Germantown, Maryland, May 1, 2013 – Intrexon Corporation, a next generation synthetic biology company, today announced that it has closed a Series F preferred investment round of $150 million, bringing the company’s total capital raised to $509 million. New investors accounted for the majority of the round, with current investors, including affiliates of Randal J. Kirk, Intrexon’s Chairman and CEO, and Third Security, LLC, taking the balance of the round.   The funding will be used to provide working capital for the establishment of additional exclusive channel collaborations in Intrexon’s core sectors, including Healthcare, Food, Energy, and Environment, continued development of the company’s industry-leading technology platforms, expansion of sales and marketing, and research and development.    "The Intrexon team is committed to delivering results for all of our collaborations,” said Mr. Kirk. “With our proprietary technology platforms, we are helping our collaborators discover, design, develop and ultimately bring to market genetically-enhanced products that hold remarkable promise.”   Mr. Kirk added, “It is especially gratifying to our entire team that, in addition to being our largest investment series to date, a majority of the investment came from new investors who share our vision."   About Intrexon Corporation Intrexon Corporation is a privately held biotechnology company focused on the industrial engineering of synthetic biology.  Intrexon is deploying its extensive capabilities to rapidly design and produce novel and enhanced biological products and processes across multiple industry sectors, including: human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science.  The company's advanced bioindustrial engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly, and optimization to enable unprecedented control over the function and output of living cells. More information about the Company is available at www.dna.com.   Safe Harbor Statement Some of the statements made in this press release are forward-looking statements.  These forward-looking statements are based upon our current expectations and projections about future events and generally relate to our plans, objectives and expectations for the development of our business.  Although management believes that the plans and objectives reflected in or suggested by these forward-looking statements are reasonable, all forward-looking statements involve risks and uncertainties and actual future results may be materially different from the plans, objectives and expectations expressed in this press release.   ###   For more information regarding Intrexon Corporation, contact:   Corporate Contact:    Investor Contact: Marie L. Rossi, Ph.D.    The Ruth Group Manager, Technical Communications Intrexon Corporation Tel: +1 301-556-9944 mrossi@intrexon.com      Stephanie Carrington / Nicole Greenbaum Tel: +1 646-536-7017/7009 scarrington@theruthgroup.com ngreenbaum@theruthgroup.com   

Immunotherapeutic Strategy Results Presented at AACR 2013 Annual Meeting   NEW YORK, NY – April 9, 2013 – ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), a biopharmaceutical company focused on the development and commercialization of new cancer therapies, announced today the presentation of results from a study in a breast cancer murine model demonstrating the anti-tumor effects and tolerability of Ad-RTS-mIL-12, a viral vector DNA-based therapeutic for the controlled, local expression of IL-12, an important protein for enhancing antitumor immunity.  The data were presented at the American Association for Cancer Research 2013 Annual Meeting (AACR 2013) taking place April 6-10, 2013 in Washington, D.C.  The study was conducted jointly by ZIOPHARM and Intrexon Corporation, a synthetic biology company that utilizes its proprietary technologies to provide control over cellular function.  ZIOPHARM is Intrexon’s exclusive channel partner for the development of in vivo therapeutics in oncology.   For the study, intratumoral administration of Ad-RTS-mIL-12 (Ad) was examined in a 4T1 BALB/c mouse breast carcinoma model. Production of murine IL-12 was controlled using Intrexon’s RheoSwitch Therapeutic System® (RTS®) platform and oral administration of the activator ligand INXN-1001 (AL).  Oral administration of AL was found to elicit a dose-related increase in plasma AL levels, which correlated with increasing tumor levels of AL. The increase in tumor AL levels in combination with Ad in turn resulted in a dose-related increase in expression of mIL-12 in the tumor, with minimal increase in serum mIL-12.  This increase in AL-regulated tumor IL-12 levels correlated with an increase in tumor-infiltrating CD4+ and CD8+ T cells in and adjacent to the tumor, concomitant with a decrease in tumor regulatory T cells.  This resulted in a dose-related decrease in tumor growth rate.  Moreover, the therapeutic strategy appears to be well tolerated, as no change in clinical signs or body weight was observed in the treated animals when compared with vehicle alone.    Samuel Broder, M.D., Chairman of Intrexon’s Therapeutic Opportunities Committee and former Director of the NCI (National Cancer Institute), stated, “Two major obstacles for the development of immunotherapeutics in the treatment of cancer are the ability of tumors to evade the anti-cancer capabilities of the immune system and the toxicity often associated with the systemic administration of immunomodulating agents.  To overcome these challenges, we have developed Ad-RTS-IL-12, a DNA-based system for the regulated expression of IL-12, that allows for localized, controlled expression of immunomodulating cytokines and activation of their corresponding anti-tumor effects.  This strategy is now being tested in the clinic, with the recent launch of a Phase 2 Study of Ad-RTS-IL-12 combined with palifosfamide in the treatment of advanced breast cancer.”   Jonathan Lewis, M.D., Ph.D., Chief Executive Officer of ZIOPHARM, commented, “These results support the hypothesis that localized delivery of IL-12 results in an increase in tumor infiltrating lymphocytes concomitant with a reduction in tumor growth.  These findings suggest the applicability of this strategy in the treatment of breast cancer, especially in the context of recent literature addressing the positive correlation of survival with immune response measured in breast cancer tumors treated with non-immune therapies.  This novel synthetic biology approach, which is being explored in several ongoing clinical studies, holds transformative potential for the treatment of cancer.”   About ZIOPHARM Oncology, Inc.:   ZIOPHARM Oncology is a biopharmaceutical company focused on the development and commercialization of new cancer therapies. The Company's clinical programs include:   Ad-RTS-IL-12 is currently being tested in two Phase 2 studies, the first for the treatment of advanced melanoma, and the second in combination with palifosfamide for the treatment of non-resectable recurrent or metastatic breast cancer.  Ad-RTS-IL-12 uses synthetic biology to enable controlled delivery of therapeutic interleukin-12 (IL-12), a protein important for enhancing the development of an immune response to cancer.  Being developed in partnership with Intrexon Corporation, ZIOPHARM’s DNA synthetic biology platform employs an inducible gene-delivery system that enables controlled delivery of genes that produce therapeutic proteins to treat cancer.  This is achieved by placing IL-12 under the control of Intrexon’s proprietary biological “switch” (the RheoSwitch Therapeutic System® or RTS® platform) to turn on/off the therapeutic protein expression at the tumor site.   Palifosfamide (ZIO-201) is a potent, bi-functional DNA alkylating agent that has activity in multiple tumors by evading typical resistance pathways.  Palifosfamide is in the same class as bendamustine, cyclophosphamide, and ifosfamide.    Indibulin (ZIO-301) is a novel, tubulin binding agent that is expected to have several potential benefits, including oral dosing, application in multi-drug resistant tumors, no neuropathy and a tolerable toxicity profile.  It is currently being studied in a Phase 1/2 trial in metastatic breast cancer.   Darinaparsin (ZIO-101) is a novel mitochondrial-and hedgehog-targeted agent (organic arsenic) currently in ongoing studies with Solasia Pharma K.K.   ZIOPHARM's operations are located in Boston, MA, and New York City.  Further information about ZIOPHARM may be found at www.ziopharm.com.   Forward-Looking Safe Harbor Statement:   This press release contains certain forward-looking information about ZIOPHARM Oncology that is intended to be covered by the safe harbor for "forward-looking statements" provided by the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. Words such as "expect(s)," "feel(s)," "believe(s)," "will," "may," "anticipate(s)" and similar expressions are intended to identify forward-looking statements. These statements include, but are not limited to, statements regarding our ability to successfully develop and commercialize our therapeutic products; our ability to expand our long-term business opportunities; financial projections and estimates and their underlying assumptions; and future performance.  All of such statements are subject to certain risks and uncertainties, many of which are difficult to predict and generally beyond the control of the Company, that could cause actual results to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include, but are not limited to: whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, or any of our other therapeutic products will advance further in the clinical trials process and whether and when, if at all, they will receive final approval from the U.S. Food and Drug Administration or equivalent foreign regulatory agencies and for which indications; whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, and our other therapeutic products will be successfully marketed if approved; whether any of our other therapeutic product discovery and development efforts will be successful; our ability to achieve the results contemplated by our collaboration agreements; the strength and enforceability of our intellectual property rights; competition from pharmaceutical and biotechnology companies; the development of and our ability to take advantage of the market for our therapeutic products; our ability to raise additional capital to fund our operations on terms acceptable to us; general economic conditions; and the other risk factors contained in our periodic and interim SEC reports filed from time to time with the Securities and Exchange Commission, including but not limited to our Annual Report on Form 10-K for the fiscal year ended December 31, 2012.  Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof, and we do not undertake any obligation to revise and disseminate forward-looking statements to reflect events or circumstances after the date hereof, or to reflect the occurrence of or non-occurrence of any events.   Contact:   For ZIOPHARM David Pitts or Lourdes Catala Argot Partners 212-600-1902 ziopharm@argotpartners.com   Media Contacts: David Schull or Lena Evans Russo Partners, LLC 858-717-2310 212-845-4262 david.schull@russopartnersllc.com lena.evans@russopartnersllc.com  

