**Exhibit 10.23**

**[ * ] = Certainconfidential information contained in this document, marked by brackets, hasbeen omitted and filed separately with the Securities and Exchange Commissionpursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended.**

May18, 2001

Biosearch Italia, S.p.A.Via Lepetit, 3421040 GerenzanoItaly

Re:  License and Supply Agreement betweenIntraBiotics Pharmaceuticals, Inc. (“IntraBiotics”) and Biosearch Italia,S.p.A. (“Biosearch”) dated as of May 8, 1998 (the “Agreement”)

Ladiesand Gentlemen:

InMay 1998, IntraBiotics and Biosearch entered into the Agreement to permitIntraBiotics to develop and commercialize, in the United States and Canada,formulations other than [*] formulations of Biosearch’s proprietary compound,Ramoplanin, for the treatment or prevention of infectious diseases andconditions in humans.  Since that time,IntraBiotics has worked for the Development of Licensed Products, including commencingclinical trials for oral Ramoplanin as a treatment for vancomycin resistant *Enterococcusfaecium* (“VRE”). IntraBiotics has now determined that because of limited cash resourcesand higher than expected program expenses, IntraBiotics must terminate suchtrials immediately to conserve resources. Accordingly, Biosearch intends toreacquire, at the terms specified hereinbelow, the rights in and to theLicensed Compound and/or Licensed Products granted to IntraBiotics under theAgreement.  The foregoingnotwithstanding, IntraBiotics shall, for a certain transition period, continuethe development of Ramoplanin in order to avoid any interruption of the relatedactivities and enable Biosearch to continue and complete under its control theDevelopment and Commercialization contemplated in the Agreement; and in thisperspective Biosearch is ready to advance to IntraBiotics the related necessarycosts. Accordingly, IntraBiotics and Biosearch hereby agree to amend theAgreement as follows:
| 1.     | **Definitions.**Unless otherwise expressly provided herein, defined  terms used in this Amendment shall have the same meaning as set forth in the  Agreement, and all terms herein shall be incorporated into the Agreement. |
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| 2.     | The following new **Article 15**** Transition Period**  shall  be added to the agreement as follows:                                                                                                               |

**“15.1  Reacquisition of Licensed Products.**The Parties hereby acknowledge and agree that effective upon expiration of theTransition Period (as hereinafter defined) IntraBiotics’ rights under Sections5.1 and 5.3 of the Agreement with respect to Licensed Products (but not TopicalProducts) shall be terminated and will revert to Biosearch, subject toIntraBiotics’ option rights under Section 15.6.  Thereafter, Biosearch will have the right to conduct Developmentand Commercialization of Licensed Products (but not Topical Products) subjectto a royalty obligation to IntraBiotics as set forth in Section 15.9.  During the period [*], IntraBiotics willretain the rights and licenses granted it under Sections 5.1 and 5.3 of theAgreement to conduct Development and Commercialization of Topical Products,subject to Sections 15.6 and 15.8.2.

**15.2  Transition Period. **EffectiveJune 1, 2001 through and including August 31, 2001, (the “Transition Period”),Biosearch shall be responsible for paying [*] incurred by IntraBiotics’ inconnection with Development of Licensed Products for treatment of vancomycinresistant *Enterococcusfaecium* (“VRE”) in humans as set forth in Article 2 of the Agreementduring the Transition Period.  AppendixA attached hereto sets forth a description of the specific activities to bepaid for by Biosearch.  IntraBioticswill continue to perform such Development activities with respect to treatmentof VRE during the Transition Period, or any extension thereof, so as to avoidany interruption of the activities undertaken and enable continuation of theDevelopment thereafter by or under the control of Biosearch or its licensees,aimed at achieving the milestones contemplated in Section 4.2 for LicensedProducts for treatment of VRE.

**15.3     Action during Transition Period.**During the Transition Period or any mutually agreed extension thereof,IntraBiotics will undertake such actions as are reasonable and necessary inorder to enable it, upon expiration of the Transition Period, to (i) completetransfer to Biosearch of responsibility for conducting the Development andCommercialization of Licensed Products (but not Topical Products); (ii) provideall Information regarding its Development of Licensed Products, or which isnecessary to obtain Regulatory Approval of such Licensed Products in theTerritory, not already provided to Biosearch pursuant to Section 2.2(c) of theAgreement; and (iii) assign to Biosearch as of the date of such expiration allright, title and interest in and to any regulatory filings in the Territorypertaining to Licensed Products (but not Topical Products).  Biosearch will be responsible for [*]incurred by IntraBiotics in connection with the transition activities describedin (i)-(iii) above. Should the transfer procedure indicated above not becompleted by August 31, 2001, the two parties shall mutually agree on theappropriate extension to enable completion, and update Appendix A accordingly.
**15.4     Development Expense Reports**.  IntraBiotics will provide to Biosearch [*]reports of expenses incurred in connection with IntraBiotics’ Development andtransition activities under Section 15.2 and 15.3.  Such reports will be provided [*] after [*] to which the reportpertains.  IntraBiotics will allow oneor more persons designated by Biosearch to monitor the progress of theDevelopment activities and to have reasonable access to the facilities ofIntraBiotics, during normal business hours and upon reasonable advance notice,accordingly.

