Abstract P2-18-02: Characteristics and outcome of breast cancer patients enrolled in cancer therapy evaluation program (CTEP) sponsored phase I clinical trials

Abstract

Abstract Background: Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among women. Given the availability of approved therapies and large clinical trials, historically few breast cancer patients are referred for consideration of a phase I trial. Although efficacy is not the endpoint of phase I studies, we were interested in determining whether clinical benefit rates differed in patients with breast cancer from patients with other cancers enrolled in phase I solid tumor trials. In addition a better knowledge of the characteristics and outcomes of patients with breast cancer enrolled in phase I clinical trials may contribute to better clinical trial design and patient selection. Methods: We performed a retrospective analysis of all Cancer Therapy Evaluation Program (CTEP) sponsored phase I trials for patients with solid tumors, from 1992 to 2012. CTEP phase I database which is maintained by Theradex Inc was queried. Patients treated on phase I/II trials or including hematological malignancies were excluded. We conducted an analysis of demographic variables, variables related to disease characteristics and outcomes of patients with breast cancer and compared them to patients with other oncological diagnoses enrolled in the same trials. Results: A total of 8119 patients who participated in 225 trials were identified. Of these 1367 (16.8%) patients had breast cancer. Compared with patients with other oncological diagnoses, breast cancer patients were older (51.9 vs. 45.4 years), less likely to be white (73% vs. 81.6%, p<0.001) and more likely to have received a high number of previous lines of therapy (34.2% of patients with breast cancer had received 6 or more prior regimens vs. 11.9% of patients with other cancers, p<0.001). Performance status (PS) was similar between the two groups of patients with the majority of patients presenting with PS of 1 (57.3% in the breast cancer group and 60.9% in the non-breast cancer group). The clinical benefit rate was higher for patients with breast cancer (56.1% vs. 42%, p<0.001). Breast cancer patients remained on study longer than non-breast cancer patients (mean 136.3 vs. 95.8 days, p<0.001). The toxicity related deaths were less than 1% in both groups. Discontinuation of treatment due to toxicity was observed in 6.6% of patients with breast cancer and 5.6% of patients with other cancers. Conclusions: An analysis of the CTEP-sponsored phase I trials revealed that breast cancer patients, enrolled in these trials, were older and more heavily pre-treated than patients with other types of cancer. However they seem to have better outcomes and similar toxicities when compared to the other patients. These data suggest that patients with breast cancer who have likely exhausted treatment with approved agents should be considered for phase I trials. Citation Format: Filipa Lynce, Larry Rubinstein, Pamela Harris. Characteristics and outcome of breast cancer patients enrolled in cancer therapy evaluation program (CTEP) sponsored phase I clinical trials [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-18-02.