A Study of HFB200301 as a Single Agent and in Combination With Tislelizumab in Adult Patients With Advanced Solid Tumors

Inclusion Criteria:

Previously received the following lines of systemic therapy for the advanced/metastatic disease:

Gastric cancer: at least 2 lines of therapy
Renal cell carcinoma: at least 2 lines of therapy

Melanoma:

BRAF V600E mutant: must have received at least 2 lines of therapy
BRAF V600E wild type: must have received at least 1 line of therapy
Sarcoma: at least 1 line of therapy
Testicular germ cell tumor: at least 2 lines of therapy
Cervical cancer: at least 2 lines of therapy
Mesothelioma: at least 2 lines of therapy
Non-small cell lung cancer: at least 2 lines of therapy
Head and neck squamous cell carcinoma: at least 2 lines of therapy
Suitable site to biopsy at pre-treatment and on-treatment
Measurable disease as determined by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 or modified RECIST (mRECIST) for mesothelioma
Eastern Cooperative Oncology Group performance status of 0 or 1

Exclusion Criteria:

Systemic anti-cancer therapy within 2 weeks prior to start of study drug or within 4 weeks for immune-oncologic therapy
For soft tissue sarcoma and testicular germ cell tumor patients only: prior immune therapy
Therapeutic radiation therapy within the past 2 weeks
Prior exposure to agents targeting the Tumor Necrosis Factor Receptor type 2 (TNFR2) receptor
Active autoimmune disease requiring systemic treatment in the previous 2 years
Systemic steroid therapy (>10 mg/day of prednisone or equivalent) or any immune suppressive therapy ≤ 14 days before first dose

Persisting toxicity of ≥Grade 2 (≥Grade 1 for diarrhea) relating to prior anti cancer therapy with the following exceptions:

All grades of alopecia are acceptable
Endocrine dysfunction on replacement therapy is acceptable
Severe or unstable medical condition, including uncontrolled diabetes, coagulopathy, or unstable psychiatric condition
Major surgery within 4 weeks of the first dose of study drug
History or presence of drug or non-drug induced interstitial lung disease or pneumonitis ≥Grade 2. For combination only: non-small cell lung cancer patients, mesothelioma or patients with significantly impaired pulmonary function or who require supplemental oxygen at baseline must undergo an assessment of pulmonary function at screening
History of allergic reactions, immune related reactions, or cytokine release syndrome (CRS) attributed to compounds of similar chemical or biologic composition to monoclonal antibodies or any excipient of HFB200301
Using sensitive substrates of major cytochrome P450 (CYP450) enzymes
Known active malignancy, with the exception of the specific cancer under investigation in this trial, that required treatment within the previous 2 years

For combination only:

Prior randomization in a tislelizumab study regardless of the treatment arm, until the primary and key secondary endpoints of the study have read out
Hypersensitivity to tislelizumab or any of its excipients.