TetraGenetics to receive up to $25 million in upfront license and FTE payments; is eligible to receive total contingent payments up to $248 million plus royalties up to 7%

STAMFORD, CT, and BOSTON, Imbrium Therapeutics L.P., a clinical-stage biopharmaceutical company and operating subsidiary of Purdue Pharma, L.P., and TetraGenetics, Inc., a biotech company developing novel therapeutics for pain indications and autoimmune diseases, today announced a strategic research & development collaboration to utilize TetraGenetics? antibody discovery technology platform (TetraExpress?) in the discovery and development of non-opioid biologic therapies for the treatment of chronic pain. Imbrium will leverage TetraGenetics? proprietary TetraExpress? system to advance monoclonal antibodies that target specific ion channels that are scientifically important in the modulation of pain sensation. The goal of this collaborative effort is to bring to market long-acting, non-opioid therapeutics that can treat a variety of pain conditions. ?We are encouraged by the potential of TetraGenetics? technology platform to speed the development of transformative therapies that could have a positive impact in the management of chronic pain,? said Paul Medeiros, President, Imbrium Therapeutics. ?Given the high prevalence of chronic pain in the US,¹?we are excited about progressing our partnership with the goal of bringing forward new, safe, and effective treatment alternatives. This opportunity underscores our mission to provide non-opioid pain medicines for patients in need.? ?Ion channel antibody discovery holds great promise for the treatment of chronic pain, and we are pleased to have the resources and support of Imbrium to advance this important program,? said Doug Kahn, Chairman and CEO, TetraGenetics. ?During the course of our collaboration, we expect to bring new antibody therapeutics to investigational new drug application (IND) readiness so Imbrium can advance them through clinical trials. We look forward to working with Imbrium to develop and bring to the medical community new, non-opioid therapeutic options for patients living with chronic pain.? ?Patients suffering from chronic pain need more non-opioid treatment options,? said Craig Landau, MD, President and CEO, Purdue Pharma L.P. ?This collaboration is another example of our commitment to address the evolving needs of those patients and their healthcare providers through the research & development of non-opioid solutions. It demonstrates our commitment, through Purdue?s subsidiary Imbrium, to building a pipeline through internal research, strategic collaborations and partnerships.? About Imbrium Therapeutics Imbrium is a clinical-stage biopharmaceutical company dedicated to advancing medical science through the development of important new pharmacologic and biologic therapeutics. We are pursuing treatments for disorders of the central nervous system, oncology chemotherapeutics, and non-opioid approaches to the management of pain. As an operating subsidiary of Purdue Pharma L.P., Imbrium strives to develop and bring to market new medicines that serve the unmet needs of patients, physicians, and health systems worldwide. We have built a robust and diversified pipeline of investigational drug candidates, and we actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit www.imbriumthera.com. About TetraGenetics TetraGenetics is a pre-clinical drug discovery and development company. It uses proprietary technology (TetraExpress?) to discover large molecule drugs targeting ion channel and other membrane proteins associated with many human diseases. The company?s focus is the discovery and development of first-in-class biologics for autoimmune diseases and pain. TetraGenetics establishes collaborative partnerships with major biotech companies for antibody drug discovery and pursues novel approaches to advance its proprietary drug pipeline. For more information, please visit: www.tetragenetics.com. Reference 1. Dahlhamer J, Lucas J, Zelaya, C, et al. Prevalence of Chronic Pain and High-Impact Chronic Pain Among Adults ? United States, 2016. MMWR Morb Mortal Wkly Rep. 2018;67:1001?1006. DOI: http://dx.doi.org/10.15585/mmwr.mm6736a2. # # # Media Contacts: For Imbrium Therapeutics: media@imbriumthera.com For TetraGenetics: Suzanne Gibbons-Neff Suzanne@sgnpr.com 203-858-1325