterclaim, recoupment, limitation or termination, or any breach
or alleged breach by the Buyer or any other person of any obligation to the
Seller or the Company or any violation or alleged violation of law by the Buyer
or any other person, and irrespective of any other circumstance which might
otherwise limit such obligation of the Seller to the Buyer in connection with
the issuance and delivery of the Repricing Shares. Such immediate and prompt
action shall be taken by all the parties in order to assure that there shall be
full compliance with the Seller's unqualified obligation that all Repricing
Shares to be delivered on or prior to the date the Company completes its initial
public offering or the date that the Company's shareholders sell of all of their
Ordinary



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<PAGE>

Shares. The Seller shall pay any and all transfer taxes which may be imposed
with respect to the delivery of Repricing Shares.

                                   ARTICLE II

                  REPRESENTATIONS AND WARRANTIES OF THE SELLER

     The Seller represents and warrants to the Buyer as follows:

     2.1. Organization; Power and Authority. The Seller is a corporation duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its formation and has all requisite corporate power and
authority to execute, deliver and perform its obligations hereunder, and to
consummate the transactions contemplated hereby.

     2.2. Authorization, Validity, Etc. of Shares. The Shares have been duly
authorized and validly issued and are fully paid and non-assessable. The Initial
Shares represent sixteen percent (16%) of the issued and outstanding Ordinary
Shares. The Second Shares represent two point eight percent (2.8%) of the issued
and outstanding Ordinary Shares.

     2.3. Title to Shares. The Seller has good and marketable title to the
Shares and the Repricing Shares, if any, free and clear of any and all liens,
pledges, charges, encumbrances, and claims and rights of others of any nature
whatsoever and, upon consummation of the sale and purchase of the Shares
pursuant to this Agreement, the Buyer will acquire good and marketable title to
the Shares and the Repricing Shares, if any, free and clear of any and all
liens, pledges, charges, encumbrances, and claims and rights of others of any
nature whatsoever.

     2.4. Authorization and Binding Effect. The execution, delivery and
performance of this Agreement by the Seller, and the consummation of the
transactions contemplated hereby on the part of the Seller, have been duly
authorized by all necessary action on the part of the Seller. This Agreement has
been duly executed and delivered by the Seller and constitutes the legal, valid
and binding obligation of the Seller, enforceable against the Seller in
accordance with its terms, except as may be limited by applicable bankruptcy,
reorganization, insolvency, moratorium or similar laws relating to or affecting
generally the enforcement of creditors' rights and except as the availability of
particular remedies of specific performance may be limited under generally
applicable rules of law, whether enforcement is sought at law or in equity.

     2.5. No Violation of Law or Other Agreements. The execution, delivery and
performance of this Agreement by the Seller, and the consummation of the
transactions contemplated hereby on the part of the Seller (a) do not conflict
with or constitute a violation of the organizational documents of the Seller;
(b) do not violate any material provision of applicable law or regulation or any
order, decree, judgment or award to which the Seller or any of its properties is
subject; and (c) do not and will not result in a breach of, or constitute a
default under, or constitute an event which, with notice or lapse of time, or
both, would become a default under, any indenture, loan agreement, credit
facility, material lease, or other material agreement or material instrument to
which the Seller is a party or by which the Seller or any of its properties is
bound. No authorization, approval or consent of, or notice to or filing with,
any person is or will be re-



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<PAGE>

quired for the execution, delivery or performance of this Agreement by the
Seller or the consummation by the Seller of the transactions on its part
contemplated hereby.

     2.6. Information, Access, Etc. The Seller has requested and received from
the Company all information relating to the business, properties, operations,
condition (financial or other), results of operations, plans and prospects of
the Company deemed relevant by the Seller to its decision to sell the Shares and
Repricing Shares, if any; the Seller has been afforded the opportunity to ask
questions of the Company concerning the foregoing.

