Overall survival and response pattern of castration-resistant metastatic prostate cancer to multiple cycles of radioligand therapy using [177Lu]Lu-PSMA-617.

PURPOSE: Up to 30% of patients with castration-resistant prostate cancer (CRPC) do not show any response to the first cycle of radioligand therapy (RLT) with [177Lu]Lu-PSMA-617 (Lu-PSMA). We evaluated patient response to the second and third cycles of RLT in patients that underwent at least three cycles. The second aim of this study was to calculate the median overall survival (OS) of responders and non-responders after the first cycle and after all three cycles of RLT. METHODS: CRPC patients were treated with Lu-PSMA, with a median interval of 8 weeks between each cycle. The tumour marker prostate-specific antigen (PSA) was used as the marker for response evaluation. RESULTS: Fifty-two patients underwent a total of 190 cycles of RLT (3-6 cycles per patient). Of these, 80.8% showed a decline in PSA 2 months after the first cycle, with 44.2% showing a PSA decline of ≥50%. When compared to baseline PSA, 73.1% showed a PSA decline after the third cycle. 50% of patients that did not show any response to the first cycle also did not respond to the second and third cycles. The median OS was 60 weeks in all patients. The median OS was significantly longer for patients that showed any PSA decline after the first cycle compared to patients without PSA decline (68 vs. 33 weeks). There was a significant difference in median OS between responders and non-responders for a change in PSA after the third cycle compared to baseline PSA. CONCLUSION: Patients with a positive response to RLT, regardless of the rate of decline, had a significantly longer median OS. Of the patients that did not show any response to the first cycle, 50% responded to the second or third cycles.

Possible Treatment Approach to an Extravasation of 177Lu-PSMA-617.

A rare accident of a subcutaneous extravasation in the elbow with 4280 MBq Lu-PSMA-617 occurred in our clinic. We tried to reduce the damage by warming the elbow for 12 hours, then cooling it, and recommended the patient avoid exercises with the elbow for the next 3 days. We recognized a good resorption of the radionuclide in the scintigraphic imaging in the first 2 days. No pain, burning, or necrosis occurred. The administered therapy afterward showed an adequate decrease in the tumor marker level.

[18F]Fluorodeoxyglucose Positron Emission Tomography Reveals a Complete Remission of Refractory Metastatic Melanoma after Therapy with Ipilimumab.

Ipilimumab (YERVOY) is a monoclonal CTLA-4-antibody with anti-tumor-immunogenic effect and is used to treat malignant melanoma. In this case study, we present [18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) images of a 37-year-old woman with metastatic melanoma, who was previously treated with interferon-alpha therapy and dacarbazine and still progressed. After four cycles of ipilimumab, there was a complete remission of the disease with no evidence of vital, FDG-positive tumor tissue. The follow-up for a total of 1 year confirmed the therapeutic success. This report demonstrates that FDG-PET/CT is a reliable imaging method for response monitoring in metastatic melanoma treated with ipilimumab.

Combination of 177Lu-PSMA-617 and External Radiotherapy for the Treatment of Cerebral Metastases in Patients With Castration-Resistant Metastatic Prostate Cancer.

Two castration-resistant prostate cancer patients, both with cerebral and visceral and lymphatic metastases, received multiple cycles of Lu-PSMA-617 treatments. The prognosis of both cases is dependent on brain metastases. Between Lu-PSMA-617 treatment cycles, local radiotherapy was also applied to the brain metastases. Prior to the combined therapy, all systemic metastases, including cerebral lesions, showed PSMA expression using Ga-PSMA PET/CT. Under the combined therapy, all the metastases, particularly the cerebral lesions, showed significant regression in size and PSMA expression over time.

Predictors of overall survival in metastatic castration-resistant prostate cancer patients receiving [177Lu]Lu-PSMA-617 radioligand therapy.

Prostate-specific membrane antigen (PSMA) is a promising target for the diagnosis of and therapy for metastatic castration-resistant prostate cancer (mCRPC). The aim of this study was to measure overall-survival (OS) in mCRPC patients who received either abiraterone or enzalutamide prior to PSMA therapy. The second aim of this study was to analyse the predictors of OS according to different pre-therapeutic parameters and also the responses to the first cycle of radioligand therapy (RLT) base on PSA level. Patients with mCRPC and a history of therapy with either abiraterone or enzalutamide or both, were included in this study. Different laboratory tests and pre-therapeutic parameters have been included into the analysis. One-hundred patients received a total of 347 cycles of Lu-PSMA (median: three cycles). 69 patients showed a decline in PSA two months after the first cycle, and 38 of those patients showed a PSA decline of = > 50%. The median OS was 60 weeks. In the multivariate analysis, the level of albumin, AST and haemoglobin, existence of liver metastases and a decline of > 14% in PSA level had a significant impact on overall-survival. The median OS is significantly longer in patients without hepatic involvement, with high levels of albumin and Hb and low levels of AST. A decline in PSA levels of more than 14% was the most important response parameter with regard to overall survival.

