PAT-SM6 antibody detected in biopsies of patients after they received treatment
Evidence that PAT-SM6 antibody can target and penetrate tumours at low doses
Supports the ongoing trial design

Melbourne, Australia | August 22, 2011 | Patrys Limited (ASX: PAB; “the Company”), a clinical stage biopharmaceutical company, is pleased to provide an update on data collected from patients in its PAT-SM6 melanoma clinical trial currently being held at the Royal Adelaide Hospital.

The primary trial objective is to establish safety and tolerability. To date no safety issues have been observed or reported for any patients treated with PAT-SM6. The secondary trial objective is to examine multiple secondary endpoints aimed at measuring the anti-tumour activity of PAT-SM6.
Each patient had a biopsy of their melanoma tumour both before and after treatment with PAT-SM6. In preliminary results, the Company has found the presence of PAT-SM6 in post-treatment tumour biopsies taken from two different patients. These results indicate the strong utility of the therapy and potential for it to be an effective therapeutic for the treatment of melanoma.

“We are very excited to report the detection of the PAT-SM6 product in tumours taken from patients in both the first and second dose groups. At this stage trial doses are substantially below anticipated therapeutic levels and the detection of PAT-SM6 in tumours is thus very encouraging,” said Dr Marie Roskrow, Patrys’ Chief Executive Officer.

“In both cases, PAT-SM6 was detectable in biopsy samples taken post-treatment. Neither patient had any detectable PAT-SM6 in biopsies taken pre-treatment. In addition, tissue analysis to date is suggestive the PAT-SM6 leads to apoptosis (cell death) in biopsies collected.”

Under the trial design different dosages will be evaluated in patients with a particular form of the disease called “in-transit” melanoma. This cancer is limited to a single limb and has usually undergone multiple treatments prior to the PAT-SM6 trial.

By recruiting patients with in-transit disease, Patrys can collect tissue samples to study the effects of PAT-SM6 on the tumours, although in line with standard industry practice the primary aim of this study is to measure the safety and tolerability of the drug.

Patrys recently announced The Royal Adelaide Hospital is currently recruiting the third group of patients.

About Patrys Limited:

Based in Melbourne, Australia, Patrys (ASX: PAB) is focused on the development of natural human antibody therapies for cancer. Patrys has a deep pipeline of internal development candidates and additional products that are the subject of a collaboration agreement with a larger industry partner. More information can be found at www.patrys.com.

About PAT-SM6:

The natural human antibody PAT-SM6 has been shown to have potent anti-cancer properties in a large number of laboratory and animal studies. More specifically, Patrys has now screened PAT-SM6 against more than 200 tumours from individual patients with various cancers, and the product binds to over 90% of the tumours screened regardless of cancer type or patient age, gender or disease stage. With respect to melanoma, PAT-SM6 has shown particularly strong promise. Patrys has filed patent applications to cover the PAT-SM6 antibody molecule, disease target, and the mechanism of action. In October 2010, Patrys initiated a human clinical trial to evaluate PAT-SM6 as a therapy for melanoma. To date, the second group of patients has been treated and Patrys received approval to progress the clinical trial. The clinical trial is taking place at the Royal Adelaide Hospital Cancer Centre and associated Pain and Anaesthesia Research Clinic.

About GRP78:

Patrys clinical candidate PAT-SM6 binds to a form of Glucose-regulated protein 78 (GRP78), which is expressed on the surface of cancer cells but not detected on the surface of healthy cells. Once bound, the PAT-SM6/GRP78 complex is then internalised into cancer cells inducing apoptosis and cell death. The potential of GRP78 as a target for cancer therapy is supported by extensive third party literature that has reported several roles played by GRP78 with respect to promoting tumour proliferation, tumour survival, metastases and resistance to a wide variety of existing anti-cancer therapies. As a result, GRP78 expression has been correlated with an adverse prognosis in melanoma, breast, lung, gastric, hepatocellular and prostate cancer, and drug resistance in breast cancer. Given GRP78’s reported roles with respect to several cancers, a molecule such as PAT-SM6 presents a promising anti-cancer treatment to the extent it interferes with the function of GRP78 in cancer.

Appendix: PAT-SM6 Human Clinical Trial – Melanoma

Approval: Approval for this trial was granted by the Human Ethics Committee of the Royal Adelaide Hospital on 30 July 2010 and notification given to the Australian regulatory body, the Drug and Safety Evaluation Branch of the Therapeutic Goods Administration (TGA). The trial will be conducted under the TGA’s Clinical Trial Notification (CTN) scheme.

Global Standards: The trial will be conducted in accordance with the principles of the International Conference on Harmonization (ICH), which incorporate standards of conduct for clinical trials that are essentially uniform for all the major regulatory agencies world-wide, including the United States FDA and Australia’s TGA.

Trial Title: A Single Dose, Dose Escalating, Phase I Clinical Trial of PAT-SM6 Monoclonal Antibody in Patients with Recurrent In-Transit Cutaneous Melanoma

Primary Objectives: Establish the safety profile of a single dose of the anti-GRP78 monoclonal antibody PAT-SM6 in patients with recurrent in-transit cutaneous melanoma

Major Secondary Objectives: Describe the pharmacokinetics of PAT-SM6 Screen for the development of patient antibodies against PAT-SM6 (immunogenicity) Explore the anti-tumour activity of PAT-SM6 Assess the pharmacodynamic effect(s) of PAT-SM6 in patient tumour samples Identify potential predictors (biomarkers) of therapeutic efficacy and/or safety.

Method: This trial is a multicentre, open-label, dose-escalation, Phase I study. Patients will receive a single dose of PAT-SM6 intravenously, followed 96 hours later by collection of cutaneous tumour tissue.

SOURCE: Patrys Limited