Our sales and marketing team represented Myriad RBM at the Biomarkers and Diagnostics World Congress in Philadelphia with a booth on the vendor floor. In addition to hearing the latest in the world of biomarker development, we had a chance to chat to current customers and introducing new ones to our biomarker testing services.
Of particular interest to us, was the luncheon presentation on Monday which compared different immunoassay platforms and their sensitivity in regard to IL-6. The talk by Pacific Biomarkers’ Maribeth Raines, compared IL-6 assays on the Ciraplex platform to R&D Systems’ standard ELISA, Meso Scale Discovery’s QuickPlex, and Singulex’s Erenna and showed that the ULTRA IL-6 assay had the best sensitivity between .016 and .03 pg/ml. Notably absent in the study was Quanterix’ Simoa assay, which in our hands at 0.0046 pg/ml reproducibly has a lower limit of quantification than any of the assays mentioned.
The luncheon presentation on Wednesday was sponsored by Myriad RBM and featured Dr Tasha Sims from Regeneron talking about the VELOUR trial, which enrolled FOLFIRI treated patients with metastatic colorectal cancer and studied the effects of anti-VEGF treatment plus FOLFIRI vs FOLFIRI only. The protein biomarker data from baseline samples suggests that some markers may be predictive in that patients with high levels of inflammatory molecules, including IL-8, MIF, and also VEGF/VEGF-R2, -R3 respond better to anti-VEGF treatment then those with low levels. Other markers may be prognostic, based on the observation that patients with elevated angiogenic factors such as NRP-1 and Ang-2 or specific pro-inflammatory markers like CRP seem to have poor outcome overall. The speaker emphasized the need for further studies on this topic.
Genentech’s Andy Williams, Ph.D. talked about diagnostic strategies for cancer immune therapies. He touched on first generation methods like PD-L1 IHC and then proposed new strategies including predictive biomarkers, gene expression, mutational load, multiplex IHC and blood markers. He explained three different possible immune states of a tumor: an ‘immune desert’ (no T cells present), excluded infiltrate (T cells present solely in the periphery, but excluded from the tumor), and pre-existing immunity (T cells present in the tumor, but not active). The three results call for different treatment options; immune desert requires chemotherapy to generate new antigens to induce a T cell response, exclusion can be treated with anti-VEGF factors, and the presence of anergic T cells calls for anti-PD-L1 to remove the immune blockade. T cell gene expression signatures correlate with IHC findings. The interesting question for us is: Can we reliably detect these different immune states in the periphery? With the development of more ultra-sensitive assays like Simoa mentioned above, it may be possible to detect immune signatures even when diluted in peripheral blood. Blood based biomarkers are more easily accessible then tumor tissue and avoid some problems related to tumor biopsies.