-Exclusive Channel Collaboration Driven by Need to Meet Growing World Food Demand -Intrexon Proposes to invest up to $6.0 million in AquaBounty   Germantown, MD and Maynard, MA – February 15, 2013 - Intrexon Corporation, a synthetic biology company that utilizes its proprietary technologies to provide control over cellular function, and AquaBounty Technologies, Inc. (AIM:ABTX.L), a biotechnology company focused on enhancing the productivity in aquaculture, today announced the formation of an exclusive channel collaboration (ECC) to enhance productivity in aquaculture and develop products that decrease the time to market and address growing environmental issues. As part of the ECC, Intrexon has proposed investing up to $6 million in AquaBounty to fund its operations and research.  The investment is subject to shareholder approvals including the waiver of pre-emptive rights. Thomas Kasser, President of Intrexon’s Animal Science Division, said, “Today’s developing world population is faced with increasing demand across a broad spectrum of markets including food, fuel and healthcare.   Intrexon’s mission is to apply its synthetic biology expertise and know how to provide solutions to these major global issues.  Our agreement with AquaBounty demonstrates this commitment and focus in the food arena. “The ECC with AquaBounty places Intrexon in strong position to revolutionize the aquaculture industry with faster growing, environmentally friendly products to meet the strong and growing demand for finfish.  Our priority will be to develop the next generation of AquaBounty’s existing product, AquAdvantage® Salmon, and to identify other products where our synthetic biology can implement leading edge technology to advance the sustainability and efficiency of fish production.  AquAdvantage® Salmon is capable of reaching marketable size in about half of the conventional time, reduced from approximately 28 to 36 months to 18 months, with a 30% reduction in feed required to reach market weight.  The FDA has published a draft Environmental Assessment and a preliminary draft of a Finding of No Significant Impact as one of the last steps in the approval process. The public comment period for these documents will close on April 25, 2013.” Ron Stotish, Chief Executive Officer of AquaBounty commented “This collaboration with Intrexon is a transformative event for AquaBounty by providing access to one of the most innovative genetic sciences in the world today.  It allows us to produce the next generation of existing products and new finfish products that meet today’s demand for global consumption and environmental challenges.” Under terms of the agreements: AquaBounty will utilize Intrexon’s UltraVector® platform and other technologies to research, develop, manufacture and market products involving key synthetic biology tools to improve the value of finfish intended for human consumption AquaBounty will pay Intrexon quarterly 16.66% of the gross profits calculated for each collaboration product and pay 50% of quarterly revenue obtained from a sublicensor in the event of a sublicensing agreement AquaBounty will reimburse Intrexon for the costs, on a full time equivalent basis, of certain services provided under the aquaculture program AquaBounty also announced the appointment to its board of directors of three individuals designated by Intrexon.  The appointed board members are Thomas Barton, Managing Partner, White Rock Capital Management, L.P., Thomas R. Kasser, Ph.D., President of Intrexon’s Animal Sciences Division, and James C. Turk, Jr., Partner, Harrison & Turk, P.C. About Intrexon Corporation Intrexon Corporation is a privately held biotechnology company focused on the industrial engineering of synthetic biology.  Intrexon is deploying its extensive capabilities to rapidly design and produce novel and enhanced biological products and processes across multiple industry sectors, including: human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science.  The company's advanced bioindustrial engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly, and optimization to enable unprecedented control over the function and output of living cells. More information about the Company is available at www.dna.com. About AquaBounty Technologies AquaBounty Technologies is a biotechnology company focused on improving productivity in commercial aquaculture, a $100 billion industry and the fastest growing segment of the worldwide food industry. The company’s objective is the application of biotechnology to ensure the availability of high quality seafood to meet global consumer demand.  The company is developing products to address critical production constraints in the most popular farmed species, focusing initially on salmon, trout and shrimp.  Its AquAdvantage® fish program is based upon a single, specific molecular modification in fish that results in more rapid growth in early development.   For Intrexon Corporation Corporate Contact: Marie L. Rossi, Ph.D., 301-556-9944 mrossi@intrexon.com or Investor Contact: The Ruth Group Stephanie Carrington / Nicole Greenbaum, 646-536-7017 / 7009 scarrington@theruthgroup.com ngreenbaum@theruthgroup.com

Combines Sanford-Burnham’s renowned scientific team and Intrexon’s proprietary discovery platforms to accelerate human induced pluripotent stem cell (iPSC) research   LA JOLLA, Calif., January 3, 2013 – Sanford-Burnham Medical Research Institute, a nonprofit research institution and one of the largest iPSC generators in the world, and Intrexon Corporation, a leading synthetic biology company, today announced a new collaboration to accelerate stem cell research. Under the agreement, Sanford-Burnham will gain access to sophisticated proprietary cellular selection and gene regulation technologies that are not currently on the market, including Intrexon’s Laser-Enabled Analysis and Processing (LEAP™) instrument and RheoSwitch Therapeutic System® (RTS®). As part of the agreement, Intrexon may obtain commercial and intellectual property rights resulting from technological advances made under the collaboration.   “I’m looking forward to merging and melding our expertise,” said Evan Y. Snyder, M.D., Ph.D., professor and director of Sanford-Burnham’s Stem Cell Research Center and Stem Cell and Regenerative Biology Program. “We’ll bring our iPSC and gene therapy expertise to the table. Likewise, our colleagues at Intrexon will share their knowledge of how best to use the technologies. We envision we’ll be meeting with them frequently and sharing insights to further advance the platforms for stem cell applications.”   Sanford-Burnham is currently building the world’s largest collection of human iPSCs generated from individual patients and healthy volunteers. The Stem Cell Research Center’s expertise and resources are available to all Sanford-Burnham scientists, as well as other researchers at nonprofit and for-profit research organizations around the world.   LEAP™ for induced pluripotent stem cells   The LEAP™ instrument is an automated system that provides high-throughput cell imaging coupled with versatile laser-based cell processing. The instrument’s applications include rapid and accurate in situ purification of adherent cells and cell colonies, features that are particularly useful when working with complex human iPSC cultures. The LEAP™ instrument enables scientists in Sanford-Burnham’s Stem Cell Research Center to improve and accelerate their methods for generating human iPSCs and their differentiated progeny, which are used in the study of a variety of diseases. iPSCs are stem cells derived from adult cells—a research advance that garnered the 2012 Nobel Prize in Physiology or Medicine.   “Intrexon’s LEAP™ instrument will allow us to isolate high-quality human iPSCs while eliminating non- or partially-reprogrammed cells or other undesirable cell types in the culture—a laborious process that previously took a trained technician a lot of time,” explained Yang Liu, Ph.D., manager of Sanford-Burnham’s Stem Cell Research Center. “Together with other automated equipment available in our facility, the new capabilities will free up valuable resources, allowing us to provide an even greater level of service to our internal and external users.”   “We are big believers in iPSCs and their potential for use in new therapeutic modalities,” said Fred Koller, Ph.D., vice president and executive director of the Intrexon Institute for Biomolecular Research. “It’s exciting for us to use our technology collaboratively with Sanford-Burnham’s team of premier scientists. We look forward to applying LEAP™, RTS® and other Intrexon tools in this stem cell research, and are proud to assist in the diverse medical advancements enabled by this collaborative effort with Sanford-Burnham.”   Controlling gene expression with RTS®   RTS® technology, a proprietary biological “switch” that enables inducible controlled gene expression by administering an activator ligand, will give Sanford-Burnham scientists a new method to regulate when certain genes are turned on or off in cells. The system also provides more accurate delivery of new therapeutic candidates to specific tissues in animal models.   “We’re interested in the RTS® technology because it will help us to turn genes on or off in stem cells that have been transplanted. For example, it can be used for therapeutic protein expression in stem cells that home to and help eradicate brain tumors,” said Snyder.   “New cell-based therapies may someday result from our LEAP™ and RTS® technologies,” Koller said. “Working with leaders in the field of academic stem cell research will leverage both parties’ technologies to get there faster.”   About Sanford-Burnham Medical Research Institute Sanford-Burnham Medical Research Institute is dedicated to discovering the fundamental molecular causes of disease and devising the innovative therapies of tomorrow. The Institute consistently ranks among the top five organizations worldwide for its scientific impact in the fields of biology and biochemistry (defined by citations per publication) and currently ranks third in the nation in NIH funding among all laboratory-based research institutes. Sanford-Burnham utilizes a unique, collaborative approach to medical research and has established major research programs in cancer, neurodegeneration, diabetes, and infectious, inflammatory, and childhood diseases. The Institute is especially known for its world-class capabilities in stem cell research and drug discovery technologies. Sanford-Burnham is a U.S.-based, non-profit public benefit corporation, with operations in San Diego (La Jolla), California and Orlando (Lake Nona), Florida. For more information, news, and events, please visit us at sanfordburnham.org.   About Intrexon Corporation Intrexon Corporation is a privately held biotechnology company focused on the industrial engineering of synthetic biology.  Intrexon is deploying its extensive capabilities to rapidly design and produce novel and enhanced biological products and processes across multiple industry sectors, including: human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science.  The company's advanced bioindustrial engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly, and optimization to enable unprecedented control over the function and output of living cells. More information about the Company is available at www.dna.com. Media Contact: Corporate Contact: Heather Buschman, Ph.D. Marie L. Rossi, Ph.D. Sanford-Burnham Medical Research Institute Intrexon Corporation hbuschman@sanfordburnham.org mrossi@intrexon.com (858) 795-5343 (301) 556-9944

