EX-99.(a)(1)(iv)

THE OFFER AND WITHDRAWAL RIGHTS EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, AT THE END OF THE DAY ON FRIDAY, SEPTEMBER 26, 2014, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED.

We have been engaged by Klee Acquisition Corporation, a Delaware corporation (“Purchaser”) and a wholly owned subsidiary of Roche Holdings, Inc., a Delaware corporation (“Parent”), to act as the dealer manager (the “Dealer Manager”) in connection with Purchaser’s offer to purchase all outstanding shares of common stock, par value $0.001 per share (the “Shares”), of InterMune, Inc., a Delaware corporation (“InterMune”), at a purchase price of $74.00 per Share (the “Offer Price”), net to the seller in cash, without interest, subject to any required withholding of taxes and upon the terms and subject to the conditions set forth in the Offer to Purchase dated August 29, 2014 (as it may be amended or supplemented from time to time, the “Offer to Purchase”) and the related Letter of Transmittal (as it may be amended or supplemented from time to time, the “Letter of Transmittal” and, together with the Offer to Purchase, the “Offer”) enclosed herewith.

Please furnish copies of the enclosed materials to those of your clients for whose accounts you hold Shares registered in your name or in the name of your nominee.

Enclosed herewith for your information and forwarding to your clients for whose accounts you hold Shares registered in your name or in the name of your nominee are copies of the following documents:

YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS AS PROMPTLY AS POSSIBLE. PLEASE NOTE THAT THE OFFER AND WITHDRAWAL RIGHTS EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, AT THE END OF FRIDAY, SEPTEMBER 26, 2014, UNLESS THE OFFER IS EXTENDED.

The Offer is being made pursuant to the Agreement and Plan of Merger, dated as of August 22, 2014 (the “Merger Agreement”), among InterMune, Parent and Purchaser. The Merger Agreement provides, among other things, that as soon as practicable after consummation of the Offer and subject to the satisfaction or waiver of the other conditions set forth in the Merger Agreement, Purchaser will merge with and into InterMune (the “Merger”), with InterMune continuing as the surviving corporation and a wholly owned subsidiary of Parent. At the effective time of the Merger, each outstanding Share (other than shares held by InterMune, any of its subsidiaries, Parent, Purchaser or any other subsidiary of Parent, or any stockholders who have properly exercised their appraisal rights under Section 262 of the Delaware General Corporation Law (the “DGCL”)) will be converted into the right to receive the Offer Price in cash, without interest and less any required withholding taxes. No appraisal rights are available in connection with the Offer. However, pursuant to the DGCL, if the Merger is consummated, stockholders who do not tender their Shares in the Offer will have the right, by fully complying with the applicable provisions of Section 262 of the DGCL, to choose not to accept the consideration payable for their Shares pursuant to the Merger, and instead to demand an appraisal of their Shares by the Court of Chancery of the State of Delaware and receive a cash payment of the “fair value” of their Shares as of the effective time of the Merger as determined by the Court of Chancery of the State of Delaware. The “fair value” of such Shares as of the effective time of the Merger may be more than, less than, or equal to the Offer Price. The Merger Agreement is more fully described in Section 13 of the Offer to Purchase.

The Board of Directors of InterMune (the “InterMune Board”) has duly and unanimously (i) approved the Merger Agreement and declared the Merger Agreement, the Offer, the Merger and the other transactions contemplated by the Merger Agreement to be advisable and fair to, and in the best interests of, InterMune and its stockholders, (ii) resolved that the Merger shall be governed by and effected without a stockholders’ meeting pursuant to Section 251(h) of the DGCL and that such Merger shall be consummated as soon as practicable following the closing of the Offer and (iii) recommended that the holders of the Shares accept the Offer and tender their Shares pursuant to the Offer. InterMune has been advised that all of its directors and executive officers intend to tender all of their transferrable Shares pursuant to the Offer.

The Offer is conditioned upon, among other things, (i) there being validly tendered in accordance with the terms of the Offer and not validly withdrawn, prior to the expiration of the Offer, a number of Shares (excluding Shares tendered pursuant to Notices of Guaranteed Delivery for which Shares have not been delivered) that represent at least a majority of the outstanding securities entitled generally to vote in the election of directors of InterMune, on a fully diluted basis, whether or not then vested and after giving effect to the exercise, conversion or exchange of any then outstanding options, stock units, warrants, rights or securities exercisable, convertible or exchangeable into such securities and (ii) the expiration or termination of the waiting period (and any extension thereof) or receipt of clearance under (A) the Hart-Scott-Rodino Antitrust Improvement Act of 1976, as amended, and (B) any German and Austrian antitrust, competition and merger control laws applicable to the Offer and the Merger, in each case, without the imposition of, among other things, any requirement that Parent, Purchaser or any of their affiliates (x) divest or otherwise hold separate, or take any other action with respect to any of their or InterMune’s or any of their respective affiliates’ businesses, assets or properties if required in connection with the transactions contemplated by the Merger Agreement or (y) enter into any settlement, undertaking, consent decree, stipulation or agreement with any governmental entity in connection with the transactions contemplated by the Merger Agreement. These and other conditions to the Offer are described in Sections 15 and 16 of the Offer to Purchase.

Purchaser will not pay any fees or commissions to any broker, dealer or any other person (other than to Mackenzie Partners, Inc. (the “Information Agent”) and the Depositary as described in the Offer to Purchase) for soliciting tenders of Shares pursuant to the Offer. Purchaser will, however, upon request, reimburse brokers, dealers, commercial banks, trust companies and other nominees for reasonable and necessary costs and expenses incurred by them in forwarding the enclosed materials to their clients.

Purchaser will pay all stock transfer taxes applicable to its purchase of Shares pursuant to the Offer, subject to Instruction 6 of the Letter of Transmittal.

In order to take advantage of the Offer, a duly executed and properly completed Letter of Transmittal (or a manually signed facsimile thereof), or an Agent’s Message (as defined in the Offer to Purchase) in connection with a book-entry transfer of Shares, and any other required documents, should be sent to the Depositary, and certificates representing the tendered Shares should be delivered or such Shares should be tendered by book-entry transfer, all in accordance with the instructions contained in the Letter of Transmittal and the Offer to Purchase.

If holders of Shares wish to tender, but it is impracticable for them to forward their certificates or other required documents or to complete the procedures for delivery by book-entry transfer prior to the expiration of the Offer, a tender may be effected by following the guaranteed delivery procedures described in Section 3 of the Offer to Purchase.

Any inquiries you may have with respect to the Offer should be addressed to, and additional copies of the enclosed materials may be obtained from, the undersigned or the Information Agent at their respective addresses and telephone numbers set forth on the back cover of the Offer to Purchase.

NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL RENDER YOU THE AGENT OF PARENT, PURCHASER, THE DEALER MANAGER, THE INFORMATION AGENT OR THE DEPOSITARY, OR ANY AFFILIATE OF ANY OF THEM, OR AUTHORIZE YOU OR ANY OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY STATEMENT ON BEHALF OF ANY OF THEM IN CONNECTION WITH THE OFFER OTHER THAN THE DOCUMENTS ENCLOSED HEREWITH AND THE STATEMENTS CONTAINED THEREIN.