A Study of QLS2401 Injection in Participants With Advanced Prostate Cancer

• Study participants enrolled voluntarily and signed an informed consent form. Male participants aged ≥18 years.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1.
• Expected survival time of at least 3 months.
• Histologically or cytologically confirmed prostate adenocarcinoma without evidence of neuroendocrine or small cell carcinoma features.
• Metastatic prostate cancer confirmed by imaging.
• Belong to mCRPC.
• Stage Ia participants with mCRPC who have failed or are intolerant to standard treatment.
• Stage I participants with mCRPC who have failed or are intolerant to standard treatment.
• Adequate function of major organs as defined by the protocol.
• Agreement to use effective contraception during the study (except for subjects who have undergone bilateral orchiectomy).
• Prior to the first administration of the test drug, recover from all reversible adverse events (AEs) experienced during prior anticancer therapy.

Exclusion Criteria:

1. Patients who have previously received any of the following treatments are eligible:

   Patients who have previously received targeted therapies targeting PSMA or STEAP1; for Stage Ia and Stage Ib Cohort 1, prior treatment with PSMA-targeted radionuclide ligand therapy (RLT) is permitted.

   Patients who have previously received T-cell conjugate (TCE)-based therapies; Subjects who have received other systemic small-molecule anticancer therapy within 2 weeks prior to the first dose of the investigational product, or macromolecular antitumor therapy within 28 days prior to the first dose of the investigational product, will be excluded, except for medications used to maintain castration status.

   Patients who have received traditional Chinese medicine for antineoplastic indications within 2 weeks prior to the first administration of the investigational drug; e) Patients currently receiving treatment with any drug known to prolong the QT interval or may precipitate torsades de pointes ventricular tachycardia, or who have received such drugs prior to the first administration without having reached the corresponding washout period.

2. Presence of central nervous system (CNS) metastases, leptomeningeal metastases, or metastatic spinal cord compression requiring hormonal therapy (at doses exceeding the physiological substitution dose) prior to the first administration of the investigational drug;
3. Receipt of radiotherapy involving irradiation of more than 25% of the bone marrow within 4 weeks prior to the first administration of the investigational drug; or receipt of localized radiotherapy (excluding cranial radiotherapy) within 2 weeks prior to the first administration of the investigational drug;
4. Receipt of treatment with other investigational drugs or major surgery within 4 weeks prior to the first administration of the investigational drug (sufficient wound healing following major surgery must be clinically assessed); or planned bilateral orchiectomy during the study treatment period;
5. History of epilepsy or occurrence of any condition that could trigger epileptic seizures within 12 months prior to the first administration of the investigational drug;
6. Study participants with a history of psychotropic medication abuse, alcohol use disorder, or substance use disorder; or those with a documented history of neurological or psychiatric disorders that may contribute to poor treatment adherence.
7. Has clinically significant cardiovascular or cerebrovascular disease.
8. Administer a live attenuated vaccine within 4 weeks prior to the first dose of the investigational drug; or if administration of a live attenuated vaccine is anticipated during the study period.
9. Pre-existing clinically uncontrolled third-space effusion prior to initial administration of the test drug.
10. Previous history of hypertensive crisis or hypertensive encephalopathy.
11. According to the investigator's judgment, the participant may pose an increased risk related to the study, potentially interfere with the interpretation of study results, or be deemed unsuitable for enrollment by the investigator.