Outcomes of patients ≥65 years old with advanced cancer treated on phase I trials at MD ANDERSON CANCER CENTER

Patients ≥65 years with cancer remain underrepresented in clinical trials, particularly in phase I clinical trials. We analyzed the clinical course of patients ≥65 years treated on phase I clinical trials with particular emphasis on toxicities. We identified 347 consecutive patients ≥65 years with advanced cancer in our phase I clinic from 01/2004-12/2009 and analyzed disease characteristics, toxicities, survival and response. Overall, 251 patients received a targeted agent, of whom 241 (96%) received an investigational, non-FDA-approved drug. Clinical benefit (complete response + partial response + stable disease ≥ 6 months) was noted in 61 patients (18%). Eighty-nine patients (26%) had grade 3/4 toxicity, commonly hematologic, including 6 dose-limiting toxicities and 1 treatment-related death (<0.01%). Median overall survival from first Phase I Clinic visit was 8.8 months (95% CI: 7.8–10.6); median time to treatment failure was 1.9 months (95% CI: 1.8–2.1). Multivariable analyses revealed 4 indicators of lack of clinical benefit (liver metastases, performance status [PS] >1, prior radiation, ≥5 prior treatments; p <0.0001). Patients age 70–79 years had a greater risk of grade 3/4 toxicities when treated with combinations (≥2 drugs) compared to monotherapy (p = 0.006). Predictors of shorter time to treatment failure and overall survival included PS >1, thrombocytosis, >2 metastatic sites, and elevated lactate dehydrogenase (p <0.05). Our results suggest that phase I clinical trials are well tolerated in patients ≥65 years. Additionally, we identified risk factors that may facilitate patient selection for clinical trial participation.