Trofex is Molecular Insight’s lead molecular imaging candidate for the diagnosis and monitoring of metastatic prostate cancer. Trofex is an iodine 123-labeled small molecule inhibitor of PSMA, delivered by an intravenous injection, which binds to prostate cancer cells in the body. Trofex accumulates inside the prostate cancer cells and is retained for a prolonged period of time, allowing non-invasive molecular imaging of prostate cancer. The ability to specifically visualize prostate cancer using sensitive techniques such as nuclear medicine ushers in a new era of prostate cancer care for the patient suffering from this disease.

Discovered and developed by Molecular Insight, Trofex is designed to enable the detection of subtle manifestations of metastatic disease in men with elevated serum prostate-specific antigen (PSA) but no other obvious symptoms or imaging results to identify recurring or advancing prostate cancer. Molecular Insight believes a PSA-targeted molecular imaging pharmaceutical could lead to improvements in the evaluation of metastatic prostate cancer in patients and may represent a unique opportunity to risk-stratify patients and monitor response to therapy.

The Market Opportunity

Currently more than 2.5 million American men suffer from prostate cancer.* At least 250,000 men in the United States are diagnosed with the disease annually, and it is estimated that the disease will affect one in six men between the ages of 60 and 80, leading to approximately 30,000 deaths per year**. The cancer-related mortality from the disease is second only to lung cancer. The global costs associated with prostate cancer are estimated at $15-$20 billion.

* Cancer Facts and Figures (2007)
**Health Advances (2007 Market Research)

The management of the prostate cancer patient is challenging as there are numerous clinical factors and treatment options to consider in deciding on the optimal therapy for a given patient. Since men are living much longer with the disease due to early detection, clinical decision making may have long-term consequences. Accurately defining the extent of disease burden and aggressiveness of the disease at diagnosis are important factors in treatment selection and remain elusive with existing diagnostic tools. Hence, the ability to visualize the disease is increasingly important for informing therapeutic selection and treatment planning. New imaging agents that will more accurately detect and stage the disease, as well as monitor response to therapy, will enable improved disease management allowing better patient outcome and quality of life. Although current imaging techniques offer some opportunity to visualize the disease in various parts of the body, none provides both highly specific and sensitive detection of metastatic prostate cancer. Often physicians are forced to make therapeutic guesses to define treatment selection parameters in the setting of rising PSA values in the patient with prostate cancer. A sensitive and specific means of imaging tumor burden throughout the body, in both soft tissues and bone, is the goal of Trofex, Molecular Insight’s lead molecular imaging radiopharmaceutical product candidate under development for the diagnosis and detection of prostate cancer.

Clinical Development Plan 

In 2008, Molecular Insight initiated clinical studies of Trofex in patients with documented prostate cancer and confirmed hormone refractory metastatic disease. Two internally developed Trofex compounds, MIP-1072 and MIP-1095, were evaluated for their capacity to visualize the disease and to define their pharmacokinetic profiles. Both agents rapidly detected metastatic prostate cancer lesions in soft tissues and bone, confirming that targeting the extracellular domain of PSMA is a viable approach for the molecular targeting of this cancer. The compounds were uniquely able to detect metastases within one to two hours after injection. Diagnostic images were still feasible one to two days after Trofex administration, increasing Trofex’s value as a unique diagnostic imaging candidate.

Based on Trofex’s potential demonstrated during the trial to rapidly and clearly image prostate cancer, the Company plans additional studies to investigate the performance of these radiolabeled small molecules in patients with metastatic prostate cancer. Not only does this data demonstrate the capability to rapidly visualize bone metastasis and soft tissue lesions — that may be missed by conventional imaging techniques — imaging can be done in a single day, which is not possible with some of the products currently on the market for imaging recurrent metastatic disease.