PALBOSPAIN is an observational, multicenter study to evaluate real-world practice patterns and outcomes of first-line treatment for advanced breast cancer (ABC) with Palbociclib. Results from real-world progression free survival (rwPFS) and overall survival (OS) in the total population and according to endocrine sensitivity have been previously reported. Here, we provide subgroup analysis according to age, sites and number of metastatic locations, menopausal status, and dose received. Patients diagnosed with HR+/HER2- ABC who had started first-line treatment with palbociclib between November 2017 and November 2019 were included. 762 patients received Palbociclib in combination with AIs (69.4%) or fulvestrant (30.1%). Median age was 61.9 years (17.5% < 50 y; 51.8% 50-70 y; 30.7% > 70 y). 114 patients were premenopausal (15%). A total of 418 patients had visceral disease (54.9%). At baseline, patients with 1, 2-3 and >3 metastatic locations were 42.7%, 43% and 14.3% respectively. Results of real-world Response Rate (rwRR) and rwPFS are shown in the table. A total of 377 (49.5%) patients required a dose reduction. Among patients who had a first dose reduction, 164 (21.5%) required a second dose reduction. Median rwPFS was 28 months (CI 95% 25-33) in patients who had ≥ 1 dose reductions and 19 months (CI 95% 16-23) in patients who maintained the initial dose (HR 0.71; CI 95% 0.58-0.85, p=0.003). Table: 234PrwRRrwPFSCRPRSDPDN (%)N (%)N ( %)N ( %)Months CI 95%Age<5015 (11.3)50 (37.6)46 (34.6)19 (14.3)27 (21-35)50-7022 (5.6)145 (36.7)152 (38.5)57 (14.4)21 (19-26)>7013 (5.6)87 (37.2)88 (37.6)31 (13.2)27 (22-37)Menopausal statusPremenopausal13 (11.4)44 (38.6)40 (35.1)15 (13.2)27 (20-35)Postmenopausal37 (5.7)238 (36.3)246 (38)92 (14.2)24 (21-27)Visceral metastasisYes21 (7.4)17 (41.4)141 (33.7)63 (15.1)20 (18-23)No29 (8.4)109 (31.7)145 (42.2)44 (12.8)30 (25-36)Nº of locations124 (7.4)100 (30.8)136 (41.8)46 (14.2)34 (28-39)2-323 (7.0)132 (40.2)116 (35.4)47 (14.3)20 (18.24)>33 (2.8)50 (45.9)34 (31.2)14 (12.8)19 (14-24)CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease; NA, not available; NR, not reached Open table in a new tab CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease; NA, not available; NR, not reached Age at start of the treatment and menopausal status were not associated with PFS. Patients with visceral metastasis and >1 sites of metastasis had shorter PFS. The incidence of dose reductions was higher compared with PALOMA-2 & 3 trials. However, dose reductions did not affect Palbociclib efficacy.
Abstract Purpose To evaluate the efficacy and safety of first-line therapy with palbociclib in a Spanish cohort treated after palbociclib approval. Methods PALBOSPAIN is an observational, retrospective, multicenter study evaluating real-world patterns and outcomes with 1 L palbociclib in men and women (any menopausal status) with advanced HR + /HER2– BC diagnosed between November 2017 and November 2019. The primary endpoint was real-world progression-free survival (rw-PFS). Secondary endpoints included overall survival (OS), the real-world response rate (rw-RR), the clinical benefit rate, palbociclib dose reduction, and safety. Results A total of 762 patients were included. The median rw-PFS and OS were 24 months (95% CI 21–27) and 42 months (40-not estimable [NE]) in the whole population, respectively. By cohort, the median rw-PFS and OS were as follows: 28 (95% CI 23–39) and 44 (95% CI 38-NE) months in patients with de novo metastatic disease, 13 (95% CI 11–17) and 36 months (95% CI 31–41) in patients who experienced relapse < 12 months after the end of ET, and 31 months (95% CI 26–37) and not reached (NR) in patients who experienced relapse > 12 months after the end of ET. rw-PFS and OS were longer in patients with oligometastasis and only one metastatic site and those with non-visceral disease. The most frequent hematologic toxicity was neutropenia (72%; grade ≥ 3: 52.5%), and the most common non-hematologic adverse event was asthenia (38%). Conclusion These findings, consistent with those from clinical trials, support use of palbociclib plus ET as 1 L for advanced BC in the real-world setting, including pre-menopausal women and men. Trial registration number NCT04874025 (PALBOSPAIN). Date of registration: 04/30/2021 retrospectively registered.