Spero Therapeutics, LLC, a biopharmaceutical company founded to develop novel therapies for the treatment of bacterial infections, announced that the company secured $30M million in a Series A financing. Lundbeckfond Ventures led the round as a new investor with participation from additional new investors Merck Research Ventures and The Kraft Group. All existing investors participated including Atlas Venture, SR One, and Partners Innovation Fund. The company also expanded its pipeline of novel anti-infectives through the addition of a Potentiator program targeting Gram-negative infections. Spero plans to use the proceeds from this financing to advance the Potentiator franchise into clinical development by 2016, progress its anti-virulence program in partnership with Roche through the submission of an Investigational New Drug (IND) application, and develop additional programs in its pipeline focused on unmet medical needs in bacterial infections.

'We are thrilled to be working with a company that has the potential to fill such an important unmet medical need.'

The Spero Potentiator program is a franchise of development candidate stage proprietary molecules designed for use in combination with existing anti-infectives agents. The outer membrane of Gram-negative bacteria acts as a barrier to antibiotics, limiting access of antibacterial agents to their molecular targets. Potentiators interact with the Gram-negative outer membrane to enable access, and in combination, enable agents traditionally only used for Gram-positive infections such as macrolides to treat multi-drug resistant Gram-negative infections, and increase the potency of agents used for Gram-negatives such as meropenem.

Spero has multiple combinations of approved agents with potentiators that it is advancing into clinical studies for a range of indications including complicated urinary tract infections and complicated intra-abdominal infections. These programs were in-licensed from Northern Antibiotics Ltd. Terms of this transaction were not disclosed.

In parallel, the company continues to advance its MvfR inhibitor program in collaboration with Roche, targeting mechanisms of virulence and persistence in Gram-negative organisms.

'We appreciate the support and confidence demonstrated by our new and existing investors in this round of financing,' said Ankit Mahadevia, M.D., Co-founder and Chief Executive Officer of Spero. 'Our vision is to continue growing as a premier drug discovery and development organization focused on breakthrough anti-infective therapies. Our novel approaches to the major unmet need of Gram-negative infections show tremendous breadth and promise, and this financing round will fuel our continued growth in this very promising and rapidly growing field.'

Lundbeckfond Ventures's Casper Breum and Merck's Josh Resnick, M.D. will join the Spero Board, in addition to existing members Jean Francois Formela of Atlas Venture, Vikas Goyal of SROne, Milind Deshpande of Achillion Pharmaceuticals, and Dr. Mahadevia.

'In a very short period of time, Spero has made significant progress with their strategy to leverage dramatic changes in the field of anti-infectives and create novel therapies to combat severe infections. Spero has also assembled a highly experienced scientific team that can sustainably and synergistically work across different mechanisms and with multiple collaborators,' said Casper Breum, Partner at Lundbeckfond Ventures. 'We are thrilled to be working with a company that has the potential to fill such an important unmet medical need.'

About Lundbeckfond Ventures

Lundbeckfond Ventures is a part of the asset management subsidiary of The Lundbeck Foundation which in addition to substantial financial assets has controlling ownerships in H. Lundbeck A/S, ALK-Abelló A/S and Falck A/S. Lundbeckfond Ventures has an evergreen structure and invests around $60 million annually in life science companies. The Lundbeckfond Ventures team is located in Copenhagen, Denmark, and is active in both Europe and USA.

About the Merck Research Ventures Fund

The Merck Research Ventures Fund is an investment vehicle through which Merck will help to shape the diversity and quality of external innovation, which may be captured through future partnerships and acquisitions. MRVF is jointly governed by an Investment Committee and a Scientific Management Approval Committee, each made up of senior Merck employees.

About The Kraft Group

The Kraft Group Over the years The Kraft Group has grown its portfolio to include investments across many industries and business types. It has combined the Kraft family's entrepreneurial experience with a talented team of professionals made up of financial advisors, legal counsel and tax experts - all trusted, long-standing members of The Kraft Group. This group creates an environment of streamlined due diligence and decision-making. There are no outside committees to consult before making an investment; evaluations are made using our own high standards of potential return against risk.

About Northern Antibiotics Ltd.

Founded in 2003 and headquartered in Helsinki, Finland, Northern Antibiotics Ltd is engaged in the discovery and development of novel antibiotics against multidrug-resistant Gram-negative bacteria. For more information, visit http://www.northernantibiotics.com.

About Spero

Spero is a product-focused biopharmaceutical company developing a pipeline of novel treatments for bacterial infections and is located in Cambridge, Massachusetts. The company's pipeline of anti-infective agents is one of the most unique in the industry - focused exclusively on gram-negative bacterial infections. The Spero Potentiator program provides the opportunity to increase the power of standard of care by enhancing existing drugs through a dramatic increase in their potency against multi-drug resistant gram-negative bacteria. Spero's MvfR inhibitor program works differently from existing antibiotics by targeting a pathway involved in two critical bacterial processes: virulence and persistence. Spero's pipeline of drug candidates may uniquely reduce the morbidity caused by severe infections and promote their clearance, including in bacterial strains highly resistant to even the most potent existing antibiotics. The investors in Spero include Atlas Venture, SR One, The Partners Innovation Fund, Lundbeckfond Ventures, Merck Research Ventures, and The Kraft Group. For more information, please visit www.sperotherapeutics.com.