Invitations

Exhibit 10.6

August 11, 2000

Douglas A. Melton, Ph.D.

Department of Molecular and Cellular Biology

Harvard University

Howard Hughes Medical Institute

7 Divinity Avenue

Cambridge, Massachusetts 02138

Dear Doug,

On behalf of Curis, Inc., I would like to extent two important invitations:

First, I would like to invite to you to become a member of Curis’ Board of Directors. It would be a privilege and a pleasure to have you join our professional panel. Your tenure and experience would certainly be a valuable contribution to the organization.

As a member of Curis’ Board, you would receive cash payments in the amount of an annual retainer of $10,000, as well as $1,000 for each board of directors meeting attended in person, and $500 for board meetings held by telephone conference call.

You would also