Sacituzumab Govitecan and Intrathecal Chemotherapy for Treating Leptomeningeal Metastases From Her2-negative Breast Cancer

Phase 2RecruitingNCT06462092

Guangzhou Medical University34 enrolled

Overview

Leptomeningeal metastases (LM) is a lethal complication of malignant tumors, characterized by tumor cell invasion and proliferation within the subarachnoid space. LM from HER2-negative breast cancer remains challenging to treat, with a median overall survival of only 3-6 months despite aggressive therapy. This open-label, uncontrolled Phase I/II clinical study aims to evaluate the safety, feasibility, and potential efficacy of Sacituzumab Govitecan in combination with intrathecal pemetrexed chemotherapy for LM from HER2-negative breast cancer, with the objective of identifying a more effective treatment strategy.

This study is a single-arm, prospective Phase I/II clinical trial, evaluating the safety, feasibility, and potential efficacy of combining Sacituzumab Govitecan with intrathecal pemetrexed chemotherapy for leptomeningeal metastases from HER2-negative breast cancer. The treatment regimen includes intravenous administration of Sacituzumab Govitecan (10 mg/kg) on Days 1 and 8 of each 21-day cycle, continuing until disease progression or unacceptable toxicity. Intrathecal pemetrexed chemotherapy is initiated on Day 2 via intracerebroventricular or lumbar puncture. The treatment is divided into three phases: induction therapy, 15 mg twice weekly for 2 weeks; consolidation therapy, once weekly for 4 weeks; maintenance therapy, once monthly for patients with an effective response until relapse or death. In the Phase I cohort, 3-6 patients were enrolled. If dose-limiting toxicity (DLT) occurred in ≥2 patients, the intrathecal dose of pemetrexed was reduced to 10 mg, and enrollment continued to ensure a total of 6 evaluable patients. If DLT recurred in ≥2 patients among the subsequently enrolled patients, the trial would be terminated. If DLT occurred in ≤1 patient, the trial would proceed to Phase II.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Interventions

Sacituzumab GovitecanDRUG

Patients receive Sacituzumab Govitecan 10mg/kg by intravenous infusion on days 1 and 8. Treatment cycles are every 21 days.

PemetrexedDRUG

Intrathecal pemetrexed chemotherapy, administered via intracerebroventricular or lumbar puncture, consists of three phases: induction therapy (15 mg twice weekly for 2 weeks), consolidation therapy (once weekly for 4 consecutive weeks), and maintenance therapy (once monthly).

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. A clear histopathologic diagnosis of breast cancer with HER2-negative subtype (including IHC 0, IHC 1+ or IHC 2+ and ISH negative); 2. Cerebrospinal fluid cytology confirms the presence of leptomeningeal metastases; or imaging findings combined with clinical symptoms and signs are consistent with the diagnosis of leptomeningeal metastases; 3. Age ≥ 18 years old. Exclusion Criteria: 1. Inadequate organ function: 1) Blood tests: ANC ≤ 1.5 x 10\^9/L, PLT ≤ 90 x 10\^9/L, Hb ≤ 90 g/L; 2) Blood biochemistry tests: TBIL ≥ 1.5 times the upper limit of normal; 3) ALT and AST ≥ 2.5 times the upper limit of normal; 2. Presence of serious and/or uncontrolled comorbidities that may affect participation: 1) Allergy to study drugs or adjuvant materials; 2) History of immunodeficiency (e.g., HIV-positive or other acquired or congenital immunodeficiency disease); 3) Severe concomitant diseases; 3. Pregnant and breastfeeding female patients; women of childbearing age who are unwilling or unable to use effective contraception; 4. Any other condition that, in the opinion of the investigator, makes the patient ineligible for participation in the study.

Outcomes

Primary Outcomes

Maximal tolerated dose

DLT was defined as Grade 3 neurological toxicities (e.g., chemical meningitis) or any Grade 4 toxicity. If DLT occurred in more than two patients at a given dose level, that dose level was deemed intolerable, and the maximal tolerated dose (MTD) was exceeded. In such cases, an additional three patients were treated at the next lower dose level. The MTD was defined as the dose level at which 0/3 or 1/6 patients experienced DLT, given that at least two patients experiencing DLT at the higher dose.

Time frame: From the beginning of the treatment until two months after the treatment.

Secondary Outcomes

Incidence of treatment-related adverse events

The incidence of treatment-related adverse events (AEs) was assessed to determine tolerability and safety. AEs were graded according to the Common Terminology Criteria for Adverse Events (CTCAE, version 4.03), with Grades 3-5 defined as moderate to severe events.

Time frame: From the beginning of the treatment until two months after the treatment.

Clinical response rate

The Response Assessment in Neuro-Oncology (RANO) criteria for leptomeningeal metastases were used to assess clinical response in this study.

Time frame: From the beginning of the treatment until two months after the treatment or patient death.