NEW YORK, NY – November 7, 2012 – ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), a drug development company employing small molecule and synthetic biology approaches to cancer therapy, announced today results from a preclinical study demonstrating the long-term persistence and anti-tumor effects of a new synthetic biology approach (DNA/cell plasmid) to controlled protein production in vivo. This embedded controlled bioreactor study was presented at the EORTC-NCI-AACR International Conference on Molecular Targets and Cancer Therapeutics, taking place November 6-9 in Dublin, Ireland, and was conducted jointly by ZIOPHARM and Intrexon Corporation, a synthetic biology company that utilizes its proprietary technologies to provide control over cellular function, ZIOPHARM’s exclusive channel partner for the development of DNA therapeutics. “These data demonstrate the potential of our disruptive technologies, including UltraVector®, RTS®, and our cell engineering capabilities,” said Samuel Broder, M.D., Chairman of Intrexon’s Therapeutic Opportunities Committee and former Director of the NCI (National Cancer Institute). “By using tightly controlled, purpose-built, cellular protein factories, we open up therapeutic windows for a broad array of proteins. This study demonstrates the long-term persistence of this approach, with sustained protein production and therapeutic anti-tumor efficacy drawing from only a single intramuscular administration of plasmid DNA.” Hagop Youssoufian, M.D., President of Research and Development and Chief Medical Officer of ZIOPHARM, said, “These data are very exciting, as they provide us with another systemic approach for the delivery of therapeutic proteins to a target cancer using engineered DNA transgenes. We have already seen the potential in the clinic of delivering these transgenes using dendritic cells and viral vectors. Each approach gives us a means of optimizing the timing, concentration and location of therapeutic proteins; ultimately allowing us to dislocate cancer’s signaling networks with minimal interference to our natural systems. We look forward to further our study of therapeutic anti-cancer proteins delivered via this revolutionary technology.” For this study, a RheoSwitch®-regulated (RTS®) interferon alpha (IFNα) plasmid transgene was evaluated as a means of widening the therapeutic window of IFNα in a melanoma mouse model. DNA vectors for the controlled expression of murine or human IFNα were optimized using Intrexon’s UltraVector® platform, then transfected into human fibrosarcoma cells or myoblasts, forming RTS-IFNαplasmids. These plasmids were subsequently electroporated into the skeletal muscle of normal or melanoma tumor-bearing mice, and then activated using an oral activator ligand (AL). A single intramuscular electroporation of RTS-IFNα combined with daily oral activator ligand treatment led to significant tumor growth inhibition, comparable to chemotherapy or repeated bolus injection with recombinant mIFNα protein, but without overt toxicity, as assessed by body weight change and survival. Treatment with pRTS-IFNα resulted in sustained serum and tumor expression of mouse IFNα for approximately 4 months (study termination), as well as expression of the angiogenic biomarker IP-10, and activation of T cells (CD4 and CD8), NK cells, and dendritic cells. About ZIOPHARM Oncology, Inc.: ZIOPHARM Oncology is a biopharmaceutical company focused on the development and commercialization of new cancer therapies. The Company's clinical programs include: Palifosfamide (ZIO-201) is a potent bi-functional DNA alkylating agent that has activity in multiple tumors by evading typical resistance pathways. Palifosfamide is in the same class as bendamustine, cyclophosphamide, and ifosfamide. Intravenous palifosfamide is currently being studied in a randomized, double-blinded, placebo-controlled Phase 3 trial (PICASSO 3) for the treatment of first-line metastatic soft tissue sarcoma and is also in a pivotal Phase 3 trial (MATISSE) for first-line metastatic small cell lung cancer. Additionally, the Company is developing an oral capsule form of palifosfamide. Ad-RTS IL-12 is currently being tested in a Phase 2 study. Ad-RTS IL-12 uses synthetic biology to enable controlled, local delivery of therapeutic interleukin-12 (IL-12), a protein important for an immune response to cancer. ZIOPHARM's DNA synthetic biology platform is being developed in partnership with Intrexon Corporation and employs an inducible gene-delivery system that enables controlled, local delivery of genes that produce therapeutic proteins to treat cancer. This is achieved by placing IL-12 under the control of Intrexon’s proprietary biological “switch” (the RheoSwitch Therapeutic System®, RTS®) to turn on/off the therapeutic protein expression at the tumor site. Indibulin (ZIO-301) is a novel, tubulin binding agent that is expected to have several potential benefits, including oral dosing, application in multi-drug resistant tumors, no neuropathy and a tolerable toxicity profile. It is currently being studied in a Phase 1/2 trial in metastatic breast cancer. Darinaparsin (ZIO-101) is a novel mitochondrial- and hedgehog-targeted agent (organic arsenic) currently in ongoing studies with Solasia Pharma K.K. ZIOPHARM's operations are located in Boston, MA, and New York City. Further information about ZIOPHARM may be found at www.ziopharm.com. Forward-Looking Safe Harbor Statement: This press release contains certain forward-looking information about ZIOPHARM Oncology that is intended to be covered by the safe harbor for "forward-looking statements" provided by the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. Words such as "expect(s)," "feel(s)," "believe(s)," "will," "may," "anticipate(s)" and similar expressions are intended to identify forward-looking statements. These statements include, but are not limited to, statements regarding our ability to successfully develop and commercialize our therapeutic products; our ability to expand our long-term business opportunities; financial projections and estimates and their underlying assumptions; and future performance. All of such statements are subject to certain risks and uncertainties, many of which are difficult to predict and generally beyond the control of the Company, that could cause actual results to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include, but are not limited to: whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, or any of our other therapeutic products will advance further in the clinical trials process and whether and when, if at all, they will receive final approval from the U.S. Food and Drug Administration or equivalent foreign regulatory agencies and for which indications; whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, and our other therapeutic products will be successfully marketed if approved; whether any of our other DNA-based biotherapeutics discovery and development efforts will be successful; our ability to achieve the results contemplated by our collaboration agreements; the strength and enforceability of our intellectual property rights; competition from pharmaceutical and biotechnology companies; the development of and our ability to take advantage of the market for DNA-based biotherapeutics; our ability to raise additional capital to fund our operations on terms acceptable to us; general economic conditions; and the other risk factors contained in our periodic and interim SEC reports filed from time to time with the Securities and Exchange Commission, including but not limited to our Annual Report on Form 10-K for the fiscal year ended December 31, 2011, and our Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2012. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof, and we do not undertake any obligation to revise and disseminate forward-looking statements to reflect events or circumstances after the date hereof, or to reflect the occurrence of or non-occurrence of any events. Contact: For ZIOPHARM: Nicole Jones ZIOPHARM Oncology, Inc. 617-778-2266 njones@ziopharm.com Media Contacts: David Schull or Lena Evans Russo Partners, LLC 858-717-2310 212-845-4262 david.schull@russopartnersllc.com lena.evans@russopartnersllc.com

