FORM OF NON-EMPLOYEE DIRECTOR CHANGE OF CONTROL AGREEMENT

Exhibit 10.15

COLEY PHARMACEUTICAL GROUP, INC.

Non-Employee Director Change of Control Agreement

This Non-Employee Director Change of Control Agreement, effective as of is entered into by and between Coley Pharmaceutical Group, Inc., a Delaware corporation (the “Company”), with its principal offices located at 20 William Street, Suite 115, Wellesley, Massachusetts 02481, and                     , residing at                                                  .

The Director is a non-employee member of the Board of Directors of the Company and the Company and the Director desire to arrange for certain provisions applicable in the event that the Director’s service on the Company’s Board of Directors terminates under the circumstances provided herein.

Accordingly, the parties hereto agree as follows:

1. Change of Control. For purposes of this Agreement, a “Change of Control” shall mean the occurrence of any one of the following:

1.1. the acquisition by any “person” (as such term is defined in Section 3(a)(9) of the Securities Exchange Act of 1934), other than the Company or its affiliates, from any party of an amount of the capital stock of the Company, so that such person holds or controls 50% or more of the Company’s capital stock; or

1.2. a merger or similar combination between the Company and another entity after which 50% or more of the voting stock of the surviving corporation is held by persons other than the Company or its affiliates; or

1.3. a merger or similar combination (other than with the Company) in which the Company is not the surviving corporation; or

1.4. the sale of all or substantially all of the Company’s assets or business.

2. If the Director’s service on the Board of Directors of the Company is terminated pursuant to a transaction resulting in a Change of Control, then the following provisions shall apply:

2.1. Option Vesting. 100% of any options to purchase shares of Common Stock of the Company then held by the Director, which options are then subject to vesting, shall, notwithstanding any contrary provision in the option agreement or stock option plan pursuant to which such options had been granted, be accelerated and become fully vested and exercisable on the date immediately preceding the effective date of such termination. All other terms of the Director’s options shall remain in full force and effect.

2.2. Lapsing Purchase Right. If, on the date immediately preceding the effective date of such termination, the Director then holds (i) any shares of Common Stock of the Company received upon exercise of stock options granted to the Director, which shares are

subject to a “Lapsing Purchase Right,” and/or (ii) any outstanding options to purchase shares of Common Stock of the Company, which, upon exercise thereof, would result in the issuance to the Director of shares of Common Stock subject to a “Lapsing Purchase Right,” then, notwithstanding any contrary provision in the relevant option agreement or stock option plan pursuant to which such options had been granted, such Lapsing Purchase Right shall expire in its entirety, with respect to shares of Common Stock then outstanding and with respect to shares of Common Stock issuable upon exercise of outstanding stock options, on the date immediately preceding the date of termination and all of such shares of Common Stock shall become transferable free of restriction (upon issuance, in the case of the exercise of outstanding stock options), subject to the applicable provisions of federal and state securities laws. All other terms of the Director’s options shall remain in full force and effect.