Evaluating PLX038 for advanced triple-negative breast cancer

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

This study is testing a new treatment called PLX038 to see if it can help people with advanced triple-negative breast cancer who have already had chemotherapy.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 44 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Institut Curie (Academic / other)
• Drugs / interventions: sacituzumab, pembrolizumab, chemotherapy, radiation
• Locations: 2 sites (Paris and 1 other locations)
• Trial ID: NCT06162351 on ClinicalTrials.gov

What this trial studies

This is a single-arm, open-label phase II study aimed at assessing the efficacy and safety of PLX038 in patients with locally advanced or metastatic triple-negative breast cancer (TNBC) who have previously undergone chemotherapy. Participants must have received at least two prior cytotoxic chemotherapy regimens and meet specific eligibility criteria, including measurable disease as defined by RECIST V1.1. The treatment involves administering PLX038 via IV infusion every three weeks, with ongoing assessments of tumor response and safety throughout the study duration.

Who should consider this trial

Good fit: Ideal candidates are adults with locally advanced or metastatic triple-negative breast cancer who have received prior chemotherapy and meet specific inclusion criteria.

Not a fit: Patients with early-stage breast cancer or those who have not received prior chemotherapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with advanced triple-negative breast cancer who have limited treatment alternatives.

How similar studies have performed: While there have been studies on various treatments for triple-negative breast cancer, the specific use of PLX038 in this context is novel and has not been extensively tested.

Eligibility criteria

Inclusion Criteria:

* 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.

Exclusion Criteria:

* 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 who had any major surgery within 28 days prior to inclusion.
* 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).
* Brain metastases, unless local therapy was completed and use of corticosteroids for this indication discontinued for at least 3 weeks prior to inclusion. Signs or symptoms of brain metastases must be stable for at least 28 days prior to inclusion. No known progression of brain metastases (by imaging as assessed by RECIST) can have occurred. Patients with leptomeningeal disease or meningeal carcinomatosis are excluded.
* 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).
* Severe/uncontrolled intercurrent illness within the previous 28 days prior to inclusion.
* Significant known cardiovascular impairment (NYHA CHF \> grade 2, unstable angina, myocardial infarction within the previous 6 months prior to inclusion, or existing unstable cardiac arrhythmia).
* 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.

Where this trial is running

Paris and 1 other locations

• Institut Curie — Paris, France (Recruiting)
• Institut Curie — Saint Cloud, France (Recruiting)

Study contacts

• Study coordinator: Fouzia Azzouz

Conditions Breast; Cancer; Pretreated; Metastatic; Locally; Advanced triple negative