Durable Effect of Pyrotinib and Metronomic Vinorelbine in HER2-Positive Breast Cancer With Leptomeningeal Disease: A Case Report and Literature Review

A phase II study of concurrent involved-field radiotherapy and intrathecal chemotherapy for leptomeningeal metastasis from solid tumors

BACKGROUND

The role of involved-field radiation therapy (IFRT) and intrathecal chemotherapy (IC) in leptomeningeal metastasis (LM) from solid tumors was gradually underestimated in the era of targeted therapy. This study was aimed to investigate the safety and effectiveness of concurrent IFRT and intrathecal methotrexate (MTX)/cytarabine (Ara-C) for LM, particularly for those who developed LM while receiving targeted therapy.

MATERIALS AND METHODS

Enrolled patients were given induction IC first and then concurrent treatment, which consisted of IFRT (40 Gy total; 2 Gy/f) and IC (MTX 15 mg or Ara-C 50 mg, once per week). Primary endpoint was clinical response rate (RR). Secondary endpoints were safety and overall survival (OS).

RESULTS

Fifty-three patients received induction intrathecal MTX (n = 27) or Ara-C (n = 26). Forty-two patients completed concurrent therapy. Total RR was 34% (18/53). The improvement rate of neurological symptoms and KPS scores were 72% (38/53) and 66% (35/53) respectively. Adverse events (AEs) rate was 28% (15/53). Eight patients (15%, 8/53) showed grade 3-4 AEs, including myelosuppression (n = 4) and radiculitis (n = 5). Median OS was 6.5 months (95% CI, 5.3-7.7 months). Median survival for 18 patients who had clinical response was 7.9 months (95% CI, 4.4-11.4 months), and 0.8 months (95% CI, 0.08-1.5 months) for 6 patients who had LM progression. The median survival in 22 patients who received prior targeted therapy was 6.3 months (95% CI, 4.5-8.1 months).

CONCLUSION

Concurrent IFRT and intrathecal MTX or Ara-C was proved to be a feasible treatment option with an acceptable safety profile for LM from a common tumor entity.

Effective Combination Therapies for the Treatment of HER2 Cancer

Breast cancer (BC) is the primary cause of cancer-related death among women worldwide. The human epidermal growth factor receptor type 2 (HER2)-positive BC accounts for ∼15% of all BCs and a relatively poor prognosis. The disclosure in this patent highlight relates to a combination therapy comprising inavolisib (GDC-0077) and a HER2-targeted therapy such as trastuzumab, pertuzumab, or their combination for the treatment of HER2-overexpressing breast cancer.

Combined inhibition of PARP and ATR synergistically potentiates the antitumor activity of HER2-targeting antibody-drug conjugate in HER2-positive cancers

The therapeutic management of various HER2-positive malignancies involves the use of HER2-targeted antibody-drug conjugates (ADCs). The primary mechanism of action of ADCs is the release of cytotoxic chemicals, which leads to single- or double-strand DNA breaks and cell death. Since both endogenous and exogenous sources of DNA damage are unavoidable, cells have evolved DNA damage-repair mechanisms. Therefore, combining inhibitors of DNA damage repair and HER2-targeted ADCs may be a practical strategy for treating HER2-positive cancers. Effects of the HER2-targeted ADC, DS-8201, in combination with PARPi (AZD2281), a DNA damage repair inhibitor that targets poly(ADP-ribose) polymerase, and ATRi (BAY1895344), which inhibits the serine/threonine kinase ATR, were determined by assessing cell-growth inhibition, apoptosis and cell-cycle arrest, as well as using in vivo pharmacodynamic studies. Combined use of AZD2281 and BAY1895344 synergistically potentiated the inhibitory effects of DS-8201 on the growth of HER2-positive cancer cells, inducing DNA damage and apoptosis, but had no effect on HER2-negative MDA-MB-231 breast cancer cells. Our data demonstrate that DS-8201 and DNA damage repair inhibitors together have synergistic anticancer effects in NCI-N87 xenograft models, effects that may reflect upregulation of γ-H2AX protein in tumor tissues. Collectively, our results indicate that the combination of DS-8201, BAY1895344, and AZD2281 exerts significant synergistic antitumor activity, suggesting that DNA damage-repair inhibitors in combination with HER2-targeted ADCs is a potential approach for treating HER2-positive malignancies, offering a promising strategy for future clinical applications.

Refining Therapy in Patients with HER2-Positive Breast Cancer with Central Nervous System Metastasis

Background

Brain metastasis (BM) is a major clinical problem in metastatic breast cancer (MBC), occurring in 50% of patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer. Historically omitted from clinical trials, recent studies of novel HER2-targeted agents have focused on HER2+ BM patients, addressing stable but also progressing BM and leptomeningeal carcinomatosis (LMC).

Summary

This review aimed to summarize the most relevant data on treating patients with HER2+ BM and LMC.

Key Messages

The treatment paradigm for patients with HER2+ MBC has changed. Local therapies play an important role, but accumulating evidence on the intracranial activity and clinical benefit of anti-HER2 targeting therapies might lead to a shift in the paradigm on treating BM in the next few years towards more widespread use of systemic therapy.

Systemic Therapy Approaches for Breast Cancer Brain and Leptomeningeal Metastases

OPINION STATEMENT

Brain metastasis arising from breast cancer is associated with a poor prognosis. Various systemic chemotherapy and targeted therapies which are effective against breast cancer often fail to provide benefits against brain metastasis. This is mainly due to limited penetration of the therapies across the blood-brain barrier, and divergent evolution of brain metastasis compared to the primary tumor. Thus, brain metastasis is typically treated upfront with local therapies, such as surgery and radiation, followed by systemic therapies. Systemic therapies with CNS permeability are favored in patients with brain metastasis. This paper reviews various systemic therapy options for breast cancer brain metastasis.