(p. D1) A collaboration between an immunologist helping his stepmother fight cancer and the oncologist who treated her led to a discovery that could help many more patients benefit from a transformative new therapy.
A new class of drugs called checkpoint inhibitors works by releasing a molecular brake that stops the immune system from attacking tumors. So-called immunotherapy has been approved for several types of cancers and found to extend lives of patients with advanced disease for many years. The problem is that for most patients immunotherapy doesn’t work.
The researchers, from University of California, San Francisco, said they identified a unique type of immune-system cell that “robustly” predicts whether patients will respond to one of the medicines–an achievement has the potential to significantly expand the number of cancer patients who benefit from checkpoint inhibitors.
The new discovery is based on a high-tech analysis of melanoma tissue from 40 patients treated with a checkpoint inhibitor from Merck & Co. called Keytruda, which targets an immune-system brake called PD-1. Although researchers say it will take further research to determine its value in treating patients, the finding offers fresh insight into the complex relationship between the immune system and tumor cells.
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(p. D3) The researchers analyzed results of a study involving Keytruda before it was approved. They looked at the CD8 cells that had infiltrated the melanoma tumors of 20 patients treated with the drug and found that if at least 30% of those cells were marked by PD-1 and CTLA-4, the patient responded to treatment. When fewer than 20% of the infiltrated cells had those markers, not one patient responded.
For the full story, see:
RON WINSLOW. “Road to a Cancer Advance.” The Wall Street Journal (Tues., Aug. 16, 2016): D1 & D3.
(Note: ellipsis added.)
(Note: the online version of the story has the date Aug. 15, 2016, and has the title “Chance Collaboration Yields an Advance in Cancer Treatment.”)