**15.5     IntraBiotics’ Option to Reacquire Rights to Licensed Product.**   During the period from [*], IntraBioticswill have an exclusive option to reacquire the right to conduct the Developmentand Commercialization of Licensed Products in the Territory and in the Field(the “Reacquisition Option”).  IntraBioticsmay exercise the Reacquisition Option by notifying BioSearch in writing of suchexercise not later than [*], and delivering to Biosearch (i) [*]; and (ii)written objective evidence that either (a) [*] or (b) [*]. As consideration forthe Reacquisition Option, IntraBiotics will pay to Biosearch, concurrent withIntraBiotics’ exercise of its Reacquisition Option, [*].  Upon IntraBiotics’ timely exercise of itsReacquisition Option, Sections 15.6, 15.7 and 15.8 shall be of no further forceor effect.  All materials disclosed toBiosearch in connection with IntraBiotics’ exercise of its option hereundershall be subject to the confidentiality provisions of Section 9.

**15.6     IntraBiotics’ Rights to Topical Product. **Commencingon the expiration of the Transition Period, IntraBiotics’ rights under Sections5.1 and 5.3 and obligations under this Agreement to conduct Development andCommercialization of Licensed Products shall apply only to Topical Products inthe Territory and in the Field.  IfIntraBiotics timely exercises its Reacquisition Option as set forth in Section15.5, or commences clinical development activity with respect to [*], thenIntraBiotics will retain its right to develop Topical Products until theexpiration or earlier termination of this Agreement pursuant to Section11.  If IntraBiotics does not timelyexercise its Reacquisition Option, and does not start any clinical developmentactivity for Topical Products by [*], then all rights in and to TopicalProducts shall revert to Biosearch effective [*], and IntraBiotics shall haveno rights to make, have made, use, import, offer, sell, offer for sale and havesold Licensed Products in the Field and in the Territory.  The foregoing notwithstanding, IntraBioticsshall be entitled to extend the expiration of the term specified herein from[*] provided it has given, prior to [*].

**15.7     Effect of Expiration of the Transition Period**.  Upon expiration of the Transition Period, orany extension thereof, all rights in and to Licensed Products other than TopicalProducts shall revert to Biosearch effective upon such expiration, andIntraBiotics shall have no rights to make, have made, use, import, offer, sell,offer for sale and have sold Licensed Products other than Topical Products inthe Field and in the Territory, subject to IntraBiotics’ option rights underSection 15.5.

**15.8     Effect of Termination of IntraBiotics’ Development andCommercialization Rights and Obligations.**

**15.8.1 **Upon expiration of theTransition Period, or any extension thereof, and if IntraBiotics does nottimely exercise its Reacquisition Option:

**15.8.1.1           **all rights and licensesgranted to IntraBiotics under Article 5 with respect to Licensed Product otherthan Topical Product shall terminate and revert to Biosearch, and Biosearch’sobligations under Section 3.1(a) of the Agreement shall terminate and be of nofurther force or effect;

**15.8.1.2           **IntraBiotics shall, atBiosearch’s request, return to Biosearch or destroy all Biosearch Informationand any other Confidential Information relating to such Licensed Product otherthan Topical Product, and any Bulk Licensed Compound supplied by Biosearch forclinical development or commercial distribution of such Licensed Product otherthan Topical Product;

**15.8.1.3           **IntraBiotics shall haveno further rights or obligations under this Agreement to conduct Development orCommercialization activities or to manufacture Licensed Compound for LicensedProduct other than Topical Product in the Field and in the Territory;

**15.8.1.4           **IntraBiotics shall haveno further obligation to make milestone payments with respect to LicensedProducts that are not Topical Products under Section 4.2 of this Agreement thatare not due and payable as of the expiration of the Transition Period, or anyextension thereof;

**15.8.1.5           **Biosearch shall have noobligation to manufacture and supply Bulk Licensed Compounds for LicensedProduct other than Topical Product to IntraBiotics in the Field and in theTerritory.

