Study to evaluate the safety and tolerability of camizestrant in combination with atirmociclib in women with advanced breast cancer - SERENA-1b

Inclusion Criteria

• Main Inclusion Criteria:
• • Participants with advanced adenocarcinoma of the breast and must have received prior adequate therapy in accordance with local practice for their tumor type and stage of disease.
• • Metastatic or locoregionally recurrent disease and radiological or objective evidence of progression on or after the last systemic therapy prior to starting investigational medicinal products.
• • Eastern cooperative oncology group (ECOG)/World Health Organization (WHO) performance status 0 to 1, and a minimum life expectancy of 12 weeks.
• • At least one lesion that is measurable and/or non-measurable, as per RECIST 1.1 and that can be accurately assessed at baseline and is suitable for repeated assessment by computed tomography (CT), magnetic resonance imaging (MRI), or plain X-ray, or clinical examination.
• • Menopausal status
• > Pre-menopausal women must start GnRH agonist therapy at least 4 weeks before study treatment and continue throughout the study.
• > Post-menopausal women must meet one of these criteria: bilateral oophorectomy, age ≥60 years, age ≥50 years with ≥12 months amenorrhea and intact uterus without hormonal therapy, or age <60 years with ≥12 months amenorrhea and post-menopausal hormone levels.
• • Histological or cytological confirmation of adenocarcinoma of the breast.
• • Participants of childbearing potential must agree to use one highly effective contraceptive measure.
• • Documentation of ER-positive tumor irrespective of progesterone receptor status.
• Main Exclusion Criteria:
• • A participant who has received 2 or more lines of CDK4/6 inhibitors in the advanced disease setting.
• • A participant who has received prior camizestrant or atirmociclib treatment in the advanced disease setting.
• • Patients previously treated with other next generation selective estrogen receptor degrader (SERDs) or other experimental ETs in the advanced disease setting.
• • Patients previously treated with other experimental cyclin-dependent kinase (CDK) inhibitors are not eligible.
• • Inability to swallow oral medications.
• • Any unresolved toxicities of Grade ≥ 2 from prior anti-cancer therapy (with the exception of alopecia).
• • Presence of life-threatening metastatic visceral disease.
• • Any evidence of severe or uncontrolled systemic diseases.
• • Contraindication to or known intolerance/hypersensitivity of/to camizestrant or atirmociclib.