Achillion Pharmaceuticals Inc.

New Haven, Conn. • (203) 624-7000 • www.achillion.com

Exchange and Ticker: Nasdaq: ACHN

Filing Range: 4.5M shares @ $14 to $16

Offering Price: $11.50

Close on First Day: $13.34

Offering Size: $51.8M

Shares Outstanding: 14.8M

Underwriter: SG Cowen Securities Corp.

Co-managers: CIBC World Markets Inc./JMP Securities

Company Counsel: Wilmer Cutler Pickering Hale & Dorr

Manager Counsel: Mintz Levin Cohn Ferris Glovsky & Popeo

Auditor: PricewaterhouseCoopers

Market Capitalization on 10/31/06: $198.8M

Close price at current month end: $13.40

Description

The company develops anti-HIV drugs and new inhibitors of the HIV nucleocapsid protein zinc finger domains and the reverse transcriptase enzyme as targets for the rational design of drugs that address the issue of drug resistance. The company is dedicated to the discovery and commercial development of therapeutic agents, with a particular emphasis on antiviral drugs to treat diseases caused by hepatitis and herpes viruses, as well as HIV-1. The competition includes GlaxoSmithKline, Hoffman-La Roche, Gilead Sciences and Bristol-Myers Squibb.

Venture Backers

SV Life Sciences Advisers, Atlas Venture, Advent International, Societe Generale, Connecticut Innovations Inc., Bear Stearns Health Innoventures, Oak Investment Partners, KBL Healthcare Ventures, Yale University, Oakwood Medical Investors

Source: Thomson FInancial