Phase 3 Trial of Elacestrant vs. Standard of Care for the Treatment of Patients With ER+/HER2- Advanced Breast Cancer
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: Elacestrant; Standard of Care
Intervention description: 400 mg/day once daily oral dosing; Fulvestrant: 500 mg administered intramuscularly (IM) into the buttocks as two 5 mL injections on C1D1, C1D15 and C2D1 and Day 1 of every subsequent 28-day cycle
Anastrozole 1 mg/day on a continuous dosing schedule
Letrozole: 2.5 mg/day on a continuous dosing schedule
Exemestane: 25 mg/day on a continuous dosing schedule
Intervention MeSH terms: Fulvestrant; Anastrozole
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 478.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No

Summary:

      This Phase 3 clinical study compares the efficacy and safety of elacestrant to the standard
      of care (SoC) options of fulvestrant or an aromatase inhibitor (AI) in women and men with
      breast cancer whose disease has advanced on at least one endocrine therapy including a CDK4/6
      inhibitor in combination with fulvestrant or an aromatase inhibitor (AI) .
    

Eligibility criteria:

        Critical Inclusion Criteria:

          1. Subjects with proven diagnosis of adenocarcinoma of the breast with evidence of either
             locally advanced disease not amenable to resection or radiation therapy with curative
             intent or metastatic disease not amenable to curative therapy.

          2. Subjects must be appropriate candidates for endocrine monotherapy

          3. Subjects must have measurable disease or nonmeasurable (evaluable) bone-only disease

          4. Female or male subjects age ≥ 18 years; female subjects must be postmenopausal women
             and male subjects must not allow pregnancy with their sperm (abstain, do not donate
             sperm, etc).

          5. Subjects must have ER+/HER2- tumor status

          6. Subjects must have previously received at least one and no more than two lines of
             endocrine therapy for advanced/metastatic breast cancer and meet additional previous
             treatment criteria.

          7. Subjects must have received prior treatment with a CDK4/6 inhibitor in combination
             with either fulvestrant or an aromatase inhibitor (AI).

          8. Subjects may have received no more than one line of chemotherapy in the
             advanced/metastatic setting.

          9. Subjects must have ctDNA ESR1-mut or ESR1-WT status as determined by central testing
             with Guardant360CDx® before subject is randomized.

        Critical Exclusion Criteria:

          1. Prior treatment with elacestrant, GDC-0810, GDC-0927, GDC-9545, LSZ102, AZD9496,
             bazedoxifene, or other investigational SERD or investigational ER antagonist.

          2. Prior anticancer or investigational drug treatment within the following windows:

               1. Fulvestrant treatment < 28 days before first dose of study drug

               2. Any endocrine therapy < 14 days before first dose of study drug (with the
                  exception of GnRH agonist therapy in male subjects)

               3. Chemotherapy < 21 days before first dose of study drug

               4. Any investigational anti-cancer drug therapy < 28 days or five half-lives
                  (whichever is shorter) before the first dose of study drug. Enrollment of
                  subjects whose most recent therapy was an investigational agent should be
                  discussed with the Sponsor

          3. Presence of symptomatic visceral disease as defined in protocol.