Exhibit 10.55

CONFIDENTIAL TREATMENT HAS BEEN REQUESTED FOR PORTIONS OF THIS EXHIBIT. THE
COPY FILED HEREWITH OMITS THE INFORMATION SUBJECT TO THE CONFIDENTIALITY
REQUEST. OMISSIONS ARE DESIGNATED AS ***. A COMPLETE VERSION OF THIS EXHIBIT
HAS BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.








                            ASSET PURCHASE AGREEMENT

                          dated as of December 8, 2006

                                 by and between

                                 SIEGFRIED LTD.
                              SIEGFRIED DIENSTE AG

                                       and



                             CELGENE CHEMICALS SARL

*** - indicates material omitted pursuant to a Confidential Treatment Request
and filed separately with the Securities and Exchange Commission.



        Seigfried Asset Purchase Agreement                                     1



ARTICLE 1  DEFINITIONS.........................................................5
  1.1      Definitions                                                         5
  1.2      Construction                                                        5
ARTICLE 2  PURCHASE AND SALE...................................................5
  2.1      Purchase and Sale of Assets                                         5
ARTICLE 3  PURCHASE PRICE......................................................6
  3.1      Purchase Price                                                      6
  3.2      Purchase Price Payment                                              6
ARTICLE 4  GUARANTY............................................................7
ARTICLE 5  CLOSING AND CLOSING DELIVERIES......................................7
  5.1      Closing                                                             7
  5.2      Conditions Precedent to Closing                                     7
  5.3      Closing Deliveries                                                  7
ARTICLE 5A  REPRESENTATIONS AND WARRANTIES.....................................9
  5A.1     Organization and Qualification                                      9
  5A.2     Asset Sellers' Representations or Warranties                        9
  5A.3     Litigation                                                          9
  5A.4     Transferred Employees                                               9
  5A.5     Social Security                                                    10
  5A.6     Insurance                                                          10
  5A.7     Registrations                                                      10
  5A.8     Taxes                                                              10
  5A.9     Technical Equipment and Other Personal Property                    10
  5A.10    Real Property                                                      10
ARTICLE 6  COVENANTS AND AGREEMENTS...........................................11
  6.1      Books and Records; Cooperation                                     11
  6.2      Transferred Employees                                              12
  6.3      Further Assurances                                                 13
  6.4      Real Property Deed                                                 13
  6.5      Technical Services Agreement                                       13
  6.6      Toll Manufacturing Agreement                                       13
  6.7      GMP Agreement.                                                     13
  6.8      Undertaking and Agreement in relation to the Use
           and Operation of Acquired Assets                                   13
  6.9      Maintenance and Capital Investments                                14
  6.10     Insurance                                                          14
  6.11     Environmental                                                      14
  6.12     Sale Back Option of Asset Buyer                                    15
  6.13     Right of First Refusal of Asset Sellers                            16
  6.14     Asset Sellers' Right to Buy Back the Acquired Assets               16
  6.15     Community of Co-Owners ("Stockwerkeigentumergemeinschaft").        16


        Seigfried Asset Purchase Agreement                                     2




ARTICLE 7  MISCELLANEOUS......................................................17
  7.1      Assignment                                                         17
  7.2      Expenses                                                           17
  7.3      Confidentiality                                                    17
  7.4      Public Announcement Pertaining to this Agreement
           and the Transaction Agreements                                     17
  7.5      Severability                                                       17
  7.6      Amendment                                                          17
  7.7      Waiver                                                             18
  7.8      Governing Law                                                      18
  7.9      Term of this Agreement                                             18
  7.10     Arbitration; Venue                                                 18
  7.11     Counterparts; Language                                             18
  7.12     Notices                                                            18
SCHEDULE 1.1  DEFINITIONS.....................................................21
  SCHEDULES:
  1.1      Definitions........................................................21
  2.1(a)   Real Property Documentation
  2.1(b)   Technical Equipment and Other Tangible Personal Property
  3.2      Bank Account of Asset Sellers
  6.2(a)   Transferred Employees

  EXHIBITS:
  3.1      VAT Notification Form
  3.2      Bank accounts
  4        Guaranty
  6.4      Real Property Deed
  6.5      Technical Services Agreement
  6.6      Manufacturing Agreement
  6.7      GPM Agreement

        Seigfried Asset Purchase Agreement                                     3



                            ASSET PURCHASE AGREEMENT
                            ------------------------

        THIS  ASSET   PURCHASE   AGREEMENT,   dated  as  of   December  8,  2006
("AGREEMENT"),  is entered into by and between Siegfried Ltd. ("ASSET SELLER 1")
and  Siegfried  Dienste AG ("ASSET  SELLER 2") on the one hand,  both  companies
organized  under  the laws of  Switzerland  with  registered  office  at  Untere
Bruhlstrasse 4, 4800 Zofingen,  Switzerland,  (together  "ASSET  SELLERS"),  and
Celgene  Chemicals Sarl., a company organized under the laws of Switzerland with
its registered office at Faubourg du Lac 11, 2000 Neuchatel, Switzerland ("ASSET
Buyer").  Asset  Sellers  and  Asset  Buyer  sometimes  are  referred  to herein
collectively as the "PARTIES" and individually as a "PARTY".

                               W I T N E S S E T H

        WHEREAS,  Asset Buyer is an affiliate of Celgene Corporation,  a company
organized under the laws of Delaware and listed on Nasdaq ("CELGENE"), and Asset
Sellers are affiliates of Siegfried  Holding Ltd., a company organized under the
laws of Switzerland and listed on the Swiss stock exchange ("SIEGFRIED");

        WHEREAS,  Asset Buyer has needs for a manufacturing facility in order to
manufacture  the active  pharmaceutical  ingredient  ("API")  for  Celgene  drug
products, including in particular for the Products;

        WHEREAS,  Asset Sellers have a suitable manufacturing facility available
for Asset Buyer;

        WHEREAS,  Asset Sellers  desire to sell,  transfer,  convey,  assign and
deliver,  and Asset Buyer  desires to purchase,  acquire and accept the Acquired
Assets upon the terms and subject to the conditions set forth in this Agreement.

