Clinical benefit of bone-targeted radiometabolic therapy with 153Sm-EDTMP combined with chemotherapy in patients with metastatic hormone-refractory prostate cancer.
ABSTRACT Bone metastases are responsible for most of the morbidity associated with hormone-refractory prostate cancer (HRPC). 153Sm-ethylenediaminetetramethylene phosphonate (153Sm-EDTMP) has been approved for palliation of painful skeletal metastases. We retrospectively investigated the possible synergistic effect on survival of 153Sm-EDTMP (given to HRPC patients for bone pain palliation) and chemotherapy.
Forty-five HRPC patients were evaluated, with a median age of 71 years. The number of metastatic bone sites was <or=10 in 25 patients and >10 in 20 patients. Median serum PSA was 224 ng/ml. Bone pain was mild in 6 patients, moderate in 16, severe in 22 and intolerable in 1. Fifteen patients were only treated with 153Sm-EDTMP (group A), while 30 patients also received chemotherapy (estramustine phosphate or mitoxantrone plus prednisone) at variable times: between 3 and 5 months after 153Sm-EDTMP (14 patients, group B) or within 1 month after 153Sm-EDTMP (16 patients, group C).
Haematological toxicities observed after either regimen were in general mild, consistent with common observations after either 153Sm-EDTMP or chemotherapy, and without any additive adverse effects in the patients receiving both 153Sm-EDTMP and chemotherapy. Bone pain palliation to some degree was induced by 153Sm-EDTMP in 32/45 patients (71.1%), the proportion of patients with a favourable clinical response being significantly higher in group C than in group A (87.5% vs 53.3%, p = 0.0388). Also in terms of biochemical response (serum PSA levels), patients of group C performed significantly better than patients of group A (p = 0.0235). Overall median survival from the time of administration of 153Sm-EDTMP was 15 months in the total cohort of 45 patients, and was significantly longer in group C than in either group B (30 months vs 11 months, p = 0.023) or group A (30 months vs 10 months, p = 0.008).
The results of this study confirm that 153Sm-EDTMP is effective in terms of pain relief and PSA response, with minimal toxicity. When it was administered in combination with chemotherapy, prolonged survival indicated actual clinical benefit, while there were no additive toxicities. These results provide the rationale for future prospective evaluation of combined therapeutic strategies.
Article: The use of chelated radionuclide (samarium-153-ethylenediaminetetramethylenephosphonate) to modulate phenotype of tumor cells and enhance T cell-mediated killing.[show abstract] [hide abstract]
ABSTRACT: Exposing human tumor cells to sublethal doses of external beam radiation up-regulates expression of tumor antigen and accessory molecules, rendering tumor cells more susceptible to killing by antigen-specific CTLs. This study explored the possibility that exposure to palliative doses of a radiopharmaceutical agent could alter the phenotype of tumor cells to render them more susceptible to T cell-mediated killing. Here, 10 human tumor cell lines (4 prostate, 2 breast, and 4 lung) were exposed to increasing doses of the radiopharmaceutical samarium-153-ethylenediaminetetramethylenephosphonate ((153)Sm-EDTMP) used in cancer patients to treat pain due to bone metastasis. Fluorescence-activated cell sorting analysis and quantitative real-time PCR analysis for expression of five surface molecules and several tumor-associated antigens involved in prostate cancer were done. LNCaP human prostate cancer cells were exposed to (153)Sm-EDTMP and incubated with tumor-associated antigen-specific CTL in a CTL killing assay to determine whether exposure to (153)Sm-EDTMP rendered LNCaP cells more susceptible to T cell-mediated killing. Tumor cells up-regulated the surface molecules Fas (100% of cell lines up-regulated Fas), carcinoembryonic antigen (90%), mucin-1 (60%), MHC class I (50%), and intercellular adhesion molecule-1 (40%) in response to (153)Sm-EDTMP. Quantitative real-time PCR analysis revealed additional up-regulated tumor antigens. Exposure to (153)Sm-EDTMP rendered LNCaP cells more susceptible to killing by CTLs specific for prostate-specific antigen, carcinoembryonic antigen, and mucin-1. Doses of (153)Sm-EDTMP equivalent to palliative doses delivered to bone alter the phenotype of tumor cells, suggesting that (153)Sm-EDTMP may work synergistically with immunotherapy to increase the susceptibility of tumor cells to CTL killing.Clinical Cancer Research 08/2008; 14(13):4241-9. · 7.74 Impact Factor
