Cabozantinib in chemotherapy-pretreated metastatic castration-resistant prostate cancer: results of a phase II nonrandomized expansion study

PURPOSE: Cabozantinib (XL184), an oral inhibitor of multiple receptor tyrosine kinases such as MET and VEGFR2, was evaluated in a phase II nonrandomized expansion study in castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS: Patients received open-label cabozantinib at daily starting doses of 100 mg or 40 mg until disease progression or unacceptable toxicity. The primary end point was bone scan response, defined as ≥ 30% reduction in bone scan lesion area. Other efficacy end points included overall survival, pain, analgesic use, and biomarkers. RESULTS: One hundred forty-four patients sequentially enrolled in either a 100-mg (n = 93) or 40-mg (n = 51) study cohort. Ninety-one patients (63%) had a bone scan response, often by week 6. Treatment resulted in clinically meaningful pain relief (57% of patients) and reduction or discontinuation of narcotic analgesics (55% of patients), as well as improvements in measurable soft tissue disease, circulating tumor cells, and bone biomarkers. Improvements in each of these outcomes were observed in both cohorts: bone scan response in 73% and 45%, respectively; reductions in measurable soft tissue disease in 80% and 79%, respectively. Median overall survival was 10.8 months for the entire population. Most common grade 3 or 4 adverse events were fatigue (22%) and hypertension (14%). Fewer dose reductions because of toxicity were required in the 40-mg group. CONCLUSION: The evidence suggests that cabozantinib has clinically meaningful activity in CRPC. Cabozantinib resulted in improvements in bone scans, pain, analgesic use, measurable soft tissue disease, circulating tumor cells, and bone biomarkers. Taken together, these phase II observations warrant further development of cabozantinib in prostate cancer.Matthew R. Smith, Christopher J. Sweeney, Paul G. Corn, Dana E. Rathkopf, David C. Smith, Maha Hussain, Daniel J. George, Celestia S. Higano, Andrea L. Harzstark, A. Oliver Sartor, Nicholas J. Vogelzang, Michael S. Gordon, Johann S. de Bono, Naomi B. Haas, Christopher J. Logothetis, Aymen Elfiky, Christian Scheffold, A. Douglas Laird, Frauke Schimmoller, Ethan M. Basch and Howard I. Sche

Genetic studies of body mass index yield new insights for obesity biology

Note: A full list of authors and affiliations appears at the end of the article. Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P 20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.</p