        NOW, THEREFORE, the Parties agree as follows:

        Seigfried Asset Purchase Agreement                                     4



                                    ARTICLE 1

                                   DEFINITIONS

        1.1     DEFINITIONS.  In addition to the terms  defined  above and other
terms  defined  in other  Articles  of this  Agreement,  the  terms set forth in
SCHEDULE 1.1 shall have the meanings  specified or referred to in such  Schedule
and shall be equally  applicable  to both the  singular  and plural  forms.

        1.2     CONSTRUCTION.  The language in all parts of this Agreement shall
be  construed,  in all cases,  according to its fair  meaning.  "Days" or "days"
means calendar days unless otherwise specified. The words "hereof", "herein" and
"hereunder"  and words of similar import when used in this Agreement shall refer
to this  Agreement as a whole  (including  any Schedules  hereto) and not to any
particular  provision of this Agreement,  and all Article,  Schedule and Exhibit
references are to this Agreement unless otherwise specified.


                                    ARTICLE 2

                                PURCHASE AND SALE

        2.1     PURCHASE AND SALE OF ASSETS.  Asset  Sellers  hereby  undertake,
subject to the terms of this Agreement,  to sell, transfer,  assign,  convey and
deliver to Asset Buyer, and Asset Buyer hereby undertakes,  subject to the terms
of this Agreement,  to purchase,  acquire and accept from Asset Sellers,  on the
Closing, on the terms herein provided, Seller's right, title and interest in and
to the following assets (the "ACQUIRED ASSETS"):

        (a)     Seller's  ownership in the  condominium-principled  co-ownership
unit  ("Stockwerkeigentums-Einheit"),  Grundbuch  Zofingen,  Nr.  4651.01 all as
identified and described on SCHEDULE 2.1(a),  free and clear of any Encumbrances
except for the  Permitted  Encumbrances  identified  and  described  on SCHEDULE
2.1(a), (such unit being the "REAL PROPERTY");

        (b)     all TECHNICAL  EQUIPMENT AND OTHER  TANGIBLE  PERSONAL  PROPERTY
listed on SCHEDULE 2.1(b).

        Seigfried Asset Purchase Agreement                                     5




                                    ARTICLE 3

                                 PURCHASE PRICE

        3.1     PURCHASE PRICE. The aggregate purchase price to be paid by Asset
Buyer to Asset Sellers for the Acquired  Assets is CHF 55,500,000  (Swiss Francs
fifty-five  million  five  hundred   thousand),   exclusive  of  any  applicable
value-added tax (the "PURCHASE  PRICE").  Any value-added Tax resulting from the
transactions  including self supplies will be borne and paid by Asset Buyer. The
Purchase Price includes an amount,  exclusive of any applicable value-added Tax,
of CHF 2,700,000 (Swiss Francs two million seven hundred  thousand) for the Real
Property which is sold by Asset Seller 2 to Asset Buyer.

        The  Parties  agree,  where  possible,  to  apply  the VAT  notification
procedure according to art. 47 para 3 VATL. If not possible, Asset Seller 1 will
charge  Asset  Buyer with VAT on the  Purchase  Price  portion  relating  to the
Technical Equipment and Other Tangible Personal Property. In connection with the
Real  Property,  Asset  Seller 2 will try to opt for VAT and  Asset  Buyer  will
support Asset Seller 2 in this regard.  If Asset Seller 2 successfully  opts for
VAT on the sale of the Real  Property,  Asset  Seller 2 will charge  Asset Buyer
with VAT on the Purchase Price portion relating to the Real Property.

        In the event  value-added  Taxes are to be paid by Asset Sellers,  Asset
Buyer shall  reimburse  Asset  Sellers for such  payments at the time when Asset
Buyer files its first VAT return , but no later than by June 30, 2007.


        3.2     PURCHASE  PRICE  PAYMENT.  The  Purchase  Price shall be paid by
Asset Buyer to Asset  Sellers as follows into the  notary's  and Asset  Sellers'
bank  accounts  set forth on  SCHEDULE  3.2 or, as may be the case for  payments
after the Closing,  as otherwise  designated  in written  instructions  by Asset
Sellers to Asset Buyer:

        3.2.1   at Closing the sum of CHF  15,000,000  (the  "CLOSING  PAYMENT")
shall be made into the notary's and Asset Sellers' bank accounts as set forth on
SCHEDULE 3.2.

        3.2.2   thereafter  5  annual  instalments,  each in an  amount  of four
million one  hundred  thousand  Swiss  francs  (CHF  4,100,000),  the first such
instalment  payable on June 30, 2007,  the second on June 30, 2008, the third on
June 30, 2009, the fourth on June 30, 2010 and the fifth on June 30, 2011;

        3.2.3   thereafter,  subject to ARTICLE 6.13, 5 annual instalments, each
in an amount of four  million  Swiss  francs  (CHF  4,000,000),  the first  such
instalment  payable on June 30, 2012,  the

        Seigfried Asset Purchase Agreement                                     6




second on June 30, 2013, the third on June 30, 2014, the fourth on June 30, 2015
and the last such instalment being due on June 30, 2016.

        No set off shall be allowed in respect of any of the payments owed under
this ARTICLE 3.2 against any counterclaims,  unless such counterclaim amounts to
a minimum amount of CHF 4,100,000.


                                    ARTICLE 4

                                    GUARANTY

        At the Closing,  Asset Buyer will deliver to Asset Sellers a duly signed
Guaranty of Celgene International Sarl in the form set forth in EXHIBIT 4.


                                    ARTICLE 5

                         CLOSING AND CLOSING DELIVERIES

        5.1     CLOSING.  The transactions  contemplated by this Agreement shall
be consummated at a closing (the  "CLOSING")  which shall be held at the offices
of Asset Sellers on December 8th, 2006,  except as otherwise  mutually agreed in
writing by the Parties (the "CLOSING DATE").

        5.2     CONDITIONS PRECEDENT TO CLOSING. Each Party shall be entitled to
refuse  Closing for as long as any of the following  conditions has not been met
or  waived  as being a  condition  precedent  to  Closing,  provided  that  such
condition is legally waivable:

                (i)     a  Governmental   Approval  relevant  for  the  material
consummation of this Agreement has not been obtained;

                (ii)    the Real Property Deed has not been signed;

                (iii)   only Asset Sellers shall be entitled to refuse  Closing,
if and for as long as the Guaranty  according to ARTICLE 4 of this Agreement has
not been delivered.

