Round Includes Third Rock Ventures and Pfizer Venture Investments

SAN FRANCISCO, CA, USA | June 2, 2010 | Ablexis, LLC, a biotechnology company dedicated to developing an innovative, next-generation platform for antibody drug discovery, announced today that it has completed a $12 million Series A financing. The round was led by Third Rock Ventures and included Pfizer Venture Investments. Proceeds from the financing will be used to continue advancing Ablexis’ proprietary AlivaMab Mouse transgenic mouse platform for the discovery of human therapeutic antibodies.

“In our conversations with pharma and biotech companies, Third Rock repeatedly heard about the need for a new, robust transgenic mouse antibody platform”

“There are significant unmet commercial needs for a transgenic mouse platform for therapeutic antibody discovery,” said Larry Green, Ph.D., chief executive officer of Ablexis. “In addition, advances in the understanding of immune responses, antibody drug discovery and development, and genetic engineering methods all provided a basis for innovating and improving upon existing platform technologies. Ablexis is leveraging these advances and the significant experience of our team for the creation of the AlivaMab Mouse, an efficient, innovative, next-generation transgenic mouse platform for antibody drug discovery. Ablexis will commercialize this valuable platform through creative partnering strategies.”

Over ten years of fully human antibody drug discovery have demonstrated that transgenic mouse platforms are the most productive platform for successful antibody drug discovery and development. These platforms harness the power of the in vivo immune system to yield very high affinity antibody drug candidates with desirable characteristics of potency, specificity, solubility and reduced chances of immunogenicity. Combined with their broad target applicability, transgenic mice bring an unparalleled efficiency and probability of success to the discovery and development of quality drug candidates. Recent, major changes in the landscape of providers in this space, including the acquisition of Abgenix’s XenoMouse® technology by Amgen and Medarex’s HuMAb-Mouse® technology by Bristol-Myers Squibb, have dramatically diminished access to transgenic mouse platforms for therapeutic antibody discovery.

“In our conversations with pharma and biotech companies, Third Rock repeatedly heard about the need for a new, robust transgenic mouse antibody platform,” said Cary Pfeffer, M.D., partner at Third Rock Ventures and member of Ablexis’ board of directors. “Ablexis’ solution, based on Dr. Green’s profound understanding of the strengths and limitations of earlier generation technologies represents an important step forward and promises to enhance the life-changing advancements being made through today’s antibody discovery and development efforts.”

Barbara Dalton, vice president of venture capital at Pfizer commented, “We expect that Ablexis’ innovative transgenic mouse platform will fulfill a strategic need for many companies like Pfizer as a platform to develop high quality antibody drug candidates. This investment supports an interesting business model for the development of important technology platforms for our industry.”

Dr. Green leads Ablexis as chief executive officer and brings 18 years of leadership in antibody discovery, therapeutic product development and collaborative research experience to the Ablexis team. Dr. Green was a founder of Abgenix, where he served in several executive level research positions and led or contributed to more than 50 antibody discovery projects. Dr. Green is joined by Hiroaki Shizuya, M.D., Ph.D., who serves as Ablexis’s resident advisor in molecular biology. As the creator of bacterial artificial chromosome technology, Dr. Shizuya contributes unique insights into molecular biology, DNA manipulation and genome characterization.

Joining Dr. Green and Dr. Pfeffer on Ablexis’s board of directors is Lou Tartaglia, Ph.D., partner at Third Rock Ventures. Jake Bauer, senior associate at Third Rock Ventures, Jennifer Friel Goldstein, director at Pfizer Venture Investments, and Alex Suh, managing director at California Technology Ventures, are board observers.

About Ablexis, LLC

Ablexis, LLC was founded in December 2009 and is based on technology established by Aliva Biopharmaceuticals, Inc., which was founded in 2001 by Hiroaki Shizuya, M.D., Ph.D., a pioneer of bacterial artificial chromosome technology. Ablexis is creating the AlivaMab Mouse, an innovative, next-generation transgenic mouse platform that will provide the foundation for the efficient discovery and development of the next wave of human therapeutic antibodies. Ablexis has filed patent applications covering its core technologies, compositions and utilities for its AlivaMab mice. The company is based in San Francisco, California and more information can be found by visiting the company’s website at www.ablexis.com.

About Third Rock Ventures

Third Rock Ventures is a premier venture firm focused on life sciences, investing and launching companies that make a difference in people’s lives. Collaborating with entrepreneurs, the Third Rock team applies its deep expertise to establish the roadmap and building blocks for a rapidly growing and highly successful life sciences company. The Third Rock team has a unique vision and experience in building great companies, extensive life science industry and academic networks and a collective track record for creatively managing the value creation path to deliver exceptional performance. For more information, please visit www.thirdrockventures.com.

About Pfizer Venture Investments

Pfizer Venture Investments (PVI), the venture capital arm of Pfizer Inc., was founded in 2004 and invests for return in areas of current or future strategic interest to Pfizer. PVI seeks to remain at the forefront of life science advances, looking to identify and invest in emerging companies that are developing compounds and technologies that have the potential to enhance Pfizer’s pipeline and shape the future of the pharmaceutical industry. With a strong focus on growth stage opportunities, PVI invests in a broad array of healthcare related areas, including therapeutics, platform technologies, diagnostics, drug delivery, pharmaceutical services, healthcare IT, and other technologies impacting drug discovery and development. For more information, please visit www.pfizer.com/research/licensing/venture_investments.jsp.

SOURCE: Ablexis, LLC