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Cabozantinib in metastatic prostate cancer1,2
Researchers tested cabozantinib, a tyrosine-kinase inhibitor (TKI) against MET and vascular endothelial growth factor receptor 2 (VEGF), in a large phase 2 randomized discontinuation trial in 9 tumor types. A subset of 171 patients with castrateresistant prostate cancer (CRPC) was reported in this study. Patients were treated on open label for 12 weeks, and then if stable, were randomized to receive the active drug or placebo. The trial was suspended early by the study oversight committee because: a) Cabozantinib was too toxic for the study to continue. b) The prostate-specific antigen (PSA) level fell in most of the treated patients. c) In the initial 121 patients, there was an unexpected improvement in bone scans and decrease in pain in the lead-in stage of the study. d) Unexpected rapid soft tissue progression. Bone scans improved in 78% of patients, and in 12% there was complete remission. After further analysis, the following were true except for: a) Cabozantinib interfered with technetium-99, and thus, the responses were not real, but rather an artifact. b) The PSA did not correlate with improvement in bone pain. c) Markers of bone formation and resorption showed improvement, and there was no correlation with prior bisphosphonate therapy. d) Bone scan improvement correlated with improvement in soft tissue disease.
Key points
The results in patients with prostate cancer were so striking – 72% of patients had regression in soft tissue lesions, and 68% of evaluable patients had improvement on bone scan, including complete resolution in 12% – that the subset analysis was published as a rapid communication.1,2 Because of very high response rates (5% at 12 weeks) and symptomatic improvement in the initial 122 patients who were enrolled, random assignment was discontinued. Bone markers improved in concert with the radiologic and clinical improvement. Answers c, a
Cabozantinib in metastatic prostate cancer1,2
Researchers tested cabozantinib, a tyrosine-kinase inhibitor (TKI) against MET and vascular endothelial growth factor receptor 2 (VEGF), in a large phase 2 randomized discontinuation trial in 9 tumor types. A subset of 171 patients with castrateresistant prostate cancer (CRPC) was reported in this study. Patients were treated on open label for 12 weeks, and then if stable, were randomized to receive the active drug or placebo. The trial was suspended early by the study oversight committee because: a) Cabozantinib was too toxic for the study to continue. b) The prostate-specific antigen (PSA) level fell in most of the treated patients. c) In the initial 121 patients, there was an unexpected improvement in bone scans and decrease in pain in the lead-in stage of the study. d) Unexpected rapid soft tissue progression. Bone scans improved in 78% of patients, and in 12% there was complete remission. After further analysis, the following were true except for: a) Cabozantinib interfered with technetium-99, and thus, the responses were not real, but rather an artifact. b) The PSA did not correlate with improvement in bone pain. c) Markers of bone formation and resorption showed improvement, and there was no correlation with prior bisphosphonate therapy. d) Bone scan improvement correlated with improvement in soft tissue disease.
Key points
The results in patients with prostate cancer were so striking – 72% of patients had regression in soft tissue lesions, and 68% of evaluable patients had improvement on bone scan, including complete resolution in 12% – that the subset analysis was published as a rapid communication.1,2 Because of very high response rates (5% at 12 weeks) and symptomatic improvement in the initial 122 patients who were enrolled, random assignment was discontinued. Bone markers improved in concert with the radiologic and clinical improvement. Answers c, a
Cabozantinib in metastatic prostate cancer1,2
Researchers tested cabozantinib, a tyrosine-kinase inhibitor (TKI) against MET and vascular endothelial growth factor receptor 2 (VEGF), in a large phase 2 randomized discontinuation trial in 9 tumor types. A subset of 171 patients with castrateresistant prostate cancer (CRPC) was reported in this study. Patients were treated on open label for 12 weeks, and then if stable, were randomized to receive the active drug or placebo. The trial was suspended early by the study oversight committee because: a) Cabozantinib was too toxic for the study to continue. b) The prostate-specific antigen (PSA) level fell in most of the treated patients. c) In the initial 121 patients, there was an unexpected improvement in bone scans and decrease in pain in the lead-in stage of the study. d) Unexpected rapid soft tissue progression. Bone scans improved in 78% of patients, and in 12% there was complete remission. After further analysis, the following were true except for: a) Cabozantinib interfered with technetium-99, and thus, the responses were not real, but rather an artifact. b) The PSA did not correlate with improvement in bone pain. c) Markers of bone formation and resorption showed improvement, and there was no correlation with prior bisphosphonate therapy. d) Bone scan improvement correlated with improvement in soft tissue disease.
Key points
The results in patients with prostate cancer were so striking – 72% of patients had regression in soft tissue lesions, and 68% of evaluable patients had improvement on bone scan, including complete resolution in 12% – that the subset analysis was published as a rapid communication.1,2 Because of very high response rates (5% at 12 weeks) and symptomatic improvement in the initial 122 patients who were enrolled, random assignment was discontinued. Bone markers improved in concert with the radiologic and clinical improvement. Answers c, a