Circadian Technologies (ASX: CIR) has identified two plasma biomarkers in clinical trials that create a resistance to the company’s drug Avastin® in colorectal cancer patients.
The company presented its findings at the American Society of Clinical Oncology’s annual meeting in Chicago, associating the resistance to Avastin® with increases in plasma VEGF–C and VEGF–D concentrations.
Robert Klupacs, chief executive officer, said "we are excited to see the ever increasing amount of clinical data validating VEGF-C and D as important therapeutic targets.
We remain on track to commence clinical trials in cancer patients with our VEGF-C antibody VGX-100."
VEGF or vascular endothelial growth factor is a protein produced by cells to stimulate new blood vessels after injury, muscle following exercise and new vessels to bypass blocked vessels.
The company obtained data from 42 patients treated with chemotherapy plus the drug enrolled in a phase II trial with data supporting the concept of targeting additional VEGF family proteins to improve treatment outcomes.
The data gives Circadian further rationale for the development of VEGF–C and VEGF–D based biomarker tests to monitor cancer therapy.
Mark Sullivan, head of development, said “the clinical data provide an important insight into the role that VEGF–C plays in the development of Avastin® resistance.
The findings are supportive of our strategy for combining our VEGF–C antibody (VGX – 100) with Avastin® to seek better outcomes for patients.”
Resistance to Avastin® is a frequent occurrence in the treatment of certain cancers that results in the loss of response and the disease progressing.
The study, undertaken by doctors at the University of Texas MD Anderson Cancer Centre, showed that increases in VEGF – family markers in patients with metastatic colorectal cancer are associated with Avastin® resistance.
The resistance occurred when VEGF–C increases seen in patients before and at the time of disease progression received both Avastin® and chemotherapy.
Scott Kopetz, M.D. at MD Anderson, said “we are planning prospective confirmatory studies to further evaluate and validate these findings.
The primary objective of the study was to determine the alterations in VEGF–C and VEGF–D in patients receiving chemotherapy and Avastin® .
The secondary objective of the study was to evaluate alterations in alternate VEGF ligands attributable to the drug in a large retrospective cohort.