NEW YORK, NY – October 25, 2012 – ZIOPHARM Oncology, Inc. (NASDAQ: ZIOP), a biopharmaceutical company focused on the development and commercialization of new cancer therapies, today announced that compelling clinical activity was seen in its Phase 1 study of Ad-RTS IL-12, a novel DNA-based therapeutic candidate, in advanced melanoma. Based on early activity, and determination of a biologically effective dose, the Company also announced that the study has advanced to Phase 2 in which the first patient has been dosed. Initiation of the Phase 2 study follows the successful, dose-escalation Phase 1 study in which clinical activity was observed in 5 of 7 (71%) patients dosed at the two highest dose levels. The data also showed a correlation between T-cell immune responses and clinical outcome, with no dose-limiting toxicities reported. A total of 13 patients were enrolled in the Phase 1 study, and were treated with a range of doses of an orally administered activator ligand. Three serious adverse events (SAE) were reported: two related to therapy (pyrexia and cytopenia), and one unrelated (deep vein thrombosis). Unrelated to the study therapy, one patient death was reported due to bacterial sepsis and progression of disease. The Company expects to submit full results of the study for presentation at a major medical meeting. The Phase 2 multi-center, single-arm, open-label expansion study will enroll up to 15 patients with unresectable Stage III or IV melanoma and further evaluate the safety and efficacy of intratumoral injections of Ad-RTS IL-12 in combination with an oral activator ligand. Data from this study are expected in the first half of 2013. “ZIOPHARM, working with our DNA therapy platform, is ushering in a paradigm shift in how we treat cancer, one that transforms our ability to deliver therapy, leading to better, safer treatment and ultimately, to cures,” said Samuel Broder, M.D., Chairman of Intrexon Therapeutic Opportunities Committee and former Director of the NCI (National Cancer Institute). “We look forward to seeing additional data as ZIOPHARM expands the Ad-RTS IL-12 DNA program into multiple indications, including breast cancer, and to the introduction of the next generation of DNA-based therapeutic candidates for oncology.” “This Phase 1 study demonstrates that IL-12 dosing, delivered and controlled through a pioneering DNA therapeutic strategy, is both tolerable and clinically active,” stated Hagop Youssoufian, M.D., President of Research and Development and Chief Medical Officer of ZIOPHARM. “An important early sign of this effect was manifested in lesions not injected with Ad-RTS IL-12, where clinical response was observed, indicating systemic, anti-cancer immune activity. We also saw activity in patients who had been previously exposed to ipilimumab, as well as other forms of immunotherapy, suggesting that Ad-RTS IL-12 may provide benefit for patients with advanced disease.” In connection with the achievement of this milestone, ZIOPHARM announced today that it will issue 3,636,926 shares of the Company’s common stock to Intrexon Corporation in accordance with the terms of the Exclusive Channel Partner Agreement (ECP) between the companies entered into in January 2011. All of the shares issued to Intrexon will be unregistered but certain registration rights in accordance with the Registration Rights Agreement entered into by the companies at the time of the ECP. About ZIOPHARM Oncology, Inc.: ZIOPHARM Oncology is a biopharmaceutical company focused on the development and commercialization of new cancer therapies. The Company's clinical programs include: Palifosfamide (ZIO-201) is a potent bi-functional DNA alkylating agent that has activity in multiple tumors by evading typical resistance pathways. Palifosfamide is in the same class as bendamustine, cyclophosphamide, and ifosfamide. Intravenous palifosfamide is currently being studied in a randomized, double-blinded, placebo-controlled Phase 3 trial (PICASSO 3) for the treatment of first-line metastatic soft tissue sarcoma and is also in a pivotal Phase 3 trial (MATISSE) for first-line metastatic small cell lung cancer. Additionally, the Company is developing an oral capsule form of palifosfamide. Ad-RTS IL-12 is currently being tested in a Phase 2 study. Ad-RTS IL-12 is a novel DNA therapeutic that is delivered to the patient's tumor thereby localizing expression of the therapeutic modality, interleukin-12 (IL-12), a protein important for an immune response to cancer. ZIOPHARM's DNA therapeutics are being developed in partnership with Intrexon Corporation employing a revolutionary synthetic biology platform that permits targeted, controlled production of therapeutic proteins in humans. This is achieved by placing IL-12 under the control of a proprietary biological “switch” (the RheoSwitch Therapeutic System®, RTS®) to turn on/off the therapeutic protein expression at the tumor site. Indibulin (ZIO-301) is a novel, tubulin binding agent that is expected to have several potential benefits, including oral dosing, application in multi-drug resistant tumors, no neuropathy and a tolerable toxicity profile. It is currently being studied in a Phase 1/2 trial in metastatic breast cancer. Darinaparsin (ZIO-101) is a novel mitochondrial- and hedgehog-targeted agent (organic arsenic) currently in ongoing studies with Solasia Pharma K.K. ZIOPHARM's operations are located in Boston, MA, and New York City. Further information about ZIOPHARM may be found at www.ziopharm.com. Forward-Looking Safe Harbor Statement: This press release contains certain forward-looking information about ZIOPHARM Oncology that is intended to be covered by the safe harbor for "forward-looking statements" provided by the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. Words such as "expect(s)," "feel(s)," "believe(s)," "will," "may," "anticipate(s)" and similar expressions are intended to identify forward-looking statements. These statements include, but are not limited to, statements regarding our ability to successfully develop and commercialize our therapeutic products; our ability to expand our long-term business opportunities; financial projections and estimates and their underlying assumptions; and future performance. All of such statements are subject to certain risks and uncertainties, many of which are difficult to predict and generally beyond the control of the Company, that could cause actual results to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include, but are not limited to: whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, or any of our other therapeutic products will advance further in the clinical trials process and whether and when, if at all, they will receive final approval from the U.S. Food and Drug Administration or equivalent foreign regulatory agencies and for which indications; whether Palifosfamide, Ad-RTS IL-12, Darinaparsin, Indibulin, and our other therapeutic products will be successfully marketed if approved; whether any of our other DNA-based biotherapeutics discovery and development efforts will be successful; our ability to achieve the results contemplated by our collaboration agreements; the strength and enforceability of our intellectual property rights; competition from pharmaceutical and biotechnology companies; the development of and our ability to take advantage of the market for DNA-based biotherapeutics; our ability to raise additional capital to fund our operations on terms acceptable to us; general economic conditions; and the other risk factors contained in our periodic and interim SEC reports filed from time to time with the Securities and Exchange Commission, including but not limited to our Annual Report on Form 10-K for the fiscal year ended December 31, 2011, and our Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2012. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof, and we do not undertake any obligation to revise and disseminate forward-looking statements to reflect events or circumstances after the date hereof, or to reflect the occurrence of or non-occurrence of any events. Contact: For ZIOPHARM Nicole Jones ZIOPHARM Oncology, Inc. 617-778-2266 njones@ziopharm.com Media Contacts: David Schull or Lena Evans Russo Partners, LLC 858-717-2310 212-845-4262 david.schull@russopartnersllc.com lena.evans@russopartnersllc.com

