Attrition of Patients on a Precision Oncology Trial: Analysis of the I-PREDICT Experience.

Background Precision oncology uses molecular profiling of tumors to identify biomarker-tailored therapies for patients in the hope of improving outcomes. Typically, only a minority of patients receives evaluable matched treatment. This study explored the reasons for attrition on a precision medicine trial. Materials and Methods Study participants were 190 adult patients who consented to the I-PREDICT (Investigation of molecular Profile-Related Evidence Determining Individualized Cancer Therapy) trial. Patients had metastatic and/or unresectable incurable malignancies. Patients who were not evaluable were analyzed. Results Of consented patients, 44% were not evaluable. Men were twice as likely to be not evaluable as women. Prominently, 45% of patients who were not evaluable dropped off because of death, hospice referral, or decline in organ function. Conclusion Health deterioration of consented patients is a significant barrier to being evaluable on the I-PREDICT trial. These data suggest that patients are enrolled on precision oncology trials too late in their disease course or with excessive disease burden.