Abstract 3997: Outcomes of geriatric sarcoma patients enrolled in phase 1 clinical trials

Background: Despite the rising incidence of sarcoma in the geriatric population, there is a paucity of older adults enrolled on clinical trials. Whether older sarcoma patients treated on early phase clinical trials have any meaningful differences in clinical benefit or survival outcomes compared to younger patients remains unknown. Methods: We analyzed clinical and next generation sequencing data from sarcoma patients treated on phase 1 trials at MD Anderson Cancer Center (MDACC) and performed logistic and Cox proportional hazards regression analyses to compare response rate (RR), median time to progression (mTTP), clinical benefit rate (CBR; defined as CR, PR, or SD > 6 months), and median overall survival (mOS) between patients younger and older than 65 years of age. Results: Among the 406 patients with advanced sarcomas (321 soft tissue sarcoma, 85 bone sarcomas) treated on phase 1 trials at MDACC from May 2006 to May 2018, median age was 53 (range 11-84), 48% were female, and patients had a median 3 prior lines of therapy (range 0-9). The most commonly treated soft tissue sarcoma subtypes included leiomyosarcoma (n=66; 16%), liposarcoma (n=52; 13%), GIST (n=44; 11%), UPS (n=14; 3%), and synovial sarcoma (n=11; 3%) and most commonly treated bone sarcomas included osteosarcoma (n=34; 8%), chondrosarcoma (n=28; 7%), and Ewing’s sarcoma (n=25; 6%). 25% (n=102) of sarcoma patients treated on phase 1 protocols were age 65 or older. RR in patients younger than 65 years was 7% compared to 8% in those 65 or older, odds ratio 1.21 (95% CI 0.52, 2.83), p=0.66. mTTP for patients younger than 65 was 2.7 months compared to 3.7 months in those 65 or older, hazard ratio 0.90 (95% CI 0.72, 1.14), p=0.39. CBR in patients younger than 65 years was 22% compared to 31% in those 65 or older, odds ratio 1.65 (95% CI 1.00, 2.72), p=0.05. mOS in patients younger than 65 years was 16.1 months compared to 20.0 months in those 65 years or older, hazard ratio 1.08 (95% CI 0.80, 1.46), p=0.61. Conclusion: Heavily pretreated, metastatic sarcoma patients aged 65 or older enrolled on phase 1 studies at MDACC had no significant differences in response rate, time to progression, and overall survival compared to their younger counterparts. In fact, older sarcoma patients demonstrated an improved clinical benefit rate compared to younger patients. Older patients should be encouraged to enroll on early phase clinical trials when clinically appropriate and broad eligibility criteria for such studies are needed to ensure older sarcoma patients are not excluded from these trials. Citation Format: Shiraj Sen, Roberto C. Pestana, Kenneth Hess, David S. Hong, Ishwaria M. Subbiah, Anthony Conley, Gerald S. Falchook, Robert S. Benjamin, Shreyas Patel, Funda Meric-Bernstam, Vivek Subbiah. Outcomes of geriatric sarcoma patients enrolled in phase 1 clinical trials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3997.