-- Acinetobacter Infections Pose Growing Concern in Hospitals, and in Military and Natural Disaster Trauma Centers -- Company Engages Former Pfizer/Wyeth Global Infectious Disease Pharmaceutical Executive to Provide Expertise on Advancing Infectious Disease Pipeline   Ann Arbor, MI, September 18, 2012 – Synthetic Biologics, Inc. (NYSE MKT: SYN), a developer of synthetic biologics and innovative medicines for serious diseases and unmet medical needs, today announced that it has initiated efforts to develop a monoclonal antibody (mAb) therapy for the treatment of acinetobacter infections. Many strains of Acinetobacter are multidrug-resistant and pose an increasing global threat to hospitalized patients, wounded military personnel and those affected by natural disasters. The Company also announced that it has engaged Lewis (Lew) Barrett, former Assistant Vice President, Established Products at Pfizer and Vice President Global Business Manager, Infectious Diseases at Wyeth Pharmaceuticals, to bring his expertise in the development, commercialization and launch of infectious disease product candidates to the Synthetic Biologics’ team.   Acinetobacter is a difficult to treat pathogen due to its rapid and well-established resistance to most antibiotics, making it a multidrug-resistant pathogen[1]. In addition, as a biofilm-forming pathogen, Acinetobacter has the ability to survive up to twice as long as non-biofilm-forming pathogens[2]. In the U.S., Acinetobacter has been reported to be the cause of up to 2.6% of hospital acquired infections, 1.3% of bloodstream infections and 7% of ICU respiratory tract infections[3], and more than half of the Acinetobacter isolates are multidrug-resistant[4]. Patients with infections caused by Acinetobacter have been reported having mortality rates ranging from 7.8% to 43% in the hospital and in the ICU[5]. While Acinetobacter is a well-documented pathogen in the hospital setting, this pathogen also poses an increasing danger to wounded servicemen and women in military treatment centers[6] and to those treated in trauma centers following natural disasters[7].   The initiation of mAb development for the treatment of acinetobacter infection is the first of the three initial targeted infectious diseases the Company intends to pursue as part of its most recent collaboration with Intrexon Corporation. In August 2012, Synthetic Biologics entered into a worldwide exclusive channel collaboration with Intrexon Corporation for the development and commercialization of mAb therapies to treat certain infectious diseases not adequately addressed by existing therapies. Under this collaboration, the Company intends to utilize Intrexon’s comprehensive suite of proprietary technologies, including the mAbLogix™ and LEAP™ platforms, to develop fully human mAbs to specifically and rapidly neutralize/clear acinetobacter pathogens. The collaboration may optionally be expanded to include up to an additional five infectious disease indications.   “We are pleased to begin work on a mAb therapy to treat acinetobacter infections. Acinetobacter has developed an increased resistance to antibiotics and other drugs over time, and a new therapeutic option is needed to treat infectious diseases caused by this bacteria,” said Jeffrey Riley, Chief Executive Officer of Synthetic Biologics, Inc. “Our collaboration with Intrexon provides access to state-of-the-art platforms that have tremendous potential to produce a broad spectrum of fully human antibodies to fight against Acinetobacter where other options have failed.”   Mr. Riley concluded, “We welcome Lew Barrett to our team and look forward to benefiting from his many years of experience around the development and commercialization of anti-infectives, as we develop mAbs for the treatment of acinetobacter infections. We also look forward to disclosing additional infectious disease indications we intend to pursue in the near future.”   During his 25-year career at Wyeth (acquired by Pfizer in 2009), Mr. Barrett successfully led, co-chaired or served as the senior marketing executive on teams that focused on infectious diseases, oncology, transplantation, and hemophilia. He brings to Synthetic Biologics his expertise in U.S. and global strategy, domestic/global branding, clinical development, medical affairs, supply chain, business development and strategic alliance management. He built the brand and led global commercialization efforts for Wyeth’s in-line IV antibiotic, Zosyn®/Tazocin® (the second IV antibiotic to achieve $1 billion+ in sales), and managed the U.S. launch of Wyeth’s broad-spectrum IV antibiotic, Tygacil®. In 2010, Mr. Barrett formed LL Barrett Biopharmaceutical Consulting, LLC, and utilizing his depth of experience in the anti-infective, hospital and biopharma fields, provides strategic consultation to the global life sciences field with a particular focus on brand strategy, lifecycle strategy, business development, and strategic communications.   “Acinetobacter has consistently demonstrated its ability to rapidly develop resistance to antibiotics. We believe the threat of this pathogen coupled with a scarcity of new antibiotics creates a perfect storm. Novel biologic therapies such as Synthetic Biologics’ mAbs, with new targets and mechanisms, are especially exciting,” stated Mr. Barrett. “I look forward to working with the Company as they work toward developing new therapeutic candidates for a field of medicine where the availability of effective interventions has declined.”   About Monoclonal Antibodies (mAbs)   Acting as the body's army, antibodies are proteins, generally found in the bloodstream, that provide immunity in detecting and destroying pathogens, such as viruses and bacteria and their associated toxins. MAbs can also be designed and produced as therapeutic agents, utilizing protein engineering and recombinant production technologies. The mAbs being developed under the Synthetic Biologics’ collaboration with Intrexon are intended to supplement a patient's own immune system by providing the means to specifically and rapidly neutralize and/or clear specific pathogens and toxins of interest in a process known as “passive immunity”. Many pathogens that cause infectious diseases are innately resistant to, or over time have developed increased resistance to, antibiotics and other drugs. Synthetic Biologics intends to utilize Intrexon’s comprehensive suite of proprietary mAb design and recombinant protein production technologies to efficiently create potent candidate mAbs for human testing and use to specifically treat certain infectious diseases for which current therapies are unavailable or inadequate.   About Synthetic Biologics, Inc.   Synthetic Biologics is a biotechnology company focused on the development of product candidates to address serious diseases and unmet medical needs. Synthetic Biologics is developing the following synthetic biologic candidates: a series of monoclonal antibodies (mAbs) for the treatment of serious infectious diseases not adequately addressed by existing therapies and a synthetic DNA-based therapy for the treatment of pulmonary arterial hypertension (PAH). The Company is also developing drug candidates for the treatment of relapsing-remitting multiple sclerosis (MS), cognitive dysfunction in MS, amyotrophic lateral sclerosis (ALS) and fibromyalgia (partnered with Meda AB). For more information, please visit Synthetic Biologics’ website at www.syntheticbiologics.com.   mAbLogix™ and LEAP™ are registered trademarks of Intrexon Corporation.   Zosyn®, Tazocin® and Tygacil® are registered trademarks of Pfizer or its affiliates.   This release includes forward-looking statements on Synthetic Biologics’ current expectations and projections about future events. In some cases forward-looking statements can be identified by terminology such as "may," "should," "potential," "continue," "expects," "anticipates," "intends," "plans," "believes," "estimates," and similar expressions. These statements are based upon current beliefs, expectations and assumptions and are subject to a number of risks and uncertainties, many of which are difficult to predict and include statements regarding Synthetic Biologics’ intent to develop and commercialize multiclonal antibody therapies for infectious diseases, its use of Intrexon’s technologies, the opportunity presented by Acinetobacter’s ability to resist antibiotic therapy and the expected contributions of Lewis Barrett. The forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from those reflected in Synthetic Biologics’ forward-looking statements include, among others, a failure of Synthetic Biologics’ monoclonal antibodies for the treatment of infectious diseases to be successfully developed or commercialized, a failure of the Intrexon’s intellectual property to create potent candidate mAbs, an inability to obtain regulatory approval of the infectious disease product candidates, a failure of the results of clinical trials to support the efficacy or safety of product candidates, a failure to successfully integrate newly engaged team members, a failure of the preclinical or clinical trials to proceed on schedules that are consistent with Synthetic Biologics’ current expectations or at all, Synthetic Biologics’ inability to protect its intellectual property and freedom to operate without interference of the patents of others, inability to maintain the effectiveness of the exclusive collaboration agreement, its reliance on third parties to develop its product candidates, the insufficiency of existing capital reserves to fund continued operations for a particular amount of time and uncertainties regarding Synthetic Biologics’ ability to obtain additional financing to support its operations thereafter and other factors described in Synthetic Biologics’ report on Form 10-K/A for the year ended December 31, 2011 and any other filings with the SEC. The information in this release is provided only as of the date of this release, and Synthetic Biologics undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law. For further information, please contact: Synthetic Biologics, Inc. Kris Maly Vice President of Corporate Communication (734) 332-7800, Ext. 22 [1] Roca, I, Espinal, P, Vila-Farres, X, and Vila, J. The Acinetobacter baumannii oxymoron: commensal hospital dweller turned pan-resistane menace. Frontiers in Microbiology, April 2012, Vol. 3, Article 148. [2] Espinal P, Martí S, Vila J. Effect of biofilm formation on the survival of Acinetobacter baumannii on dry surfaces. J Hosp Infect. 2012 Jan; 80(1):56-60. Epub 2011 Oct 4. [3] Jones, M, et al. Emerging resistance among bacterial pathogens in the intensive care unit – a European and North American Surveillance study (2000-2002). Ann Clin Microbiol Antimicrob. 3(14).; Wisplinghoff, H, et al. Nosocomial Bloodstream Infections in US Hospitals: Analysis of 24,179 Cases from a Prospective Nationwide Surveillance Study. Clin Infect Dis. 2004; 39(3): 309-17.; Wachter, K. Step Aside, MRSA, Here Comes Acinetobacter. OB. GYN. News, January 15, 2006. [4] The Center for Disease Dynamics, Economics & Policy. http://cddep.org/ResistanceMap/overview. Trends by U.S. Census Divisions for Multidrug-resistant Acinetobacter baumannii (2010). [5] Falagas, ME, Bliziotis, LA, and Siempos, II. Attributable mortality of Acinetobacter baumannii infections in critically ill patients: a systematic review of matched cohort and case-control studies. Critical Care 2006, 10:R48. [6] Camp, C and Tatum, OL. A Review of Acinetobacter baumannii as a Highly Successful Pathogen in Times of War.  LABMEDICINE. November 2010, Vol. 41, Number 11. [7] Camp, C and Tatum, OL. A Review of Acinetobacter baumannii as a Highly Successful Pathogen in Times of War. LABMEDICINE. November 2010, Vol. 41, Number 11.

