Common use of XXXXXX Xxxsident Clause in Contracts

XXXXXX Xxxsident. February 26, 1999 Dr. Xxxxxxx Xxxxx 00 Mxxxxxxx Xxxxxx Xxxxxx, MA 02459 Dear Ely: Xlease acknowledge the following changes to our License and Consulting Agreement dated September 30, 1994: - Effective January 1, 1999, the consulting fee will be raised to $ [CONFIDENTIAL TREATMENT REQUESTED] /*/ per hour. - The Minimum Royalty, as specified in Exhibit B, will be changed for the year 1998 only from $ [CONFIDENTIAL TREATMENT REQUESTED] /*/ to [CONFIDENTIAL TREATMENT REQUESTED] /*/. The rest of the Minimum Royalty schedule will remain unchanged. Please sign both copies of this letter and return one to me. Sincerely, /s/ Mark X. Xxxxxx President /s/ Emanxxx X. Xxxxx ---------------------------- Emanxxx X. Xxxxx /*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 PROMULGATED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. 2

XXXXXX Xxxsident. February 26, 1999 Dr. Xxxxxxx Xxxxx 00 Mxxxxxxx Xxxxxx Xxxxxx, MA 02459 [CONFIDENTIAL TREATMENT REQUESTED]/*/ [CONFIDENTIAL TREATMENT REQUESTED]/*/ Dear Ely: Xlease acknowledge the following changes to our License and Consulting Agreement dated September 30, 1994: - Effective January 1, 1999, the consulting fee will be raised to $ [CONFIDENTIAL TREATMENT REQUESTED] /*/ per hour. - The Minimum Royalty, as specified in Exhibit B, will be changed for the year 1998 only from $ [CONFIDENTIAL TREATMENT REQUESTED] /*/ to [CONFIDENTIAL TREATMENT REQUESTED] /*/. The rest of the Minimum Royalty schedule will remain unchanged. Please sign both copies of this letter and return one to me. Sincerely, /s/ Mark X. Xxxxxx President /s/ Emanxxx X. Xxxxx ---------------------------- Emanxxx X. Xxxxx /*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 PROMULGATED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. 2