The study will include a dose-escalation and dose-expansion component to establish the recommended Phase 2 dose (RP2D) for HX301 in combination with Temozolomide and to evaluate the preliminary antitumor activity of HX301.HX301 is an investigational drug that has not yet been approved by the Food and Drug Administration (FDA) or any other regulatory authorities for commercial purposes.

Inclusion Criteria:

1. Signed informed consent form;
2. Age ≥ 18 years;
3. Expected survival ≥ 12 weeks;
4. Part I:1) Histologically confirmed high-grade glioma (WHO classification grade III or IV); 2) At least one prior temozolomide treatment; 3) Patients with recurrent or progressive clinically assessed disease according to RANO criteria with evaluable lesions; Part II: Patients with histological or cytological diagnosis of glioblastoma according to World Health Organization (WHO) classification (2021) who received surgical treatment for the first time and standard concurrent chemoradiotherapy and who have not received any other prior treatment;
5. Part II: Subjects must undergo partial or complete surgical resection, and available results of postoperative brain contrast-enhanced MRI were documented as follows: 1) complete resection without gadolinium enhancement ; or 2) complete resection (80% or more);
6. Part II: Subjects must complete initial radiotherapy combined with TMZ (concurrent chemoradiotherapy) for glioblastoma according to the Stupp regimen (Stupp 2005) (total radiation dose 5 4-60 G y);
7. Part I: If radiotherapy has been performed, the completion of radiotherapy shall last for 3 months, or there shall be tumor progression or histopathological confirmation of progression in the original radiation field within 3 months; Part II: there shall be no evidence of disease progression after chemoradiotherapy, except for pseudo progression;
8. Dexamethasone was administered at ≤ 5 mg/day at study entry.Corticosteroids should be reduced as far as possible to the smallest dose necessary to control neurological symptoms before receiving study treatment;
9. Karnofsky performance status (KPS) ≥ 70 within 1 4days prior to receiving study treatment ;
10. Willing and able to comply with the protocol.

Exclusion Criteria:

1. Part II: Patients with recurrent glioblastoma;
2. Distant metastasis involving brainstem and meninges or extension of lesions to spinal cord;
3. Human immunodeficiency virus (HIV) antibody positive, syphilis antibody (Anti-TP) positive, hepatitis C virus (HCV) antibody positive and HCV RNA positive, hepatitis B virus surface antigen (HBsAg) positive and HBV DNA positive (HBsAg positive requires further detection of HBV DNA, HBV DNA ≥ 200 IU/ml, or ≥ 10 3 copies/ml);
4. Hypersensitivity to temozolomide and/or components of HX301;
5. At risk for torsades de pointes (TdP): patients with a marked prolongation of the QT/QTc interval calculated using the Fredericia QT correction formula at baseline (eg, repeated demonstration of QTc interval > 470 ms), or a history of other TdP risk factors (eg, heart failure, hypokalemia, family history of long QT syndrome), or patients who are currently taking medications that prolong the QT/QTc interval;
6. Grade ≥ 2 diarrhea at baseline;
7. Participation in another study involving an investigational drug within 30 days prior to the first dose of study drug;