Quest is an Alberta-based biotechnology company developing a portfolio of product candidates for the treatment of cancer by combining immunotherapeutic antibodies with chemotherapy, photodynamic therapy, or immunoadjuvants.

Quest believes that it can apply its portfolio of oncology product candidates to prolong, amplify and shape anti-tumor immune responses to increase the clinical benefits of its proprietary antibodies for the treatment of cancer. The following modalities are critical to that approach:      

Chemo Enhanced Immuno-Therapy - combining antibodies with chemotherapy can potentially further complement and enhance the treatment outcome compared to antibody treatment alone.

Combination Therapy –combining antibodies with a booster compound (adjuvant) that improves the immune system’s response – compared to antibody treatment alone - can potentially complement and enhance the therapeutic outcome.

SonoLight Technology – is based on a unique non-toxic family of photosensitizing and sonosensitizing, small molecular weight compounds called Hypocrellin, isolated from a parasitic fungus that grows on bamboo trees in China. Quest’s products are expected to offer high selectivity and efficacy with minimal side effects. Quest is also developing these compounds as an adjuvant to cancer immunotherapy.

Antibodies as immune Modulators: Combination Therapy to Enhance Tumour Specific Immunity and Clinical Outcome

• Quest technology platform includes a series of monoclonal antibodies that target several cancer markers such as CA125, MUC1, PSA, CA19.9 and TAG72, and has potential for development in multiple indications
• Impetus for the immunotherapeutic approach for the treatment of cancer comes from the recent FDA approvals of Dendreon’s Provenge for prostate cancer and Bristol Myers Squib’s Yervoy for melanoma
• Quest believes that combinatorial immunotherapy, which exploits the immune modulating effects of selected cytotoxic agents normally used in standard chemotherapy regimens along with specific immune adjuvants, will lead to important commercial applications of the company’s proprietary platform
• Clinical trials involving Quest’s lead product, oregovomab, in more than 950 ovarian cancer patients indicate chemo-enhanced immunotherapy results in more vigorous immune response associated with improved survival compared to mono-immunotherapy
• Quest has strong patent protection for its chemo-enhanced immunotherapy approach for the treatment of cancer
• Quest is currently conducting three carefully planned, risk mitigating confirmatory clinical trials not only to validate the superiority of the combinatorial approach but also to design a definitive product registration study
• Quest approach has created an opportunity to mobilize immunity, better, more preciously and for less cost than other methods that are in development and or recently approved

Photodynamic Therapy - Prostate Cancer

Prostate cancer is the most common cancer affecting males. Approximately 30% of men over the age of 50 years will have prostate cancer. Currently 1 in 10 North American males can expect to be afflicted by prostate cancer and 3% of men will die of this disease. The US market for prostate cancer is estimated at $1.2 billion US annually.

Compared to other experimental procedures, photodynamic therapy (PDT) potentially can provide more accurate and predictable light delivery to prostate tissue thereby minimizing toxicities. As well, selective perfusion or accumulation of photosensitizer in the target tissue (prostate) can mitigate the collateral damage to surrounding normal tissue and yield a further advantage for PDT. Therefore, unlike any other treatment modality, PDT with its dual selectivity (light and drug), has the ability to be highly tissue selective, are thereby improve prostate cancer treatment.

• Minimally invasive procedure, placement of light fibers through ultrasound guided needles
• Low carcinogenic potential compared to radiation therapy
• Maintain good quality of life – less side effects
• Post-treatment mobilization of immune response

PDT with SL052 also has potential applications in the treatment of benign prostate hyperplasia (BPH) and bladder cancer.