A Study of KC1036 in Adolescents With Advanced Ewing Sarcoma

Inclusion Criteria:

• Age between 12 and less than 18 years;

• Diagnosed with Ewing sarcoma confirmed by histopathological examination;

• Patients with locally advanced or metastatic Ewing sarcoma that is unresectable orhas failed standard treatment, and for whom no other treatment options are availableas assessed by the investigator;

• Body weight of ≥30 kg;

• Karnofsky performance status (≥16 years) or Lansky performance status (<16 years)score of ≥60%;

• Patients with at least one measurable lesions according to RECIST v1.1 (ResponseEvaluation Criteria in Solid Tumors);

• Expected survival of more than 12 weeks;

• Sufficient organ and bone marrow function;

• Female patients who have started menstruating must have a negative pregnancy test;

• The patient and their legal guardians understand and are willing to participate inthe trial, and have signed the informed consent form.

Exclusion Criteria:

• Patients with primary central nervous system tumors;

• Presence of central nervous system metastases as diagnosed by imaging;

• History of or concurrent other malignancies within the past 5 years;

• Gastrointestinal abnormalities;

• Cardiovascular or cerebrovascular abnormalities;

• Patients who have previously received VEGFR-TKI small molecule treatment;

• Currently participating in another therapeutic clinical trial; received anyanticancer treatment within 2 weeks or 5 half-lives (whichever is longer) before thestart of the study treatment; received whole-brain radiation therapy within 14 daysbefore the start of the study treatment; received stereotactic radiosurgery within 7days before the start of the study treatment; or received herbal or traditionalChinese medicine for anticancer purposes within 2 weeks before the study treatment;

• Underwent major surgery within 2 months before enrollment or have not fullyrecovered, or plan to undergo surgery during the current study period;

• Persistent toxicity from previous anticancer treatment that has not improved to ≤Grade 1 (according to CTCAE v5.0), excluding alopecia;

• Unhealed skin wounds, surgical sites, traumatic sites, severe mucosal ulcers, orfractures;

• Uncontrolled significant pleural effusion, ascites, or pericardial effusion;

• Active bacterial, viral, or fungal infections; unexplained fever >38.5°C within 2weeks before enrollment;

• Hepatitis B surface antigen (HBsAg) positive with HBV-DNA ≥500 IU/mL or 2500copies/mL; Hepatitis C virus (HCV) antibody positive with HCV RNA ≥200 IU/mL orpositive test results; HIV-positive individuals;

• Presence of psychiatric or neurological disorders; or cognitive impairment;

• Fertile patients (e.g., females who have started menstruating or males who havestarted ejaculating) who do not agree to use contraception (e.g., birth controlpills or condoms) during the study and for 6 months after the study ends;

• Patients with insufficient compliance as evaluated by investigator;

• The investigator believes that it is not suitable to patient in this clinical trial.