Article: (188)Re-HEDP combined with capecitabine in hormone-refractory prostate cancer patients with bone metastases: a phase I safety and toxicity study.[show abstract] [hide abstract]
ABSTRACT: (188)Re-HEDP is indicated for the treatment of pain in patients with painful osteoblastic bone metastases, including hormone-refractory prostate cancer patients. Efficacy may be improved by adding chemotherapy to the treatment regimen as a radiation sensitizer. The combination of (188)Re-HEDP and capecitabine (Xeloda(R)) was tested in a clinical phase I study. Patients with hormone-refractory prostate cancer were treated with capecitabine for 14 days (oral twice daily in a dose escalation regimen with steps of 1/3 of 2,500 mg/m(2) per day in cohorts of three to six patients, depending on toxicity). Two days later patients were treated with 37 MBq/kg (188)Re-HEDP as an intravenous injection. Six hours after treatment post-therapy scintigraphy was performed. Urine was collected for 8 h post-injection. Follow-up was at least 8 weeks. The primary end-point was to establish the maximum tolerable dose (MTD) of capecitabine when combined with (188)Re-HEDP. Secondary end-points included the effect of capecitabine on the biodistribution and pharmacokinetics of (188)Re-HEDP. Three patients were treated in the first and second cohorts, each without unacceptable toxicity. One of six patients in the highest cohort experienced unacceptable toxicity (grade 4 thrombopaenia). The MTD proved to be the maximum dose of 2,500 mg/m(2) per day capecitabine. No unexpected toxicity occurred. Capecitabine had no effect on uptake or excretion of (188)Re-HEDP. Capecitabine may be safely used in combination with (188)Re-HEDP in a dose of 2,500 mg/m(2) per day and 37 MBq/kg, respectively. Efficacy will be further studied in a phase II study using these dosages.European Journal of Nuclear Medicine 04/2009; 36(9):1425-33. · 4.53 Impact Factor
Article: Phase I trial with a combination of docetaxel and ¹⁵³Sm-lexidronam in patients with castration-resistant metastatic prostate cancer.[show abstract] [hide abstract]
ABSTRACT: This study was designed to evaluate toxicity and preliminary efficacy of 2 cycles of concomitant standard dose/schedule of (153)Sm-lexidronam plus Q 3 weeks schedule escalating doses of docetaxel in metastatic castration-resistant prostate cancer (mCRPC). mCRPC patients with progressive bone metastases were treated in 4 cohorts. Docetaxel doses were escalated from 50, 50, 0 mg/m(2) (on days 1, 22, 43, per 12-week cycle) to 75, 75, 75 mg/m(2). (153)Sm-lexidronam was administered on days 2 (Q 12 weeks) at dose of 1 mCi/kg/cycle (maximum of 2 cycles). Thirteen patients received an average of 3.6 doses of docetaxel (range, 2-6 doses, median 4) and 1.5 doses of (153)Sm-lexidronam (range, 1-2, median 2). Toxicity was primarily hematologic. There were total 35 episodes grade 3/4 neutropenia with a median 7 (range 7-14) days to recovery to ≤grade 1. One dose limiting grade 3 thrombocytopenia occurred on cohorts 3 and 4. Eight of 13 (62%) patients had PSA > 50% decrease as best response during the treatment. Median time to bone disease progression was 5.2 months (range 91 days-10 months+); 6/13 (46%) patients had stable/improved bone scans at 6 months and 6/6 (100%) symptomatic patients had improvement in pain. Concurrent 6-month administration of 4 doses (75 mg/m(2)) of standard Q 3 weeks schedule of docetaxel with 2 Q 3 months infusions of 1 mCi/Kg (153)Sm-lexidronam is feasible with reversible bone marrow suppression, and deserves further testing in mCRPC patients with extensive bone metastasis.Urologic Oncology 12/2009; 29(6):670-5. · 3.22 Impact Factor