**             15.8.2 **Thereafter, ifIntraBiotics does not commence clinical development of [*], then:

**15.8.2.1           **all rights and licensesgranted to IntraBiotics under Article 5 with respect to Topical Informationrelating to such Topical Product, and any Bulk Licensed Compound supplied byBiosearch for clinical development or commercial distribution of such TopicalProduct;

**15.8.2.2           **IntraBiotics shall haveno further rights or obligations under the Agreement to conduct Development orCommercialization activities or to manufacture Licensed Compound for TopicalProduct in the Field and in the Territory;

**15.8.2.3           **IntraBiotics shall haveno further obligation to make milestone payments under Section 4.2 of thisAgreement with respect to Topical Products that are not due and payable as ofthe expiration of the Transition Period;

**15.8.2.4           **Biosearch shall have noobligation to manufacture and supply Bulk Licensed Compounds for TopicalProduct to IntraBiotics in the Field and in the Territory;

**15.9     Compensation**.  In consideration for the Development workperformed by IntraBiotics with respect to Licensed Products in the Field,Biosearch shall pay to IntraBiotics (a) starting from the execution of thisAmendment, [*], the corresponding amounts for such months calculated accordingto Appendix A attached hereto, [*] upon which IntraBiotics will draw to fundthe Development work for the ongoing VRE BSI prevention Phase III trial; (b)[*]; and (c) upon Commercialization of Licensed Product other than TopicalProduct [*], royalties [*] of Biosearch’s Net Sales of such Licensed Product[*], until the later of (x) the date upon which the last to expire of theBiosearch Patents and IntraBiotics Patents covering the manufacture, use, sale,offer for sale or import of such Licensed Product in such country expires, or(y) [*] after first commercial sale of such Licensed Product in suchcountry.  If, upon completion of alltransition activities required to be performed under Section 15.3, [*],IntraBiotics will [*].  For the purposeshereof, “Biosearch Net Sales” shall mean the amount invoiced for sales of aLicensed Product other than a Topical Product in final dosage form byBiosearch, its Affiliates or its licensees to a Third Party end user, less (i)discounts, including cash discounts, or rebates (including government-mandatedrebates), retroactive price reductions or allowances actually allowed orgranted from the billed amount, (ii) credits or allowances actually grantedupon claims, rejections or returns of such Licensed Products, includingrecalls, (iii) freight, postage, shipping and insurance charges paid fordelivery of such Licensed Product, to the extent billed, and (iv) taxes, dutiesor other governmental charges levied on or measured by the billing amount whenincluded in billing, as adjusted for rebates and refunds. The provisions ofSections 8.4(b) – 8.8 shall apply to Biosearch with respect to any amountspayable by Biosearch.

3.          A new Section 1.33 shall be added asfollows:

**1.33  *“Topical Product*”**meansany product including or incorporating the Licensed Compound in a form orformulation suitable solely for topical and external use (such as gel, creams,sprays, and the like), including product delivered transdermally.

 
4.Effective as from the expiration of the  Transition Period or any extension thereof and provided that IntraBiotics  does not exercise its option pursuant to Section 15.5, Section 1.10 shall be  deleted in its entirety and shall be replaced with the following:
**“1.10 “*Excluded Formulations*”**means any formulation of the Licensed Compound except those suitable solely fortopical and external use (such as gel, creams, sprays, and the like).
5.Section 11.4 shall be deleted in its  entirety and shall be replaced with the following:
             **11.4**     **Effect of Termination**

                           **(a)**         Upon termination ofthis Agreement by BioSearch for IntraBiotics’ material breach pursuant toSection 11.2 or by IntraBiotics pursuant to Section 11.3, [which terminationoccurs while IntraBiotics is developing or commercializing a Licensed Product,all rights and licenses granted to IntraBiotics with respect to the LicensedProduct under Article 5 shall terminate. Furthermore, upon termination by BioSearch pursuant to Section 11.2 orby IntraBiotics pursuant to Section 11.3 at any time, IntraBiotics shall payall sums accrued hereunder which are then due (except as expressly otherwiseprovided in this Agreement), and IntraBiotics shall promptly assign toBioSearch all right, title and interest in and to any regulatory filings in theTerritory pertaining to Licensed Products and shall deliver to BioSearch anyIntraBiotics Information necessary to obtain the Regulatory Approval ofLicensed Products in the Territory which has not been obtained as of the dateof termination.  If this Agreement isterminated by BioSearch pursuant to Section 11.2 or by IntraBiotics pursuant toSection 11.3 at any time, IntraBiotics shall return to BioSearch, or atBioSearch’s request destroy, all BioSearch Information and any otherConfidential Information relating to the Licensed Compound or LicensedProducts, and any Bulk Licensed Compound supplied by BioSearch for clinicaldevelopment or commercial distribution.