Dallas, Texas & Germantown, Maryland - August 2, 2012 - BioLife Cell Bank, Inc., the leader in cryogenic storage of adipose (fat) tissue and adult mesenchymal stem and regenerative cells, and Intrexon Corporation, a synthetic biology company that utilizes its proprietary products to provide control over cellular function, announced today the formation of a global exclusive research collaboration.  Under the collaboration, BioLife, with its extensive physician network and stem cell experience coupled with Intrexon’s innovative technology, will strive to produce new treatments for Spinal Muscular Atrophy (SMA).   “With the tremendous potential of this collaboration, we are more than excited for the SMA community,” said John A. Carbona, Chief Executive Officer of BioLife.  “Intrexon’s impressive suite of technologies will give researchers access to unprecedented resources including new techniques and processes which could rapidly propel us toward the development of new treatments and products to help treat children with SMA.” Carbona continued, “I am happy to help realize the dream of our founders, Dr. David G. Genecov and John D. Harkey Jr., to make a positive and sustainable impact in health care. We’re elated by our new collaboration with Intrexon and will undertake immediately the establishment of relationships with the world’s leading scientists in SMA research such as: Dr. Arthur Burghes of Ohio State, Dr. Brian Kaspar of Nationwide Children’s Hospital, Dr. Charlotte Sumner of Johns Hopkins, Dr. Chris Lorson at the University of Missouri, and Dr. Kathy Swoboda at the University of Utah.  BioLife, through its ongoing relationships with Intrexon and these dedicated individuals, hopes for great strides toward lessening the impact of this terrible disease, if not curing it completely—which, of course, is our ultimate goal.” Thomas D. Reed, Ph.D., Founder and Chief Science Officer of Intrexon, said, “Intrexon's mission is to invent, acquire, and integrate the diverse technology platforms required to modulate cellular behavior through genome re-engineering.  We are dedicated to building the molecular toolbox and scientific expertise needed to empower clinicians to treat previously intractable diseases.  SMA is a devastating genetic disorder that requires a gene rescue paradigm.  Intrexon looks forward to working with BioLife and their growing network of clinical specialists to define, explore, and develop several different cell therapy approaches for treating SMA.”  Under the collaboration, Intrexon, acting through its Human Therapeutics Division, will be applying its technologies to the discovery of autologous, genetically-modified stem cell therapeutics.  BioLife will be supplying the collaboration with stem cells and clinical expertise. BioLife also will be responsible for conducting preclinical and clinical development of candidate SMA therapeutic products that may be advanced out of the collaboration, as well as for aspects of manufacturing and regulatory approval. About Spinal Muscular Atrophy Spinal Muscular Atrophy (SMA) is an autosomal-recessive genetic disorder characterized by progressive weakness of the lower motor neurons.  SMA is caused by a genetic defect in the SMN1 gene which codes SMN, a protein necessary for survival of motor neurons. SMA kills more infants than any other genetic disease in today’s world.   About BioLife As part of their core business, BioLife Cell Bank, Inc. offers individuals a way to safely store their adipose (fat) tissue and/or their adipose-derived stem and regenerative cells—giving patients and physicians easy, multi-use access to cells and tissue for future cosmetic, reconstructive, and regenerative therapies. Tissue is extracted via liposuction and sent to BioLife in a collection kit (validated to E.T.L. standards). Tissue is processed using proprietary technology and Cytori Therapeutics’ (NASDAQ: CYTX) products. Tissue is cryogenically preserved, and may be stored indefinitely. BioLife is registered with the FDA as a processing bank and complies with FDA regulations and guidance including current Good Tissue Practice (cGTP). BioLife is based in Dallas, Texas, at Forest Park Medical Center. For more information: www.biolifecellbank.com.   About Intrexon Corporation Intrexon Corporation is a privately held biotechnology company focused on the industrial engineering of synthetic biology.  Intrexon is deploying its extensive capabilities to rapidly design and produce novel and enhanced biological products and processes across multiple industry sectors, including: human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science.  The company's advanced bioindustrial engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly, and optimization to enable unprecedented control over the function and output of living cells. For BioLife   Corporate Contact: John A. Carbona, 972-331-1905 Chief Executive Officer jcarbona@biolifecellbank.com Media Contact: Kristin Laminack, 972-331-9626 Director, Marketing and Media kristin@biolifecellbank.com     For Intrexon Corporation   Corporate Contact:  Donald P. Lehr, 301-556-9809 Chief Legal Officer dlehr@intrexon.com Investor Contact: The Ruth Group Stephanie Carrington / Nicole Greenbaum, 646-536-7017 / 7009 scarrington@theruthgroup.com / ngreenbaum@theruthgroup.com

Krish S. Krishnan, M.S., M.B.A., appointed Chief Operating Officer Blacksburg, Virginia, December 5, 2011. Intrexon Corporation, a privately held synthetic biology engineering company, today announced the appointment of Krish S. Krishnan, M.S., M.B.A., to Chief Operating Officer. Mr. Krishnan will have overarching executive responsibility for all of Intrexon’s operating divisions. Mr. Krishnan brings many years of experience in the life sciences industry, having held key executive roles at several companies including, most notably, his tenure as Chief Financial Officer, Chief Operating Officer and board member of New River Pharmaceuticals, Inc. Mr. Krishnan started his career as an engineer with E.I. Dupont de Nemours in Wilmington, Delaware. He received a B.S. in Mechanical Engineering from the Indian Institute of Technology, a M.S. in Engineering from The University of Toledo, and an M.B.A. in Finance from The Wharton School at the University of Pennsylvania. Intrexon’s Chairman and CEO Randal J. Kirk welcomes Mr. Krishnan stating, “Krish has an exceptional talent for driving smart execution of high value biotech strategies, as evidenced by the fast trajectory and tremendous upside return we realized together at New River Pharmaceuticals. Krish joins Intrexon at a time when his engineering and operational leadership skills can be applied across many such opportunities and drive the robust success of our partnerships and collaborations.” Kirk continues, “I have no doubt that he will bring an even greater industrial engineering discipline to the design and metrics of our processes and, in so doing, deliver further scalability, deeper cost reductions and even faster turnaround times. It is my great pleasure to welcome Krish to the Intrexon leadership team and the opportunity to go well beyond the previous level of achievement we have attained together.” Mr. Krishnan echoed the comments of Mr. Kirk, and added, “I am very excited to join Intrexon, and look forward to working closely with RJ to drive strong execution of this game changing biotech strategy and business model.” About Intrexon Corporation Intrexon Corporation is a privately held biotechnology company focused on the industrial engineering of synthetic biology. Intrexon is deploying its extensive engineering platform and capabilities to rapidly design and produce novel biofunctions and applications for human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science. The company’s advanced industrial engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly and optimization. More information about the company is available at www.DNA.com. Contact: Andrew Udell Intrexon Corporation Phone: 301-556-9850 E-mail: audell@intrexon.com

