Using biomarkers to guide treatment in clinical trials may yield higher response rates than similar drugs not guided by biomarkers, according to an abstract presented at the American Society of Clinical Oncology Annual Meeting (June 3-7, 2016; Chicago, IL).
The meta-analysis, which was led by Maria Schwaederle, PharmD, University of California, San Diego, included 351 individual single-agent phase 1 trials encompassing 13,203 patients. Researchers broke the trials into two groups: those deemed to use a “personalized” approach (n=58), and those that did not (n=293).
Among those that used a personalized approach, the response rate was found to be more than 5 times higher than what was observed the group that did not use a personalized approach (31% vs 5%, respectively). In addition, the biomarker-selected approach also yielded a significantly longer progression-free survival, though not all trials included this as an outcome measure. In the 7 trials that did report it, median PFS was 5.7 months compared with 2.95 months in trials without a personalized approach. Interestingly, genetic biomarkers resulted in a better response rate than protein biomarkers, at 42% and 22.4%, respectively.
Additional analysis also revealed that targeted therapies were only effective when personalized approached were used. In 57 studies with targeted therapies using biomarker selection, the median response rate was 31.1% compared with 5.1% in a 177 trials that did not use personalized approaches.
The researchers concluded that personalized approaches to treatment may be an indicator of improved outcomes. Further, targeted agents without biomarker-based strategies yielded worse results than those that included personalized medicine.
“We think that the results [of this study] were striking,” said Dr Shwaderle. “Targeted drugs in and of themselves were not effective—they absolutely must be given to the right patients.”