     2.7. Evaluation. In determining to enter into this Agreement and to sell
its Shares and Repricing Shares, if any, the Seller has relied upon the
information referred to in Section 2.6 and the Seller's own assessment of the
merits and risks of a sale of the Shares and Repricing Shares, if any, and has
not received or relied on any advice or evaluation by the Buyer.

     2.8. Litigation. There is no action, suit, or proceeding or investigation
pending or, to the knowledge of the Seller, currently threatened, in any such
case against the Seller or the Company or any of their respective directors,
officers, members or affiliates which questions the validity of this Agreement
or the right of the Seller to enter into this Agreement, to consummate the
transactions contemplated by this Agreement or to perform its obligations under
this Agreement, or which might result, either individually or in the aggregate,
in any material adverse change in the business, properties, operations,
condition (financial or other), results of operations, or prospects of the
Company. Neither the Seller nor the Company is a party or subject to the
provisions of any order, writ, injunction, judgment or decree of any court or
government agency or instrumentality. There is no action, suit, proceeding or
investigation by the Company currently pending or which the Company intends to
initiate.

     2.9. Approvals, Filings, Etc. No authorization, approval or consent of, or
filing with, any United States or foreign court, governmental body, regulatory
agency, self-regulatory organization, or arbitrator or any other person or
entity is required to be obtained or made by the Seller or the Company for the
execution, delivery and performance by the Seller and the Company of this
Agreement and the transactions contemplated by this Agreement.

     2.10. Organization of Company. The Company is a corporation duly organized,
validly existing and in good standing under the laws of Italy and has all
requisite corporate power and authority to own and lease its properties, to
carry on its business as presently conducted.

     2.11. Capitalization. The authorized capital shares of the Company consists
of 13,330,100 Ordinary Shares, of which 5,000,000 Ordinary Shares are issued and
outstanding. Except for (i) 2,216,100 shares which are reserved for issuance to
holders of the $8,010,000 aggregate principal amount of Series A Convertible
Notes issued by the Company and related warrants to purchase Ordinary Shares;
and (ii) 1,560,000 shares reserved for issuance under employee option plans, of
which 85,000 options have been granted, there are no outstanding securities of
the Company convertible into, exchangeable for, or otherwise entitling the
holder to acquire Ordinary Shares or other rights, agreements or arrangements of
any character under which the Company is or may be obligated to issue any
Ordinary Shares or other equity securities of any kind. Except for the Investor
Rights Agreement, the Investors' Rights Agreements between



                                      -4-
<PAGE>

the Company and each of the holders of the Company's Series A Senior Convertible
Promissory Notes and related warrants and the Investors' Rights Agreement made
as of January 10, 2005 among the Company and the other parties thereto, the
Seller has no knowledge of any voting agreements, buy-sell agreements, option or
right of first purchase agreements or other agreements of any kind among any of
the security holders of the Company relating to the securities of the Company
held by them. Except for the Investors' Rights Agreement, the Investors' Rights
Agreements between the Company and each of the holders of the Company's Series A
Senior Convertible Promissory Notes and related warrants and the Investors'
Rights Agreement made as of January 10, 2005 among the Company and the other
parties thereto, the Company has not granted any person the right to require the
Company to register any securities of the Company under the Securities Act of
1933, as amended, whether on a demand basis or in connection with the
registration of securities of the Company for its own account or for the account
of any other person.

     2.12. No Related Agreements. The Seller has not, directly or indirectly,
entered into any agreement or understanding pursuant to which the Seller is
entitled to any rights, or subject to any obligations, with respect to the
Shares, including, without limitations, registration rights, rights of first
refusal, rights of first purchase, preemptive rights, tag along rights, drag
along rights, or voting rights.

