Combination Creates Global Leader In Emerging Field of Targeted Oncolytic Immunotherapy

BUSAN, South Korea & SAN FRANCISCO, CA, USA I November 25, 2013 I SillaJen, Inc., a privately-held biotherapeutics and contract research company focused on the development of targeted biological products for cancer, announced today that it had executed a definitive merger agreement to acquire San Francisco-based Jennerex, Inc. Privately-held Jennerex is a clinical-stage biotechnology company globally recognized as the leader in the development of best-in-class targeted oncolytic immunotherapies for solid tumors.

Following the acquisition, Jennerex will become a wholly-owned subsidiary of SillaJen, but will keep its name and remain headquartered in San Francisco. The acquisition, subject to normal closing conditions and completion of financing by SillaJen, is expected to close in the first quarter of 2014. Including potential future milestone payments, total consideration for the all-cash transaction could reach approximately $150 million. Wedbush PacGrow Life Sciences is acting as exclusive financial advisor to SillaJen, while Latham & Watkins LLP is serving as legal advisor. Centerview Partners LLC and Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP are acting as financial and legal advisors to Jennerex, Inc, respectively.

“We are very excited to announce this defining acquisition today,” stated Dr. Eun-Sang Moon, Co-Chief Executive Officer of SillaJen. “The clinical data with Jennerex’s lead asset, Pexa-Vec (JX-594), is compelling in multiple tumor types. In a randomized Phase 2 trial, as published in Nature Medicine in February 2013, Pexa-Vec demonstrated an overall survival advantage as first-line therapy for patients with advanced hepatocellular carcinoma (“HCC”, or primary liver cancer). Given the high unmet medical need in this patient population, these initial results are highly encouraging and warrant confirmation in a Phase 3 trial. We have also seen promising activity in colorectal and kidney cancers, the latter of which included two patients with complete tumor responses.”

Dr. Moon added, “As published in Nature, Pexa-Vec is also the only agent in this therapeutic class that can reproducibly target and destroy tumors by intravenous administration, a key point of differentiation and competitive advantage. We believe this strategic acquisition both provides SillaJen immediate global leadership in the emerging and exciting field of oncolytic immunotherapy, and is consistent with our mission of bringing innovative biotherapeutics to cancer patients worldwide.”

“This combination is the natural evolution of our long-standing relationship with Jennerex. As an active clinical research partner since 2007 and the Company’s largest shareholder, we have come to know Jennerex and its world-class team well. It is our desire to complement and build from the Company’s many strengths by providing the capital and research and development support required to maximize clinical and commercial success,” stated Dr. Yong-Han Lee, Co-Chief Executive Officer of SillaJen. “To this end, SillaJen is actively collaborating with Jennerex and its global partners on transition planning, including finalizing a robust clinical development plan. It remains an immediate goal to advance Pexa-Vec into a Phase 3 pivotal trial for first-line treatment of patients with advanced HCC by Q4 2014,” continued Dr. Lee.

Stated David A. McDonald, Chief Business Officer of SillaJen and future head of Jennerex upon closing of the transaction, “We would like to thank Jennerex Founder Dr. David Kirn, the board and the executive management team of Jennerex for providing excellent leadership that has brought Pexa-Vec to this point in its journey. We look forward to working together with the talented Jennerex team and established medical advisory board to achieve the common vision of becoming the leading global provider of oncolytic immunotherapies for cancer patients worldwide.”

“We are thankful to our loyal shareholders who have continued to support us since Jennerex was launched in 2006. We are also grateful to the talented Jennerex team who has pioneered the field of oncolytic immunotherapy and committed themselves to the success of Pexa-Vec, and we are pleased that they will become part of the SillaJen family and continue to contribute their knowledge and determination toward seeing these important oncology immunotherapy products through to commercialization,” stated Laurent Fischer, M.D., current Chairman and Chief Executive Officer of Jennerex.