        5.3     CLOSING  DELIVERIES.

        (a)     At the Closing, Asset Sellers shall deliver to Asset Buyer:

        Seigfried Asset Purchase Agreement                                     7




                (i)     any notarial  deeds or other  transaction  agreements or
documents required under Swiss law for Asset Sellers to sell,  assign,  transfer
and convey  and, as  appropriate,  record and  perfect  unencumbered  title to a
particular  Acquired  Asset to Asset  Buyer,  duly  executed  by Asset  Sellers,
including in particular  the Real Property Deed and the related  application  to
the real estate  register,  completed  and signed by Asset Sellers and ready for
immediate filing with the real property register by Asset Buyer;

                (ii)    the means  necessary for Asset Buyer to take  possession
of the Acquired Assets;

                (iii)   a receipt  from Asset  Sellers for the  Closing  Payment
paid to Asset Sellers;

                (iv)    copy of a resolution  of the board of directors of Asset
Sellers   authorizing   and  approving  this  Agreement  and  the   transactions
contemplated under this Agreement;

                (v)     the Transaction  Agreements to which Asset Seller 2 is a
Party, duly executed by Asset Seller 2;

                (vi)    the Transaction  Agreements to which Asset Seller 1 is a
Party, duly executed by Asset Seller 1; and

                (vii)   copy of the complete employment files of all Transferred
Employees  (including  their  employment  agreements  and any other  employment,
compensation and benefits related documentation).

        (b)     At the Closing, Asset Buyer shall deliver to Asset Seller:

                (i)     the amount of the  Closing  Payment by wire  transfer of
immediately  available funds to the bank accounts as designated by Asset Sellers
in SCHEDULE 3.2 ;

                (ii)    a  receipt  evidencing  Asset  Buyer's  receipt  of  the
Acquired Assets;

                (iii)   the  Transaction  Agreements  to which  Asset Buyer is a
party, duly executed by Asset Buyer;

                (iv)    copy of a resolution  of the board of directors of Asset
Buyer authorizing and approving this Agreement and the transactions contemplated
under this Agreement; and

                (v)     the Guaranty.

        Seigfried Asset Purchase Agreement                                     8




                                   ARTICLE 5A

                         REPRESENTATIONS AND WARRANTIES

        5A.1    ORGANIZATION  AND  QUALIFICATION.  Asset Sellers on the one hand
and Asset Buyer on the other hand represent and warrant to each other that as of
the time of signing of this Agreement and as of the Closing Date:

                (i)     They are duly organized and validly existing under Swiss
law,

                (ii)    They have the  requisite  power and  authority  to enter
into and to perform this Agreement and the Transaction Agreements and have taken
all  necessary  corporate  actions to  authorise  the  execution,  delivery  and
performance of this Agreement and the Transaction Agreements;

                (iii)   This Agreement and the other documents  thereto executed
and delivered by the Parties at the time of signing of this Agreement  and/or on
the Closing Date (including the Transaction  Agreements) constitute legal, valid
and binding  obligations of the Parties  enforceable  against them in accordance
with their respective terms; and

                (iv)    The execution,  delivery and  performance by the Parties
of this Agreement  and/or of the  Transaction  Agreements will not (a) result in
breach of any  provision of each Party's  articles of  association  and internal
regulations,  and (b) result in a breach of any order, judgment or decree of any
court or governmental agency by which either Party is bound.

        5A.2    ASSET  SELLERS'  REPRESENTATIONS  OR  WARRANTIES.  Asset Sellers
represent  and  warrant  to Asset  Buyer for a period of ***  months as from the
Closing Date (except where  otherwise  indicated) that as of the time of signing
of this Agreement and as of the Closing Date (except where otherwise indicated):

        5A.3    LITIGATION.  There is no  material  litigation  or  arbitration,
administrative proceedings, governmental inquiries or investigations pending or,
to the  knowledge  of Asset  Sellers,  threatened  in  writing  relating  to the
Acquired Assets and/or the Transferred Employees.

        5A.4    TRANSFERRED  EMPLOYEES.  All  Transferred  Employees are insured
according to Swiss labor laws and are  beneficiaries of requisite pension funds.
All  dues  to  pension  funds  with  respect  to  the   Transferred   Employees'
compensation have been paid or shall be paid when due. As of the signing of this
Agreement,  none of the  Transferred  Employees  hereto has  tendered or, to the
knowledge of Asset  Sellers,  threatened  his/her  resignation.  The  employment
agreements of the  Transferred  Employees are valid and in full force and effect
as of the Closing Date in all

        Seigfried Asset Purchase Agreement                                     9




material  respects.  Asset Sellers have not given notice of  termination  of any
such  agreement.   No  employees  other  than  Transferred  Employees  shall  be
transferred to the Asset Buyer.

        5A.5    SOCIAL SECURITY. All social security returns,  reports and forms
relating to Transferred  Employees  required to be filed in accordance  with all
applicable  laws  have  been  prepared  and  filed  in the  manner  required  by
applicable  law, are true,  correct and complete in all material  respects,  and
reflect in all  material  respects  the  liability  for social  security for the
relevant  terms.  All social  security  contributions  relating  to  Transferred
Employees  and to any period  prior to  Closing  have been paid in due course or
shall be paid when due.  There are no audits,  investigations  or  reassessments
relating to social  security  pending  or, to the  knowledge  of Asset  Sellers,
threatened with respect to the Transferred  Employees.  This  representation and
warranty shall survive and be valid and enforceable until expiry of the relevant
statute of limitation.

        5A.6    INSURANCE.  The  Acquired  Assets,  and in  particular  the Real
Property,  are covered by currently  effective insurance policies with insurance
companies in such minimum  types and amounts as are  consistent  with  customary
practices  applicable  in  Switzerland  for  pharmaceutical  API  manufacturing.
Insurance  policies  held by and  previously  disclosed  to Asset Buyer by Asset
Sellers are in full force and effect.  As of Closing,  Asset  Sellers are not in
material  default under any of them nor, to the knowledge of Asset Sellers,  has
any insurer  threatened  in writing to terminate  any of these  policies.  As of
Closing,  no claims exist under any insurance policy in relation to the Acquired
Assets.