                                  ARTICLE III

                   REPRESENTATIONS AND WARRANTIES OF THE BUYER

     The Buyer represents and warrants to the Seller as follows:

     3.1. Authorization and Binding Effect. This Agreement has been duly
executed and delivered by the Buyer, and this Agreement constitutes the legal,
valid and binding obligation of the Buyer, enforceable against such Buyer in
accordance with its terms, except as may be limited by applicable bankruptcy,
reorganization, insolvency, moratorium or similar laws relating to or affecting
generally the enforcement of creditors' rights and except as the availability of
particular remedies of specific performance may be limited under generally
applicable rules of law, whether enforcement is sought at law or in equity.

     3.2. Purchase for Investment; Circumstances of Offer. The Buyer is an
"accredited investor" as that term is defined in Rule 501 under the Securities
Act of 1933, as amended (the "1933 Act"), and, in particular, is a corporation
not formed for the specific purpose of acquiring the Shares or the Repricing
Shares and has total assets in excess of $5,000,000. The Buyer is purchasing the
Shares and Repricing Shares, if any, for its own account for investment and not
with a view towards the public sale or distribution thereof within the meaning
of the 1933 Act; and the Buyer has no intention of making any distribution,
within the meaning of the 1933 Act, of the Shares and Repricing Shares, if any,
except in compliance with the registration requirements of the 1933 Act or
pursuant to an exemption therefrom.

     3.3. Reoffers and Resales. The Buyer will not, directly or indirectly,
offer, sell, pledge, transfer or otherwise dispose of (or solicit any offers to
buy, purchase or otherwise acquire or take a pledge of) any of the Shares and
Repricing Shares, if any, unless registered un-



                                      -5-
<PAGE>

der the 1933 Act and the rules and regulations promulgated thereunder or
pursuant to an exemption from registration under the 1933 Act.

     3.4. Information, Access, Etc. The Buyer has requested and received from
the Seller and the Company all information relating to the business, properties,
operations, condition (financial or other), results of operations or prospects
of the Company deemed relevant by the Buyer; and the Buyer has been afforded the
opportunity to ask questions of the Company concerning the foregoing.

     3.5. Evaluation. In determining to enter into this Agreement and to
purchase the Shares and Repricing Shares, if any, the Buyer has relied upon the
information referred to in Section 3.4 and the Buyer's own assessment of the
merits and risks of a purchase of the Shares and has not received or relied on
any advice or evaluation by the Seller.

     3.6. No Violation of Law or Other Agreements. The execution, delivery and
performance of this Agreement by the Buyer, and the consummation of the
transactions contemplated hereby on the part of the Buyer (a) do not conflict
with or constitute a violation of the organizational documents of the Buyer; (b)
do not violate any material provision of applicable law or regulation or any
order, decree, judgment or award to which the Buyer or any of its properties is
subject; and (c) do not and will not result in a breach of, or constitute a
default under, or constitute an event which, with notice or lapse of time, or
both, would become a default under, any indenture, loan agreement, credit
facility, material lease, or other material agreement or material instrument to
which the Buyer is a party or by which the Buyer or any of its properties is
bound. No authorization, approval or consent of, or notice to or filing with,
any person is or will be required for the execution, delivery or performance of
this Agreement by the Buyer or the consummation by the Buyer of the transactions
on its part contemplated hereby.

                                   ARTICLE IV

                CONDITIONS PRECEDENT TO OBLIGATIONS OF THE SELLER

     The obligation of the Seller to sell the Shares to the Buyer pursuant to
this Agreement is subject to the satisfaction of the following conditions at or
before the Closing (any or all of which may be waived by the Seller in its sole
discretion):

     4.1. Buyer's Performance. All of the covenants and agreements to be
complied with and performed by the Buyer on or before the Closing Date shall
have been complied with and performed in all material respects.

     4.2. Correctness of Buyer's Representations. All representations and
warranties of the Buyer contained in this Agreement shall be true and correct in
all material respects on and as of the Closing Date with the same force and
effect as if such representations and warranties had been made on and as of the
Closing Date.

     4.3. Investors' Rights Agreement. The Investors' Rights Agreement shall
have been executed and delivered by the parties thereto.



