UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 5, 2012

INTERMUNE, INC.

(Exact name of registrant as specified in its charter)

3280 Bayshore Boulevard

Brisbane, CA 94005

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including area code: (415) 466-2200

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 8.01 Other Events.

On April 5, 2012, InterMune, Inc. (“InterMune”) announced that the Transparency Commission of the French National Health Authority, the French agency responsible for assessing medicinal products and advising the health authorities on whether those products provide sufficient benefit to be covered by French National Health Insurance, has issued a favorable opinion for the reimbursement of Esbriet^® (pirfenidone) by French National Health Insurance. The Transparency Commission noted that no other treatment provided evidence of a clinical benefit in IPF and considering all available information, Esbriet was granted an Amélioration du Service Medical Rendu (ASMR) rating of level IV. ASMR is a rating of added clinical value in comparison with existing therapies. The Transparency Commission focused on the risk/benefit ratio for assessing the actual medical benefit, and rated it as “Low.”

In addition, InterMune provided an update on patient enrollment in its Phase 3 “ASCEND” study, which is designed to confirm the efficacy and safety of pirfenidone and to support an NDA re-submission for FDA approval of Esbriet in the United States. InterMune now expects ASCEND to be fully enrolled around the end of 2012. InterMune’s previous guidance was the second quarter of 2012. As a result of the later projected date for completion of enrollment, InterMune now expects to report data from the ASCEND trial in the first half of 2014.

This Report contains forward-looking statements within the meaning of section 21E of the Securities Exchange Act of 1934, as amended, that reflect InterMune’s judgment and involve risks and uncertainties as of the date of this release, including without limitation the statements related to reimbursement for Exbriet for patients in France and statements related to our ASCEND trial, including projected timing for completion of enrollment of the trial and for reporting data from the trial. All forward-looking statements and other information included in this Report are based on information available to InterMune as of the date hereof, and InterMune assumes no obligation to update any such forward-looking statements or information. InterMune’s actual results could differ materially from those described in InterMune’s forward-looking statements.

Factors that could cause or contribute to such differences include, but are not limited to, those discussed in detail under the heading “Risk Factors” in InterMune’s most recent annual report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 29, 2012 (the “Form 10-K”), and other periodic reports filed with the SEC, including but not limited to the following: (i) risks related to unexpected regulatory actions or delays or government regulation generally; (ii) risks related to government, industry and general public pricing pressures; (iii) risks related to our ability to successfully launch and commercialize Esbriet in the EU, including successfully establishing a commercial operation in the EU and receiving favorable governmental pricing and reimbursement approvals in each EU country; and (iv) risks related to the timing of enrollment of our ASCEND clinical trial and timing to report the results of such trial. The risks and other factors discussed above should be considered only in connection with the fully discussed risks and other factors discussed in detail in the Form 10-K and InterMune’s other periodic reports filed with the SEC.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.