Quest PharmaTech Announces Results Showing its Photosensitizer, SL052, is an Effective Immuno-Stimulant when combined with Immunotherapy for the Removal of Solid Tumors

TSX Venture: QPT

EDMONTON, March 4 /PRNewswire-FirstCall/ - Quest PharmaTech Inc. (TSX-V: QPT), ("Quest" or the "Company") a pharmaceutical company developing and commercializing products for the treatment of cancer and dermatological conditions, today announced results from a study designed to investigate the effectiveness of its proprietary SL052 for photodynamic therapy (PDT) used in combination with immunotherapeutic agents in solid tumor animal models. The study, conducted by Dr. Mladen Korbelik at the BC Cancer Agency in Vancouver, demonstrated that SL052 increased the potency and effectiveness of immunotherapeutic agents when used in combination with SL052 PDT.

The results also confirmed that SL052 was an effective and well tolerated photosensitizer for PDT ablation of two highly tumorigenic, solid murine tumors. Further, the results demonstrated that photodynamic therapy generated direct local cytotoxicity and induced a systemic immune response, which could enhance its therapeutic effect on both primary tumors and metastases at distant sites.

The study tested several applications of SL052 and evaluated host recognition and immunological destruction of solid tumors. The results indicate the potential of SL052 PDT for use in combination with cancer vaccines to generate a superior immune response compared with vaccines alone. The study also revealed that SL052 PDT may be effectively combined with either single or multiple-complementary effectors of the host's immune response to substantially boost the frequency of permanent cures.

"The effects of immunotherapy can be amplified when combined with photodynamic therapy, potentially making immunophotodynamic therapy a superior systemic cancer treatment modality," said Thomas Woo, Vice President of Product Development at Quest.

SL052 is a non-toxic agent with broad potential to treat a variety of solid tumors using photodynamic (light activation) therapy or sonodynamic (ultrasound activation) therapy. Photodynamic therapy is applicable for superficial level solid tumors and sonodynamic therapy targets more deeply seated solid tumors.

"These results further define the therapeutic profile of SL052," stated Dr. Madi R. Madiyalakan, Chief Executive Officer at Quest. "While its activation through either photodynamic or sonodynamic therapy was already established, we now have a clear indication of its potential to act as either an immune response stimulator or as a cancer vaccine. Taken together, these characteristics of SL052 provide a new potential treatment modality for cancer therapy."

About SL052

SL052 is a member of Quest PharmaTech's SonoLight Portfolio with the potential to reduce or eliminate the side effects associated with currently available cancer treatment modalities: surgery, chemotherapy and radiotherapy. Its properties of activation with harmless physical agents (light and ultrasound), combined with its ability to generate cancer vaccines and stimulate an anti-cancer immune response warrant further development in a broad-spectrum oncology arena. With these results, the next development stage for SL052 is a Phase I clinical trial for the treatment of Prostate Cancer. Quest is presently awaiting approval from Health Canada that will allow it to initiate a Phase I clinical trial for SL052.

About Quest PharmaTech Inc.

Quest is a publicly traded, Alberta-based pharmaceutical company committed to the development and commercialization of new pharmaceutical products. It is developing a series of products for the treatment of cancer and dermatological conditions based on its unique photodynamic and sonodynamic therapy platforms.

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SOURCE Quest PharmaTech Inc.