A meta-analysis of 346 phase I clinical trials involving more than 13,000 patients found that patients whose treatment was selected based on the molecular characteristics of their tumor had significantly better outcomes. The study was featured in a press briefing today and will be presented by Schwaederle et al Monday, June 6, at the 2016 ASCO Annual Meeting in Chicago (Abstract 11520).
“Our study suggests that, with a precision medicine approach, we can use a patient’s individual tumor biomarkers to determine whether they are likely to benefit from a particular therapy, even when that therapy is at the earliest stage of clinical development,” said lead study author Maria Schwaederle, PharmD, of the Center for Personalized Cancer Therapy at the University of California, San Diego, School of Medicine. “This strategy often results in good outcomes for patients, and I hope it will encourage and reassure doctors and patients considering enrollment in precision medicine–based phase I trials.”
About the Study
Previous meta-analyses of phase II and phase III trials by the same researchers observed similarly improved outcomes with precision medicine approaches. According to the authors, this is the first study to show that such benefits are apparent even at the first stage of clinical development. It suggests that tumor biomarkers should be increasingly used to select patients for phase I clinical trials.
The study examined efficacy and safety data from 346 phase I trials published between 2011 and 2013. The analysis included 58 treatment arms that employed precision medicine—defined as using biomarkers to select patients for treatment—and 293 that did not. (All but one of these precision medicine trials evaluated a targeted agent; that trial evaluated the chemotherapy drug topotecan, which is believed to inhibit hypoxia-inducible factor 1-alpha [HIF-1 alpha], and patients in that trial were tested for this marker.)
Key Findings
The researchers found that in treatment arms employing precision medicine, the tumor shrinkage rate was 30.6%, compared to 4.9% in those that did not. Patients in precision medicine arms also had a longer progression-free survival compared to other arms (median = 5.7 vs 2.95 months).
Results were similar in a subanalysis that included 57 trials of targeted therapies. In this group, treatment arms using biomarkers to assign patients to treatments had tumor shrinkage rates of 31.1%, compared to 5.1% for those that did not. Additionally, researchers found that matching patients to therapy based on genomic biomarkers resulted in a higher tumor shrinkage rate (42%) compared to protein biomarkers (22.4%).
In this analysis, the high tumor shrinkage rate and prolonged time to disease progression observed with precision medicine approaches suggest that phase I studies, which have traditionally focused on safety, can also provide important insights into efficacy and the patients likely to benefit most. Incorporating survival endpoints into phase I trials may help accelerate development of important new therapies, the authors suggested.
ASCO Perspective
Chair of ASCO’s Cancer Communications Committee Don S. Dizon, MD, FACP, remarked, “Precision medicine is not the future of cancer care—it is the present. This study reinforces that the more we personalize treatment to the patient and the tumor, the better the outcomes—even in the earliest phases of research. This is the same approach that ASCO’s TAPUR trial is using, and we anticipate it will also bring new insights that lead to better therapies for patients in need.”
This study received funding and support from the Joan and Irwin Jacobs Philanthropic Fund.
This article was published online by The Asco Post on May 18, 2016. View it here.
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