Adeona Pharmaceuticals and Intrexon Announce Worldwide Exclusive Collaboration for Synthetic DNA-based Therapy for Pulmonary Arterial Hypertension For Immediate Release Ann Arbor, MI, & Germantown, MD, November 21, 2011 – Adeona Pharmaceuticals, Inc. (NYSE Amex: AEN), a developer of innovative disease-modifying medicines for serious illnesses, and the Human Therapeutics Division of Intrexon Corporation, a synthetic biology company that utilizes its proprietary technologies to provide control over cellular function, announced today the formation of a global exclusive channel collaboration through which Adeona intends to develop and commercialize a DNA-based therapeutic using Intrexon's UltraVector® platform and RheoSwitch Therapeutic System® for the treatment of pulmonary arterial hypertension (PAH). Under the collaboration, Adeona will utilize Intrexon's advanced transgene engineering platform for the controlled, precise and continuous in vivo cellular production of prostaglandin synthase (PGIS), a specific effector enzyme that regulates the production of prostacyclin. PGIS expression is decreased in the lungs of PAH patients and deficiency in prostacyclin production is strongly implicated in PAH. Prostacyclin is a short-acting vasodilator and inhibitor of platelet aggregation that has demonstrated a survival benefit in primary pulmonary hypertension patients when administered by continuous central venous catheter infusion (p<0.003).  DNA-based in vivo expression of PGIS has demonstrated the ability to increase prostacyclin levels and improve survival in animal models of PAH. Intrexon employs its modular genetic engineering platform in the areas of therapeutics, protein production, animal sciences, industrial products, and agriculture products. The exclusive channel collaboration between Intrexon and Adeona has been established specifically for the in vivo production of PGIS for PAH. Under the collaboration, Intrexon will be responsible for technology discovery efforts and managing the patent estate as well as for certain aspects of manufacturing. Adeona will be responsible for conducting preclinical and clinical development of candidates, as well as for other aspects of manufacturing and the commercialization of the candidate product. Intrexon's core synthetic biology technology is designed to create Better DNA™ at industrial scale, enabling unprecedented control over the function and output of living cells by providing external control over in vivo activation and regulation of potent effectors. This platform, called UltraVector®, provides speed, flexibility, consistency and precision to the design, production and testing of rationally designed complex transgenes and their encoded genetic circuits. These qualities allow an iterative and rational approach to transgene design, which can be continually engineered until the host cell performance is optimized. Through this process, Intrexon is able to overcome the challenges inherent in current therapeutic strategies, including recombinant protein therapies and constitutive gene therapies, thereby enhancing capabilities, improving safety and lowering cost for human therapeutics. “Our collaboration with Intrexon is consistent with Adeona’s strategy of building shareholder value through continuous evaluation of new product opportunities and acting upon those that meet Adeona’s mission of delivering disease-modifying therapies for serious illnesses. We believe that this product opportunity and collaboration far and away exceeds these criteria, and we are pleased to be working with Intrexon to make this important new therapy available to PAH patients,” stated Adeona’s Chairman, Jeffrey Riley. “Current sales of approved therapies for PAH are an estimated $3 billion per year. While current therapies may improve quality of life, they have for the most part shown only modest improvements in survival, if any. We believe that by having the ability to correct what is considered to be a critical pathophysiological defect in PAH, namely reduced expression of prostaglandin synthase, we may have the opportunity to fundamentally change the course of PAH. We further believe that the ‘second generation’ rational nature of Intrexon’s genetic engineering technology provides the enabling technology necessary to make this goal a practical reality for PAH patients. We are pleased to be working with Intrexon in this exciting and potentially disease changing collaboration,” stated James S. Kuo, M.D., M.B.A., Chief Executive Officer of Adeona. "We are very pleased to collaborate with Adeona in this further demonstration of the breadth of Intrexon's UltraVector® platform and embedded controllable bioreactor approach to novel therapeutics. We are impressed with Adeona’s demonstrated ability to operate efficiently and decisively and we believe these qualities will serve both parties well as we navigate through the drug development process and commercialization," stated Glenn Nedwin, President, Human Therapeutics Division at Intrexon. Under terms of the agreement: •    Subject to the pre-approval of the NYSE Amex, Adeona will issue to Intrexon at $0.001 par value per share, 3,123,558 shares of its common stock, representing 9.995% of Adeona's issued and outstanding shares following and after taking into account such issuance; Adeona has agreed to issue to Intrexon an equal number of additional shares of its common stock at $0.001 par value per share, representing an additional 9.995%, upon dosing of the first patient in an Adeona-sponsored U.S. Phase II clinical trial of the candidate product using Intrexon technology; •    Intrexon has been granted the right to purchase up to 19.99% of securities offerings that may be conducted by Adeona in the future, subject to certain conditions and limitations; •    Intrexon has been granted the right to make purchases of Adeona’s common stock in the open market up to an additional 10% of Adeona’s common stock; and •    Subject to certain expense allocations, Adeona will pay Intrexon 50% of the cumulative net quarterly profits derived from the sale of products developed from the channel collaboration. “Because of the very wide breadth of applications that our technologies may enable, we believe that we can play a democratizing role among companies within traditional life science industries and among those in other industries that look to life science to supply solutions that their existing industrial processes have been otherwise unable to provide,” stated RJ Kirk, Intrexon’s Chairman and CEO. “In therapeutics, in particular, we see many opportunities for game changing strategies to be deployed against indications both large and small, complex and simple. In consequence, and as part of our business strategy, we look for opportunities to align ourselves with smaller, more entrepreneurial companies around focused opportunities that may be fully explored at costs and on timelines that previously were not available. Our new collaboration with Adeona around PAH exemplifies such an alignment and we celebrate our partner’s entrepreneurial spirit, vision and dedication to the service of patients as we begin the work of producing a meaningful improvement to the lives of people with this unfortunate but theoretically treatable condition.” If the NYSE Amex approval of the issuance of the securities described above is not received within 60 days of the date of the execution of the exclusive channel agreement, Intrexon has the right to terminate the exclusive channel collaboration. Griffin Securities served as financial advisor to Intrexon in connection with the transaction. About Pulmonary Arterial Hypertension (PAH) Pulmonary arterial hypertension is a progressive, disabling and life-threatening disorder characterized by abnormally high blood pressure (hypertension) in the pulmonary artery, the blood vessel that carries blood from the heart to the lungs. Hypertension occurs when most of the very small arteries throughout the lungs narrow in diameter, which increases the resistance to blood flow through the lungs. To overcome the increased resistance, pressure increases in the pulmonary artery and in the heart chamber that pumps blood into the pulmonary artery (the right ventricle). Signs and symptoms of pulmonary arterial hypertension occur when increased pressure cannot fully overcome the elevated resistance and blood flow to the body is insufficient. Shortness of breath during exertion and fainting spells are the most common early symptoms of pulmonary arterial hypertension. Despite current treatments, the outcome of PAH is generally very poor and associated with high rates of mortality within three to five years of diagnosis. About Intrexon Corporation Intrexon Corporation is a privately held synthetic biology company that employs modular DNA control systems to enhance capabilities, improve safety and lower cost in human therapeutics, protein production, industrial products, agricultural biotechnology, and animal science. The company’s advanced transgene engineering platform enables Better DNA™ technology by combining revolutionary DNA control systems with corresponding advancements in modular transgene design, assembly and optimization.  More information about the company is available at www.DNA.com. About Adeona Pharmaceuticals, Inc. Adeona is a pharmaceutical company focused on the development of innovative disease-modifying medicines for serious illnesses. Adeona is developing, or has partnered the development of, drug product candidates to treat primary pulmonary hypertension, multiple sclerosis, fibromyalgia, amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. For more information, please visit Adeona's website at www.adeonapharma.com. This release includes forward-looking statements on Adeona's current expectations and projections about future events. In some cases forward-looking statements can be identified by terminology such as "may," "should," "potential," "continue," "expects," "anticipates," "intends," "plans," "believes," "estimates," and similar expressions. These statements are based upon current beliefs, expectations and assumptions and are subject to a number of risks and uncertainties, many of which are difficult to predict and include statements regarding Adeona’s intent to develop and commercialize a DNA-based therapeutic for PAH, Adeona’s belief that the new product opportunity and collaboration will build shareholder value, Adeona’s ability to use the technology to develop a product that will correct a biological defect in PAH and the benefits to be derived from Intrexon’s genetic engineering technologies. The forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from those reflected in Adeona's forward-looking statements include, among others, a failure of Adeona’s DNA-based therapeutic for the treatment of PAH to be successfully developed or commercialized, an inability to obtain regulatory approval of the PAH product candidates, a failure of the results of clinical trials to support Adeona’s claims, a failure of the preclinical or clinical trials to proceed on schedules that are consistent with Adeona’s current expectations or at all, Adeona’s inability to protect its intellectual property and freedom to operate without interference of the patents of others, inability to maintain the effectiveness of the exclusive collaboration agreement, its reliance on third parties to develop its product candidates, the insufficiency of existing capital reserves to fund continued operations for a particular amount of time and uncertainties regarding Adeona’s ability to obtain additional financing to support its operations thereafter and other factors described in Adeona's report on Form 10-K for the year ended December 31, 2010 and any other filings with the SEC. The information in this release is provided only as of the date of this release, and Adeona undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law. For more information, contact: Jeffrey Riley Chairman Adeona Pharmaceuticals, Inc. Tel: (734) 332-7800 i Humbert M, Sitbon O, Simonneau G., Treatment of pulmonary arterial hypertension, N Engl J Med. 2004 Sep 30;351(14):1425-36. ii Ito T, Okada T, Mimuro J, Miyashita H, Uchibori R, Urabe M, Mizukami H, Kume A, Takahashi M, Ikeda U, Sakata Y, Shimada K, Ozawa K. Adenoassociated virus-mediated prostacyclin synthase expression prevents pulmonary arterial hypertension in rats. Hypertension. 2007 Sep;50(3):531-6.

Blacksburg, Virginia, October 11, 2011. Intrexon Corporation, a privately held synthetic biology company, today announced the formation and launch of its Cell Engineering Unit (CEU) in San Diego, CA. The new unit will be under the leadership of the company’s Chief Science Officer and Founder, Thomas D. Reed, Ph.D. As part of the launch, Intrexon simultaneously announced the acquisition of GT Life Sciences, Inc. and the purchase of assets comprising the LEAP cell-processing platform from Cyntellect, Inc. The two transactions provide the foundational technology, facilities, exclusive IP portfolios, and team for the new scientific unit. Terms of the transactions were not disclosed.

