Real world evidence on effectiveness of palbociclib in Indian patients with breast cancer: A single centre, investigator-initiated, retrospective study.

e13054 Background: Cyclin dependent kinase 4/6 inhibitors in combination with endocrine therapy are the standard of care in patients with hormone receptor positive, HER-2 negative metastatic breast cancer (HR+/HER2− MBC). The present study reports the real-world data of Palbociclib in Indian patients with HR+/HER2− BC. Methods: A single centre, investigator-initiated, retrospective study of patients with HR+/HER2− BC, who received palbociclib with hormonal agents at Medanta Hospital, Gurugram, India from May 2016 to April 2024 was conducted. Clinical and demographic information and survival data was retrieved from the electronic medical records. The primary endpoint was overall response rate (ORR), the secondary endpoints included progression-free survival (PFS) and overall survival (OS). Results: A total of 214 patients were enrolled, including 206 (96.3%) females. The baseline demographics are presented in table 1. Out of 187 patients whose responses were assessed, complete response (CR) was seen in 6 (3.2%) and partial response (PR) in 66 (35.3%), with an overall response rate (ORR) of 38.5%. Thirty seven patients (19.8%) had stable disease (SD) and 78 (41.7%) had progressive disease (PD). Among 50 patients who received Palbociclib in first line, 2 (4%) had CR, 31 (62%) had PR, 9 (18%) had SD and 8 (16%) had PD, with ORR of 66%. The CR, PR, SD and PD rates were 2.7%, 29.7%, 21.6% and 45.9% in 2 nd line (n=74), 4.8%, 23.8%, 16.6% and 54.8% in 3 rd line (n=42) and 0, 14.3%, 23.8% and 61.9% in &gt; 3 lines (n=21) respectively. At a median follow-up period of 11 months, the median PFS was 11.9 (95% CI; 9.7-14.1) months; median OS was not reached. The safety was in line with the published data. Conclusions: Our real-world data of palbociclib in Indian population suggests similar effectiveness to previously published real-world evidence in the management of HR+/HER2− BC. Baseline demographics. Variables, n (%) Overall (n= 214) Age in yrs, Median (SD) 54 (11.9) ECOG PS 1 120 (56.1) 2 43 (20.1) ≥3 14 (6.5) Menopausal status Premenopausal 95 (44.4) Postmenopausal 111 (51.9) Histology Invasive ductal 138 (64.5) Invasive lobular 7 (3.3) Stage at presentation Early 37 (17.4) Locally advanced 52 (24.4) Metastatic 94 (44.1) Brain metastasis Present 4 (1.9) Site of metastasis Visceral 48 (22.6) Bone only 74 (34.9) Lymph node only 132 (62.3) Prior chemotherapy in metastatic disease Yes 69 (32.2) No 137 (64.0) Previous hormonal therapy in Metastatic disease Yes 147 (68.7) No 59 (27.6) Line of starting Palbociclib therapy 1st line 56 (26.2) 2nd line 88 (41.1) 3rd line <jats:td colspan="1" rowspan