        5A.7    REGISTRATIONS.   Asset  Sellers   possess  all  those   material
governmental licenses,  permits and authorizations necessary for the manufacture
of the Products as currently produced.

        5A.8    TAXES.  There are no  encumbrances on any of the Acquired Assets
that arose in  connection  with any  failure or alleged  failure to pay any Tax.
This  representation  and warranty  shall  survive and be valid and  enforceable
until expiry of the relevant statute of limitation.

        5A.9    TECHNICAL  EQUIPMENT AND OTHER PERSONAL  PROPERTY.  There are no
charges,  pledges or any other liens on any of the Technical Equipment and Other
Personal Property and Asset Seller 1 represents and warrants that it is the sole
owner of all Technical Equipment and Other Personal Property,  where applicable.
Asset Seller 1 further represents and warrants that all Technical  Equipment and
Other Personal Property are in good working condition, subject to usual wear and
tear, and have been properly maintained and revised in due time so that they can
be effectively used for their intended purposes as stated in this Agreement.

        5A.10   REAL PROPERTY.  Asset Seller 2 is the legal and beneficial owner
of the Real  Property and Asset Seller 1 has  exclusive  occupation  of the Real
Property.  There are no

        Seigfried Asset Purchase Agreement                                    10




circumstances  which would  entitle  any third  party to exercise  any powers or
rights of entry or to take  possession  which may restrict in any way whatsoever
the ownership  and/or  continued  possession,  use and/or  enjoyment of the Real
Property, except for the Permitted Encumbrances.

        Subject  to filing of the real  estate  register  applications  by Asset
Buyer upon  Closing,  there are, upon Closing,  no  Encumbrances  other than the
Permitted  Encumbrances  in respect of the Real  Property.  There is no dispute,
claim, action, demand or complaint which is outstanding or threatened in respect
of the Real Property or any part thereof.

        The current use of the Real  Property is a lawful use under all relevant
municipal,  cantonal and federal  planning and  administrative  legislation  and
Asset  Sellers  are not  aware  of any  outstanding  orders,  notices  or  other
requirements of any authority which may adversely affect the existing and future
use of the Real Property.

        No development,  alterations, extensions or other improvements have been
carried out in relation to any part of the Real  Property  which are unlawful or
have been carried out without all necessary consents, approvals, orders, permits
and permissions.

        There  are no  resolutions,  proposals,  orders  or  acts  made  for the
compulsory  acquisition  or  change  in  approved  use of any  part of the  Real
Property.

        The Real  Property  is free of any  asbestos,  except in the roof in the
form of  Eternit  cement  tiles.  In the  event  that,  at any  time,  any legal
obligation  to remove or treat such  asbestos  arises,  all such costs  shall be
exclusively  borne by Asset  Sellers.  The Real  Property is  currently  in full
conformity  with  all the  fire  security  laws,  regulations  and  requirements
applicable in Zofingen.

                                    ARTICLE 6

                            COVENANTS AND AGREEMENTS

        6.1     BOOKS  AND  RECORDS;  COOPERATION.  Asset  Sellers  shall,  upon
request  of Asset  Buyer,  deliver  copies or,  where no longer  needed by Asset
Sellers or where  legally  required by Asset  Buyer,  originals of all books and
records,  documents and other  information,  in whatever  form,  relevant to the
Acquired Assets and the Transferred Employees, to Asset Buyer at any time during
the term of this Agreement.  Asset Sellers shall permit Asset Buyer,  during the
whole term of this Agreement,  to inspect books,  records and  documentation  in
relation to the Acquired Assets when and as reasonably  required by Asset Buyer.
To the extent that the books and records, documents and other information relate
partially to Asset Sellers'  assets and contracts other than the Acquired Assets
and  Transferred  Employees,  Asset Seller  shall  provide  Asset Buyer  excised
portions of such  information.  This Article also covers Asset  Sellers' duty to

        Seigfried Asset Purchase Agreement                                    11




provide to Asset Buyer,  at any time during the duration of this  Agreement upon
Asset  Buyer's  request,  copy of the  Regulatory  Documentation,  including the
Registrations  and all quality  and safety  related  documentation,  that may be
required  to obtain or maintain  all  necessary  licences  from  authorities  to
operate the facility for the intended manufacturing of the Products.

        6.2     TRANSFERRED  EMPLOYEES.  (a)  Asset  Seller 1 shall use its best
efforts to cause all the  employees of Asset Seller 1 listed on SCHEDULE  6.2(a)
(the "TRANSFERRED  EMPLOYEES") to remain employed with Asset Buyer in accordance
with the provisions of ARTICLE 6.2(b) below. SCHEDULE 6.2(a) contains a complete
and accurate list of the names of the Transferred  Employees,  containing  their
positions,  start dates, base pay, bonus payments,  age, settlement  agreements,
company cars (any  deductions,  tax  treatment,  allowances,  including  savings
supplements by Asset Seller 1), benefits, any other incentives, company loans to
employees and any other ongoing deductions.

        (b)     Asset Seller 1 and Asset Buyer acknowledge and agree that due to
the sale of the Acquired  Assets by Asset Sellers to Asset Buyer,  the contracts
of employment of the Transferred Employees are being transferred by operation of
law (art.  333 et seq. of the Swiss Code of  Obligations)  to Asset Buyer on the
Closing as if originally made between Asset Buyer and the Transferred Employees.
To the extent  required by Swiss law,  Asset Seller 1 shall be  responsible  for
complying  with all  obligations  under  applicable  law to send a  notification
and/or consult with any  Transferred  Employee with respect to the  transactions
contemplated by this  Agreement,  in accordance with applicable law prior to the
Closing.  Immediately following execution of this Agreement, Asset Sellers shall
or shall procure that all information  and  consultation  processes  pursuant to
applicable law, any collective  bargaining,  company-wide  collective agreement,
shop,  trade  union,  recognition,  work  council  or other  similar  agreement,
undertaking or practice are complied with in respect of informing and consulting
with the Transferred Employees.

