A Study of Samuraciclib in Combination With Fulvestrant in Metastatic or Locally Advanced Breast Cancer in Adult Participants

NCT05963984 | Completed Phase 2 FDA Drug

• 3 other identifiers: CT7001_0022023-503903-27-00Z0041001
• Study Type: interventional
• Target: 60
• Locations: 5 countries
• Sites: 32

Brief Summary

The purpose of this study is to evaluate the safety and efficacy of samuraciclib in combination with fulvestrant versus fulvestrant alone in adult participants with metastatic or locally advanced Hormone Receptor (HR) positive and Human Epidermal Growth Factor Receptor (HER)2-negative breast cancer.

Conditions

Metastatic Breast Cancer; Locally Advanced Breast Cancer; Breast Cancer

Keywords

Metastatic Breast Cancer; Advanced Breast Cancer; Breast Cancer; HR Positive; HER2-Negative

Outcome Measures

Primary Outcomes (1)

• Clinical Benefit Response (CBR)

  CBR is defined as the overall complete response (CR), partial response (PR), or stable disease (SD) ≥ 24 weeks according to RECIST version 1.1 recorded from randomization until disease progression, or death due to any cause.

  From randomization until Week 24

Secondary Outcomes (7)

• Objective Response Rate (ORR)

  Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

• Duration of Response (DOR)

  Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

• Progression Free Survival (PFS)

  Time from the date of first dose of study intervention until the first documentation of disease progression, death, withdrawal of consent, or start of new anticancer therapy (assessed up to week 48)

• Incidence and severity of adverse events (AEs) as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0

  From first dose of any study intervention through 28 days after the last dose of any study intervention

• Samuraciclib plasma exposure: Cmax

  Day 1 of Cycles 2 and 3 (each cycle is 28 days)

Study Arms (3)

Arm A

EXPERIMENTAL

Participants will receive 360 mg of samuraciclib on cycles of 28 days (Cycle 1 to 6), 56 days (Cycle 7 to 9) and up to 84 days (Cycles 10 onwards in combination with fulvestrant administered monthly, plus an additional dose at Cycle 1 Day 15.

Drug: Samuraciclib; Drug: Fulvestrant

Arm B

EXPERIMENTAL

Participants will receive 240 mg of samuraciclib on cycles of 28 days (Cycle 1 to 6), 56 days (Cycle 7 to 9) and up to 84 days (Cycles 10 onwards in combination with fulvestrant administered monthly, plus an additional dose at Cycle 1 Day 15.

Drug: Samuraciclib; Drug: Fulvestrant

Arm C

EXPERIMENTAL

Participants will receive fulvestrant administered monthly, plus additional dose at Cycle 1 Day 15.

Drug: Fulvestrant

Interventions

Samuraciclib DRUG

Samuraciclib tablet by mouth once a day

Arm A; Arm B

Fulvestrant DRUG

Injection administered monthly (i.e., every 4 weeks), plus additional dose at Cycle 1 Day 15

Also known as: Faslodex

Arm A; Arm B; Arm C

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed diagnosis of ER-positive, HER2-negative locally advanced or metastatic breast cancer.
• Documented objective disease progression while on or within 6 months after the end of the most recent therapy.
• Received prior AI in combination with a CDK4/6i as the last therapy
• Known TP53 mutation status.
• Participants must have measurable disease or bone only disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
• Pre/peri-menopausal participants must have commenced treatment with a luteinizing hormone-releasing hormone (LHRH) agonist at least 4 weeks prior to first dose of study intervention.
• Eastern Cooperative Oncology Group (ECOG) performance status ≤1 with no deterioration over the past 2 weeks.
• Expected life expectancy of \>12 weeks in the judgement of the treating investigator.

You may not qualify if:

• Inflammatory breast cancer.
• Participants with any other active malignancy within 3 years prior to enrollment, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ of the cervix.
• More than 1 line of endocrine treatment for locally advanced or metastatic disease treatment.
• Inadequate hepatic, renal, and bone marrow function.
• Clinically significant cardiovascular disease.
• Any current or prior central nervous system metastases, carcinomatous meningitis, or leptomeningeal disease.
• Pregnant or breastfeeding women.