                                      -6-
<PAGE>

                                   ARTICLE V

                CONDITIONS PRECEDENT TO OBLIGATIONS OF THE BUYER

     The obligation of the Buyer to purchase the Shares pursuant to this
Agreement is subject to the satisfaction of the following conditions at or
before the Closing (any or all of which may be waived by the Buyer in its sole
discretion):

     5.1. Seller's Performance. All of the covenants and agreements to be
complied with and performed by the Seller on or before the Closing Date shall
have been complied with and performed in all material respects.

     5.2. Correctness of Seller's Representations. All representations and
warranties of the Seller contained in this Agreement and any other written
materials delivered to the Buyer shall be true and correct in all material
respects on and as of the Closing Date with the same force and effect as if such
representations and warranties had been made on and as of the Closing Date.

     5.3. Investors' Rights Agreement. The Investors' Rights Agreement shall
have been executed and delivered by the parties thereto.

     5.4. Issuer Acknowledgment and Agreement. The Issuer shall have
acknowledged the transfer of the Shares and Repricing Shares, if any, pursuant
to this Agreement and shall have agreed with the Buyer as set forth in the
Acknowledgement and Agreement appearing after the signatures of the parties to
this Agreement, all as evidenced by the execution and delivery to the Seller and
the Buyer of the Acknowledgement and Agreement in the form appearing after the
signatures of the parties to this Agreement.

                                   ARTICLE VI

                     CERTAIN COVENANTS; REPRESENTATIONS, ETC

     6.1. Best Efforts. The Seller and the Buyer shall use their best efforts to
cause the respective conditions to their obligations to close the transactions
contemplated hereby to be satisfied on or before the Closing Date. The Seller
and the Buyer agree to furnish a copy of this Agreement to the Company promptly
following execution and delivery hereof in order to obtain the confirmation by
the Company and the execution and delivery of instruments contemplated by this
Agreement.

     6.2. "Market Stand-Off" Agreement. The Buyer hereby agrees that, during a
period not to exceed one hundred and eighty (180) days (as determined by the
Company's Board of Directors and the proposed underwriters for a public offering
of the Company's securities under the 1933 Act), following the effective date of
a registration statement of the Company filed under the 1933 Act, it shall not,
to the extent requested in writing by the Company and such underwriter, sell or
otherwise transfer or dispose of (other than to donees who agree to be similarly
bound) any Ordinary Shares of the Company acquired hereunder held by it at any
time during such period except Ordinary Shares included in such registration and
to enter into a lock-up



                                      -7-
<PAGE>

agreement in usual and customary form with such underwriters providing that,
unless otherwise consented to by the managing underwriter, the holder of the
Shares will abide by the same restrictions as were approved by the Company's
Board of Directors; provided that, all officers and directors and greater than
one percent (1%) shareholders of the Company enter into similar agreements; and
provided further, however, that such lock up agreement shall not prohibit the
transfer of Repricing Shares, if any, from the Seller to the Buyer pursuant to
this Agreement. In order to enforce the foregoing covenants, the Company may
impose stop-transfer instructions with respect to the Shares, and Repricing
Shares, if any (and the shares or securities of every other person subject to
the foregoing restriction) until the end of such period.

     6.3. Capital Contribution to the Company. The Seller hereby agrees that
100% of the proceeds of the sale of the Shares (net of transfer taxes and the
fees payable to I-Bankers Securities) shall be irrevocably contributed to the
capital of the Company within one business day of the Closing Date, and that
Seller shall provide to Buyer copies of the documentation for such capital
contribution within five business days of the Closing Date.

     6.4. Board Nominee. The Seller hereby agrees to vote its Ordinary Shares in
favor of one nominee to the Company's Board of Directors selected by the Buyer.