        (c)     Asset Buyer shall be responsible for all employer liabilities in
connection with any Transferred  Employees  actually  transferred to Asset Buyer
(including  any wages or amounts due under any of Asset  Sellers' or Siegfried's
group plans or employee benefit plans accruing after the Closing.  Asset Sellers
shall  be  responsible  for all  employer  liabilities  in  connection  with any
Transferred  Employees actually  transferred to Asset Buyer (including any wages
or  amounts  due under  any of Asset  Sellers'  or  Siegfried's  group  plans or
employee  benefit plans accruing up to and including the Closing;  this includes
any  and  all  severance   benefits  and/or  government   required   termination
liabilities).  Upon  written  demand and  receipt of proper  documentation,  the
Parties  shall  reimburse  each  other to the extent  they pay for any  employer
liability in connection with any Transferred Employees that is, under the regime
of this Article, owed by the other Party.

        Seigfried Asset Purchase Agreement                                    12




        (d)     Asset  Seller 1 shall  take all  steps  within  its  control  to
procure that all the pension fund  entitlements of the Transferred  Employees be
transferred  to  the  pension  scheme  to be  set  up by  the  Asset  Buyer  or,
alternatively,  as the case may be,  Asset Seller 1 shall fully  cooperate  with
Asset  Buyer to procure  that the  pension  scheme and all  entitlements  of the
Transferred  Employees  deriving  from such  pension  scheme come along with the
Transferred  Employees and continue to be in place at least as beneficial as for
the Transferred Employees as before the Closing. Asset Seller 1 shall inform the
various insurance  carriers  regarding the transfer of the benefit  arrangements
and retirement  plans and insurance  contracts  that pertain to the  Transferred
Employees.  Asset Buyer  shall  execute,  make,  acknowledge  and  deliver  such
instruments,  agreements and other documents as may be required by the insurance
carriers.

        (e)     The Parties shall take all steps within their control to procure
that those  Transferred  Employees who are a party to Siegfried Holding Employee
Share  Purchase  Plan agree upon the  replacement  of this  participation  by an
equitable increase of their salary.

        6.3     FURTHER  ASSURANCES.  Following  the Closing,  Asset Sellers and
Asset Buyer will execute and deliver  such  additional  instruments,  documents,
conveyances or assurances and take such other actions as shall be necessary,  or
otherwise  reasonably  requested by Asset Sellers or Asset Buyer, as applicable,
to confirm and assure the rights and obligations  provided for in this Agreement
and any other  transaction  agreements and render  effective the consummation of
the transactions contemplated hereby and thereby.

        6.4     REAL  PROPERTY  DEED.  At the signing of this  Agreement,  Asset
Buyer and Asset Sellers shall sign the Real Property  Deed, in the form attached
hereto as EXHIBIT 5.4

        6.5     TECHNICAL SERVICES AGREEMENT.  At the signing of this Agreement,
Asset Buyer and Asset Seller1 have entered into the Technical Services Agreement
attached hereto as EXHIBIT 5.5

        6.6     TOLL MANUFACTURING  AGREEMENT. At the signing of this Agreement,
Asset Buyer and Asset Seller1 have entered into the Toll Manufacturing Agreement
attached hereto as EXHIBIT 5.6

        6.7     GMP AGREEMENT. At the signing of this Agreement, Asset Buyer and
Asset  Seller1  shall have entered  into the GMP  Agreement  attached  hereto as
EXHIBIT 6.7.

        6.8     UNDERTAKING  AND  AGREEMENT IN RELATION TO THE USE AND OPERATION
OF ACQUIRED ASSETS. (a) Asset Buyer undertakes to comply at all times with Asset
Sellers' safety,  health,  environmental  and technical  standards.  Asset Buyer
further  undertakes  to only produce  products

        Seigfried Asset Purchase Agreement                                    13




and use  substances in respect of which Asset Buyer can  demonstrate  that their
production,  use and  handling on site is and will be in  compliance  with Asset
Sellers'  safety,  health  and  environmental  standards  as well as with  Asset
Sellers' permit framework.

        (b)     Asset  Seller  1  shall  have  the  right  to  use  ***%  of the
production  capacity of the Acquired  Assets for Siegfried's  production.  Asset
Seller 1 shall pay Asset Buyer for Asset  Buyer's *** costs  including  material
costs and costs charged pursuant to the Technical Services Agreement. This right
shall include the pro rata use of  Transferred  Employees ***. In the event that
more production capacity is available Asset Buyer may offer to Asset Seller 1 to
use it at the same  cost  terms as for the  right to use ***% of the  production
capacity,  including the right to make pro rata use of the Transferred Employees
***.

        6.9     MAINTENANCE AND CAPITAL INVESTMENTS.  Asset Sellers have advised
Asset Buyer that the estimated cost in order to maintain the Acquired  Assets in
a condition  similar to their current  condition for the  foreseeable  future is
around CHF *** for the next *** year period;  it is estimated  that the value of
the replacement  investments will amount to approximately CHF ***. These figures
are estimates and for information only.

        6.10    INSURANCE.  Asset  Sellers  undertake to maintain and insure all
assets not expressly  forming part of the Acquired Assets,  including all assets
in or for common  use.  Asset  Sellers  further  undertake  to keep  appropriate
insurance  cover for all property and assets in Asset Sellers' care,  custody or
control.  The  premiums  and costs shall be shared among the Parties pro rata to
their interest share in the Acquired Assets and non transferred assets. The Real
Property insurance will be maintained by Asset Seller 2, insuring Asset Seller 2
and  Asset  Buyer  each for  their  respective  ownership  interest  in the Real
Property.  Asset Buyer undertakes to maintain and insure all Acquired Assets and
to maintain appropriate  insurance cover for all Acquired Assets,  except to the
extent insured by Asset Sellers'.