Metastatic Prostate Cancer With Restored Hormone-Response After Radioligand Therapy With 177Lu-PSMA-617.

An 80-year-old patient with castrate-resistant prostate cancer presented to our department for PSMA imaging because of a rising prostate-specific antigen (PSA) level. The tumor was diagnosed in 2004. GnRh analog was the only treatment the patient received. Two cycles of Lu-PSMA-617 were performed with a 2-month interval in between. Ten months after finishing with 2 cycles of Lu-PSMA therapy, we noticed a continuous falling PSA level and a decreasing tumor spread in the PET/CT imaging just under the hormone therapy.

Successful Treatment of Hepatic Metastases of Hormone Refractory Prostate Cancer Using Radioligand Therapy With 177Lu-PSMA-617.

An 81-year-old castrate-resistant prostate cancer man with multiple lymph node, bone, and hepatic metastases received four cycles of Lu-PSMA-617 treatments at our department from May to December 2015. All of his liver metastases showed PSMA expression in Ga-PSMA PET performed before the first cycle. Under this therapy, all of the metastases showed significant regression in size and PSMA expression over time.

Positive Influence of 177Lu PSMA-617 Therapy on Bone Marrow Depression Caused by Metastatic Prostate Cancer.

A 75-year-old man with castrate-resistant prostate cancer and increasing prostate-specific antigen (PSA) level developed severe bone marrow depression during Ra radionuclide therapy. Because of this, he was treated with Lu-PSMA in compassionate use for this not-yet-approved therapy. At the beginning of Lu-PSMA therapy, repeated blood transfusions (BT) were necessary. Six months after the last BT, after 3 cycles of Lu-PSMA, his blood count stabilized. He required no further BTs and his PSA level remained lowered.

68Ga-Labeled Anti-Prostate-Specific Membrane Antigen Peptide as Marker for Androgen Deprivation Therapy Response in Prostate Cancer.

Prostate cancer was diagnosed in a 71-year-old man with an elevated prostate-specific antigen. The CT of the abdomen showed multiple para-aortal lymph nodes, and thus, a Ga anti-prostate-specific membrane antigen (PSMA-11) PET/CT was initiated, which showed, aside from the prostate cancer and multiple iliacal and para-aortal lymph node metastases, an increased tracer uptake in a lymph node left cervical. According to this advanced disease, a palliative therapy with GnRH agonist was initiated. A second PSMA-11 PET/CT was performed 4 months later, which showed a very good response; thus, additional radiation of the pelvis and the draining lymphatic system was performed.

68Ga-PSMA-11 PET Represents the Tumoricidal Effect of 223Ra in a Patient With Castrate-Resistant Metastatic Prostate Cancer.

A 64-year-old man with prostate cancer and an increasing prostate-specific antigen (PSA) level under therapy with abiraterone acetate underwent a therapy with Ra. Before the first therapy and 4 weeks after the last cycle, the patient underwent Ga-PSMA PET, which showed a clear response of bone metastases.

Therapeutic response and side effects of repeated radioligand therapy with 177Lu-PSMA-DKFZ-617 of castrate-resistant metastatic prostate cancer.

Prostate-specific membrane antigen (PSMA) is highly expressed on prostate epithelial cells and strongly up-regulated in prostate cancer (PC), making it an optimal target for the treatment of metastasized PC. Radioligand therapy (RLT) with 177Lu-PSMA-DKFZ-617 (Lu-PSMA) is a targeted therapy for metastatic PC. In this study, we retrospectively analyzed the side effects and the response rate of 24 hormone and/or chemorefractory PC patients with a mean age of 75.2 years (range: 64-82) with distant metastases and progressive disease according to the PSA level, who were treated with Lu-PSMA. Median PSA was 522 ng/ml (range: 17-2360). Forty-six cycles of Lu-PSMA were performed. Of the 24 patients, 22 received two cycles. Eight weeks after the first cycle of Lu-PSMA therapy 79.1% experienced a decline in PSA level. Eight weeks after the second cycle of Lu-PSMA therapy 68.2% experienced a decline in PSA relative to the baseline value. Apart from two cases of grade 3 anemia, there was no relevant hemato- or nephrotoxicity (grade 3 or 4). These results confirmed that Lu-PSMA is a safe treatment option for metastatic PC patients and has a low toxicity profile. A positive response to therapy in terms of decline in PSA occurs in about 70% of patients.