Nucorion Pharmaceuticals, Inc. Overview 2016

Ligand Non-Confidential Nucorion Pharmaceuticals, Inc.  Newly formed US-based biotech company, initially funded with $5 million of venture capital  Focused on developing anti-cancer and anti-viral agents, initially focused on Chinese market  Proprietary technology platforms keys to drive long-term growth ‒Prodrug technology designed to deliver active compounds specifically to liver ‒Improving drugs to become better “next generation” medicines ‒Modified nucleos(t)ide analogues designed to overcome limitations of approved therapies  Uniquely positioned to address unmet medical needs in China as well as other major pharmaceutical markets 2

Ligand Non-Confidential Background  Co-founded by Ligand Pharmaceuticals and Dr. Zucai Suo (Professor, The Ohio State University)  Technologies licensed from Ligand and The Ohio State University ‒Liver Targeting Prodrug (LTP Technology™) licensed from Ligand ‒Nucleos(t)ide technology from laboratories of Dr. Zucai Suo 3

Ligand Non-Confidential Board of Directors 4  From Silver River International Investments Ltd: ‒Xiaodong (James) Gu, Chairman of the Board ‒Meiyao (Melissa) He ‒Linchao Huang  From Ligand Pharmaceuticals: ‒Lin Zhi, PhD

Ligand Non-Confidential Scientific Advisory Board ‒Zucai Suo, Ph.D. Nucorion Co-Founder and Chair of Scientific Advisory Board The Ohio State University - current Professor of Chemistry & Biochemistry Fudan University (Shanghai) - B.S., M.S. ; Pennsylvania State University - Ph.D.; Harvard Medical School - Postdoctoral Eli Lilly & Co (US) - former Senior Biochemist ‒Stephen J. Benkovic, Ph.D. National Medal of Science recipient (2010) Pennsylvania State University (Evan Pugh Professor and Eberly Chair in Chemistry) Anacor Pharmaceuticals Co-Founder and Director National Academy of Science member (US) ‒John Kozarich, Ph.D. ActivX Biosciences (Chairman and President); Ligand Pharmaceuticals (Chairman); Scripps Research Institute (adjunct professor) Serves on the boards of QLT, Inc., Retrophin Inc. and Board of Trustees of The Gordon Research Conferences Merck & Co. (former Vice President, Research); University of Maryland (professor); Yale University (professor) ‒Jack W. Szostak, Ph.D. Nobel Laureate (2009 Nobel Prize for Physiology or Medicine) Howard Hughes Medical Institute (Investigator); Harvard Medical School (Professor of Genetics) Massachusetts General Hospital (Alexander Rich Distinguished Investigator) National Academy of Science member (US) ‒Lin Zhi, Ph.D. Ligand Pharmaceuticals (Vice President of Chemistry and Pharmaceutical Sciences); over 23 years discovery & development experience Co-author of more than 60 publications and 87 issued US patents Inventor of LTP Technology™ platform 5

Ligand Non-Confidential Technologies  Ligand proprietary technology  Broadly applicable liver-targeting prodrug technology  Liver CYP3A4 as activation enzyme  Previous technology clinically validated in the US and China ‒4 clinical-stage programs ‒Most advanced (Pradefovir; Ph 2b)  LTP Technology designed to deliver broader range of drugs to liver ‒License Agreement with AstraZeneca for dyslipidemia (2014) LTP Technology™ 6  Developed by Prof. Zucai Suo  Novel chemical structures of marketed drugs  Bypass mechanisms of resistance in cancer cells  Oral administration  Multiple patent applications filed  Related know-how in the field Nucleos(t)ide Technology

Liver-Targeting Prodrug Technology (LTP Technology™)

Ligand Non-Confidential Achieving Liver-Targeting via Prodrugs Advantages of Ligand’s technology:  Increases drug concentration in the liver: ‒Better activity treating liver diseases  Decreases drug concentration in other tissues: ‒Reduction in side effects  Only known prodrug technology leveraging liver-specific enzymes 8 Prodrug (inactive) Prodrug Drug Conversion Delivery Drug Elimination Liver specific CYP3A4 as key activation enzyme Previous chemical class LTP Technology TM chemical class

Pipeline

Ligand Non-Confidential Pipeline Program Lead Identification Lead Optimization Clinical Candidate NUC-404 HBV Nucleotide Analog plus LTP Technology TM NUC-202 Gemcitabine Analog Technology plus LTP Technology TM NUC-101 HCV Nucleotide Analog plus LTP Technology TM NUC-303 Gemcitabine Analog 10