Exhibit 10.106



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|---- |  | --------------------------------------------------------------------------------------------------------------------------------------------
|LOGO |  | WIL House, Shannon Business Park, Shannon,
County Clare, Ireland T (+353 61) 362533, (+353 1) 709 4040 F (+353 61) 362097, (+353 1) 709 4083



May 17, 2004



Incara Pharmaceuticals Corporation

P.O. Box 14287

79 T.W. Alexander Drive

4401 Research Commons, Suite 200

Research Triangle Park, North Carolina
27709

Attn: Richard Reichow, Secretary



Fax: (919) 558-8686



Dear Mr. Reichow:



Under Section 5(b) of the
Securities Purchase Agreement dated as of December 21, 2000 among Incara Pharmaceuticals Corporation (Incara), Elan International Services, Ltd. (EIS) and Elan Pharma International Limited (EPIL), so long as EIS
or its affiliates, directly or indirectly, collectively own at least 5% of Incara on a fully diluted basis EIS shall be entitled to nominate one director for election to Incaras board of directors.



EIS has not previously exercised such right and by this letter EIS and EPIL renounce the
right granted to EIS under Section 5(b) to nominate a director and covenant that EIS will not exercise such renounced right or attempt to assign or assign such renounced right to any person or entity. EIS and EPIL represent and warrant that no other
entity has been assigned such renounced right prior to the date of this letter and that, other than EIS, no person or entity, including any affiliate of EIS or EPIL, has any right, claim or interest in or to such renounced right.



Please file this letter in your corporate records. If you have any questions please call EIS
or EPIL. Thank you for your attention to this matter.



|                                     |  |                                   |  |        |  |                
|------------------------------------ |  | --------------------------------- |  | ------ |  | ---------------
|Elan International Services, Limited |  | Elan Pharma International Limited
|                                     |  |                                   | 
|By:                                  |  | /s/ D.M. Buryj                    |  | By:    |  | /s/ Liam Daniel
|Name:                                |  | D.M. Buryj                        |  | Name:  |  | Liam Daniel    
|Title:                               |  | Vice President                    |  | Title: |  | Director       



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|-------------------------------- |  | ------------------------------------------------------------------------
|                                 |  | Elan Pharma International Limited                                       
|                                 |  | a member of the Elan Group                                              
|                                 | 
|                                 |  | Directors: P. Breen, S. Cooke, W.F. Daniel,                             
|BIOPHARMACEUTICALS·DRUG DELIVERY |  | S. Mulligan, M. OReilly.                                               
|                                 | 
|                                 |  | Registered Office: WIL House, Shannon Business Park, Shannon, Co. Claire
|                                 | 
|                                 |  | Registered in Ireland, No. 222276