        6.11    ENVIRONMENTAL.  Asset  Buyer and  Asset  Sellers  agree  that in
relation to any pollution or contamination  in, on or above the land of the Real
Property  existing  before the Closing  (including,  for the sake of clarity any
pollution or contamination with asbestos), as mentioned in the Siegfried reports
from Pit Hofer dated 28 August 2001 ("Altlasten-Voruntersuchung") and updated on
6 February 2002 and on 6 January 2004 and since the site is presently  mentioned
in the cantonal  register of polluted  sites,  Asset Sellers shall be solely and
exclusively  liable for the  payment  of any  investigation  expenses  or of any
excavation,  depollution  or  sanitation  costs  and for  any and all  liability
created  either to Asset Buyer or to any third  parties or public  entities  for
damages  and cost  incurred  by Asset  Buyer or such  third  parties  or  public
entities as a result of any such pollution or contamination existing at Closing,
as well as for any and all cost of  remediation  to be undertaken  upon order of
the competent authority or voluntarily  undertaken as reasonably required in any
given  circumstances.  In the event of any

        Seigfried Asset Purchase Agreement                                    14




new  pollution or  contamination  in, on or above the land of the Real  Property
being  created  after  the  Closing,  while  Asset  Buyer  is  owner of the Real
Property,  liability  shall  extend  exclusively  to the Party  causing or being
otherwise  responsible  for such  pollution  - e.g.  based on art.  55 CO - (the
"POLLUTER")  and any and all cost of remediation to be undertaken  upon order of
the competent  authority or upon  unilateral  but  reasonable  request of either
Party shall be borne by the Polluter. If more than one Party is a Polluter, then
such  Polluters  shall  share  in the  liability  to  third  parties  and in any
remediation  cost in accordance with their  contribution in the causation of the
liability or cost and, if applicable, in accordance with their responsibility on
other grounds - e.g.  based on art. 55 CO.  However,  any possible  liability of
Asset  Buyer  for such a new  pollution  or  contamination  shall be in any case
extinguished  *** years after the sale of the Real  Property to any Asset Seller
or to any third  party,  except for  liability  of Asset  Buyer to  persons  and
entities other than Asset Sellers. In addition, to the extent responsibility for
any  new  pollution  or  contamination  created  after  the  Closing  cannot  be
attributed to a Party as set forth in this  Article,  liability to third parties
or public  entities  and cost for  remediation  shall be  attributed  solely and
exclusively to the Asset Sellers.  Notwithstanding  the above, during the period
of *** years  after the sale of the Real  Property  by Asset  Buyer to any Asset
Sellers  or to any third  party,  Asset  Buyer  shall  only be  responsible  for
pollution or contamination  that (a) Asset Sellers can prove originates from the
period of Asset Buyer's  ownership of the Real Property , and (b)  constitutes a
pollution  or  contamination  comprising  of ***, its  intermediates  or another
product (or  intermediate  thereof)  produced by Asset Buyer and not produced by
Asset Sellers.

        6.12    SALE BACK  OPTION OF ASSET  BUYER.  (a) Upon  serving *** months
written  notice,  Asset Buyer shall for a period of *** months have the right to
sell the Real Property back to any of the two Asset Sellers for *** Swiss Franc,
the  first  time  upon  the  fifth  anniversary  of the  Closing  and  then  ***
thereafter,  provided that the Real Property shall not have a *** due to a cause
attributable to Asset Buyer. In any event,  any  contamination or pollution that
is not  exclusively  attributable to Asset Buyer shall not be taken into account
while assessing the value of the Acquired  Assets.  Such *** shall be determined
by an international  audit or valuation firm mutually  agreeable by the Parties.
In the event of a *** Asset  Sellers  would be entitled to refuse to  repurchase
the Real Property.

(b) Upon serving *** months  written  notice,  Asset Buyer shall for a period of
*** months have the right to sell all  Technical  Equipment  and Other  Tangible
Personal  Property  back to Asset Seller 1 for *** Swiss  Franc,  the first time
upon  the  fifth  anniversary  of the  Closing  and then  quarterly  thereafter,
provided that all Technical Equipment and Other Tangible Personal Property shall
not have a *** due to a cause  attributable  to Asset Buyer.  In any event,  any
contamination  or pollution that is not exclusively  attributable to Asset Buyer
shall not be taken  into  account  while  assessing  the  value of the  Acquired
Assets. Such *** shall be determined by an international audit or valuation firm
mutually agreeable by the Parties.

        Seigfried Asset Purchase Agreement                                    15




In the event of a *** Assets  Sellers  would be entitled to refuse to repurchase
all Technical Equipment and Other Tangible Personal Property.

        (c)     The  Parties  shall share  equally all notary and real  property
register fees, as well as all transfer Taxes and other transfer costs.

        (d)     Any of the  instalment  payments  pursuant to ARTICLE 3.2.3 that
have not  become  due up to the moment of  completion  of the sale back  options
hereunder shall be automatically cancelled as of such completion date.

        (e)     The sale  back  option of Asset  Buyer as  provided  under  this
Article for the Real Property shall be incorporated in the Real Property Deed.

        6.13    RIGHT OF FIRST  REFUSAL  OF ASSET  SELLERS.  (a) For a period of
twenty-five  (25) years from the  Closing,  Asset Seller 2 shall have a right of
first refusal ("Vorkaufsrecht") according to art. 216 CO as further specified in
the Real  Property  Deed in relation to the Real  Property,  exercisable  at the
lower of the price offered by a third party buyer or CHF ***. The right of first
refusal shall be entered ("vorgemerkt werden") in the real property register.

        (b)     For a period of  twenty-five  (25)  years  from  Closing,  Asset
Seller 1 shall  have a right of first  refusal  ("Vorkaufsrecht")  in analogy to
art. 216 in relation to all Technical Equipment and Other Tangible Property.

        6.14    ASSET SELLERS' RIGHT TO BUY BACK THE ACQUIRED  ASSETS.  (a) Upon
serving  *** months  written  notice,  Asset  Seller 2 shall for a period of ***
months have the right to buy back the Real  Property sold to Asset Buyer for ***
Swiss  Franc,  the first time upon the ***  anniversary  of the Closing and then
annually upon each  anniversary of the Closing until the 25th anniversary of the
Closing. This right to buy back is to be set forth in the Real Property Deed and
shall be registered ("vorgemerkt werden") in the real property register.

        (b)     Upon serving *** months written notice, Asset Seller 1 shall for
a period  of ***  months  have the  right to buy back "en  bloc"  all  Technical
Equipment  and Other  Tangible  Personal  Property for *** Swiss  Franc,  to the
extent still  available,  the first time upon the *** anniversary of the Closing
and  then  annually  upon  each  anniversary  of  the  Closing  until  the  25th
anniversary of the Closing.

