Fulvestrant met en zonder palbociclib in receptor-positieve, HER2-negatieve gemetastaseerde borstkanker
ArrayChicago ASCO Annual Meeting 2015: Press Briefing Voortgang zeldzame en voorkomende vormen van kanker : zaterdag 30 mei – Nicholas C. Turner , Jungsil Ro , Fabrice Andre , et al. PALOMA3 : Een dubbelblinde , fase III trial van fulvestrant met of zonder palbociclib in pre- en post-menopauzale vrouwen met hormoon-receptor – positieve , HER2 – negatieve gemetastaseerde borstkanker die eerdere hormonale therapie hebben gehad.
Background: The growth of hormone receptor (HR) positive breast cancer (BC) is dependent on the cyclin dependent kinases CDK4/6, that promote G1-S phase cell cycle progression. Resistance to endocrine treatment remains a major clinical problem for patients with hormone receptor positive breast cancer. The PALOMA3 study assessed the efficacy of palbociclib and fulvestrant in endocrine-resistant advanced breast cancer.
Methods: In this double-blind phase 3 study women with HR positive/HER2 negative advanced metastatic BC whose cancer had relapsed or progressed on prior endocrine therapy, were randomized 2:1 to palbociclib (Palbo, 125 mg/d orally for 3 wk followed by 1 wk off) and fulvestrant (F, 500 mg per standard of care) or placebo (PLB) and F. Pre- and peri-menopausal women also received goserelin. One previous line of chemotherapy for metastatic disease was permitted. The primary endpoint was investigator assessed progression-free survival (PFS). Secondary endpoints included overall survival (OS), response assessment, patient-reported outcomes, and safety and tolerability. A pre-planned interim analysis was performed after 195 PFS events by an independent data monitoring committee.
Results: 521 pts were randomized, 347 to receive Palbo+F and 174 to PLB+F. Baseline characteristics were well balanced. The median age was 57 and 56 years, 79% were post-menopausal, 60% had visceral disease, and 79% were sensitive to prior endocrine therapy. Prior therapy included chemotherapy for advanced disease in 33% of pts. At the time of the interim analysis the study met the primary endpoint, median PFS was 9.2 months for Palbo+F and 3.8 months for PLB+F (HR 0.422, 95% CI 0.318 to 0.560, P<0.000001). Consistent benefit from Palbo was seen in pre- and post-menopausal women. The most common adverse effects Palbo+F versus PLB+F were neutropenia (78.8% vs. 3.5%), leucopenia (45.5% vs. 4.1%), and fatigue (38.0% vs. 26.7%). Febrile neutropenia was reported in 0.6% pts on Palbo+F and 0.6% pts on PLB+F. The discontinuation rate due to adverse events was 2.0% on Palbo and 1.7% on PLB.
Conclusions: Palbociclib combined with fulvestrant improved progression free survival in hormone receptor positive advanced breast cancer that had progressed on prior endocrine therapy, and can be considered as a treatment option for these patients. Clinical trial information: NCT01942135
Abstracts by Nicholas C. Turner:
Meeting: 2015 ASCO Annual Meeting | Abstract No: TPS1108
Meeting: 2015 ASCO Annual Meeting | Abstract No: 11098
Category: Tumor Biology – Other
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