A Phase I Trial of SIM1811-03 in Subjects With Advanced Solid Tumors and Cutaneous T-cell Lymphoma

Inclusion Criteria:

• Written informed consent must be obtained prior to any procedures that are notconsidered standard of care
• ≥18 years old on the day of signing informed consent, male or female
• Histologically and/or cytologically documented advanced/metastatic solid tumors orhistologically confirmed CTCL. Patients with lymphoma other than CTCL are noteligible.
• Have relapsed or refractory advanced solid tumors or CTCL, whose disease hasprogressed during or after standard therapy
• At least one measurable tumor lesion (RECIST 1.1) for patients with solid tumors.Tumor lesions previously treated with radiotherapy or local therapy should not beconsidered as measurable unless progression is documented.
• For patients with CTCL, the following criteria must be met:
• Have at least one measurable lesion (mSWAT criteria) , the lesion that haspreviously been treated with local therapy should not be considered as measurableunless progression is documented;
• Provide tissue from a punch biopsy of the skin at screening (except for patientsin phase Ia dose escalation phase, for whom skin biopsies is recommended only).
• Mycosis fungoides (MF) or Sézary Syndrome (SS) (Stage IIb-IV based on Tumor NodeMetastasis Blood [TNMB] staging system for SS and MF diagnosed at screening)failed of at least 2 prior systemic therapies
• Meet clinical criteria for systemic treatment (patients that can be treated withradiotherapy and/or skin-directly therapies only are to be excluded)
• No current large cell transformation
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1
• Life expectancy of ≥ 12 weeks
• Adequate organ and marrow functions
• Provide archival tumor samples or fresh tumor biopsy (mandatory for Phase Ib, andrecommended for Phase Ia)
• Females of childbearing potential require strict contraception during the study

Exclusion Criteria:

• Participated in an interventional clinical trial or has used investigational deviceswithin 28 days prior to first dose of study drug or received any following systemicanti-cancer treatments:

1. cytotoxic chemotherapy, targeted therapy, immune checkpoint inhibitor within 4weeks (such as PD-1 inhibitor, PD-L1 inhibitor, or CTLA-4 inhibitor);
2. radiotherapy within 2 weeks (palliative radiotherapy is allowed at least 1 weekbefore the study drug treatment).

• Toxicity and side effects (due to previous anticancer treatments) have not recoveredto ≤ grade 1, unless such AE is not considered to pose safety risks (such as hair lossand neuropathy ≤ grade 2 caused by chemotherapy).
• Required use of corticosteroids for more than 7 consecutive days within 14 days priorto the first dose of study treatment (> 10 mg daily prednisone equivalent for solidtumors; > 20 mg daily prednisone equivalent for CTCL)
• Patients with active or history of or risk of autoimmune disease
• Major surgery (except biopsy) or unhealed wound within 4 weeks prior to first dose ofstudy drug
• Any other current or previous malignancy within the past 2 years except a) adequatelytreated basal cell or squamous cell skin cancer, b) carcinoma in situ of the cervix,c) carcinoma in situ of the breast d) local prostate cancer after radical resectionand/ or definitive radiotherapy with stable prostate specific antigen (PSA) levels for 1 years
• Has known active central nervous system (CNS) metastases
• History of interstitial lung disease, drug-induced interstitial lung disease,radiation pneumonitis, symptomatic interstitial lung disease or evidence of activepneumonia that is not considered appropriate by the investigator
• History of immunodeficiency (including HIV infection)
• Known active hepatitis B or C infection
• Patients with clinically significant cardiovascular diseases
• History of severe allergic reaction to the study drug or excipients used in theprotocol
• Has had an allogeneic tissue/solid organ transplant or graft-versus-host disease
• Other conditions that researchers consider inappropriate for inclusion