OBI Pharma Reports Topline Results from OBI-822/821 Randomized Controlled Phase 2/3 Clinical Trial in Patients with Metastatic Breast Cancer

Plans to Advance to Global Phase 3 Clinical Program

TAIPEI, TAIWAN, February 21, 2016 — OBI Pharma, Inc., a Taiwan biotech company (TPex: 4174), today announced the topline results of the Phase 2/3 study of OBI-822/821 (formerly OPT‐822/OPT‐821), which evaluated the clinical benefit and immunogenicity of the investigational immunotherapy in patients with metastatic breast cancer. Based on the data available to date, the study (Protocol Number OPT-822-001) did not meet the primary efficacy end point of progression-free survival. However, patients who demonstrated an immune response (IgG or IgM) showed highly significant improvement in progression-free survival and the secondary endpoint of overall survival is trending towards statistical significance.  OBI-822/821 was generally well tolerated with no major safety concerns. Full results will be presented at an upcoming international scientific conference.

“The interesting and somewhat complex results achieved with this novel mechanism of action indicate that OBI-822 may have a benefit in patients that are able to generate an immune response,” said Chiun‐Sheng Huang, MD, PhD, Professor of Surgery and Director of the Breast Center at the National Taiwan University Hospital and Principal Investigator of the study.  “Further understanding of the data will help us identify the patient population that will see the greatest response to OBI-822 therapy and further assist physicians in their efforts to more effectively treat metastatic breast cancer.”

“While the study did not meet its originally designed primary endpoint, the encouraging efficacy seen in patients who demonstrated an immune response to the vaccine support the validity of an immunological approach to treating breast cancer and these data will help us develop a global phase 3 study that will provide the data to further elucidate the value of OBI-822 and support the registration of this promising new product,” said Hope S. Rugo, MD, Professor of Medicine, Director, Breast Oncology and Clinical Trials Education, University of California San Francisco Helen Diller Family Comprehensive Cancer Center and OBI-822 investigator.

“Based on the positive immune response results and the overall safety of OBI-822/821, we will meet with the regulatory authorities in Taiwan, US, and Europe to discuss the most appropriate design for an upcoming global phase 3 clinical trial,” said Nathan Chen, MD, PhD, Chief Medical Officer, OBI Pharma Inc.

Study Design

The study was a multinational, multicenter, randomized, double-blind, placebo-controlled, Phase 2/3 trial (NCT01516307) consisting of 9 injections of OBI-822 in a 41-week treatment period, a disease progression follow-up period of up to 2 years from randomization, and a survival follow-up period of up to 5 years. A total of 349 previously treated women with histologically or cytologically confirmed metastatic breast cancer were randomly assigned (2:1) to treatment with subcutaneous OBI-822 (equivalent to 30 µg Globo H)/OBI-821 (100 µg) or control, both in combination with intravenous low-dose CTX (300 mg/m2). Study participants were recruited from 45 medical centers in Taiwan, Hong Kong, the U.S., Korea and India.

About OBI-822 and OBI-821

OBI-822 is a new, investigational anti-cancer treatment that belongs to a novel class of active immunotherapies. It is a synthetic glycoprotein comprised of a Tumor-Associated Carbohydrate Antigen (TACA), Globo H, covalent bounded to a carrier protein, Key Limpet Hemocyanin. OBI-821 is a saponin-based adjuvant. Globo H is expressed in high levels on the surface of malignant tumors in many epithelial cancers, such as breast, prostate, gastric, lung, colon, pancreatic, and ovarian cancer, etc. The immunogenicity of the antigen is enhanced by conjugating Globo H to the KLH carrier protein to form OBI-822 (Globo H-KLH), and co-administered with an adjuvant, OBI-821. It is exclusively licensed to OBI from Memorial Sloan-Kettering Cancer Center (MSKCC).

About OBI Pharmaceuticals

OBI Pharma, Inc. is a Taiwan biopharmaceutical company established in 2002. OBI’s mission is to develop novel therapeutic agents for unmet medical needs, including cancer and infectious diseases. The company’s flagship product is OBI-822, a first-in-class active immunotherapy for metastatic breast cancer. OBI is also developing next generation active immunotherapies for difficult to treat cancers, including lung, prostate, pancreatic, stomach, and ovarian. Additional information can be found at www.obipharma.com/en.

Forward-Looking Statements

Statements included in this press release that are not a description of historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include, but are not limited to, statements about future clinical trials, results and the timing of such trials and results. Such risk factors are identified and discussed from time to time in OBI Pharma’s reports and presentations, including OBI Pharma’s filings with the Taiwan Securities and Exchange Commission.

###