Palbociclib Plus Fulvestrant in Women With Hormone Receptor Positive and Human Epidermal Growth Factor Receptor Type 2 Negative Locally Advanced or Metastatic Breast Cancer Previously Treated With a CDK4/6 Inhibitor in Combination With Hormonal Therapy

Metastatic Breast Cancer Clinical Trial

Official title: Palbociclib Plus Fulvestrant in Women With Hormone Receptor Positive and Human Epidermal Growth Factor Receptor Type 2 Negative Locally Advanced or Metastatic Breast Cancer Previously Treated With a CDK4/6 Inhibitor in Combination With Hormonal Therapy: a Multicenter, Phase II Trial

Status Recruiting

Clinical Trial Summary

The aim of the present study is to evaluate the efficacy and safety of palbociclib plus fulvestrant after failure of a combined treatment of hormonal therapy (aromatase inhibitor or tamoxifen ± LHRHa) plus a CDK4/6 inhibitor, in women with HR+ and HER2- LABC or MBC.

Primary endpoint:

1. To assess the clinical benefit rate (CBR) of the combination treatment palbociclib plus fulvestrant at progression of a combined treatment of hormonal therapy (aromatase inhibitor or tamoxifen ± LHRHa) and a CDK4/6 inhibitor.

Clinical benefit rate for primary efficacy endpoints derivation will be based on the local (treating center's) radiologist's/investigator's tumor assessment.

• For patients with measurable disease at baseline, progression will be determined according to the RECIST criteria v1.1.

• In the absence of measurable disease at baseline, patients with bone only lesions, lytic or mixed (lytic + sclerotic), will be allowed to enter the study and the following will be considered disease progression among these patients:

• The appearance of one or more new lytic lesions in bone,

• The appearance of one or more new lesions outside of bone,

• Unequivocal progression of existing bone lesions.

Note: Pathologic fracture, new compression fracture, or complications of bone metastases will not be considered as evidence of disease progression, unless one of the above-mentioned criteria is fulfilled.

2. To assess the Quality of Life (QoL) of patients receiving the combination treatment palbociclib plus fulvestrant at progression of a combined treatment of hormonal therapy (aromatase inhibitor or tamoxifen ± LHRHa) and a CDK4/6 inhibitor.

Secondary Endpoints:

1. To evaluate the efficacy of the combination of fulvestrant plus palbociclib at the progression of a combined treatment of hormonal therapy (aromatase inhibitor or tamoxifen ± LHRHa) and CDK4/6 inhibitors with respect to:

• Overall response rate (ORR)

• Progression Free Survival (PFS)

• Overall Survival (OS)

• Safety and tolerability

2. To assess predictive biomarkers of response/resistance to fulvestrant plus palbociclib using metastatic tumor tissue samples and liquid biopsies.

This study will be performed in pre- and post-menopausal women with HR+/HER2- LABC or MBC whose disease is progressing to a CDK4/6 inhibitor in combination with hormonal therapy (aromatase inhibitor or tamoxifen ± LHRHa).

Patients enrolled will receive study medication until disease progression, unacceptable toxicity, withdrawal of consent or death, whichever comes first.

Clinical Trial Description

This is a Phase II, multicentre, single-arm study following a Simon's two-stage optimal design

Screening phase At screening, the investigator or his/her authorized designee will assign a unique number to patients being considered for the study. The patient should provide a signed Informed Consent Form prior to any study screening evaluations. Once the patient Informed Consent Form has been signed and eligibility is confirmed (all inclusion/exclusion criteria has been verified), the patient can be enrolled. All screening evaluations will be performed within 28 days prior to Treatment Day 1. Patients may be re-screened.

Treatment phase Eligible patients will receive Fulvestrant plus palbociclib. Patients will be treated with fulvestrant 500 mg i.m. on Days 1, 15 and 29 and every 28 days thereafter and palbociclib125 mg oral day 1 to 21 every 28 days.

Dose adjustment (reduction, interruption) according to toxicity of study treatment will be allowed. Study treatment will continue until one of the following conditions apply - whichever comes first:

• tumor progression

• unacceptable toxicity according to investigator's judgment

• death

• discontinuation from the study for any other reason Further treatments after discontinuation will be at the investigator's discretion. During the study, visits will be performed monthly and at the end of treatment. Tumor assessment will be performed every 3 cycle of treatment.

For each patient enrolled in the present study a blood sample (mandatory) at study enrollment and at disease progression (mandatory) will be provided. Additionally, a tissue sample from the most accessible metastatic site will be collected at study enrollment and at disease progression (optional). Blood and tumor samples will be used to investigate the mechanisms of response and resistance to therapy with palbociclib in combination with fulvestrant. ;

Related Conditions & MeSH terms

• Breast Neoplasms
• Locally Advanced Breast Cancer
• Metastatic Breast Cancer

• NCT number: NCT04318223
• Study type: Interventional
• Source: Consorzio Oncotech
• Contact: Grazia Arpino, MD
• Phone: +390817463772
• Email: grazia.arpino@unina.it
• Status: Recruiting
• Phase: Phase 2
• Start date: July 16, 2019
• Completion date: July 31, 2023