A Phase I Clinical Study of HLX3902 in Patients With mCRPC and Other Advanced Tumours

Prior treatment

• Active malignancies within two years prior to the first dose, except cured carcinoma in situ or basal cell carcinoma of the skin.
• Prior STEAP1-targeted therapy, or Radium-223/PSMA radionuclide therapy within 6 months.
• Major surgery, radiotherapy, chemotherapy, biological therapy, immunotherapy, or endocrine therapy (excluding LHRH/GnRH analogues) within 28 days; small molecule drugs within 14 days.
• Vaccination with live vaccines within 28 days.
• Systemic corticosteroids (\> 10 mg/day Prednisone equivalent) or other immunosuppressants within 14 days.
• Adverse events from prior therapy not resolved to Grade ≤ 1, except for alopecia, ear toxicity, or stable Grade ≤ 2 taxane-related neurotoxicity.
• History of Grade ≥ 2 immune-related pneumonitis or myocarditis, or severe/life-threatening immune-mediated adverse events during prior immunotherapy.

Other illness

• Poorly controlled cardiovascular disease within 6 months, unstable angina, stroke, thromboembolic events, or uncontrolled hypertension or arrhythmia.
• Evidence of interstitial lung disease, or active non-infectious pneumonitis.
• Active or suspected autoimmune disease, hypophysitis, or unstable pituitary dysfunction requiring systemic therapy.
• Active systemic infectious diseases requiring intravenous antibiotics within 2 weeks, active tuberculosis, or positive for HIV, active HBV (HBV DNA ≥ 500 IU/mL), or HCV.
• History of organ transplantation, central nervous system diseases within 12 months (e.g., seizures, dementia), or any condition that makes the participant unsuitable per Investigator.

Other

• Presence of histological types other than adenocarcinoma in mCRPC; or neuroendocrine or small cell differentiation in other solid tumours.
• Active or symptomatic central nervous system metastases, carcinomatous meningitis, or spinal cord compression (stable treated brain metastases meeting protocol criteria are allowed).
• Currently participating in another interventional study or within 4 weeks of the end of treatment in such a study.

• Voluntarily signed written informed consent and willing to comply with study procedures.
• Age: ≥ 18 years, regardless of gender.
• Histologically confirmed advanced or metastatic solid tumours (e.g., metastatic castration-resistant prostate cancer (mCRPC), non-small cell lung cancer, or gastric cancer) following failure of standard therapy.
• mCRPC specifics: 1）Progression or refractory status after ≥ 1 novel anti-androgen agent and failure of 1-2 taxane-based regimens.
  • 2）Ongoing surgical or medical castration (gonadotropin-releasing hormone agonist or antagonist) with serum testosterone ≤ 50 ng/dL.
  • 3）Documented disease progression (prostate-specific antigen, nodal, visceral, or bone) .
  • 5\. Presence of at least one measurable lesion per RECIST criteria version 1.1. 6. ECOG Performance Status of 0-1. 7. Expected survival exceeding 3 months. 8. Agreement to provide archived or fresh tumour tissue. 9. Adequate organ function. 10. Agreement to use effective contraception for both genders and negative pregnancy test for females of childbearing potential.