FOB Synthesis, Inc.

Achillion and FOB Synthesis Announce Collaboration for the Development of Carbapenem Compounds

NEW HAVEN, Conn. and KENNESAW, Ga., Apr 8, 2008 (PrimeNewswire via COMTEX News Network) -- Achillion Pharmaceuticals, Inc. (Nasdaq:ACHN) and FOB Synthesis, Inc. today announced that the companies have signed an exclusive agreement granting Achillion worldwide rights for the research, development and commercialization of certain FOB compounds for the treatment of serious bacterial infections. The licensed carbapenem compounds show excellent activity against a broad spectrum of bacterial isolates, including methicillin-resistant Staphylococcus aureus, or MRSA.

Under the terms of the agreement, Achillion will pay to FOB a $500,000 upfront license payment, and FOB could also earn additional license and milestone payments of up to $10 million, based upon the achievement of certain development and regulatory goals. FOB will collaborate with Achillion on the further characterization and development of the compounds for at least the next year. Achillion will receive exclusive worldwide license rights and will pay FOB a royalty on net sales of future products arising from the collaboration.

"We are very excited about our collaboration with FOB Synthesis," said Michael D. Kishbauch, President and Chief Executive Officer of Achillion. "This agreement provides Achillion with an important addition to our existing pipeline of internally-developed anti-infective compounds, and FOB's considerable expertise in this area will ensure that the program advances rapidly. It is unique in our experience to find compounds with this combination of spectrum of activity and truly impressive potency against MRSA. By licensing and further developing these compounds, Achillion is holding true to its commitment to develop drug candidates for the growing problem of antibiotic-resistant infections. We look forward to collaborating with FOB on bringing these compounds into the clinic."

"We hope that through this agreement, Achillion and FOB Synthesis will successfully develop important antibiotics against drug resistant strains of bacteria and make a significant contribution to the area of infectious disease where great medical needs are still unmet," stated David Menaldino, Vice President of Research of FOB Synthesis.

Serious bacterial infections caused by bacteria resistant to currently available therapies have been increasing dramatically over the past few decades, according to data from the U.S. Centers for Disease Control. One of the most common pathogens is a gram-positive bacterium referred to as Staphylococcus aureus, which can cause serious infections of the skin, bloodstream, bones or joints. In recent years, the majority of S. aureus hospital infections were due to strains that were resistant to methicillin. Frequently, these methicillin resistant S. aureus strains, commonly referred to as MRSA, are also resistant to other classes of antibacterials such as cephalosporins and quinolones. The increasing difficulty in treating MRSA and other multi-drug-resistant hospital-based infections has led to higher morbidity and mortality rates, increasing health care expenditures, and the continued need for new and better antibiotic therapies.

About FOB Synthesis, Inc.

FOB Synthesis, Inc. is a chemistry-driven drug discovery and custom synthesis company dedicated to discovering new therapeutic agents for the treatment of life-threatening diseases. The company's extensive background in synthetic organic and medicinal chemistry has played a critical role in their success of identifying a novel class of carbapenem antibiotics with excellent activity against both drug- and multidrug-resistant bacterial strains including MRSA and vancomycin-resistant Enterococci (VRE).

About Achillion Pharmaceuticals, Inc.

Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease. The company's proven discovery and development teams have advanced multiple product candidates with novel mechanisms of action. Achillion is focused on solutions for the most challenging problems in infectious disease - HIV, hepatitis and resistant bacterial infections.

This press release includes forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, that are subject to risks, uncertainties and other factors, including risks related to Achillion's ability to develop and commercialize this product. For example, the data from this trial may not warrant further development of this compound and initiating and completing clinical trials may take longer or cost more than expected. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. The reader is cautioned not to rely on these forward-looking statements. These and other risks are described in detail in Achillion's Annual Report on For10-K, which was filed with the U.S. Securities and Exchange Commission on March 5, 2008. All forward-looking statements are based on information currently available to Achillion, and the company does not assume any obligation to update any such forward-looking statements.

ACHN-G

For more information on Achillion Pharmaceuticals, please visit the company's web site at www.achillion.com or call Achillion at 1-203-624-7000.

This news release was distributed by PrimeNewswire, www.primenewswire.com

SOURCE: Achillion Pharmaceuticals, Inc

FOB Synthesis, Inc.

Media: David S Menaldino (404) 601-1415 Investors: Woo-Baeg Choi (404) 601-1412

Achillion Pharmaceuticals, Inc.

Media: Kari Watson (781) 235-3060 Investors: Mary Kay Fenton (203) 624-7000

News Provided by COMTEX