A Study to Investigate the Safety, Tolerability, Pharmacokinetics and Preliminary Antitumor Activity of SIM0237 in Adult Participants with Advanced Solid Tumors

Inclusion Criteria:

• Written informed consent;

• ≥18 years of age;

• Histological/cytological diagnosis of selected locally advanced unresectable ormetastatic solid tumor not amenable to local therapies (clinical diagnosis of HCC isallowed); participants must have failed to derive clinical benefit on standardtherapies, or ineligible for the standard of care therapy

• Presence of at least one measurable lesion according to RECIST Version 1.1

• ECOG performance status score of 0 or 1;

• Life expectancy of ≥12 weeks;

• Participant must have adequate main organ function.

• Women of childbearing potential (WOCBP) must have a negative serum pregnancy testwithin 72 hours prior to the start of study treatment. WOCBP must be willing to useeither 2 adequate barrier methods or a barrier method plus a hormonal method ofcontraception to prevent pregnancy or to abstain from heterosexual activitythroughout the study, starting from the first dose of the study treatment through 180 days after the last dose of study treatment.

• Male participants must agree to use adequate contraception starting from the firstdose of the study treatment through 180 days after the last dose of the studytreatment.

Exclusion Criteria:

• Within the defined washout periods for prior anti-cancer treatments;

• Participant is currently participating or has participated in a study of aninvestigational agent or using an investigational device within 4 weeks of firstdose of SIM0237.

• Any other malignancy within 2 years prior to the first dose of the study treatmentexcept for localized cancers that are considered to have been cured and in theopinion of the Investigator present a low risk for recurrence.

• Participant has not recovered (i.e., to Grade 1 or to baseline) from previousanticancer therapy-induced AEs.

• Participants with a history of recently (within previous 2 years of the first doseof the study treatment) active diverticulitis or symptomatic peptic ulcer disease;

• Major surgery within 2 weeks of receiving the first dose of study treatment;

• Participant has symptomatic central nervous system (CNS) metastases, or CNSmetastases requiring CNS-directed local therapy (such as radiotherapy or surgery) orcorticosteroids therapy within 2 weeks of first dose of study treatment;

• Participants with a history of active pulmonary tuberculosis infection within 1year; participants with history more than 1 year prior to the first dose of studytreatment may be considered suitable if there is no evidence of active pulmonarytuberculosis judged by the Investigator;

• Participants with clinically significant cardiovascular diseases, in the past 6months prior to the first dose of the study treatment; symptomatic coronary heartdisease requiring drug treatment; arrhythmia requiring drug treatment; QTcF interval >480 msec; or uncontrolled hypertension;

• Participants who have ascites requiring drainage or pleural effusion or pericardialeffusion requiring drainage within 28 days after previous drainage; Known humanimmunodeficiency virus (HIV) infection or known acquired immunodeficiency syndrome (AIDS);

• Active or chronic hepatitis B or hepatitis C infection; participant with HBsAgpositive or detective HBV-DNA at screening should receive antiviral treatment as perlocal practice during the study.

• Concomitant therapy with any other anti-cancer therapy or chronic use ofimmunosuppressive doses (more than 10 mg/day of prednisone or equivalent) ofsystemic corticosteroids.

• Active known or suspected autoimmune disease.

• History of non-infectious pneumonitis that has required a course of oral orintravenous steroids to assist with recovery, or interstitial lung disease or severeobstructive pulmonary disease;

• History of severe hypersensitivity reactions to mAbs;

• History of allogeneic organ transplantation or graft-versus-host disease;

• Use of any live vaccine therapy within 4 weeks prior to the first dose of studytreatment;

• Any active infection requires systemic treatment via intravenous infusion within 2weeks prior to the first dose of study treatment;

• Known psychiatric disorder or drug abuse that would interfere the trialrequirements;

• Previous treatment with IL-15 agonists;

• Participant is pregnant or breastfeeding, or expecting to conceive or fatherchildren within the projected duration of the study.

• Other conditions that researchers consider inappropriate for inclusion.