        6.15    COMMUNITY  OF   CO-OWNERS   ("STOCKWERKEIGENTUMERGEMEINSCHAFT").
Asset  Buyer  and  Asset  Seller  2  shall  delegate  one  or  more   authorized
representatives into the meetings of the Community of Co-Owners.

        Seigfried Asset Purchase Agreement                                    16




                                    ARTICLE 7

                                  MISCELLANEOUS

        7.1     ASSIGNMENT.  This  Agreement  may not be assigned  or  otherwise
transferred by either Party without the consent of the other Parties which shall
not be  unreasonably  withheld.  Any  purported  assignment  in violation of the
preceding sentence shall be void. Nothing in this Agreement, express or implied,
is  intended  to or shall  confer  upon any other  Person or Persons any rights,
benefits  or  remedies  of any  nature  whatsoever  under or by  reason  of this
Agreement.

        7.2     EXPENSES.  Except as otherwise specified in this Agreement, each
Party shall bear its own expenses with respect to the transactions  contemplated
by this  Agreement,  including,  without  limitation,  attorneys' fees and other
expenses  related to the  preparation  and  execution of this  Agreement and any
Transaction  Agreement and the completion of this Agreement and any  Transaction
Agreement.  All of the  notary  cost for the  parceling,  the  formation  of the
Stockwerkeigentum  units  in  relation  to the Real  Property  Deed and any real
property  transfer Tax shall be equally  shared between Asset Seller 2 and Asset
Buyer.

        7.3     CONFIDENTIALITY.  During the term of this  Agreement the Parties
shall and shall cause their employees,  representatives and advisors to maintain
in  confidence  the  content of this  Agreement  and the  Ancillary  Agreements,
subject always to the Parties' legal obligations.

        7.4     PUBLIC  ANNOUNCEMENT   PERTAINING  TO  THIS  AGREEMENT  AND  THE
TRANSACTION  AGREEMENTS.  Asset Buyer and Asset  Sellers  shall  consult  before
issuing media releases or otherwise making any public  statements and they shall
not issue any such media release or statement  without the prior approval of the
other, it being  understood that the Parties shall be free to timely comply with
legal  disclosure  requirements  (in particular  with  requirements of the stock
exchanges  where a Party is listed)  without the prior  approval  from the other
Party, in which case such Party shall immediately inform the other Party of such
disclosure requirements and of the contents of the planned disclosure.

        7.5     SEVERABILITY. Each of the provisions contained in this Agreement
shall be  severable,  and the  unenforceability  of one  shall  not  affect  the
enforceability of any others or of the remainder of this Agreement.

        7.6     AMENDMENT.  This Agreement may not be amended,  supplemented  or
otherwise  modified  except by an  instrument  in  writing  signed by all of the
Parties hereto.

        Seigfried Asset Purchase Agreement                                    17




        7.7     WAIVER.  The  failure of any Party to enforce any  condition  or
part of this  Agreement  at any time shall not be  construed as a waiver of that
condition  or part,  nor shall it  forfeit  any  rights  to  future  enforcement
thereof.

        7.8     GOVERNING LAW. This Agreement and all documents  related thereto
shall be  governed  by the laws of  Switzerland,  excluding  the United  Nations
Convention on the  International  Sales of Goods,  except if otherwise stated in
writing in any such related document.

        7.9     TERM OF THIS  AGREEMENT.  This  Agreement  is firm  for a period
expiring at the 25th anniversary of the Closing,  except to the extent otherwise
agreed in writing by the Parties  and except to the extent it becomes  redundant
before.

        7.10    ARBITRATION;  VENUE.  Any and all disputes arising in connection
with this  Agreement  shall be finally  settled by  arbitration  under the Swiss
Rules of International Arbitration of the Swiss Chambers of Commerce in force on
the date when the notice of arbitration is submitted.  The number of arbitrators
shall be three. The seat of the arbitration shall be in Zurich and English shall
be the language of the  arbitration.  If disputes are arising out of or relating
to two or more agreements connected to this Agreement, the same arbitrators will
be appointed in all cases.

        7.11    COUNTERPARTS;  LANGUAGE.  The Parties may execute this Agreement
in one or more counterparts, and each fully executed counterpart shall be deemed
an original.  This Agreement in the English  language  shall be the  controlling
text in as far as allowable under applicable law.

        7.12    NOTICES.  All communications,  notices and consents provided for
herein shall be in writing and be given in person or by means of facsimile (with
request  for  assurance  of  receipt  in  a  manner   typical  with  respect  to
communications  of that type) or by registered  mail or overnight  courier,  and
shall become effective:  (a) on delivery if given in person;  (b) on the date of
transmission  if sent by  facsimile  or (c) upon  receipt if  delivered  through
registered mail or courier service.



        Notices  shall be addressed  as follows:

        If to one or both of the Asset Sellers, to:

                      Siegfried Ltd.
                      Untere Bruhlstrasse 4
                      4800 Zofingen

        Seigfried Asset Purchase Agreement                                    18




        With copy to:          Siegfried Holding Ltd.
                               CFO
                               Untere Bruhlstrasse 4
                               4800 Zofingen

        If to Asset Buyer to:  Celgene Chemicals Sarl
                               Untere Bruhlstrasse 4
                               4800 Zofingen

        With copy to:          Celgene International Sarl
                               Faubourg du Lac 11
                               CH-2000 Neuchatel

        PROVIDED,  HOWEVER,  that if any Party shall have designated a different
        address by notice to the others, then to the last address so designated.



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        Seigfried Asset Purchase Agreement                                    19




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

        ASSET SELLER 1:                     ASSET SELLER 2:

        Siegfried Ltd.                      Siegfried Dienste AG


        By: __________________________      By:  __________________________
        Name:  Hubert Stuckler              Name:  Hans Baumann
        Title: Head Siegfried Actives       Title: Head Engineering


        By: __________________________      By:  __________________________
        Name:  Richard Schindler            Name:  Richard Schindler
        Title: Chief Financial Officer      Title: Chief Financial Officer



        ASSET BUYER:

        Celgene Chemicals Sarl



        By: __________________________
        Name:  Michael Morrissey
        Title: Board Member



        By: __________________________
        Name:  Jurg Oehen
        Title: Board Member

        Seigfried Asset Purchase Agreement                                    20




                                  SCHEDULE 1.1

                                   DEFINITIONS

         "ACQUIRED  ASSETS"  is defined in  ARTICLE  2.1 and  includes  the Real
Property,  on the one hand,  and all  Technical  Equipment  and  Other  Tangible
Personal Property, on the other.

