Item 7.01. Regulation FD Disclosure.

On Wednesday, February 13, 2013, Achillion Pharmaceuticals, Inc. (the "Company") management will provide an update on the Company's therapeutic pipeline at the Leerink Global Healthcare Conference 2013. The Company plans to report that it has received regulatory clearance from the Food and Drug Administration, or FDA, to proceed with a Phase 2 clinical trial that will evaluate the 12 week treatment consisting of sovaprevir (formerly ACH-1625) and ACH-3102 for the treatment of genotype 1 hepatitis C viral infection, or HCV. Final preparations are being made to begin dosing in a randomized, double-blind study during the second quarter of 2013. Furthermore, Achillion plans to provide an update on its ongoing Phase 2 clinical trial evaluating 12 weeks of ACH-3102 and ribavirin for the treatment of genotype 1b CC HCV. To date, no viral breakthrough or viral relapse has been observed for any of the eight patients enrolled, including patients who are currently receiving or have completed 12 weeks of therapy. On January 7, 2013, the Company announced that three patients had completed 12 weeks of therapy and it plans to provide an update today that these patients successfully achieved undetectable viral levels 4 weeks post end of treatment, or SVR4.

The information in this Item 7.01 shall not be deemed "filed" for purposes of
Section 18 of the Exchange Act or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except as expressly set forth by specific reference in such a filing.

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