Table 2.

Primary and secondary endpoints and definitions.

Primary endpoint

Progression-free survival (PFS): time from randomization to the earlier of first documented tumor progression based on Response Evaluation Criteria in Solid Tumors (RECIST 1.1) 39 as assessed by the investigator or radiologist, or death from any cause

Key secondary endpoint

Overall Survival (OS): time from randomization to death

Secondary efficacy endpoints

Objective response rate: proportion of patients who have a confirmed partial or complete response as the best overall response determined by RECIST 1.1 from randomization to the earliest of disease progression, death, cutoff date, or initiation of post-treatment anti-cancer therapy

Duration of response: time from CR or PR until progressive disease or death

Clinical benefit rate: proportion of patients with confirmed CR, PR, or SD for at least 24 weeks from the date of randomization until disease progression, death, study cutoff date, or initiation of post treatment anti-cancer therapy

PFS on next line of therapy (PFS2): time from the date of randomization to the date of first documentation of progressive disease on the next systemic anti-cancer therapy

Time to first chemotherapy: the time interval from the date of randomization to the start date of the first chemotherapy after study treatment discontinuation

Other secondary endpoints

Pharmacokinetics of amcenestrant and palbociclib

Health-related QoL, as evaluated by EORTC QLQ-C30, QLQ-BR23/BR45 and EQ-5D-5L

Safety, evaluated through AEs, serious AEs, laboratory abnormalities

AEs, adverse events; CR, complete response; EORTC QLQ-C30, European Organization for Research and Treatment of Cancer core quality of life questionnaire; EQ-5D-5L, EuroQoL questionnaire with 5 dimensions and 5 levels per dimension; PR, partial response; QLQ-BR23/BR45, EORTC QLQ breast cancer–specific module; QoL, quality of life; RECIST, Response Evaluation Criteria in Solid Tumors; SD, stable disease.