Sponsors & Collaborators

• Carrick Therapeutics Limited: lead
• Pfizer: collaborator

Study Sites (32)

Ocala Oncology Center PL DBA Florida Cancer Affiliates

Ocala, Florida, 34474, United States

Location

Mfsmc-Hjwci

Baltimore, Maryland, 21237, United States

Location

Saint Luke's Cancer Institute

Kansas City, Missouri, 64111, United States

Location

Sidney Kimmel Cancer Center - Jefferson Health

Philadelphia, Pennsylvania, 19107, United States

Location

The Center for Cancer and Blood Disorders

Fort Worth, Texas, 76104, United States

Location

Szent Borbala Korhaz

Tatabánya, Komárom-Esztergom, 2800, Hungary

Location

Nograd Varmegyei Szent Lazar Korhaz

Salgótarján, Nógrád megye, 3100, Hungary

Location

Semmelweis Egyetem

Budapest, 1082, Hungary

Location

Actualidad Basada en la Investigación del Cáncer

Guadalajara, Jalisco, 44280, Mexico

Location

Renati Innovation S.A.P.I de C.V

Guadalajara, Jalisco, 44680, Mexico

Location

Soltmed SMO

Mexico City, Mexico City, 03650, Mexico

Location

Cryptex Investigación Clínica S.A. de C.V.

Cuauhtémoc, 06100, Mexico

Location

Oaxaca Site Management Organization S.C.

Oaxaca City, 68000, Mexico

Location

Centro de Investigacion Clinica de Oaxaca

Oaxaca City, 68020, Mexico

Location

Institut Català d'Oncologia - L'Hospitalet

L'Hospitalet de Llobregat, Barcelona, 08908, Spain

Location

Hospital Universitario Marqués de Valdecilla

Santander, Cantabria Comunidad de, 39002, Spain

Location

Hospital Clinico San Carlos

Madrid, Madrid, Comunidad de, 28040, Spain

Location

Hospital Infanta Cristina

Badajoz, 06080, Spain

Location

Parc de Salut Mar - Hospital del Mar

Barcelona, 08003, Spain

Location

Hospital Universitari Vall d'Hebron

Barcelona, 08035, Spain

Location

MD Anderson Cancer Center

Madrid, 28015, Spain

Location

Hospital Vithas Málaga

Málaga, 29016, Spain

Location

Hospital Universitario de Salamanca - Complejo Asistencial Universitario de Salamanca

Salamanca, 37007, Spain

Location

Hospital Clinico de Valencia

Valencia, 46010, Spain

Location

Gulhane Egitim ve Arastirma Hastanesi

Ankara, 06010, Turkey (Türkiye)

Location

Gazi University

Ankara, 06120, Turkey (Türkiye)

Location

Dr. Abdurrahman Yurtaslan Ankara Onkoloji Egitim ve Arastırma Hastanesi

Ankara, 06200, Turkey (Türkiye)

Location

Hacettepe Universite Hastaneleri

Ankara, 06230, Turkey (Türkiye)

Location

Trakya University

Edirne, 22030, Turkey (Türkiye)

Location

Istanbul Universitesi Istanbul Tıp Fakultesi Hastanesi

Istanbul, 34093, Turkey (Türkiye)

Location

TC Saglik Bakanligi Goztepe Prof. Dr. Suleyman Yalcin Sehir Hastanesi

Istanbul, 34722, Turkey (Türkiye)

Location

I.E.U. Medical Point Hastanesi

Izmir, 35575, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Breast Neoplasms

Interventions

Fulvestrant

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Estradiol; Estrenes; Estranes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Estradiol Congeners; Gonadal Steroid Hormones; Gonadal Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 30, 2023
• First Posted: July 27, 2023
• Study Start: November 16, 2023
• Primary Completion: March 20, 2025
• Study Completion: August 28, 2025
• Last Updated: December 26, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (5); TU (8); ES (10); HU (3); ME (6)