Anadys Pharmaceuticals Commences Phase I Clinical Trial of ANA773 in Cancer Patients

SAN DIEGO, Feb. 28 /PRNewswire-FirstCall/ -- Anadys Pharmaceuticals, Inc. (Nasdaq: ANDS) today announced that patient dosing has commenced in a Phase I study of ANA773, the company's oral TLR7 agonist prodrug, in patients with advanced solid tumors. This first-in-human trial is a safety and tolerability study designed to identify pharmacologically active doses and preliminary antitumor activity as well as to select the dose and schedule for Phase II trials.

The Phase I trial is a multiple, ascending dose study conducted at several sites in the United States. In addition to safety and tolerability, patients will be monitored for pharmacodynamic responses indicative of immunological stimulation. Initially, patients will be dosed every other day. The company also expects to investigate additional schedules during this first clinical trial and anticipates that up to 60 patients will be enrolled in the study.

"The extensive preclinical investigation Anadys has conducted with ANA773 over the last 18 months has taught us much about the pharmacology of orally administered TLR7 agonists, including the importance of schedule in sculpting the profile of immune activation," said James Freddo, M.D., Anadys' Chief Medical Officer. "We believe ANA773 holds promise for the treatment of a range of malignancies and may have utility when combined with targeted agents, therapeutic antibodies and/or chemotherapy. We are excited about having initiated this first clinical study."

Steve Worland, Ph.D., Anadys' President and Chief Executive Officer, said, "This is an important milestone for Anadys. The initiation of this trial marks the resumption of our clinical investigation of oral TLR7 agonists and moves us closer toward our objective of developing ANA773 as a novel therapy for patients with cancer. We anticipate identifying the dose and schedule for Phase II investigation by the end of this year."

About ANA773

ANA773 is an orally administered prodrug of a novel TLR7-specific agonist. Pharmacology studies have shown that ANA773 can elicit desired immune responses and components of the response can be modulated by both dose and schedule of administration.

Data presented at the AACR-NCI-EORTC meeting in October 2007 showed that activation of TLR7 by the biologically active metabolite of ANA773 initiates a cascade of immune stimulatory events that has the potential to mediate anti-tumor activity by the induction of cytolytic activity by CD8 T cells against tumor cells and cytolytic activity of NK cells against tumor cells directly or through antibody-dependent cellular cytotoxicity (ADCC). Anadys also demonstrated that the immunostimulatory responses can be modulated by schedule of administration. Earlier in 2007, data presented at the AACR meeting showed that ANA773 and its active metabolite stimulate secretion of interferon alpha and other cytokines as well as enhance rituximab-mediated ADCC against transformed B cells.

About TLR7 agonists in cancer therapy

The potential benefits of the TLR7 mechanism in cancer therapy arise from the fundamental role of this receptor in immune activation. The host immune system, once activated, plays an essential role in controlling the ability of cancer cells to grow, invade and metastasize. Immunotherapy has had some success in treating selected tumors, and the potential to harness the immune system as a therapeutic modality remains of great interest to many oncologists.

TLR7 agonists are of particular interest because there is precedent for their use in cancer. Small molecule ligands for this receptor have been identified, including topical imiquimod (Aldara(R)) which is approved for the treatment of basal cell carcinoma in the United States. Imiquimod and other TLR7 agonists have also demonstrated early clinical activity against other tumor types, including melanoma and chronic lymphocytic leukemia.

About Anadys

Anadys Pharmaceuticals, Inc. is a biopharmaceutical company dedicated to improving patient care by developing novel medicines in the areas of hepatitis C and oncology. The Company is developing ANA598, a small-molecule, non-nucleoside inhibitor of the NS5B polymerase for the treatment of chronic hepatitis C and ANA773, an oral TLR7 agonist prodrug for cancer.

Safe Harbor Statement

Statements in this press release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, references to the planned scope and trial design of the ANA773 clinical trial, the belief that ANA773 holds promise for the treatment of a range of malignancies, and that it may have utility when combined with targeted agents, therapeutic antibodies and/or chemotherapy, Anadys' ability to identify a dose and schedule for Phase II investigation by the end of this year and the ability to develop ANA773 as a therapy for patients with cancer. Such forward-looking statements involve known and unknown risks, uncertainties and other factors, which may cause Anadys' actual results to be materially different from historical results or from any results expressed or implied by such forward-looking statements. For example, the results of preclinical studies may not be predictive of future results, and Anadys cannot provide any assurances that ANA773 will not have unforeseen safety issues, will have favorable results in future clinical trials or will receive regulatory approval. In addition, Anadys' results may be affected by risks related to competition from other biotechnology and pharmaceutical companies, its effectiveness at managing its financial resources, its ability to successfully develop and market products, difficulties or delays in its preclinical studies or clinical trials, difficulties or delays in manufacturing its clinical trials materials, the scope and validity of patent protection for its products, regulatory developments involving future products and its ability to obtain additional funding to support its operations. Risk factors that may cause actual results to differ are more fully discussed in Anadys' SEC filings, including Anadys' Form 10-K for the year ended December 31, 2006, and Anadys' Form 10-Q for the quarter ended September 30, 2007. All forward-looking statements are qualified in their entirety by this cautionary statement. Anadys is providing this information as of this date and does not undertake any obligation to update any forward-looking statements contained

SOURCE Anadys Pharmaceuticals, Inc.