A Study of BL-M08D1 in Patients With Recurrent or Metastatic Nasopharyngeal Carcinoma and Other Solid Tumors

• BL-M08D1 (Drug): Administration by intravenous infusion for a cycle of 3 weeks.

Primary outcomes

• Recommended Phase II Dose (RP2D) [Up to approximately 24 months]: The RP2D is defined as the dose level chosen by the sponsor (in consultation with the investigators) for phase II study, based on safety, tolerability, efficacy, PK, and PD data collected during the dose escalation study of BL-M08D1.
• Objective Response Rate (ORR) [Up to approximately 24 months]: ORR is defined as the percentage of participants, who has a CR (disappearance of all target lesions) or PR (at least a 30% decrease in the sum of diameters of target lesions). The percentage of participants who experiences a confirmed CR or PR is according to RECIST 1.1.

Secondary outcomes

• Progression-free Survival (PFS) [Up to approximately 24 months]: Progression-free survival (PFS) as assessed by BICR is defined as the time between the date subjects were randomized and the first observation of disease progression (based on BICR's image-based assessment) or death.
• Disease Control Rate (DCR) [Up to approximately 24 months]: Disease Control Rate (DCR) : Percentage of all randomized subjects who rated the best overall response (BOR) as complete response (CR), partial response (PR), and disease stabilization (SD) according to RECIST 1.1 criteria.
• Duration of Response (DOR) [Up to approximately 24 months]: Duration of Response (DOR) is defined as the period from the date when tumor response is first recorded to the date when objective tumor progression is first recorded or the date of death.
• Treatment-Emergent Adverse Event (TEAE) [Up to approximately 24 months]: TEAE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally emerging, or any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a pre-existing condition during the treatment of BL-M08D1 . The type, frequency and severity of TEAE will be evaluated during the treatment of BL-M08D1.
• Cmax [Up to approximately 24 months]: Cmax is defined as the maximum observed drug concentration in plasma after administration.
• Tmax [Up to approximately 24 months]: Tmax is defined as the time required to reach the maximum drug concentration in plasma following drug administration.
• T1/2 [Up to approximately 24 months]: T1/2 is defined as the time required for the plasma concentration of a drug to decrease by 50% during the elimination phase.
• AUC0-t [Up to approximately 24 months]: AUC0-t is defined as area under the serum concentration-time curve from time 0 to the time of the last measurable concentration.
• CL (Clearance) [Up to approximately 24 months]: Clearance (CL) is the volume of plasma from which a drug is completely removed per unit time.
• Ctrough [Up to approximately 24 months]: Ctrough is defined as the lowest serum concentration prior to the next dose will be administered.
• Anti-drug Antibody (ADA) [Up to approximately 24 months]: Frequency of anti-BL-M08D1 antibody (ADA) will be investigated.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

1. Voluntarily sign the informed consent form and agree to comply with the protocol requirements;
2. No gender restriction;
3. Age: ≥18 years and ≤75 years;
4. Expected survival time ≥3 months;
5. Recurrent or metastatic nasopharyngeal carcinoma and other solid tumors;
6. Agree to provide archived tumor tissue specimens or fresh tissue samples from the primary or metastatic lesions within 3 years;
7. Must have at least one measurable lesion as defined by RECIST v1.1;
8. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, with no deterioration within 2 weeks prior to the first dose;
9. Toxicity from prior anti-tumor therapy must have recovered to ≤ Grade 1 as defined by NCI-CTCAE v6.0;
10. No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥50%;
11. Organ function levels must meet the required criteria;
12. Coagulation function: international normalized ratio (INR) ≤1.5, and activated partial thromboplastin time (aPTT) ≤1.5 × upper limit of normal (ULN);
13. Urine protein ≤1+ or ≤1000 mg/24h;
14. For premenopausal women of childbearing potential, a serum pregnancy test must be performed within 7 days prior to the start of treatment and must be negative, and they must be non-lactating; all enrolled patients (both male and female) must adopt adequate barrier contraceptive measures throughout the entire treatment period and for 6 months after the completion of treatment;
15. The trial participant must be capable of and willing to comply with the visit schedule, treatment plan, laboratory tests, and other study-related procedures specified in the protocol.

Exclusion Criteria:

1. Use of chemotherapy, biotherapy, immunotherapy, or other systemic anti-cancer therapies within 4 weeks or 5 half-lives prior to the first dose;
2. History of severe cardiac or cerebrovascular disease;
3. Prolonged QTc interval, complete left bundle branch block, third-degree atrioventricular block, or frequent and uncontrolled arrhythmias;
4. Active autoimmune diseases and inflammatory diseases;
5. Diagnosis of another primary malignancy within 5 years prior to the first dose;
6. Unstable thrombotic events requiring therapeutic intervention within 6 months prior to the first dose;
7. Hypertension inadequately controlled by antihypertensive medications;
8. Poorly controlled blood glucose (diabetes);
9. History of interstitial lung disease (ILD) requiring corticosteroid therapy, or current ILD, or radiation pneumonitis of Grade ≥2;
10. Severely impaired respiratory function;
11. Active central nervous system (CNS) metastases;
12. History of, or concurrent, central nervous system disorders;
13. History of allergy to recombinant humanized antibodies or human-mouse chimeric antibodies, or hypersensitivity to any excipient component of BL-M08D1;
14. Prior organ transplantation or allogeneic hematopoietic stem cell transplantation;
15. Positive for human immunodeficiency virus (HIV) antibodies, active tuberculosis, active hepatitis B virus infection, or active hepatitis C virus infection;
16. Active infection requiring systemic therapy within 4 weeks prior to the first dose of study drug;
17. Pleural, peritoneal, or pericardial effusion requiring drainage and/or associated with symptoms within 4 weeks prior to the first dose of study drug;
18. Imaging findings indicating that the tumor has invaded or encased major blood vessels (e.g., abdominal or thoracic vessels), the pericardium, or the heart;
19. Use of another investigational drug within 4 weeks or 5 half-lives prior to the first dose;
20. Pregnant or breastfeeding women;
21. Other conditions that, in the opinion of the investigator, make the patient unsuitable for participation in this clinical trial.