OBJECTIVES : Palbociclib in combination with hormonotherapy changed the paradigm of treatment in HR+/HER2- advanced breast cancer patients. The aim of the present study was to explore effectiveness, Healthcare Resources Utilization(HCRU) and Quality of Life(QoL) among palbociclib patients.

METHODS : Real-world retrospective study, including 130 patients treated with palbociclib in a Portuguese Comprehensive Cancer Center(PCCC) between march/17-december/19. Data was collected from medical/administrative records. Treatment outcomes such as progression free-survival(PFS), overall survival(OS), treatment duration(TD), QoL and HCRU were evaluated. Additionally, the mean cost per patient of the prescribed drug regimen was calculated. QoL was assessed using the C30+BR23 during treatment follow-up visits. Clinical characteristics and HCRU were evaluated using descriptive statistics and changes in QoL scores with a paired-sample(T-test). Kaplan-Meier method was used for survival analysis.

RESULTS : Median age was 55y/o, 98.5% were women, 22.7% pre-menopausal, 93.1% ECOG≤1, 50.4% visceral metastasis, 38% bone metastasis only.

Palbociclib was prescribed with fulvestrant(76.2%) or letrozole(23.8%); 43.8% in first line therapy(LOT1). Median PFS was 18.4m for LOT1, 8.9m for subsequent lines(LOT2+). Two-year OS probability was 82.8%/60.5% for patients in LOT1/LOT2+ respectively. The median TD was 18.5m for LOT1, 8.4m for LOT2+.

QoL was evaluated for 71patients, 31 were excluded due to missing baseline questionnaire. There was no deterioration in QoL during treatment, however, differences were statistically significant just for pain dimension(p=0.006).

On average, there were 12 visits to an oncologist and 5 CTscans performed during treatment. 15 patients were referred to best-supportive care. Proportion of patients admitted in emergency was 26%; 16.9% were hospitalized. The mean cost per patient of the prescribed drug regimen was 32,210€ for palbociclib+fulvestrant, 28,143€ for palbociclib+letrozol.

CONCLUSIONS : This study supports the clinical benefit derived from palbociclib in addition to hormonotherapy, adding important insights regarding Patient-Reported Outcomes in a PCCC. Prolonged follow-up of these patients will result in more robust data and deeper understanding of drug effectiveness.