        "AFFILIATE" means, with respect to any Person, any other Person directly
or indirectly  controlling or controlled by, or under direct or indirect  common
control with, such Person.  For purposes of this  definition,  a Person shall be
deemed to control another Person if it owns or controls, directly or indirectly,
at least fifty  percent (50%) of the voting equity of the other Person (or other
comparable ownership if the Person is not a corporation).

        "AGREEMENT"  shall mean this Asset  Purchase  Agreement  (including  its
Schedules), as amended, modified or supplemented from time to time.

        "BUSINESS  DAY" shall mean a day other than a Saturday,  Sunday or other
day on which  commercial  banks in Switzerland are authorized or required by Law
to close.

        "CC" means the Swiss Civil Code  ("Schweizerisches  Zivilgesetzbuch") as
amended from time to time.

        "CLOSING" shall mean the date of consumption of this Agreement as stated
in -ARTICLE 5.1

        "CLOSING DATE" shall have the meaning ascribed to it in ARTICLE 5.1

        "CLOSING PAYMENT" means the payment according to ARTICLE 3.3.1

        "CO"   means   the   Swiss   Code   of   Obligations   ("Schweizerisches
Obligationenrecht") as amended from time to time

        "CONSENT" shall mean any consent, approval, authorization, consultation,
waiver,  permit,  grant,  agreement,  license,  certificate,  exemption,  order,
registration,  declaration,  filing or notice of, with or to any Person or under
any  law,  in each  case  required  to  permit  the  consummation  of any of the
transactions contemplated hereby.

        "ENCUMBRANCE"  shall mean with respect to any Acquired Assets, any lien,
mortgage,  adverse  ownership claim,  restriction,  pledge,  security  interest,
easement, servitude, other encumbrance and/or any other third party rights.

        "GOVERNMENTAL  APPROVAL"  shall  mean  any  Consent  of,  with or to any
Governmental Authority.

        Seigfried Asset Purchase Agreement                                    21




        "GOVERNMENTAL  AUTHORITY" shall mean any federal,  state,  provincial or
local government,  quasi-governmental  authority, or other political subdivision
thereof; any entity,  authority,  instrumentality or body exercising  executive,
legislative,  judicial,  regulatory  or  administrative  functions  of any  such
government, quasi-governmental authority or other political subdivision; and any
supranational  organization  exercising such functions for any sovereign states,
whether international, multinational, regional or otherwise.

        "GOVERNMENTAL  ORDER"  shall  mean,  with  respect  to any  Person,  any
judgment, order, writ, injunction, decree, stipulation, agreement, determination
or award entered or issued by or with any Governmental  Authority and binding on
such Person.

        "GUARANTY" shall mean the Guaranty  according to ARTICLE 4 and set forth
on EXHIBIT 4.

        "PERMITS" shall mean licenses,  consents,  approvals,  permits and other
Governmental Approvals.

        "PERMITTED ENCUMBRANCE" shall mean exclusively easements, encroachments,
restrictions of way,  servitudes or other restrictions valid by virtue of law or
registered in the real property register, as well as zoning,  building and other
similar public law restrictions.

        "PERSON"  shall mean an  individual  or a legal entity or a  quasi-legal
entity such as a partnership.

        "POLLUTER" is defined in ARTICLE 6.11.

        "PRODUCTS" shall mean *** and ***.

        "PURCHASE PRICE" is defined in ARTICLE 3.1.

        "REAL PROPERTY" is defined in ARTICLE 2.1(A).

        "REAL PROPERTY DEED" is defined in ARTICLE 6.4 and shown as EXHIBIT 6.4.

        "REGISTRATIONS" shall mean the product  registrations  currently held by
Asset Sellers relating to the Products, issued by the Governmental Authorities.

        "REGULATORY  DOCUMENTATION"  shall mean,  in relation to Products or the
Acquired Assets, the Registrations supported by and including:  (i) the original
documents  under the possession of Asset Seller (or that are accessible to Asset
Seller using  commercially  reasonable  efforts)  evidencing  the  Registrations
issued to Asset Seller by a Governmental  Authority,  in each case to the extent
assignable  with or without the consent of the issuing  Governmental  Authority;
and (ii) all related  Registration  applications,  clinical  research  and trial
agreements and other documentation,  research tools, laboratory notebooks, files
and correspondence with regulatory

        Seigfried Asset Purchase Agreement                                    22




agencies  and  quality  reports  and  all  relevant   pricing   information  and
correspondence  with  Governmental  Authorities  with  respect  to such  pricing
matters.

        "TAX OR  TAXES"  shall  mean any  taxes of any kind  including,  but not
limited to those measured on, measured by or referred to as, income, alternative
or add-on  minimum,  gross  receipts,  capital,  capital gains,  sales,  use, ad
valorem, franchise, profits, license, privilege, transfer, withholding, payroll,
employment, social, excise, severance, stamp, occupation,  premium, value added,
property,  environmental or windfall profits taxes,  customs,  duties or similar
fees, assessments or charges of any kind whatsoever,  together with any interest
and  any  penalties,  additions  to tax or  additional  amounts  imposed  by any
Governmental Authority.

        "TECHNICAL  EQUIPMENT  AND  OTHER  TANGIBLE  PROPERTY"  shall  mean  all
tangible personal property, including machinery, equipment, mechanical and spare
parts, supplies, fixtures, tools and other tangible property of any kind held by
Asset Seller to the extent listed on SCHEDULE 2.1 (b)

         "TRANSACTIONS  AGREEMENTS"  shall mean the Real  Property  Deed and the
agreements and  undertakings  shown in Exhibits to this  Agreement,  as amended,
modified or supplemented from time to time.

        "TRANSFERRED EMPLOYEES" is defined in ARTICLE 6.2.



        Seigfried Asset Purchase Agreement                                    23