Rib-X Pharmaceuticals Announces New Executive Leadership and Board of Directors Appointments

NEW HAVEN, Conn., April 3, 2013 — Rib-X Pharmaceuticals, Inc. announced today new appointments to the executive team and Board of Directors.  Mary Szela has been appointed as Chief Executive Officer, bringing 25 years of experience as an accomplished pharmaceutical executive to the Company.  Eugene Sun, M.D., has been appointed Executive Vice President, Research and Development, bringing clinical and scientific leadership and expertise to the Company. Michael Kenston has been appointed Chief Commercial Officer, bringing a broad range of commercial, sales and business development experience to the Company.  Rib-X also announced today that director, Thomas Koestler, Ph.D., has been appointed Chairman of the Board.  Ms. Szela, who joined the Company's Board in January, will remain a director.

Commenting on these appointments, Kevin Ferro, CEO of Vatera Holdings LLC, said, "The experience and expertise that Mary, Eugene, Mike and Tom bring to Rib-X is impressive and represents a new beginning for the Company.  We are committed to ensuring that the novel and much needed antibiotics being developed by a dedicated team of scientists at Rib-X are appropriately resourced and brought to patients as soon as possible."

"Rib-X is a highly energized biopharmaceutical company developing the right products at the right time," commented Ms. Szela.  "Never has there been more of a need for novel drugs to combat the proliferation of resistant pathogens emerging worldwide.  Rib-X has an exciting broad spectrum antibiotic poised to enter multiple pivotal studies as well as a discovery platform based on Nobel Prize-winning science that utilizes unprecedented structural insights to target the vulnerabilities of pathogens."

"Mary brings to Rib-X the leadership, product development and commercial experience to build Rib-X into a leading specialty pharmaceutical company delivering important new anti-infective agents to clinicians and patients," commented Dr. Koestler.

With more than two decades in senior roles at Abbott Laboratories (now AbbVie), Ms. Szela most recently served as Senior Vice President, Global Strategic Marketing and Services of the Pharmaceutical Products Group. Previously, she served as Senior Vice President of U.S. Pharmaceuticals, an $8 billion business.  For over seven years, she directed the development, launch and growth of eight new pharmaceutical products, including leadership of AbbVie's flagship product, Humira.

Prior to 2001, Ms. Szela held a series of senior positions in Abbott's hospital products division where she was responsible for the peri-operative, intensive care and pain management pharmaceutical business, the global One-2-One outsourcing business, the critical care device business and the vascular medicine pharmaceutical business.

Dr. Sun joins Rib-X following 17 years at Abbott Laboratories (now AbbVie), where he most recently served as Corporate Vice President, Global Pharmaceutical Clinical Development. In this role, Dr. Sun was responsible for global clinical development, medical affairs, and clinical operations for all pipeline compounds and marketed products across the pharmaceutical portfolio. Prior to 2005, he held increasingly senior leadership positions in the R&D organization. During his tenure at Abbott, Dr. Sun oversaw the development and approval of multiple indications for Humira, and also led the development and worldwide regulatory approval of the landmark HIV protease inhibitor Kaletra.

From 2001 to 2007, Dr. Sun served as the industry representative on the Antiviral Drugs Advisory Committee of the Food and Drug Administration. Dr. Sun received his undergraduate degree from Harvard University, his M.D. from New York University School of Medicine, and completed his residency in Internal Medicine and fellowship in Infectious Diseases at the University of California, San Francisco.

"Dr. Sun has a unique ability to translate science into commercial understanding and success," said Ms. Szela.  "Dr. Sun's extensive clinical and global regulatory experience across multiple therapeutic areas made him an invaluable asset at Abbott where I had the privilege of working with him for over ten years, and he will be instrumental to Rib-X as we continue the clinical development of our pipeline and move towards approval and commercialization."

Ms. Szela continued, "Delafloxacin represents an incredible opportunity to address the high unmet medical need for better anti-infectives across multiple indications in both IV and oral formulations.  Mike brings over 20 years of commercial experience and a diverse skillset to help Rib-X successfully execute the commercial strategy for this promising candidate as well as for our broader pipeline."

Mr. Kenston joins Rib-X with over 20 years of commercial, sales and business development experience.  He most recently served as Vice President, Commercial Analysis at Reata Pharmaceuticals where he led marketing research, forecasting and SG&A optimization for the pre-launch of Bardoxolone Methyl.  Prior to Reata, Mr. Kenston was Vice President, Commercial Analysis and Business Development Search & Evaluation for Lundbeck, Inc. (formerly Ovation Pharmaceuticals).  Mr. Kenston played an instrumental role in the sale of Ovation to Lundbeck and continued on to lead the core commercial analysis processes for the company.  Mr. Kenston held several commercial roles over 16 years at Abbott Laboratories (now AbbVie), including Director level positions in promotional analytics and marketing research and assessment.  While at Abbott, Mr. Kenston also served as Product Manager for the adult respiratory segment of the antibiotic Biaxin.

Mr. Kenston has a Bachelor of Science degree from Northern Illinois University and received his MBA in finance from Indiana University.

Dr. Koestler, an Executive Director of Vatera Holdings LLC, joined the Rib-X Board in 2012.  In his nearly 30-year career in the pharmaceutical industry, Dr. Koestler established a track record of building high-performance teams that drove global success in research and development.  Most recently, he served as Executive Vice President of Schering-Plough Corporation and President of Schering-Plough Research Institute (SPRI), the pharmaceutical Research and Development arm of Schering-Plough Corporation.  Under his leadership, the company developed an industry-leading pipeline that contributed to the turnaround of the business.  Dr. Koestler's accomplishments include over 80 product approvals including over 30 New Molecular Entities/BLAs. Before joining Schering-Plough, Dr. Koestler was Senior Vice President and Head of Global Regulatory Affairs for Pharmacia Corporation.  Prior to joining Pharmacia, he was Senior Vice President and Global Head, Drug Regulatory Affairs, Compliance Assurance, Clinical Safety and Epidemiology for Novartis.  Before that appointment, he was Senior Director, Drug Regulatory Affairs, at Ortho McNeil and a Director of Regulatory Affairs at Bristol-Myers Squibb, Westwood Pharmaceuticals.

Dr. Koestler is also a member of the Board of Directors of Novo Nordisk A/S, Momenta Pharmaceuticals Inc., Pearl Therapeutics Inc., ImmusanT Inc., and Arisaph Pharmaceuticals Inc.  Dr. Koestler also chairs the Scientific Advisory Board of Bausch & Lomb.  Dr. Koestler has a Bachelor of Science, Biology, from Daemen College and a Ph.D. in Medicine & Pathology from the Roswell Park Memorial Institute.

About Rib-X:

Rib-X Pharmaceuticals, Inc. is a biopharmaceutical company developing new antibiotics to provide superior coverage, safety and convenience for the treatment of serious and life-threatening infections.  The Company's proprietary drug discovery platform is based on Nobel Prize-winning science and provides an atomic-level, three-dimensional understanding of interactions between drug candidates and their bacterial targets and enables design of antibiotics with enhanced characteristics.  Rib-X's lead program is Delafloxacin, an enhanced spectrum IV/oral antibiotic intended for use as first-line monotherapy to treat multiple bacterial diseases, which recently completed a Phase 2b clinical trial for the treatment of acute bacterial skin and skin structure infections.  The Company's pipeline also includes its preclinical RX-04 program and other discovery stage anti-infective programs.  Rib-X is privately held and backed among others by Vatera Healthcare and Warburg Pincus.  For more information, please visit www.rib-x.com.

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