SYHA-1813

SYHA1813 is a potent multikinase inhibitor that targets vascular endothelial growth factor receptors (VEGFRs)/colony-stimulating factor 1 receptor (CSF1R). This study aimed to evaluate the safety, pharmacokinetics (PK), and antitumor activity of escalating doses of SYHA1813 in patients with recurrent high-grade gliomas (HGGs) or advanced solid tumors. This study adopted a combination of accelerated titration and a 3 + 3 design for dose escalation, with a starting dose of 5 mg once daily. The dose escalation continued at successive dose levels until the maximum tolerated dose (MTD) was determined. A total of 14 patients were enrolled and treated, including 13 with WHO grade III or IV gliomas and 1 with colorectal cancer. Two patients experienced dose-limiting toxicities (grade 4 hypertension and grade 3 mucositis oral) at 30 mg SYHA1813. The MTD was defined as 15 mg once daily. Hypertension (n = 6, 42.9%) was the most frequent treatment-related adverse event. Among evaluable patients (n = 10), 2 (20%) patients achieved partial response, and 7 (70%) had stable disease. The exposure increased with increasing doses within the studied dose range of 5 to 30 mg. Biomarker assessments demonstrated significant reductions in the levels of soluble VEGFR2 (P = .0023) and increases in the levels of VEGFA (P = .0092) and placental growth factor (P = .0484). The toxicities of SYHA1813 were manageable, and encouraging antitumor efficacy was observed in patients with recurrent malignant glioma. This study is registered with the Chinese Clinical Trial Registry (www.chictr.org.cn/index.aspx; identifier ChiCTR2100045380).

Meningioma is a common tumor of the central nervous system but effective therapies for malignant meningiomas are still lacking. Therefore, the development of novel therapeutic reagents is urgently needed. SYHA1813 is a novel compound and our previous study demonstrated its potent anti-tumor activity on glioblastoma through the inhibition of macrophages and human umbilical vein endothelial cells (HUVECs). However, the precise functional role of SYHA1813 in meningiomas remains unclear.

We aimed to investigate the direct tumor-inhibitory effects of SYHA1813 on meningioma both in vitro and in vivo, and explore its potential molecular mechanisms.

Our results showed that SYHA1813 suppressed the proliferation, colony formation, migration, and invasion of meningioma cells in vitro. Furthermore, we found SYHA1813 induced G2/M cell cycle arrest, apoptosis, and cellular senescence. Mechanistically, RNA-seq revealed that SYHA1813 activated the P53 pathway and impaired DNA repair. In vivo, SYHA1813 effectively inhibited the growth of meningioma xenografts in a mouse model. Additionally, in an ongoing first-inhuman phase I trial, this patient with recurrent meningioma provided preliminary clinical evidence supporting the anti-tumor activity of SYHA1813.

This study unveiled a novel antitumor mechanism of SYHA1813, showing its ability to directly target and kill meningioma cells in vitro and in vivo. Our findings highlighted the promising potential of SYHA1813 as a therapeutic agent for treating malignant meningiomas.