Clinical research uncovers two applications for human benefit
G250: Diagnosis and Therapy
Currently, patients with metastatic renal cell carcinoma (RCC) have a five year survival rate of approximately 30%. While new RCC chemotherapeutics are showing benefit in the clinic, therapeutic advances are still critically needed. Laboratory and clinical research conducted by LICR has led to the G250 antibody entering commercial drug development for both diagnosis and therapy of RCC.
The G250 antibody binds to the CAIX molecule, which is present on the surface of more than 85% of RCC cells, but is not present on normal kidney cells. Clinical trials sponsored and conducted by LICR determined that this monocloncal antibody is safe for patients, has a long half-life in the body and that shows excellent targeting to RCC tumors. Wilex AG (Munich, Germany), a biotechnology company with which LICR has had a long-standing research and development collaboration, is conducting phase III clinical trials to assess the potential of the G250 antibody as an adjuvant therapy, i.e. a therapy given after surgical removal of the tumor, in patients who have non-metastatic RCC. Wilex is developing the therapy application of G250 under the product name Rencarex®.
Another LICR-sponsored pilot trial assessing the use of G250 as a diagnostic tool for clear cell RCC, the most aggressive subtype of RCC, produced extraordinary results. The LICR team showed that using iodine-124 (124I)-labeled G250 antibody followed by positron emission tomography (PET) imaging, accurately identified clear cell RCCs with the specificity and positive predictive accuracy both at the 100% level. The development of a non-invasive diagnostic tool for clear cell RCC will make a substantial difference to the care and welfare of people suspected of having RCC, as they will not have to undergo surgery in order to differentiate between clear cell and non-clear cell RCC. Wilex AG is conducting a pivotal phase III trial to confirm radiolabeled G250 antibody is able to diagnose clear cell RCC with PET imaging. The diagnostic application of G250 is being developed under the product name Redectane®.
Specific targeting of clear cell renal cancer by I-124 cG250 immunoPET.The left image shows two lesions (solid and broken arrow) in the left kidney, evident on a CT scan. ImmunoPET (middle image) shows radioactivity in only one of those lesions (solid arrow). The right image is a superimposition (“fusion”) image, confirming radioactivity in the inferior lesion, which was the only one of the two to be of clear cell histology.
