X0304 4 2011-09-19 0 0001070336 ACHILLION PHARMACEUTICALS INC ACHN 0001378586 Shah Gautam C/O ACHILLION PHARMACEUTICALS 300 GEORGE STREET NEW HAVEN CT 06511 0 1 0 0 SVP and Chief Compliance Ofc. Common Stock 2011-09-16 4 M 0 2719 1.05 A 5844 D Common Stock 2011-09-16 4 S 0 2719 5.90 D 3125 D Employee Stock Option (Right to Buy) 1.05 2011-09-16 4 M 0 2719 0 D 2018-12-15 Common Stock 2719 25336 D This option was granted on December 15, 2008 and vests over a four year period with 25% of the shares vesting on the first anniversary of the date of grant and an additional 6.25% vesting at the end of each three-month period thereafter. The transactions reported on this Form 4 were executed pursuant to a Rule 10b5-1 trading plan adopted by Mr. Shah on December 17, 2010. /s/ Gautam Shah 2011-09-16