A Study to Evaluate the Efficacy and Toxicities of PLX038, in Patients With Locally Advanced or Metastatic Triple-negative Breast Cancer

NCT06162351 | Terminated Phase 2

• 1 other identifier: IC 2020-16
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 2

Brief Summary

Single arm phase II study for with primary objective to evaluate the efficacy of PLX038 on response rate for patients with pretreated, metastatic or locally advanced triple negative breast cancer.

Conditions

Breast; Cancer

Keywords

Pretreated; Metastatic; Locally; Advanced triple negative

Outcome Measures

Primary Outcomes (1)

• Best tumor response

  Best tumor response (defined as PR or CR in the first 6 months of treatment, assessed by investigators per RECIST v1.1 criteria).

  24 weeks

Secondary Outcomes (11)

• Time to response (TTR)

  Until 24 months

• SAEs (all grade, per NCI-CTCAE v5.0)

  Until 30 days after the last dose of IMP (24 months + 30 days)

• Correlation between PLX038 efficacy and homologous recombination (HR) defect (assessed by HR genes mutational status and BCRAness phenotype)

  Until 24 months

• PK analysis

  Until 24 months

• Duration of Response (DoR)

  Until 24 months

Study Arms (1)

Single arm: treatment with PLX038

EXPERIMENTAL

Patients will be treated at a dose of 1730mg/m2 IV infusion on Day 1 of each cycle Q3W (every 21 days, 1 cycle = 1 injection).

Drug: PLX038

Interventions

PLX038 DRUG

Study treatment will be at a dose of 1730mg/m2 IV infusion on Day 1 of each cycle Q3W (every 21 days, 1 cycle = 1 injection). Patients with a clinical benefit could be treated as long as study is ongoing. Patients are followed from inclusion until documented disease progression, withdrawal of consent, or death.

Single arm: treatment with PLX038

Eligibility Criteria

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

You may qualify if:

• Willing and able to comply with the protocol and provide written informed consent prior to study-specific screening procedures.
• Age ≥ 18 years.
• Females and males with cytologically or histologically confirmed breast carcinoma (either the primary or metastatic lesions).
• Locally advanced or metastatic disease that is not amenable to curative treatment.
• Triple negative breast cancer (both ER and PR \<10%, HER2-negative or HER2-low).
• Measurable disease (per RECIST version 1.1).
• Prior therapy (administered in the neoadjuvant, adjuvant and/or metastatic setting) with chemotherapy by an anthracycline, taxane and sacituzumab-govitecan (unless not medically appropriate or contraindicated for the patient).
• Received a minimum of two prior cytotoxic chemotherapy regimens for locally advanced or metastatic breast cancer.
• Patients with known gBRCA mutations must have received a PARP inhibitor in the metastatic setting.
• Patients whose cancer has a CPS score ≥10 must have received prior pembrolizumab unless (i) contra-indicated (ii) CPS score or pembrolizumab not available at time of first line treatment start.
• Resolution of chemotherapy and radiation therapy related toxicities to NCI-CTCAE version 5.0 Grade 1 or lower severity, except for stable sensory neuropathy (≤ Grade 2), alopecia (any grade), presence of clinically managed chronic autoimmune AEs from prior immune therapy.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Adequate organ function (obtained within 14 days prior to treatment start) as evidenced by:
• i. Absolute neutrophil count (ANC) ≥ 1.5 X 109/L; ii. Hemoglobin (Hgb) ≥ 9 g/dL; iii. Platelet count ≥ 100 X 109/L; iv. Bilirubin ≤ 1.5 X upper limit of normal (ULN), except for patients with a documented history of Gilbert's disease (≤ 2 X ULN); v. Alanine aminotransferase (ALT), and aspartate aminotransferase (AST) ≤ 2.5 X ULN (for patients with liver metastases ≤ 5 X ULN); vi. Alkaline phosphatase (AP) ≤ 3 X ULN (for patients with liver metastases, ≤ 5 X ULN); vii. Serum creatinine ≤ 1.5 mg/dL (133 μmol/L) or calculated creatinine clearance ≥ 50 mL/min (using Cockcroft-Gault formula); viii. Women of childbearing potential (WCBP): negative serum pregnancy test.
• Patients covered by social security or health insurance in compliance with the national legislation relating to biomedical research.

You may not qualify if:

• Patients who had a last dose of IV chemotherapy within 21 days, last dose of oral cytotoxic chemotherapy, radiotherapy, biological therapy, or investigational therapy within 14 days prior to treatment start.
• Patients with chronic inflammatory bowel disease and/or bowel obstruction.
• Concomitant use of other agents for the treatment of cancer or any investigational agent(s).
• Women who are either pregnant, lactating, planning to get pregnant.
• Patients receiving pharmacotherapy for hepatitis B or C, tuberculosis, or HIV.
• Patients with known liver disease diagnosed with Child-Pugh A or higher cirrhosis.
• Prior stage III or IV malignancy (other than breast cancer).
• Any other significant medical, psychological, social or geographic conditions that in the opinion of the Investigator would impair study participation or cooperation.
• Patients deprived of their liberty or under guardianship.

Sponsors & Collaborators

• Institut Curie: lead
• ProLynx LLC: collaborator

Study Sites (2)

Institut Curie

Paris, 75248 Cedex, France

Location

Institut Curie

Saint-Cloud, 92210, France

Location

MeSH Terms

Conditions

Neoplasms; Neoplasm Metastasis

Condition Hierarchy (Ancestors)

Neoplastic Processes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Single arm phase II study

Study Record Dates

• First Submitted: November 13, 2023
• First Posted: December 8, 2023
• Study Start: April 17, 2024
• Primary Completion: May 15, 2025
• Study Completion: May 15, 2025
• Last Updated: January 2, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: Data requests can be submitted starting 9 months after last article publication and will be made accessible for up to 12 months.
• Access Criteria: Access to trial individual participant data can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a data sharing agreement (DSA).

Locations

FR (2)