UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington D.C. 20549

Form 10-K/A

(Amendment No. 2)

(Mark One)

For the fiscal year ended December 31, 2015

Or

For the transition period from __________ to __________

Commission File Number: 001-36480

Aradigm Corporation

(Exact Name of Registrant as Specified in Its Charter)

3929 Point Eden Way, Hayward, CA 94545

(Address of Principal Executive Offices)

Registrant’s telephone number, including area code:

(510) 265-9000

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.   Yes ¨ No þ

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.   Yes ¨ No þ

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.   Yes þ No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).   Yes þ No ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No þ

The aggregate market value of the registrant’s common stock held by non-affiliates of the registrant, based upon the closing price of a share of the registrant’s common stock on June 30, 2015 was: $38,322,138.

The number of shares of the registrant’s common stock outstanding as of March 7, 2016 was: 14,761,351.

DOCUMENTS INCORPORATED BY REFERENCE

EXPLANATORY NOTE

This Amendment No. 2 to Form 10-K, or this Amendment, amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2015 originally filed on March 30, 2016, or the Original Filing, and amended on May 9, 2016, or Amendment No. 1, by Aradigm Corporation, a California corporation. This Amendment is being filed solely for the purpose of correcting typographical errors in the certifications of the registrant’s chief executive officer and chief financial officer filed with Amendment No. 1. The corrected certifications, filed as Exhibits 31.3 and 31.4 with this Amendment No. 2, supersede Exhibits 31.1 and 31.2 as initially filed with Amendment No. 1.

Except as discussed above, we have not modified or updated disclosures presented in the Original Filing and Amendment No. 1. Accordingly, this Amendment No. 2 does not reflect events occurring after the filing of our Original Filing, or modify or update those disclosures affected by subsequent events. Information not affected by this Amendment No. 2 is unchanged and reflects the disclosures made at the time of the Original Filing and Amendment No. 1.

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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Amendment to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Hayward, State of California, on the 10^th day of May 2016.

Date: May 10, 2016

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EXHIBIT INDEX

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