Palbociclib combined with endocrine therapy in heavily pretreated HR+/HER2- advanced breast cancer patients: Results from the compassionate use program in Spain (PALBOCOMP).

BACKGROUND: This study evaluated efficacy and safety of palbociclib, a CDK4/6 inhibitor, in heavily-pretreated hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) patients during the compassionate use program in Spain from February 2015 to November 2017. PATIENTS AND METHODS: Patient data were collected retrospectively from 35 hospitals in Spain. Patients with HR+/HER2- mBC who had progressed on ≥4 treatments for advanced disease were eligible. RESULTS: A total of 219 patients received palbociclib in combination with aromatase inhibitors (110; 50.2%), fulvestrant (87; 39.7%), tamoxifen (8; 3.6%) or as single agent (10; 4.6%). Mean age of the patients was 58 years; 31 patients (16.1%) were premenopausal and 162 (83.9%) were postmenopausal at the beginning of treatment with palbociclib. Patients had received a median of 3 previous lines of endocrine therapy (ET) for advanced disease. Real-world tumor response (rwTR) and clinical benefit rate were 5.9% (n = 13) and 46.2% (n = 101), respectively. The median real world progression-free survival (rwPFS) was 6.0 months (95% CI 5.7-7.0) and the median overall survival was 19.0 months (95% CI 16.4-21.7). Subgroup analysis revealed a significant difference in median rwPFS in patients treated with palbociclib plus fulvestrant depending on the duration of prior treatment with fulvestrant monotherapy (>6 versus ≤6 months; HR 1.93, 95% CI 1.37-2.73, p < 0.001). The most frequently reported toxicities were neutropenia, asthenia, thrombopenia and anemia. CONCLUSIONS: Palbociclib can be an effective and safe treatment option in patients with heavily pretreated endocrine-sensitive mBC, especially in those with longer PFS to previous ET.

Palbociclib and Trastuzumab in HER2-Positive Advanced Breast Cancer: Results from the Phase II SOLTI-1303 PATRICIA Trial.

PURPOSE: To assess palbociclib in combination with trastuzumab with or without endocrine therapy in patients with HER2-positive advanced breast cancer. PATIENTS AND METHODS: PATRICIA is a prospective, open-label, multicenter phase II trial. Patients had received 2-4 prior lines of anti-HER2-based regimens. Treatment consisted of palbociclib 200 mg daily for 2 weeks and 1 week off plus trastuzumab. The study was based on a Simon two-stage design comprising three cohorts: estrogen receptor (ER)-negative (cohort A), ER-positive (cohort B1), and ER-positive with letrozole (cohort B2). ER-positive patients were randomized to cohorts B1 or B2. Primary endpoint was progression-free survival rate at 6 months (PFS6). Secondary objectives included safety and evaluation of the PAM50 intrinsic subtypes. RESULTS: Seventy-one patients were recruited (n = 15 in cohort A and 28 in each cohort B). The PFS6 rate in cohorts A, B1, and B2 was 33.3% (5/15), 42.8% (12/28), and 46.4% (13/28), respectively. Regarding safety, grade 1-2 and 3-4 toxicities occurred in 97.7% and 84.4% of patients, respectively. The most common grade 3-4 toxicities were neutropenia (66.4%) and thrombocytopenia (11.3%). Regarding PAM50, 59 (83.1%) tumors were profiled. Luminal disease defined by PAM50 was found independently associated with longer PFS compared with non-luminal disease (10.6 vs. 4.2 months median PFS; adjusted hazard ratio = 0.40; P = 0.003). CONCLUSIONS: Palbociclib in combination with trastuzumab is safe and exhibits promising survival outcomes in trastuzumab pretreated ER-positive/HER2-positive advanced breast cancer with a PAM50 Luminal A or B subtype. The enrollment was stopped prematurely, and a new randomized cohort was opened in this population.

Phase III study to evaluate patient's preference of subcutaneous versus intravenous trastuzumab in HER2-positive metastatic breast cancer patients: Results from the ChangHER study (GEICAM/2012-07).

OBJECTIVE: We compared patients' preferences for intravenous (IV-t) versus subcutaneous (SC-t) trastuzumab administration. METHODS: Phase III, open-label, multicentre study in HER2-positive metastatic breast cancer. Patients were receiving IV-t for at least 4 months without progression. Randomisation was 1:1 to administer 2 cycles of SC-t with vial followed by 2 cycles with single injection device (SID) or the reverse sequence (600mg SC-t every 3 weeks for 4 cycles). PRIMARY OBJECTIVE: patients' preference for IV-t versus SC-t; secondary objectives: patients' preference for vial versus SID, healthcare professional (HCP) preference and safety. RESULTS: We randomised 166 patients in 26 sites. Median number of previous lines of chemotherapy and/or endocrine therapy was 1 (1-7). Median duration of prior IV-t was 1.8 years (0.3-14). Of the159 patients completing the questionnaires, 86.2% preferred SC-t, 6.9% preferred IV-t, and 6.9% had no preference. Patients preferred SID (59.2%) over vial (26.3%). Most (87.2%) HCP preferred SC-t of whom 51.3% and 28.2% preferred SID and vial respectively. Related adverse events included G1-2 injection site reactions in 18 patients (10.8%), G1 pain in 8 (4.8%), G1-2 allergic reaction in 2 (1.2%), one G3 heart failure and 1 G2 ejection fraction decrease. CONCLUSIONS: SC-t is preferred with no safety impact.