177Lu-PSMA-EB-01 in Patients With Metastatic Castration-resistant Prostate Cancer

Safety and Dosimetry of 177Lu-PSMA-EB-01 in Patients With Metastatic Castration-resistant Prostate Cancer

This is a pilot study to assess the safety and measure image-based absorbed dose of 177Lu-PSMA-EB-01, a new PSMA-specific radiopharmaceutical, in patients with metastatic castration resistant prostate cancer (mCRPC) who will undergo radioligand therapy (RLT). All patients underwent 68Ga-PSMA and 18F-FDG PET/CT for selection and were randomly divided into three groups of 3 people each.The three groups received an approximately 1.11 GBq (30mCi), 1.85 GBq (50 mCi) and 2.59 GBq (70mCi) of 177Lu-PSMA-EB-01 up to 2 cycles, respectively.

Prostate cancer is the most frequent malignant tumor in men worldwide. Prostate-specific membrane antigen (PSMA), is a surface molecule specifically expressed by prostate tumors which was shown to be a valid target for radiotherapy. 177Lu-PSMA-617, a urea-based compound, provide an effective target for the treatment of metastatic castration-resistant prostate cancer. However, a major problem in the therapeutic use of 177Lu-PSMA-617 has been its short half-life and fast rate of clearance. The investigators designed and synthesized a new radiopharmaceutical, named 177Lu-PSMA-EB-01. EB（Evans Blue）can bind to albumin to slow down its plasma clearance rate, thereby increasing tumor accumulation and reducing the total dosage of Lu-177. Hence, EB-PSMA-01 may be an option for consideration due to limited supply of Lu-177, by which more patients may be benefited by this version of 177Lu-EB-PSMA-01. This study was designed to investigate the safety, dosimetry and preliminary effects of 177Lu-EB-PSMA-01 in patients with metastatic castration resistant prostate cancer.

All patients were intravenous injected with single dose 1.11 GBq (30 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

All patients were intravenous injected with single dose 1.85 GBq (50 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

All patients were intravenous injected with single dose 2.59 GBq (70 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

All patients were intravenous injected with single dose 1.11 GBq (30 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

All patients were intravenous injected with single dose 1.85 GBq (50 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

All patients were intravenous injected with single dose 2.59 GBq (70 mCi) of 177Lu-PSMA-EB-01 then monitored at 3 hours, 24 hours, 48 hours, 72 hours, and 168 hours post-injection.

The semiquantitative dosimetry will be performed based on SPECT/CT acquisitions after the first administration of 177Lu-PSMA-EB-01. The dose delivered to normal organs and tumors will be recorded.

Hematologic status were performed before and every 2 weeks after administration of radiopharmaceutical. Adverse events were categorized using the Common Toxicity Criteria for Adverse Events 5.0

Liver function, and renal function were performed before and 4 weeks after administration of radiopharmaceutical. Adverse events were categorized using the Common Toxicity Criteria for Adverse Events 5.0.

The serum PSA response was documented semimonthly until 6 weeks after the administration of 177Lu-PSMA-EB-01. PSA response was classified as the following: partial response (PR) if PSA decrease ≥50%, progressive disease (PD) if PSA increase ≥ 25% and stable disease (SD) if PSA increase <25% or PSA decrease <50%.

Inclusion Criteria: progressive metastatic castration-resistant prostate cancer tumors with high PSMA expression confirmed on 68Ga-PSMA PET/CT Exclusion Criteria: a serum creatinine level of more than 150 μmol per liter a hemoglobin level of less than 10.0 g/dl a white-cell count of less than 4.0× 109/L a platelet count of less than 100 × 109/L a total bilirubin level of more than 3 times the upper limit of the normal range a serum albumin level of more than 3.0 g per deciliter cardiac insufficiency