About SillaJen, Inc.

SillaJen, Inc., headquartered in Busan, South Korea with offices in San Francisco, California is a contract R&D company specializing in the translational and clinical development of complex biologics. The SillaJen translational research, assay, and clinical research teams offer an array of services in a quality systems environment to bring investigational products from bench to bedside. Located on the campus of Pusan National University, the company is comprised of dedicated in-house teams that collaborate closely with a network of local and USA-based world-class scientists and physicians. Born from a desire to revolutionize therapeutic approaches for patients with serious unmet medical needs and honed through years of pioneering experience guiding oncolytic vaccinia through clinical trials in Korea, the SillaJen operations are uniquely poised to assist in the development of similar cutting-edge gene and viral therapies. Additional information about SillaJen can be found at www.sillajen.com.

About Jennerex

Jennerex is a clinical-stage biotechnology company focused on the development and commercialization of groundbreaking oncolytic immunotherapies for patients with life-threatening cancers. The company’s lead product candidate, Pexa-Vec (JX-594), is in mid-stage clinical development for the treatment of advanced primary liver cancer, colorectal cancer, kidney cancer and ovarian cancer, and its next generation product candidate, JX-929, is under investigation for a variety of other solid tumors. Jennerex is headquartered in San Francisco and has related research and development operations in Ottawa, Canada and South Korea. Pexa-Vec is partnered in Europe with Transgene, a member of the Institute Merieux group, in South Korea with Green Cross Corporation and in China with Lee’s Pharmaceutical Holdings. For more information about Jennerex, please visit www.jennerex.com.

About Pexa-Vec

Pexa-Vec (JX-594, pexastimogene devacirepvec) is derived from vaccinia, which has been used for decades as a vaccine in healthy individuals, and is engineered to selectively target cancer cells. Pexa-Vec is also engineered to express GM-CSF, a white blood cell growth factor, which activates a systemic immune response to kill tumor cells throughout the body. Pexa-Vec exploits the unique characteristics of vaccinia, including its stealth extracellular enveloped form, which allows the virus to survive in the bloodstream in the presence of neutralizing antibodies, leading to its ability to be administered both intravenously (IV) and intratumorally (IT). Unlike many targeted therapies that rely on a single target, Pexa-Vec is applicable to multiple solid tumor types.

Phase 1 and Phase 2 clinical trials in multiple cancer types have shown that Pexa-Vec,, delivered either directly into tumors or intravenously, induces tumor shrinkage and/or necrosis and has been well-tolerated in over 250 patients treated to date (Breitbach et al., Nature, 2011, Heo et al. Nature Medicine 2013). Objective tumor responses have been demonstrated in a variety of cancers including liver, colon, kidney, lung cancer and melanoma. Pexa-Vec has had a predictable and manageable safety profile to date which includes flu-like symptoms that typically resolve in 24 hours.

Pexa-Vec is currently being evaluated in a Phase 2 clinical trial in patients with treatment-refractory colorectal cancer as monotherapy and in combination with irinotecan, and in a Phase 2 clinical trial in treatment-refractory kidney cancer patients.

Hepatocellular Carcinoma: A Global Unmet Need

Hepatocellular carcinoma is the fifth most common cancer worldwide and the third leading cause of cancer death, with over 600,000 new cases diagnosed annually resulting in more than 90 percent mortality.i The annual incidence rate in the U.S., Europe, Japan and China are estimated to be 20,000, 55,000, 40,000 and 350,000 patients, respectivelyii. Currently, there is only one approved systemic treatment for advanced HCC patients that has demonstrated a survival benefit.

i  http://www.who.int/mediacentre/factsheets/fs297/en/

ii Ferlay J, Shin HR, Bray F, Forman D, Mathers C and Parkin DM.GLOBOCAN 2008 v2.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer; 2010. Available from:  http://globocan.iarc.fr

SOURCE: SillaJen