NEW YORK, NY (August 30, 2011) — ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) today announced that the first patient has been dosed in a Phase 1 clinical study of ZIN ATI-001, a novel DNA-based therapeutic candidate, in patients with advanced melanoma. ZIN ATI-001 is the second clinical oncology product candidate from the ZIOPHARM-Intrexon Corporation exclusive synthetic biology channel partnership. The multi-center, single-arm, open-label, dose-escalation study, treating patients with unresectable Stage III or IV melanoma, will assess the safety and tolerability of intratumoral injections of ZIN ATI-001 (Ad-RTS-IL-12 or INXN-2001). Secondary endpoints include a determination of the recommended Phase 2 dose, an evaluation of T cell immunity markers, and preliminary anti-tumor activity. “ZIN ATI-001 demonstrates the ability to engineer complex, controllable transgenes whose properties cannot be reproduced through traditional therapeutic approaches,” said John Nemunaitis, MD, Executive Medical Director, Mary Crowley Medical Research Center. “ZIN ATI-001 is designed to express a potent anti-cancer cytokine with a known ability to stimulate the immune system against cancer directly within tumor cells and under the control of an ‘oral activator drug’. Melanoma is a cancer particularly susceptible to immune-modulating therapy and this early, melanoma-focused study will provide a preliminary understanding of the properties of this DNA-based therapeutic. Such results may then allow for an accelerated clinical program in other cancer types.” About ZIN ATI-001: ZIN ATI-001 employs an adenoviral vector to deliver, directly into the patient's own cells, a gene which expresses Interleukin-12 (IL-12), a potent, naturally occurring anticancer cytokine that is central to the initiation and regulation of cellular anti-cancer immune responses. Production of IL-12 within cells is then tightly regulated by the Intrexon RheoSwitch Therapeutic System® (RTS®), a "gene switch" controlled by an orally administered activator ligand (AL). Preclinical studies have shown that the immunological mechanism of action of ZIN ATI-001 is similar to that of ZIN-CTI-001 (DC-RTS-IL-12 + AL), ZIOPHARM's most advanced DNA-based therapeutic candidate, currently in a nearly completed Phase 1b trial. Positive clinical data of ZIN-CTI-001, the first-ever to demonstrate small molecule-controlled production of an anticancer protein in humans, were recently presented at the 2011 Annual Meeting of the American Society of Clinical Oncology. About ZIOPHARM Oncology, Inc.: ZIOPHARM Oncology is a biopharmaceutical company engaged in the development and commercialization of a diverse portfolio of cancer therapeutics. The Company is currently focused on several clinical programs. Palifosfamide (Zymafos™ or ZIO-201) is a novel DNA cross-linker in class with bendamustine, ifosfamide, and cyclophosphamide. ZIOPHARM is currently enrolling patients in a randomized, double-blinded, placebo-controlled Phase 3 trial with palifosfamide administered intravenously for the treatment of metastatic soft tissue sarcoma in the front-line setting. The company is also currently conducting a Phase 1 intravenous study of palifosfamide in combination with standard of care addressing small cell lung cancer and an oral form of the drug for treatment of solid tumors is currently in the advanced preclinical stage of development. Darinaparsin (Zinapar™ or ZIO-101) is a novel mitochondrial-targeted agent (organic arsenic) being developed intravenously for the treatment of relapsed peripheral T-cell lymphoma likely with a two-stage potentially pivotal study expected. An oral form is in a Phase 1 trial in solid tumors. Indibulin (Zybulin™ or ZIO-301) is a novel, oral tubulin binding agent that is expected to have several potential benefits including oral dosing, application in multi-drug resistant tumors, no neuropathy and a quite tolerable toxicity profile. It is currently being studied in Phase 1/2 in metastatic breast cancer. ZIOPHARM is also pursuing the development of novel DNA-based therapeutics in the field of cancer pursuant to an exclusive channel partnership with Intrexon Corporation. The partnership includes two existing clinical-stage product candidates, both of which are currently in Phase 1 study. ZIOPHARM's operations are located in Boston, MA and Germantown, MD with an executive office in New York City. Further information about ZIOPHARM may be found at www.ziopharm.com. ZIOP-G Forward-Looking Safe Harbor Statement: This press release contains forward-looking statements for ZIOPHARM Oncology, Inc. that involve risks and uncertainties that could cause ZIOPHARM Oncology's actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from these statements. Among other things, there can be no assurance that any of ZIOPHARM Oncology's development efforts relating to its product candidates will be successful, or such product candidates will be successfully commercialized. Other risks that affect forward-looking information contained in this press release include the possibility of being unable to obtain regulatory approval of ZIOPHARM Oncology's product candidates, the risk that the results of clinical trials may not support ZIOPHARM Oncology's claims, the risk that pre-clinical or clinical trials will proceed on schedules that are consistent with ZIOPHARM Oncology's current expectations or at all, risks related to ZIOPHARM Oncology's ability to protect its intellectual property and its reliance on third parties to develop its product candidates, risks related to the sufficiency of existing capital reserves to fund continued operations for a particular amount of time and uncertainties regarding ZIOPHARM Oncology's ability to obtain additional financing to support its operations thereafter, as well as other risks regarding ZIOPHARM Oncology's that are discussed under the heading "Risk Factors" in ZIOPHARM Oncology's filings with the United States Securities and Exchange Commission. Forward-looking statements can be identified by the use of words such as "may," "will," "intend," " should," "could," "can," "would," "expect," "believe," "estimate," " predict," "potential," "plan," "is designed to," "target" and similar expressions. ZIOPHARM Oncology assumes no obligation to update these forward-looking statements, except as required by law. Contacts: For ZIOPHARM: Tyler Cook ZIOPHARM Oncology, Inc. 617-259-1982 tcook@ziopharm.com Media: David Pitts Argot Partners 212-600-1902 david@argotpartners.com

NEW YORK, NY (June 10, 2011) — ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), a drug development company employing small molecule and synthetic biology approaches to cancer therapy, announced today that the U.S. Food & Drug Administration (FDA) has accepted the Company’s investigational new drug (IND) application to begin clinical study of ZIN ATI-001, a novel DNA-based therapeutic candidate also known as Ad-RTS-IL-12 + AL (INXN 2001/1001), in oncology. When initiated, the Phase I study will evaluate safety in addition to immunological and biological effects of the therapeutic candidate in patients with melanoma. ZIN ATI-001 is the second clinical oncology product candidate from the ZIOPHARM-Intrexon Corporation exclusive synthetic biology channel partnership.

SAN DIEGO and FOSTER CITY, Calif., June 6, 2011 — Halozyme Therapeutics, Inc. (Nasdaq: HALO) and Intrexon Corporation, today announced the signing of a worldwide exclusive licensing agreement for the use of rHuPH20 (recombinant human hyaluronidase) in the development of a subcutaneous (under the skin) injectable formulation of Intrexon Corporation’s recombinant human alpha 1-antitrypsin (rHuA1AT). Under terms of the agreement, Halozyme may receive up to $63 million, commencing with an upfront payment of $9 million and total potential future milestone payments of $54 million dependent upon the achievement of clinical and regulatory targets, plus up to 11% royalty on future sales of the combination of rHuA1AT with rHuPH20. The license provides Intrexon Corporation, a next generation synthetic biology company, with exclusivity to alpha 1-antitrypsin, for the indications resulting from A1AT deficiency. Additional terms of the transaction have not been disclosed.

SEATTLE, WA (May 20, 2011) – ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), and Intrexon Corporation announced today that results from two preclinical studies examining the tightly controlled, intra-tumoral expression of a novel protein, interleukin-12 (IL-12), in melanoma, colon, lung, leukemia, breast and pancreatic cancer models in mice, were presented at the 2011 Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT), held May 18 – 21 in Seattle, Washington.

Germantown, Maryland, April 27, 2011. Intrexon Corporation, a next generation synthetic biology company, today announced the launch of its Animal Science Division and appointment of Thomas R. Kasser, Ph.D. as Division President and a Senior Vice President of the Corporation. The Division is located in Germantown, Maryland, and focused on pioneering novel approaches that protect and enhance the health of companion and production animals, improve production animal efficiency, and enable more relevant animal research models.

Blacksburg, VA, January 07, 2011. — Intrexon Corporation today announced that Randal J. Kirk, Chairman and Chief Executive Officer, will be presenting a corporate overview at the 29th Annual J.P. Morgan Healthcare Conference. Intrexon's presentation will take place at 4:00 p.m. PST on Monday, January 10, 2011 at The Westin St. Francis hotel, San Francisco, CA.

Germantown, Maryland, October 7, 2010 – Intrexon Corporation, a privately held synthetic biology company, today announced the appointment of William E. Fogler, Ph.D., as Senior Director of Portfolio Analysis and Planning for its Human Therapeutics Division. Dr. Fogler’s efforts will focus on identifying high value therapeutic opportunities for which Intrexon’s proprietary technologies and capabilities confer an unparalleled advantage.