e23130 Background: Patients on Phase I trials help advance science through their participation but there is a paucity of data regarding QoL of patients and their caregivers. Methods: Phase I trial patients from a single Asian centre were assessed at baseline and at 3 time intervals after treatment initiation with EORTC-core (QLQ-C30) and Comprehensive Score for Financial Toxicity (COST) questionnaires. Caregivers’ QoL were assessed with Zarit-Burden Interview (ZBI). Paired-sample t-tests were used to test for QoL differences at different time intervals. Results: 35 patients have been recruited with 70 individual visits so far. 60% of patients were female, 74% were Chinese. The most common cancer types were gastrointestinal (51.5%) and gynaecological (25.7%). Patients had a median of 3 lines of prior treatment (range: 0-9). QLQ-C30 scores range from 0 to 100, higher scores represent a high level of QoL/functioning. At baseline, the mean global QoL score was 51.9 (range: 16.7-100). The mean physical, role, cognitive, emotional and social functioning scores (FS) were 74.1 64.7, 86.6, 78.8 and 69.5 respectively. Patients were most bothered by fatigue and pain. 65.7% experienced grade 1 or 2 financial toxicities based on COST. There were significant improvements in physical (14.5 +/- 16.7, p < 0.001), cognitive (18.1 +/- 25.0, p = 0.002) and emotional (10.5 +/- 18.4, p = 0.012) FS at baseline and 1-month post treatment. Patients experienced a reduction in fatigue, but no change in pain or financial concerns. Only 28.6% of patients were referred to palliative care medicine. Of 19 caregivers surveyed with ZBI, 10 experienced little/no burden, 8 had mild-moderate levels of burden and 1 reported severe burden. Conclusions: This is the first Asian study reporting QoL of cancer patients and their caregivers in Phase I clinical trials. In this group of heavily pre-treated patients, Phase I options can result in QoL improvement. Two-thirds of caregivers had minimal burden. Identifying QoL issues of patients and their caregivers will improve supportive care rendered to them.