                                  ARTICLE VII

                                     GENERAL

     7.1. Entire Agreement. This Agreement and the Investors' Rights Agreement
contains the entire agreement between the parties hereto with respect to the
subject matter hereof. This Agreement may not be amended, waived or modified
except by a writing signed by the party to be charged with enforcement.

     7.2. Binding Effect. This Agreement shall be binding upon and inure to the
benefit of the parties hereto and their respective successors and permitted
assigns; provided, however, this Agreement and all rights hereunder may not be
assigned by any party hereto without the prior written consent of the other
party hereto.

     7.3. Separate Counterparts. This Agreement may be executed in counterparts
and by the parties hereto on separate counterparts, each of which when so
executed shall constitute an original and all of which when taken together shall
constitute but one and the same instrument. A telephone line facsimile
transmission of this Agreement bearing a signature on behalf of a party hereto
shall be legal and binding on such party.

     7.4. Transaction Costs. Each party to this Agreement shall be responsible
for its own costs attendant to the transactions contemplated by this Agreement,
whether or not the Closing occurs.

     7.5. Cumulative Remedies. The remedies of the parties hereunder shall be
cumulative, and the exercise by the Seller of any of its remedies at law or in
equity to recover any damages shall not affect any other remedy available to the
Seller and the exercise by the



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<PAGE>

Buyer of any of its remedies at law or in equity to recover any damages shall
not affect any other remedy available to the Buyer.

     7.6. Survival of Representations and Warranties. The respective
representations and warranties of the Seller and the Buyer set forth in this
Agreement shall survive the Closing notwithstanding any investigation made by or
on behalf of any such party.

     7.7. Notices. Except as otherwise expressly provided herein, all notices
hereunder, to be effective, shall be in writing and shall be mailed by certified
mail, postage and fees prepaid, or delivered personally or by telephone line
facsimile transmission to the party to be notified as follows:

If to the Seller:          FinSirton S.p.A.
                           Piazza XX Seppembre 2
                           22079 Villa Guardia (Como)
                           Italy
                           Facsimile No.:      011 39 031 385 241
                           Telephone No.:      011 39 030 385 217
                           Email:              scarsana@sirton.it

If to the Buyer:           Sigma Tau Finanziaria S.p.A.
                           Via Sudafrica 20
                           00144 Roma
                           Italy
                           United States of America
                           Facsimile No.:      011-39-06-542294-56
                           Telephone No:       011-39-06-542771-62
                           Email:              antonionicolai@sigma-tau.it

and shall be effective on receipt. A party may change the address to which such
communications are to be directed to it by giving written notice to the other
party hereto of such change in the manner above provided.

     7.8. Severability. The provisions of this Agreement are severable, and the
invalidity or unenforceability of any provision shall not affect the validity of
any other provision.

     7.9. No Waiver. The failure of a party at any time or times to require
performance of any provision hereof shall in any manner affect its right at a
later time to enforce the same. No waiver by a party of any condition, or of the
breach of any term, covenant, representation, warranty or agreement contained in
this Agreement, whether by conduct or otherwise, in any one or more instances
shall be deemed to be or construed as a further or continuing waiver of any such
condition or breach or a waiver of any other condition or of the breach of any
other term, covenant, representation, warranty or agreement contained in this
Agreement.

     7.10. Brokers, Finders, Etc. Each of the parties represents and warrants to
the other party that (except for I-Bankers Securities which has been retained by
the Seller and whose fees shall be payable solely by the Seller) it has not
retained or dealt with any person as broker,



                                      -9-
<PAGE>

finder or otherwise (each, a "Claimant") as would entitle any such person to any
fee or other compensation in connection with the transactions contemplated by
this Agreement and each of the parties agrees to indemnify and hold harmless the
other parties against any claim, cost or liability from any Claimant claiming by
or through the party giving such indemnity.

     7.11. Governing Law. Except for matters required under the laws of Italy
for the valid transfer of the Shares which shall be governed by the laws of
Italy, this Agreement shall be governed by and construed in accordance with the
laws of the internal laws of the State of New York.

