Results from Phase II/III Clinical Trials Show Improvement in Subset of Patients who Developed an Immune Response to Vaccination
TAIPEI, Taiwan, June 4, 2016 /PRNewswire/ -- OBI Pharma, Inc., a Taiwan biotech company (TPex: 4174), today announced that Phase II/III data evaluating the clinical benefit and immunogenicity of OBI-822/OBI-821 (formerly OPT‐822/OPT-821), an investigational active immunotherapy in patients with metastatic breast cancer, was presented via oral presentation (Abstract 1003) at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. The study did not meet the primary efficacy end point of progression-free survival (PFS) in patients with late stage metastatic breast cancer. However, a significant improvement in PFS was seen in a subset of ~50 percent of patients who demonstrated an immune response to the vaccine therapy, compared to those receiving placebo. Overall survival (OS) data is immature.
"These results are encouraging and provide important signals about the benefit of OBI-822/OBI-821, a novel active immunotherapy in patients with metastatic breast cancer," 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 study investigator. "The data from this trial will guide us in shaping the design of our upcoming Phase III clinical trial, allowing us to identify the patient population most likely to benefit from this immunotherapy."
About the Phase ll/lll Trial
The study was a multinational, multicenter, randomized, double-blind, placebo-controlled, Phase II/III trial (NCT01516307) consisting of nine injections of OBI-822/OBI-821 or placebo for 41-weeks followed by follow-up for up to two years from randomization, and survival follow-up for up to five years. A total of 349 women previously treated with one to three lines of therapy for metastatic breast cancer, with stable or responding disease to the last line of therapy, were randomly assigned (2:1) to receive subcutaneous OBI-822 (30 μg Globo H)/OBI-821 (100 μg) or placebo on weeks 1, 2, 3, 5, 9, 13, 17, 25 and 37 or until progressive disease (PD), in combination with intravenous low-dose cyclophosphamide (300 mg/m2). Concomitant hormone therapy was allowed.
Seventy percent had hormone receptor positive breast cancer, 13 percent were triple negative and 62 percent received hormone therapy. No difference was observed in PFS (HR, 0.96 [95% CI, 0.74-1.25] P = .77) or in interim OS (HR, 0.79 [95% CI, 0.51-1.22] P = .29) in the entire study population. However, PFS and interim OS were improved in the 50 percent of patients who developed a Globo H specific IgG response to OBI-822/OBI 821 with a titer ≥1:160 at any time during treatment versus patients treated with control vaccine (HR, 0.71 [95% CI, 0.52-0.97] P = .029 for PFS; HR, 0.57 [95% CI, 0.33-0.97] P = .04 for OS) and versus those without an immune response (HR, 0.52 [95% CI, 0.37-0.71] P < .0001 for PFS; HR, 0.52 [95% CI, 0.29-0.92] P = .025 for OS), adjusted for baseline disease status/hormone use.
In a time-dependent Cox model, PFS was improved in patients who received all nine injections of OBI 822/821 versus control (HR, 0.66 [95% CI, 0.42-1.01] P = .057). Overall, therapy was well tolerated during the study with the main side effects from the vaccine including minor pyrexia and local injection reactions.
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, Keyhole 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/OBI-821, 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.
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.
OBI Pharma, Inc.
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