             **             (b)**Upon termination of this Agreement by IntraBiotics for BioSearch’smaterial breach pursuant to Section 11.2, which termination occurs whileIntraBiotics is developing or commercializing a Licensed Product, all licensesgranted to IntraBiotics shall survive, subject to the payment of a royalty toBioSearch equal to [*] of Licensed Products by BioSearch, its Affiliates orsublicensees, [*].  The provisions ofSections 8.4 through 8.8 shall apply with respect to any such royalties payableunder this Section 11.4(b).  IfBioSearch is manufacturing Licensed Bulk Compound at the time of anytermination by IntraBiotics of this Agreement for BioSearch’s material breach,BioSearch shall continue to provide for manufacture of Bulk Licensed Compoundto the extent provided prior to notice of such termination until such time asIntraBiotics is able to secure an equivalent alternative commercialmanufacturing source for the Territory, as requested by IntraBiotics; *provided,however,* that IntraBiotics shall pay to BioSearch [*] plus anadditional [*] thereof.  Further, uponIntraBiotics’ request, BioSearch shall provide such technical assistance asneeded by IntraBiotics to commence manufacture of Bulk Licensed Compound, at[*].
6.If IntraBiotics does not [*], and does  not [*] by [*], then Sections  10.2,  10.5, 10.6, 10.7 and 10.8 shall expire and shall be of no further force or  effect.
7.          The following new Section 13.4 shallbe inserted after Section 13.3:

**13.4  Indemnification after the TransitionPeriod. **Uponexpiration of the Transition Period, or any extension thereof, then withrespect to Licensed Products to which Biosearch has reacquired the right tomake, have made, use import, sell, offer, offer for sale and have sold in theField and in the Territory, the following indemnification provisions shallapply:

             **(a) Indemnification by Biosearch.**  Biosearch hereby agrees to indemnify, holdharmless and defend IntraBiotics against any and all expenses, costs of defense(including without limitation attorneys’ fees, witness fees, damages,judgments, fines and amounts paid in settlement) and any amounts IntraBioticsbecomes legally obligated to pay because of any Third Party claim or claimsagainst it to the extent that such claim or claims result from (i) Biosearch’snegligence, (ii) Biosearch’s breach or alleged breach of any representation orwarranty by Biosearch or of any other provision of the Agreement, or (iii) thepossession, manufacture, use, handling, storage, sale, administration or otherdisposition of Bulk Licensed Compound or of products containing the LicensedCompound by Biosearch, its agents or licensees or sublicensees (other thanIntraBiotics), except to the extent such claim or claims arise from thenegligence, recklessness or willful misconduct of IntraBiotics or any breach ofany representation or warranty of IntraBiotics made pursuant to Section 12 ofthe Agreement; provided that IntraBiotics provides Biosearch with prompt noticeof any such claim and the exclusive ability to defend (with the reasonablecooperation of IntraBiotics) and settle any such claim.

             **(b)Indemnification by IntraBiotics. **IntraBiotics hereby agrees to indemnify, holdharmless and defend Biosearch against any and all expenses, costs of defense(including without limitation attorneys’ fees, witness fees, damages,judgments, fines and amounts paid in settlement) and any amounts Biosearchbecomes legally obligated to pay because of any Third Party claim or claimsagainst it to the extent that such claim or claims arise out of (i)IntraBiotics’ negligence, recklessness or willful misconduct or (ii)IntraBiotics’ breach or alleged breach of any representation or warranty byIntraBiotics or of any other provision of the Agreement; provided thatBiosearch provides IntraBiotics with prompt notice of any such claim and theexclusive ability to defend (with the reasonable cooperation of Biosearch) orsettle any such claim, and provided further that such indemnities shall notapply to losses resulting from Biosearch matters covered under Section 13.1above.

             **(c)****Mechanics.** The provisions ofSection 13.3 of the Agreement shall apply in the event the Parties cannot agreeas to the identification of any particular loss or claim.

8.          IntraBiotics’ notice address as setforth in Section 14.9 is hereby amended in part as follows:

IntraBioticsPharmaceuticals, Inc.2021 Stierlin CourtMountain View, CA  94043Attention:  Chief Executive OfficerTelephone:  (650) 526-6800Telecopy:  (650) 969-0663

9.          Except as otherwise amended herein,the Agreement shall remain in full force and effect.
10.This Amendment may be signed by  facsimile and in one or more counterparts, each of which shall be deemed an  original, and all of which together shall constitute a single instrument.
ThisAmendment shall be effective as of June 1, 2001.
Sincerely,Acknowledged and Agreed:  /s/ Kenneth J. Kelley/s/ Claudio QuartaKenneth  J. KelleyClaudio  QuartaIntraBiotics Pharmaceuticals, Inc.Biosearch Italia, S.p.A.   May 28, 2001 May 28, 2001 DateDate
 

             **Attachment A**

             **Ramoplanin VRE Program BudgetAnalysis(from BI perspective of IBPI proposed aggreement)**

             [*]
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[ * ] = Certain confidential information contained inthis document, marked by brackets, has been omitted and filed separately withthe Securities and Exchange Commission pursuant to Rule 24b-2 of the SecuritiesExchange Act of 1934, as amended.