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

Phase 1

Recruiting

• Conditions: Leptomeningeal Metastases
• Interventions: Drug: Sacituzumab Govitecan; Drug: Pemetrexed

• Registration Number: NCT06462092
• Lead Sponsor: Guangzhou Medical University

Brief Summary

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.

Detailed Description

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 Timeline

• Study First Submitted: 2024-06-12
• Study First Submitted QC: 2024-06-12
• Study First Posted: 2024-06-17
• Status Verified: 2025-09
• Last Update Submitted: 2025-09-24
• Last Update Posted: 2025-09-29
• Study Start: 2026-01-01
• Primary Completion: 2027-01-15
• Study Completion: 2027-06-15

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 34

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Group	Sacituzumab Govitecan	In the Phase I cohort, a minimum of 3 patients and a maximum of 6 patients were enrolled. If DLT occurred in ≥2 patients, the dose of intrathecal pemetrexed was reduced to 10 mg, and enrollment continued with 6 consecutive patients. If DLT recurred in ≥2 patients, the trial was terminated. if DLT occurred in ≤1 patient, the study advanced to Phase II.
Group	Pemetrexed	In the Phase I cohort, a minimum of 3 patients and a maximum of 6 patients were enrolled. If DLT occurred in ≥2 patients, the dose of intrathecal pemetrexed was reduced to 10 mg, and enrollment continued with 6 consecutive patients. If DLT recurred in ≥2 patients, the trial was terminated. if DLT occurred in ≤1 patient, the study advanced to Phase II.

Primary Outcome Measures

Name	Time	Method
Maximal tolerated dose	From the beginning of the treatment until two months after the treatment.	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.

Secondary Outcome Measures

Name	Time	Method
Clinical response rate	From the beginning of the treatment until two months after the treatment or patient death.	The Response Assessment in Neuro-Oncology (RANO) criteria for leptomeningeal metastases were used to assess clinical response in this study.
Incidence of treatment-related adverse events	From the beginning of the treatment until two months after the treatment.	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.

Trial Locations

Locations (1)

The Affiliated Huizhou Hospital, Guangzhou Medical University; 🇨🇳 Huizhou, Guangdong, China