Access Pharmaceuticals initiates Phase I/II dose escalating study for Thiarabine

Access Pharmaceuticals, Inc. (OTC Bulletin Board: ACCP), today announced it has initiated a Phase I/II dose-escalating study of its proprietary, anti-cancer drug, Thiarabine, a nucleoside analog for patients with hematologic malignancies (cancers of the blood).  The primary objective of the study is to determine the maximum tolerated dose (MTD) in two different dosing schedules with various leukemias and lymphomas and recommended Phase II dose. The program is being led by Hagop Kantarjian, M.D., Chair of the Department of Leukemia at The University of Texas MD Anderson Cancer Center in Houston, Texas.  

The clinical development program follows previously conducted Phase I and Phase II trials of Thiarabine in solid tumors, where myelosuppression (decrease in the production of blood cells), particularly lymphopenia (abnormally low white blood cell levels) was dose limiting.  Access believes an agent that produces significant lymphopenia can be a strong active against lymphoproliferative disorders like acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), myeloma and lymphoma.

"We are pleased to have Dr. Kantarjian lead our continued clinical development of Thiarabine," said David Nowotnik, Access Pharmaceuticals, Inc.'s Senior Vice President for R&D.  He continued, "The findings in preclinical and clinical studies to this point have given us a strong indicator that Thiarabine could be highly beneficial in treating patients with hematologic malignancies.  The new Phase I/II trial at MD Anderson, one of the country's leading cancer centers, is the next step in our comprehensive plan to build on the strong set of data and clinical results that have been generated to date on Thiarabine."

Thiarabine is a novel nucleoside analog with considerable potential for the treatment of cancer. Great interest has been shown in this class of molecules. Three nucleoside analogs have been approved in recent years and extensive research continues to produce compounds with improved activity. In preclinical models, Thiarabine has exhibited significant activity, including regressions or cures, in six leukemia or lymphoma cell lines.  The compound produced better activity than the approved nucleoside analogs, cytarabine, gemcitabine and clofarabine. Two monotherapy phase I studies were conducted with Thiarabine in patients with solid tumors. In the first phase I study, 26 patients with incurable advanced and/or metastatic solid nine patients experienced stable disease; seven of 27 in the second study achieved stable disease.  Lymphopenia observed in these studies coupled with the excellent preclinical results in leukemia models indicate that Thiarabine is an excellent candidate for treating advanced hematologic malignancies. Access has signed an agreement to conduct a clinical study in this indication at MD Anderson, and the study is expected to start enrolling in August 2010.