Palbociclib Plus Fulvestrant Improves PFS Among Premenopausal Patients With Breast Cancer

Premenopausal women with breast cancer who receive palbociclib — a cyclin-dependent kinase (CDK) 4/6 inhibitor — combined with fulvestrant and goserelin may see prolonged progression-free survival (PFS), according to a study published in The Oncologist.¹

The randomized, double-blind, placebo-controlled phase 3 PALOMA-3 trial (ClinicalTrials.gov identifier: NCT01942135) enrolled 521 women age 18 or older who were endocrine therapy–refractory and diagnosed with hormone receptor–positive/HER2-negative breast cancer, among whom 108 were premenopausal.

Patients were randomized 2:1 to receive fulvestrant ­with/without goserelin with palbociclib or placebo.

Patients receiving palbociclib saw a significant improvement in PFS vs placebo: 9.5 vs 5.6 months, respectively (hazard ratio [HR], 0.50; 95% CI: 0.29-0.87; 2-sided P = .013) in the premenopausal group, and 9.9 vs 3.9 months, respectively (HR, 0.45 [0.34-0.59]; 2-sided P < .0001) in the post-menopausal group.

The addition of palbociclib did not have antagonistic effects on the levels of fulvestrant and did not demonstrate any additional toxicities.

The most frequently occurring adverse effects with palbociclib with concurrent goserelin were leukopenia, infections, and neutropenia.

The results of the study showed that palbociclib in combination with fulvestrant and goserelin could provide clinically significant benefits.

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The authors concluded that these “results support the use of palbociclib in combination with fulvestrant and goserelin for women with [hormone receptor–positive, advanced breast cancer], and these findings have expanded the treatment options for premenopausal women.”