Trastuzumab deruxtecan shows +results in brain/lepromeningeal

[Lani]

https://www.eurekalert.org/news-releases/1104745
metastatic her2+ breast cancer


Trastuzumab deruxtecan shows positive results in rare breast cancer with brain metastasis
?This solid evidence is seemingly leading into a new and groundbreaking BC treatment era.?

5-Nov-2025
Peer-Reviewed Publication
Impact Journals LLC

?This solid evidence is seemingly leading into a new and groundbreaking BC treatment era.?

BUFFALO, NY ? November 5, 2025 ? A new case report was published in Volume 12 of Oncoscience on October 9, 2025, titled "Metastatic breast cancer with leptomeningeal carcinomatosis treated with trastuzumab deruxtecan ? a case report."

In this report, Cristiana Honrado Martins, Jos? Miguel Rocha, Catarina Portela, Ricardo Fernandes, and Cl?udia Caeiro from Hospital de Braga, ULS de Braga, describe a rare case of advanced HER2-positive breast cancer (BC) that had spread to the membranes surrounding the brain and spinal cord?a condition known as leptomeningeal carcinomatosis.

The patient, a 37-year-old woman, initially responded to standard treatment but experienced a relapse two years later. At that point, her cancer had progressed to involve the central nervous system, severely affecting her neurological function. Given the complexity of her condition and limited standard options, the medical team initiated off-label treatment with trastuzumab deruxtecan.

Trastuzumab deruxtecan, a targeted antibody-drug conjugate, was selected based on data from recent clinical trials and multidisciplinary discussions. The patient began to improve after three treatment cycles. Imaging showed a reduction in the size and extent of the cancer, and her neurological symptoms gradually improved, allowing her to regain independence in daily activities. She continued on treatment for more than two years, during which the disease in her brain and spinal membranes remained stable.

This case illustrates the potential of antibody-drug conjugates like trastuzumab deruxtecan in treating breast cancers that reach the central nervous system. It also underscores the need for personalized and flexible treatment approaches in oncology, especially in cases of advanced or treatment-resistant breast cancer. Therapies like trastuzumab deruxtecan may become important tools for managing these types of tumors.

Continue reading: https://doi.org/10.18632/oncoscience.631

Correspondence to: Cristiana Honrado Martins - cristiana.honrado.martins@ulsb.min-saude.pt

Abstract video: https://www.youtube.com/watch?v=7CplmXaDyvc

Keywords: cancer, breast cancer, leptomeningeal carcinomatosis, HER2 positive, antibody-drug conjugate, trastuzumab-deruxtecan

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About Oncoscience:

Oncoscience is a peer-reviewed, open-access, traditional journal covering the rapidly growing field of cancer research, especially emergent topics not currently covered by other journals. This journal has a special mission: Freeing oncology from publication costs. It is free for the readers and the authors.

Oncoscience is indexed and archived by PubMed, PubMed Central, Scopus, META (Chan Zuckerberg Initiative) (2018?2022), and Dimensions (Digital Science).



Metastatic breast cancer with leptomeningeal carcinomatosis treated with trastuzumab deruxtecan ? a case report

Article Publication Date

9-Oct-2025

COI Statement

Authors have no conflicts of interest to declare.

[Lani]

the latest on treatment for l-m metastasis:
Combination treatment benefits patients with advanced breast cancer that has spread to brain
18-Mar-2026
Peer-Reviewed Publication
University of Texas M. D. Anderson Cancer Center

Leptomeningeal metastasis occurs when cancer spreads to the thin layers of tissue and fluid that surround the brain and spinal cord

Treatment for leptomeningeal metastasis is limited, and the disease often has poor outcomes

Targeted therapy plus chemotherapy regime is found to be safe and effective in Phase II trial

HOUSTON, MARCH 18, 2026 ― Patients with leptomeningeal metastasis (LM) have historically had few treatment options. Now, researchers from The University of Texas MD Anderson Cancer Center have found a combination of targeted therapies, tucatinib and trastuzumab, plus the chemotherapy drug, capecitabine, may improve symptoms and extend survival in some breast cancer patients with LM.

The Phase II study, published today in Nature Cancer, included 17 female patients with newly diagnosed LM and HER2+ breast cancer. Median overall survival (OS) in those treated with the combination therapy increased from a historical average of 4.4 months to 10 months. At the 18-month mark, 41% of patients were still alive. Under the combination treatment, disease progression also stalled, with a median of seven months before central nervous system progression, and seven of 12 evaluable patients also had improved neurologic deficits.

?The combination achieved a clinically meaningful improvement in overall survival compared to historical controls,? said lead author Rashmi Murthy, M.D., associate professor of Breast Medical Oncology. ?For these patients, who often face limited treatment options, our results represent a step forward, offering new hope in how we treat and manage leptomeningeal metastasis.?

Why are there limited treatments for patients with leptomeningeal metastasis?

Leptomeningeal metastasis is difficult to treat primarily because the blood-brain barrier may block drugs from reaching the spinal fluid, where the metastatic cells are found. Additionally, LM is not a solid tumor but is made up of metastatic cells living in fluid, making them more difficult to target. Historically, there also are few studies about this specific disease.

?In addition to encouraging survival outcomes, throughout this study we observed improvements in neurologic symptoms,? said co-lead author Barbara O?Brien, M.D., associate professor of Neuro-Oncology. ?Treatments for breast cancer leptomeningeal metastasis have historically focused on stabilizing disease rather than improving symptoms, making these findings particularly meaningful and encouraging.?

How do the treatments in this combination therapy work?

Tucatinib is a targeted therapy pill that blocks the HER2 protein, which helps some breast cancers grow. Trastuzumab is a targeted antibody that attaches to the HER2 protein on cancer cells and helps the immune system destroy them. Finally, capecitabine is a chemotherapy pill that turns into 5-fluorouracil (5-FU) in the body to eliminate fast-growing cancer cells.

The single arm, non-randomized, multi-phase study enrolled patients at four sites in the U.S., including UT MD Anderson. Eligible patients were at least 18 years old with histologically proven metastatic HER2+ breast carcinoma. These patients were treated with 21-day cycles of oral tucatinib (300 mg) twice daily, plus oral capecitabine (1000 mg/m2) twice daily on days 1-14 and intravenous trastuzumab (6 mg/kg) on day 21.

What are other key findings of the study?

Side effects included diarrhea, nausea, vomiting, hand-foot syndrome, and liver function test elevation. Most adverse effects improved or resolved with appropriate care and dose modifications. One patient saw alanine aminotransferase elevation after one cycle, which led to discontinuation of the combination, and symptoms resolved after one month.

Study limitations include early termination due to slow accrual following Food & Drug Administration (FDA) approval of the combination therapy. Additionally, LM from HER2+ metastatic breast cancer is rare, resulting in limited published data. As a result, the study design was informed by the small amount of available retrospective evidence.

***

This study was sponsored by Translational Breast Cancer Research Consortium and its foundation partners: the Breast Cancer Research Foundation and Susan G. Komen and Seagen Inc. For a full list of collaborating authors, disclosures and funding sources, see the full paper in Nature Cancer.

Journal

Nature Cancer