     7.12. Jurisdiction. The parties hereby agree that all actions or
proceedings arising directly or indirectly from or in connection with this
Agreement shall be litigated only in the Supreme Court of the State of New York
or the United States District Court for the Southern District of New York
located in New York County, New York. The Seller consents and submits to the
jurisdiction and venue of the foregoing courts and consents that any process or
notice of motion or other application to either of said courts or a judge
thereof may be served on the Seller inside or outside the State of New York or
the Southern District of New York (but with respect to any party hereto, such
consent shall not be deemed a general consent to jurisdiction and service for
any third parties) by registered mail, return receipt requested, directed to the
Seller at its address provided in or pursuant to this Agreement (and service so
made shall be deemed complete three days after the same has been posted as
aforesaid) or by personal service or in such other manner as may be permissible
under the rules of said courts. The Seller hereby waives any right to object to
a proceeding in such courts based on inconvenience of the forum, waives any
right to a jury trial in connection with any litigation pursuant to this
Agreement and hereby waives, and agrees not to assert in any proceeding, any
claim that it is not personally subject to the jurisdiction of any such state or
federal court sitting in the City of New York. If either party shall commence a
proceeding to enforce any provision of this Agreement, then the prevailing party
shall be reimbursed by the other party for its attorney's fees and other costs
and expenses incurred with the investigation, preparation and prosecution of
such proceeding.

     7.13. Headings. The Article and Section headings, captions, headers and
footers contained in this Agreement are for convenience only and shall not form
part of or affect the interpretation of this Agreement.

     7.14. Further Assurances. Each party to this Agreement will perform any and
all acts and execute any and all documents as may be necessary and proper under
the circumstances in order to accomplish the intents and purposes of this
Agreement and to carry out its provisions.

     7.15. Certain Defined Terms. Capitalized terms defined in the introductory
paragraph of the recitals to this Agreement have the respective meaning in this
Agreement as so defined.

                            [Signature Page Follows]




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<PAGE>



     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement,
or caused this Agreement to be duly executed by their respective representatives
thereunto duly authorized, as of the date first above written.

                                  FINSIRTON S.P.A.


                                  By:
                                      ----------------------------
                                         Name:
                                         Title:


                                  SIGMA TAU FINANZIARIA S.P.A.


                                  By:
                                      ----------------------------
                                         Name:
                                         Title:



<PAGE>


                          ACKNOWLEDGEMENT AND AGREEMENT


     Gentium S.p.A., a corporation incorporated under the laws of Italy (the
"Company"), hereby:

          (1) consents to and acknowledges the transfer of the Shares and the
     Repricing Shares, if any, as provided in the foregoing Share Purchase
     Agreement (the "Agreement");

          (2) agrees that the Buyer shall have no liability or obligation, and
     the Company shall have no right or remedy against the Buyer, in respect of
     any breach or violation, or alleged breach or violation, by the Seller of
     any of its representations, warranties, obligations or agreements arising
     under or in connection with the any agreements between the Company and the
     Seller relating to the Shares or Repricing Shares, if any, or applicable
     law; and

          (3) acknowledges and agrees that the representations and warranties
     made by the Seller with respect to the Company in Article II of the
     Agreement are true and correct on the date hereof with the same force and
     effect as if such representations and warranties had been made by the
     Company on and as of the date hereof.

Capitalized terms used herein and not defined herein have the respective
meanings provided in the Agreement. By execution of this Acknowledgment and
Agreement, the Company does not become a party to the Agreement for any purpose
other than as expressly set forth in this Acknowledgement and Agreement. The
provisions of Article VII of the Agreement shall apply to this Acknowledgement
and Agreement and by this reference are incorporated herein as if set forth in
full at this place.

                                    GENTIUM S.P.A.


                                    By:
                                         -------------------------------
                                           Name:
                                           Title:


                                    Date:
                                         -------------------------------