Background: Histone deacetylase blockade can promote heat shock protein 90 (HSP90) acetylation, abrogating androgen receptor signaling. A phase II trial of the histone deacetylase inhibitor (HDACi) romidepsin was conducted in patients with progressing, metastatic, castration-resistant prostate cancer (CRPC). Patients and methods: A dose of 13 mg/m2 was administered i.v. over 4 h on days 1, 8 and 15 every 28 days. The primary end point was rate of disease control defined as no evidence of radiological progression at 6 months. A sample size of 16 assessable patients in stage 1 and nine assessable patients in stage 2 was selected; progression to stage 2 required one or more patients with disease control in stage 1 (Ho = 0.10, Ha = 0.30; α and β = 0.10). Results: Thirty-five patients were enrolled. Two patients achieved a confirmed radiological partial response (RECIST) lasting ≥6 months, along with a confirmed prostate-specific antigen decline of ≥50%. Eleven patients experienced toxicity necessitating early discontinuation. The commonest adverse events were nausea (30 patients; 85.7%), fatigue (28 patients; 80.0%), vomiting (23 patients; 65.7%) and anorexia (20 patients; 57.1%). There was no significant cardiac toxicity. Conclusions: At the dose and schedule selected, romidepsin demonstrated minimal antitumor activity in chemonaive patients with CRPC. Further studies of improved HDACi, alone and in combination with other therapies, should nevertheless be investigated.
Chondrosarcoma is a malignant tumor of bones, characterized by the production of cartilage matrix. Due to lack of effective treatment for advanced disease, the clinical management of chondrosarcomas is exceptionally challenging. Current research focuses on elucidating the molecular events underlying the pathogenesis of this rare bone malignancy, with the goal of developing new molecularly targeted therapies. Signaling pathways suggested to have a role in chondrosarcoma include Hedgehog, Src, PI3k–Akt–mTOR and angiogenesis. Mutations in IDH1/2, present in more than 50% of primary conventional chondrosarcomas, make the development of IDH inhibitors a promising treatment option. The present review discusses the preclinical and early clinical data on novel targeted therapeutic approaches in chondrosarcoma.
1 July 2013 in Critical Reviews in Oncology/Hematology
Purpose: To determine the safety, maximum tolerated dose, and pharmacokinetic-pharmacodynamic profile of a histone deacetylase inhibitor, LAQ824, in patients with advanced malignancy. Patients and Methods: LAQ824 was administered i.v. as a 3-h infusion on days 1, 2, and 3 every 21 days. Western blot assays of peripheral blood mononuclear cell lysates and tumor biopsies pretherapy and posttherapy evaluated target inhibition and effects on heat shock protein-90 (HSP90) client proteins and HSP72. Results: Thirty-nine patients (22 male; median age, 53 years; median Eastern Cooperative Oncology Group performance status 1) were treated at seven dose levels (mg/m2): 6 (3 patients), 12 (4 patients), 24 (4 patients), 36 (4 patients), 48 (4 patients), 72 (19 patients), and 100 (1 patient). Dose-escalation used a modified continual reassessment method. Dose-limiting toxicities were transaminitis, fatigue, atrial fibrillation, raised serum creatinine, and hyperbilirubinemia. A patient with pancreatic cancer treated at 100 mg/m2 died on course one at day 18 with grade 3 hyperbilirubinemia and neutropenia, fever, and acute renal failure. The area under the plasma concentration curve increased proportionally with increasing dose; median terminal half-life ranged from 8 to 14 hours. Peripheral blood mononuclear cell lysates showed consistent accumulation of acetylated histones posttherapy from 24 mg/m2; higher doses resulted in increased and longer duration of pharmacodynamic effect. Changes in HSP90 client protein and HSP72 levels consistent with HSP90 inhibition were observed at higher doses. No objective response was documented; 3 patients had stable disease lasting up to 14 months. Based on these data, future efficacy trials should evaluate doses ranging from 24 to 72 mg/m2. Conclusions: LAQ824 was well tolerated at doses that induced accumulation of histone acetylation, with higher doses inducing changes consistent with HSP90 inhibition.